Extended platelet-rich fibrin.

Platelet-rich fibrin (PRF) has been characterized as a regenerative biomaterial that is fully resorbed within a typical 2-3 week period. Very recently, however, a novel heating process was shown to extend the working properties of PRP/PRF from a standard 2-3 week period toward a duration of 4-6 months. Numerous clinicians have now utilized this extended-PRF (e-PRF) membrane as a substitute for collagen barrier membranes in various clinical applications, such as guided tissue/bone regeneration. This review article summarizes the scientific work to date on this novel technology, including its current and future applications in periodontology, implant dentistry, orthopedics and facial aesthetics. A systematic review was conducted investigating key terms including "Bio-Heat," "albumin gel," "albumin-PRF," "Alb-PRF," "extended-PRF," "e-PRF," "activated plasma albumin gel," and "APAG" by searching databases such as MEDLINE, EMBASE and PubMed. Findings from preclinical studies demonstrate that following a simple 10-min heating process, the transformation of the liquid plasma albumin layer into a gel-like injectable albumin gel extends the resorption properties to at least 4 months according to ISO standard 10 993 (subcutaneous animal model). Several clinical studies have now demonstrated the use of e-PRF membranes as a replacement for collagen membranes in GTR/GBR procedures, closing lateral windows in sinus grafting procedures, for extraction site management, and as a stable biological membrane during recession coverage procedures. Furthermore, Alb-PRF may also be injected as a regenerative biological filler that lasts extended periods with advantages in joint injections, osteoarthritis and in the field of facial aesthetics. This article highlights the marked improvement in the stability and degradation properties of the novel Alb-PRF/e-PRF technology with its widespread future potential use as a potential replacement for collagen membranes with indications including extraction site management, GBR procedures, lateral sinus window closure, recession coverage among others, and further highlights its use as a biological regenerative filler for joint injections and facial aesthetics. It is hoped that this review will pioneer future opportunities and research development in the field, leading to further progression toward more natural and less costly biomaterials for use in medicine and dentistry.

Effects of low crystalline carbonate apatite on proliferation and osteoblastic differentiation of human bone marrow cells.

Carbonated apatite (CO3Ap) is the inorganic component of bone. We have proposed a new method for the fabrication of CO3Ap blocks based on a dissolution-precipitation method using a synthetic precursor. The aim of this study is to examine the effects of low crystalline CO3Ap on initial cell attachment, proliferation and osteoblastic differentiation of human bone marrow cells (hBMCs) using sintered hydroxyapatite and tissue culture plates as controls. Initial cell attachment and proliferation were assessed with a MTT assay. Expression of osteoblastic markers was examined by reverse transcription-polymerase chain reaction. XRD and FT-IR results showed formation of B-type carbonate apatite with lower crystallinity. No difference was observed for initial cell attachment between HAp and CO3Ap discs. hBMSC attached more significantly on tissue culture plate than on HAp and CO3Ap discs. The number of cells on HAp was higher than that on CO3Ap until day 7, after which the number of cells was similar. hBMSC proliferated more significantly on tissue culture plate than on HAp and CO3Ap discs. In contrast, hBMCs incubated on CO3Ap demonstrated much higher expression of osteoblastic markers of differentiation, such as type I collagen, alkaline phosphatase, osteopontin and osteocalcin, than hBMCs on HAp. On the tissue culture plate, they were not any change throughout the culture period. These results demonstrated that low crystalline CO3Ap exhibit higher osteoinductivity than HAp.

O2 saturation in the intercostal space during moderate and heavy constant-load exercise.

To examine the hypothesis that the relationship between minute ventilation (VE) and deoxygenation from the intercostal space (IC) would be steady regardless of exercise protocols, if an increase in O2 consumption of the accessory respiratory muscles with an increase of VE brings about deoxygenation in IC, we measured the relationship between VE and O2 saturation in IC (SO2IC) during a constant-load exercise test (CET), and the relationship was compared with that during a ramp incremental exercise test (RIET). Six male subjects performed RIET. On a different day, the subjects performed a moderate and heavy CET (CET_MOD and CET_HVY, respectively). SO2IC decreased from the start of both CET_MOD and CET_HVY and changed little from 2 min. Moreover, SO2IC was significantly lower during CET_HVY than during CET_MOD. In comparison between RIET and CET_HVY at the similar VE level, SO2IC was significantly higher during CET_HVY than RIET. These results suggest that the decrease in SO2IC was caused not only by an increase in O2 consumption in IC with an increase in VE but also by a decrease in O2 supply.

Which is the best indicator of muscle oxygen extraction during exercise using NIRS?: Evidence that HHb is not the candidate.

Recently, deoxygenated hemoglobin (HHb) has been used as one of the most popular indicators of muscle O2 extraction during exercise in the field of exercise physiology. However, HHb may not sufficiently represent muscle O2 extraction, as total hemoglobin (tHb) is not stable during exercise. The purpose of this study was to measure various muscle oxygenation signals during cycle exercise and clarify which is the best indicator of muscle O2 extraction during exercise using NIRS. Ten healthy men performed 6-min cycle exercise at both moderate and heavy work rates. Oxygenated hemoglobin (O2-Hb), HHb, tHb, and muscle tissue oxygen saturation (SmO2) were measured with near-infrared spatial resolved spectroscopy from the vastus lateralis muscle. Skin blood flow (sBF) was also monitored at a site close to the NIRS probe. During moderate exercise, tHb, O2-Hb, and SmO2 displayed progressive increases until the end of exercise. In contrast, HHb remained stable during moderate work rate. sBF remained stable during moderate exercise but showed a progressive decrease at heavy work rate. These results provide evidence that HHb may not sufficiently represent muscle O2 extraction since tHb is not stable during exercise and HHb is insensitive to exercise-induced hyperaemia.

Transoral open reduction with rigid internal fixation for subcondylar fractures of the mandible using a small angulated screwdriver system: is endoscopic assistance necessary?

PURPOSE: Although endoscopically assisted transoral open reduction and internal fixation of condylar mandible fractures is currently a popular technique, the need for it and its benefits remains unclear. This prospective study evaluated the efficacy and safety of open reduction and rigid internal fixation of subcondylar fractures of the mandible using a new small angulated screwdriver system without endoscopic assistance. PATIENTS AND METHODS: Fifteen patients with 15 linear subcondylar fractures were treated using this intraoral approach from June 2007 through March 2010 at the Division of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, Kagawa, Japan. The anatomic reduction of the displaced condylar segments and rigid fixation with 2 2.0-mm locking miniplates were performed using a small angulated screwdriver system, with an average follow-up of 13 months (range, 6 to 30 months). RESULTS: Correct anatomic reduction of the condylar segments at centric occlusion followed by immediate functional recovery was achieved in all patients. Mean operating time was 50 minutes (range, 35 to 70 minutes) when performed by the consultant surgeon and the residents. In addition, all patients had good temporomandibular joint articular function, with no harmful clinical symptoms or deviation. CONCLUSIONS: The surgical treatment of linear subcondylar fractures of the mandible can be achieved with an intraoral approach alone, using a small angulated screwdriver system, without endoscopic assistance, offering reliable clinical results and safe and minimally invasive surgery.

Oral rehabilitation of a maxillectomy defect using bone transport distraction and dental implants.

Bone transport distraction is a reliable procedure in various maxillofacial bony defect reconstruction techniques. It is minimally invasive and it eliminates donor site morbidity. We introduce a new surgical technique for maxillary backward bone transport distraction reconstruction performed in a 77-year-old woman with a posterior partial maxillary defect. Transport distraction was successful for posterior maxillary alveolar bony regeneration, which helped close an oroantral fistula. One month after the distraction device was removed, 3 dental implants were placed in the reconstructed alveolus, followed by successful oral functional rehabilitation by use of an implant-anchored prosthesis. Two and a half years have passed since the patient's dental implant-based prosthesis was activated, and the functional occlusal reconstruction by use of bone transport distraction and dental implants after repair of the maxillectomy defect has proven to be effective with patient satisfaction.

Unchanged muscle deoxygenation heterogeneity during bicycle exercise after 6 weeks of endurance training.

The purpose of this study was to examine the changes in muscle oxygen saturation (SmO(2)) level and its heterogeneity after 6 weeks of endurance training using multi-channel near infrared spatially resolved spectroscopy (NIR(SRS)). Nine healthy subjects participated in this study (Male = 6, Female = 3, age: 27 +/- 5 years, height: 168.7 +/- 7.4 cm, weight: 62.4 +/- 12.4 kg). The subjects performed a 30 W ramp incremental bicycle exercise test until exhaustion before and after endurance training. The NIR(SRS) probe was attached to the left vastus lateralis muscle along the direction of the long axis. The subjects performed bicycle exercise for 30 min/day, 3 days/week for 6 weeks. The work rate during training was set at 60%V(O)(2peak) and increased every 5%V(O)(2peak) when the subjects could maintain the work rate three times consecutively. After training, V(O)(2peak) was significantly increased (Pre: 42.7 +/- 9.9 ml/kg/min, Post: 52.3 +/- 7.2 ml/kg/min, p < 0.001) and the mean SmO(2) within measurement sites at was significantly decreased (Pre: 56.1 +/- 1.1 %, Post: 53.3 +/- 2.2 %, p < 0.05). Conversely, the heterogeneity of the SmO(2) during exercise was not changed by training. These results suggest that the functional heterogeneity of O(2) balance did not change due to endurance training, and the O(2) balance heterogeneity may not interfere with O(2) exchange in the activating muscle in healthy individuals.

Comparison of muscle O(2) dynamics at different sites of the forearm flexor muscles during incremental handgrip exercise.

This study investigated heterogeneity of muscle O(2) consumption (diffusive m-VO(2)) and muscle oxygenation difference (m-O(2) difference) within the forearm flexor muscles using multi-optical fibers near-infrared continuous wave spectroscopy (NIRcws) during incremental exercise. Nine healthy male subjects performed incremental dynamic handgrip exercise until exhaustion. The workload was increased by 5% maximal voluntary contraction (MVC) every 1 min, starting at 10% MVC. The NIRcws probes (10 channels) were placed on the right forearm flexor muscles to monitor muscle oxygenation. The diffusive m-VO(2) and the m-O(2) difference were evaluated at each exercise stage. The diffusive m-VO(2) at the medial site was significantly greater than the lateral site at 25% MVC (p < 0.05). Similarly, m-O(2) difference at the medial site increased significantly over the lateral site (p < 0.05), whereas there were no significant differences in diffusive m-VO(2) or m-O(2) difference between the proximal and distal sites. These results in forearm muscle were different from the previous study which found that there were longitudinal differences in muscle VO(2) in the femoral muscle.

Submandibular approach through the submandibular gland fascia for treating mandibular fractures without identifying the facial nerve.

BACKGROUND: : The submandibular, or Risdon, approach is the classic, reliable extraoral approach for treating mandibular fractures. Although the intraoral approach has been used recently for open reduction and internal fixation, in some cases, such as comminuted fractures or fractures in an atrophic mandible, the submandibular approach is still prerequisite. Damage to the marginal mandibular branch of the facial nerve is the only concern other than skin scarring. METHODS: : To minimize the risk of neuropraxia, we prospectively assessed an approach for treating mandibular fractures at 24 surgical sites in 22 patients (17 men, 5 women; mean age, 54.3 years) using direct submandibular gland capsule fascial layer elevation that did not require identifying the facial nerve. RESULTS: : As complications, one patient (4.2%) had temporary facial weakness in the mandibular branch, but this resolved completely within 3 months. The postoperative clinical course was uneventful in the other patients with one minor fistula and minimal scarring. CONCLUSIONS: : In conclusion, submandibular gland capsular layer elevation without facial nerve identification is a safe and less time-consuming technique applying the submandibular approach for the treatment of mandibular fractures.

Cloning of a novel splicing variant of RIN1 and its expression in gastric and colon cancer.

The regular RIN1 gene is a molecule located on chromosome 1lq13.2, and contains a coding region of 2352 bp with a 3' domain that binds to H-Ras protein, suggesting that it is an important molecule in the intracellular signaling pathway. In this study, we confirmed the existence of a novel form of the RIN1 gene with a different splicing pattern, successfully cloned it, and examined its expression in gastric and colon cancer cell lines. A 612-bp band (the RIN1 variant mRNA) was identified in the RT-PCR product from the colon cancer cell line Colo320D. (A 2352-bp band representing the regular RIN1 gene in HT29 cell line.) The 612-bp band was sequenced and compared with that of the regular RIN1 gene. As a result, the 612-bp product was found to contain a tyrosine phosphorylation site on the 5' side and Ras and 14-3-3 binding domains on the 3' side, indicating that it is a product with a different splicing pattern. The expression of the RIN1 variant mRNA was observed in two of six gastric cancer cell lines and four of five colon cancer cell lines. We identified a novel RIN1 gene with a splicing pattern different from that of the regular RIN1 gene. Comparison of both genes revealed that the novel RIN1 products had a structure conserving the Ras and 14-3-3 binding domains, but lacking two tyrosine phosphorylation sites. Novel RIN1 variant protein was expressed primarily in the cytoplasm and no expression in the cell membrane, and RIN1 variant protein was bound to 14-3-3 protein. In addition, the novel RIN1 mRNA was found to be expressed in gastric and colon cancer cell lines, suggesting that it is an important gene for the function of cancer cells.

Clinicopathological analysis of colorectal cancers in the elderly.

The average life expectancy of Japanese is 78 years for males and 85 years for females, being the longest in the world. In this study, elderly patients with colorectal cancer who underwent surgery and their non-elderly counterparts were compared to characterize the elderly patients. Of 387 colorectal cancer patients, 98 were over 75 years old, and 106 were between 45 and 60 years of age. These two groups of patients were analyzed for clinicopathological parameters, prognosis, and the expression of matrix metalloprotease 9 (MMP-9) and E-cadherin molecules as indicators of the invasive and metastatic ability of colorectal cancer. The elderly and non-elderly groups did not significantly differ in the clinicopathological findings. Molecular genetic analysis showed that the rates of MMP-9 or E-cadherin protein expression in the elderly and non-elderly groups were not significantly different. Considering that colorectal cancers in the elderly do not significantly differ from those in the non-elderly in tumor stage or malignancy grade, treatment policies should be comprehensively based on individual coexisting diseases and the general condition including physiological age.

Clinicopathological study of the colorectal mucinous carcinomas.

Histopathologically, the incidence of mucinous carcinomas in Europe and the United States is approximately 10% and that in Japan is low, at 2.9% to 7.4%. The prognosis of mucinous carcinomas is generally thought to be poor, but their clinical and histological features are not well known. In this study, we attempted to clinicopathologically characterize colorectal mucinous carcinomas. Of the 607 colorectal cancer patients, a group of 20 mucinous carcinoma patients (3.3%) and a group of 553 control patients were included in this study. The mucinous carcinomas were subclassified into the following two types to analyze clinicopathological parameters and outcomes: the papillotubular (PT) type and the mucocellular (MC) type. Clinicopathologically, the MC type showed higher rates of venous invasion, lymph node metastasis, liver metastasis, and peritoneal dissemination and higher frequencies of TNM stage III and IV cancers than the PT type. The MC type had a significantly poorer 3-year survival rate of 27% compared with 60% for the PT type. The MC-type mucinous carcinomas showed a significantly higher expression rate (37.5%) of MMP-9 than that (16.6%) in the PT-type mucinous carcinomas. Overall, the colorectal mucinous carcinomas progressed more rapidly and had a poorer prognosis than the control (nonmucinous) cancers. The histological subclassifications MC and PT tended to be molecular-biologically different, and the MC type was poorer in terms of clinicopathological parameters and outcomes.

Angiogenesis and tumor proliferation/metastasis of human colorectal cancer cell line SW620 transfected with endocrine glands-derived-vascular endothelial growth factor, as a new angiogenic factor.

Endocrine glands-derived-vascular endothelial growth factor (EG-VEGF) was recently cloned as a new angiogenic factor that selectively acts on the endothelium of endocrine gland cells. We evaluated the involvement of EG-VEGF in colorectal cancer. The expression of EG-VEGF was confirmed in all of the colorectal cancer cell lines. (On the other hand, the expression of EG-VEGF mRNA was not detected in colorectal normal mucosae.) Stable EG-VEGF infectors of colorectal cancer cell line SW620 were produced, EG-VEGF transfectants were implanted into cecum and s.c., and cell proliferation was evaluated. Angiogenesis was evaluated by dorsal air sac method. Liver metastasis was evaluated after the implantation of EG-VEGF transfectants into the mouse spleen. Tumor proliferation (cecum, s.c.) was significantly higher in the EG-VEGF transfectants than in the control cells. The small vessels were significantly increased in EG-VEGF transfectants as compared with those in control cells. Also, liver metastatic ratio was higher in the EG-VEGF transfectants than in the control cells. In this study, EG-VEGF, a new angiogenic factor, may lead to angiogenesis, promoting cell proliferation and liver metastasis in colorectal cancers. When the EG-VEGF gene-overexpressing colorectal cancer cell line that had been treated with phosphorothioate antisense EG-VEGF oligonucleotides was injected s.c. into mice, angiogenesis and tumor growth were inhibited. Although the novel angiogenesis factor EG-VEGF was not expressed in the normal colorectal mucosa, it was expressed in colorectal cancer cells, which indicates that it is a cancer-specific and possibly tissue-specific angiogenesis factor in the large intestine, and which suggests that it can be targeted by a novel antiangiogenesis therapy.

[Significance of peritonectomy for peritonitis carcinomatosis].

We analyzed patients who underwent multimodal treatment with peritonectomy as an aggressive treatment for peritonitis carcinomatosis. Peritonectomy was treated in eighteen cases (eleven gastric cancer, seven colon cancer). Out of these eighteen cases, nine were initial operation, six were recurrence after first operation and three were for relief after palliative operation for peritoneal dissemination. Five cases of recurrence included ileus. Of all eighteen patients, ten had received preoperative chemotherapies. Peritonectomy made complete resection possible principle, and the procedure included resection of the primary lesion, subtotal colectomy and peritonectomy. An intestinal stoma was needed in nine cases, consequently. All patients cases underwent continuous hyperthermic peritoneal perfusion (CHPP). Early postoperative peritoneal chemotherapy was given in five cases. By peritonectomy for a first time operation, macroscopically complete resection was possible in six cases. In relief and recurrence cases few tumor cells remained in five cases. Ileus due to peritoneal carcinomatosia was eliminated in all cases, and caloric intake became possible. Fourteen cases had postoperative complication (morbidity 78%), and treatment-related death occurred in three cases (mortality 17%). It became possible to resect even the peritoneal dissemination that was inoperable by conventional surgery, and improvement of QOL was achieved by peritonectomy in cases of carcinomatous peritonitis. However, postoperative care is important since aggression becomes more intense.