Involvement of Nax sodium channel in peripheral nerve regeneration via lactate signaling

Na_x, a sodium concentration‐sensitive sodium channel, is expressed in non‐myelinating Schwann cells of the adult peripheral nervous system, but the pathophysiological role remains unclear. We found that functional recovery of the hind paw responses from the sciatic nerve transection was delayed in Na_x knockout ( ) mice. Histological analyses showed a decrease in the number of regenerated myelinated axons in sciatic nerves. The delay in the recovery in mice was improved by lactate and inhibited by a monocarboxylate transporter inhibitor. In vitro experiments using cultured Schwann cells showed that lactate release was enhanced by endothelin (ET)‐1 and blocked by an ET receptor type B antagonist. Here, it is conceivable that Na_x was activated by ET‐1. The amount of lactate release by ET‐1 was lower in mice than in wild‐type mice. These results indicated that Na_x is functionally coupled to ET for lactate release via ET receptor type B and is involved in peripheral nerve regeneration.     

Memory consolidation during sleep and adult hippocampal neurogenesis

In anticipation of the massive burden of neurodegenerative disease within super-aged societies, great efforts have been made to utilize neural stem and progenitor cells for regenerative medicine. The capacity of intrinsic neural stem and progenitor cells to regenerate damaged brain tissue remains unclear, due in part to the lack of knowledge about how these newly born neurons integrate into functional circuitry. As sizable integration of adult-born neurons naturally occurs in the dentate gyrus region of the hippocampus, clarifying the mechanisms of this process could provide insights for applying neural stem and progenitor cells in clinical settings. There is convincing evidence of functional correlations between adult-born neurons and memory consolidation and sleep; therefore, we describe some new advances that were left untouched in our recent review.     

Effect of novel dithiooctanoate monomers, in comparison with various sulfur-containing adhesive monomers, on adhesion to precious metals and alloys

This study investigated the effect of novel dithiooctanoate monomers, in comparison with conventional sulfur-containing monomers, on adhesion to precious metals and alloys. Nine experimental primers containing 5.0 wt% 2-methacryloyloxyethyl 6,8-dithiooctanoate (2-MEDT), 6-methacryloyloxyhexyl 6,8-dithiooctanoate (6-MHDT), 10-methacryloyloxydecyl 6,8-dithiooctanoate (10-MDDT), bis(2-methacryloyloxyethyl) disulfide (BMEDS), bis(5-methacryloyloxypentyl) disulfide (BMPDS), bis(10-methacryloyloxydecyl) disulfide (BMDDS), 6-(4-vinylbenzyl-n-propyl) amino-1,3,5-triazine-2,4-dithione (VBATDT), N-(4-mercaptophenyl)methacrylamide (MPMA), or 4-methacryloyloxyethoxycarbonylphthalic anhydride (4-META; control) were prepared. After primer pretreatment and bonding using modified MMA-PMMA/BPO-DEPT resin, tensile bond strengths to precious metals and alloys after 2,000 thermal cycles were measured. For bonding to Au or Ag, novel 2-MEDT, 6-MHDT, and 10-MDDT exhibited significantly higher tensile bond strengths than conventional BMEDS, BMPDS, BMDDS, VBATDT, MPMA, and 4-META (p<0.05). For bonding to Au alloy, Ag alloy, and Au-Ag-Pd alloy, all the novel dithiooctanoate monomers showed significantly higher tensile bond strengths than conventional BMEDS, BMPDS, VBATDT, MPMA, and 4-META (p<0.05). It was found that novel dithiooctanoate monomers exhibited excellent bonding to precious metals and alloys when compared with conventional sulfur-containing monomers.     

Primary Stability of a Hybrid Self‐Tapping Implant Compared to a Cylindrical Non‐Self‐Tapping Implant with Respect to Drilling Protocols in an Ex Vivo Model

Background: Modifications of implant design have been intending to improve primary stability. However, little is known about investigation of a hybrid self‐tapping implant on primary stability. Purposes: The aims of this study were to evaluate the primary stability of two hybrid self‐tapping implants compared to one cylindrical non‐self‐tapping implant, and to elucidate the relevance of drilling protocols on primary stability in an ex vivo model. Materials and Methods: Two types of hybrid self‐tapping implants (Straumann® Bone Level implant [BL], Straumann® Tapered Effect implant [TE]) and one type of cylindrical non‐self‐tapping implant (Straumann® Standard Plus implant [SP]) were investigated in the study. In porcine iliac cancellous bones, 10 implants each were inserted either using standard drilling or under‐dimensioned drilling protocol. The evaluation of implant‐bone interface stability was carried out by records of maximum insertion torque, the Periotest® (Siemens, Bensheim, Germany), the resonance frequency analysis (RFA), and the push‐out test. Results: In each drilling group, the maximum insertion torque values of BL and TE were significantly higher than SP (p = .014 and p = .047, respectively). In each group, the Periotest values of TE were significantly lower than SP (p = .036 and p = .033, respectively). The Periotest values of BL and TE were significantly lower in the group of under‐dimensioned drilling than standard drilling (p = .002 and p = .02, respectively). In the RFA, no statistical significances were found in implants between two groups and between implants in each group. In each group, the push‐out values of BL and TE were significantly higher than SP (p = .006 and p = .049, respectively). Conclusion: Hybrid self‐tapping implants could achieve a high primary stability which predicts them for use in low‐density bone. However, there is still a debate to clarify the influence of under‐dimensioned drilling on primary stability.     

Transthoracic percutaneous radiofrequency ablation for liver tumors in the hepatic dome

Computed tomography (CT)-guided transthoracic radiofrequency ablation was performed for nine liver tumors of eight patients, which were located in the hepatic dome and undetectable by ultrasound (US). A total 11 sessions of ablation were performed. Complications were noted in five sessions (45%) and no complications were noted in six sessions (55%). Pneumothorax was noted in five sessions (45%), including two sessions (18%) with major pneumothorax requiring a chest tube. Major complications were seen in two sessions (18%), major pneumothorax and both major pneumothorax and moderate pleural effusion, respectively. CT-guided transthoracic radiofrequency ablation may be an alternative for treatments of liver tumor in the hepatic dome.     

Clinical evaluation of transcatheter arterial embolization for the management of retroperitoneal bleeding in cases of pelvic fracture

PURPOSE: We evaluated the clinical efficacy of TAE for the management of retroperitoneal bleeding in a case of pelvic fracture. MATERIALS AND METHODS: A retrospective review of 206 patients with pelvic fractures was performed. Thirty-four patients who were hemodynamically unstable or had evidence of ongoing hemorrhage required TAE. Rescue rate, effective rate, and mortality rate among the patients with multiple organ injuries were calculated. Charts were reviewed for age, Japanese coma scale (JCS), hemoglobin, blood pressures, extent of retroperitoneal hemorrhage, pelvic fracture pattern/extent of embolization, and time from judging indication of TAE to angiography. Data of patients who died of pelvic fracture hemorrhage was compared with that of others. Statistical analysis was done with analysis of variance, and the two groups were compared using Student's t-test. RESULTS: Rescue rate, success rate, and mortality rate were 76% (26/34), 91% (31/34), and 33% (8/24), respectively. Only JCS reached statistical significance. The complications of gluteal skin and muscle necrosis were experienced in one patient. Two patients with lung contusion and one patient who had suffered from idiopathic interstitial pneumonia died from disseminated intravascular coagulation associated with pneumonia. Viscorectal dysfunctions, which were observed in ten patients, were considered to be independent of TAE. CONCLUSION: TAE for pelvic fracture hemorrhage was considered effective. Complications of gluteal skin and muscle necrosis should be kept in mind.     

Comparison of FDG PET and SPECT for detection of bone metastases in breast cancer

OBJECTIVE: The purpose of our study was to evaluate the efficacy of FDG PET and bone SPECT for diagnosing bone metastases in breast cancer. SUBJECTS AND METHODS: The study was a prospective series of 15 patients with breast cancer who underwent both PET and bone scanning with SPECT. Comparison was performed on a lesion-by-lesion analysis. MDCT, MRI, and the patient's clinical course were used as references. RESULTS: In the lesion-by-lesion analysis (n = 900), the sensitivity for diagnosing bone metastases was 85% for SPECT and 17% for PET, specificity was 99% for SPECT and 100% for PET, and accuracy was 96% for SPECT and 85% for PET. In the statistical analysis, bone SPECT was significantly superior to FDG PET for its sensitivity (p < 0.0001) and accuracy (p < 0.0001). No statistically significant difference was seen with regard to specificity. When classifying the bone metastases as osteoblastic or osteolytic, bone scanning classified 92% of metastases as osteoblastic and 35% of metastases as osteolytic, whereas PET classified 6% of metastases as osteoblastic and 90% of metastases as osteolytic. CONCLUSION: Bone SPECT is superior to FDG PET in detecting bone metastases in breast cancer. The sensitivity of osteoblastic lesions is limited with FDG PET. Surveillance of metastatic spread to the skeleton in breast cancer patients based on FDG PET alone is not possible.     

With-time change of hemodynamics in fMRI: linearity consideration after stimulation ends from stimulation beginning

The BOLD signal responses that occur after a few seconds at the beginning and the end of stimulus are due to hemodynamic delay. A temporary increase of deoxyhemoglobin just after the beginning of stimulus causes an initial dip in the hemodynamic signal (response). After the initial dip, an increase of BOLD signal causes an overshoot. After the overshoot, a decrease of the BOLD signal due to the end of stimulus causes an undershoot. Many reports have examined the period of stimulus, but only a few have described the period after stimulus. This paper reports on a peak between the overshoot and undershoot. After the end of stimulus, the signal does not simply decrease, but shows a peak after some delay. An activated map showed the same tendency as the hemodynamics signal. This peak was termed hemodynamic over-saturation (HOS). Time control in chronological order is important to obtain a hemodynamic change in chronological order and a large, significant difference between the task and rest signal. The entire hemodynamic signal was evaluated by controlling the timing of the scan using an external trigger and by indicating the beginning of the task (rest) period using sound. The timing of the external trigger and sound are built into the sequence design as a program. From the results of the hemodynamic signal, the causal relationship between this signal and the fluctuation in oxyhemoglobin and deoxyhemoglobin can be considered.     

A case of unexpected gallium-67 uptake by sternum in non-hodgkin’s lymphoma with pleuritis

A case of non-Hodgkin's lymphoma with pleural effusion was presented. Pleural effusion is not a common manifestation of this disease and 67Ga-citrate scintigraphy gave the clue for the diagnosis. The possibility of malignant lymphoma should be considered in cases with pleural effusion, and we showed that 67Ga-citrate scintigraphy can be useful in a case with pleural effusion of undetermined cause.     

Postoperative ischemic change in bronchial stumps after primary lung cancer resection.

BACKGROUND: The bronchopleural fistula (BPF) is a major complication after lung surgery. We have reviewed our experience with ischemic changes in bronchial stumps, some of which resulted in BPFs (we term this postoperative ischemic bronchitis (POIB)) and studied predisposing factors. METHODS: A total of 1015 patients undergoing curative resection of lung cancers between 1991 and 2002 were reviewed. Details regarding bronchofiberscopic findings within the first 15 postoperative days were carefully reviewed with particular attention to factors possibly affecting the occurrence of POIB: the techniques for bronchial closure and mediastinal lymph node dissection (LND). Information about clinical profiles and histologic status was also analyzed. RESULTS: The incidence of POIB was 2.5% (29/1015), affecting 26 males and 3 females. The most common site was the right intermediate trunk stump (n=4; 7.1%), followed by the left upper (n=8; 3.4%), right lower (n=5; 3.4%), right middle (n=2; 3.3%), and left lower (n=4; 3.2%) lobar bronchial stumps. BPFs eventually resulted in 3 patients (10%) out of 29 with POIB and in 4 (0.4%) out of 986 without it (p<0.0001). Being male, a smoker, having diabetes mellitus, having postoperative respiratory complications and subcarinal LND proved to exert a significant impact with regard to POIB. CONCLUSIONS: Surgeons must bear in mind the possibility of POIB occurrence, especially in cases undergoing particular types of lobectomy (right middle and lower, left upper, right lower or right middle) accompanied by subcarinal LND and having postoperative respiratory complications. Moreover, in appropriate groups with tumors of the right upper lobe or left upper segment, limited mediastinal LND might allow avoidance of POIB.