The oral disposition index calculated from a meal tolerance test is a crucial indicator for evaluating differential normalization of postprandial glucose and triglyceride excursions in morbidly obese patients after laparoscopic sleeve gastrectomy.

To determine the normalization of postprandial blood glucose (PG) and triglyceride (TG) excursions in 30 morbidly obese patients with or without diabetes mellitus (DM) 1-year after they underwent a laparoscopic sleeve gastrectomy (LSG) vs. their pre-surgery data, we administered the 75-g oral glucose tolerance test (OGTT) and a meal tolerance test (MTT) using a 75-g glucose-equivalent carbohydrate- and fat-containing meal. The results were as follows; (i) Postoperative body-weight reduction was associated with DM remission and reduced multiple cardiometabolic risks. (ii) OGTT data showing postprandial hyper-insulinemic hypoglycemia in many post-surgery patients were associated with overdiagnosis of improved glucose tolerance. However, postoperative MTT data without hypoglycemia showed no improvement in the glucose tolerance vs. pre-surgery data. (iii) The disposition index (DI) i.e., [Matsuda index] × (Glucose-induced insulin secretion) was progressively worsened from normal glucose tolerance to DM patients after LSG. These post-surgery DI values measured by the MTT were correlated with 2h-plasma glucose levels and were not normalized in DM patients. (iv) The baseline, 2h-TG, and an increase in 2h-TG values above baseline were correlated with the insulin resistance index, DI, or HbA1c; These TG values were normalized post-LSG. In conclusion, the glucose tolerance curve measured by the MTT was not normalized in T2DM patients, which was associated with impaired normalization of the DI values in those patients 1-year after the LSG. However, the baseline TG and a fat-induced 2h-TG values were normalized postoperatively. The MTT can be used to assess normalization in postprandial glucose and TG excursions after LSG.

Regeneration of Functional Bladder Using Cell-seeded Amnion and P(LA/CL) Scaffolds.

Long-term bladder regeneration has not been successful instead of augmentation with gastrointestinal segments, as is commonly performed for bladder reconstruction. To evaluate whether or not cell-seeded bioabsorbable materials regenerate half-resected bladder in a rabbit model. Female Japanese white rabbits were divided two groups: cell-seeded material (CSM) group and Control (n = 6 each). Control rabbits underwent resection of half the bladder. CSM rabbits were sutured with cell-seeded amniotic membrane and P(LA/CL) material after bladder resection. After 6, 12, and 18 months, rabbits underwent X-ray and cystometry, and bladder tissues after 18 months were subjected to functional and histological analyses. X-ray confirmed the peristaltic movements of the reconstructed bladders in the CSM group. On cystometry, the mean maximum bladder volume, maximum bladder pressure, and 25 mL bladder volume compliance in the CSM group were significantly greater than in the Control group at 6, 12, and 18 months. In addition, organ bath studies showed good contraction under electrical stimulation with increasing stimulation frequency in the CSM group, while, the Control group showed weak contraction on both tests in the central marginal zone. Furthermore, the rates of neovascularization, urothelial and smooth muscle formation, and neurofilamentation in the CSM group were significantly greater than in the Control group. Oral mucosal cell-seeded amniotic membrane and stomach smooth muscle cell-seeded P(LA/CL) scaffold with omentum after abdominal implantation regenerated functional bladder with satisfactory epithelium and smooth muscle without scarring more than 1 year. Impact Statement Regeneration of functional bladder without using gastrointestinal segments has been a huge challenge to urological reconstruction. Various materials, such as nonbioabsorbable materials and biomaterials have been attempted to reconstruct bladder in animal models. However, the long-term results more than a year failed due to the low biocompatibility, high risks, and difficulty creating the materials. In this study, we revealed long-term bladder regeneration using cell-seeded amniotic membrane and P(LA/CL) material in a rabbit model. The new method of bladder reconstruction seems able to regenerate functional bladder with satisfactory bladder epithelium and bladder smooth muscle function without scarring for more than 1 year successfully.

Effects of a new 75 g glucose- and high fat-containing cookie meal test on postprandial glucose and triglyceride excursions in morbidly obese patients.

A new meal tolerance test (MTT) using a 75 g glucose- and high fat-containing meal was applied to classify glucose intolerance in morbidly obese patients. According to the MTT data, the concordance rate of diagnosis was 82.5% compared to the 75 g oral glucose tolerance test (OGTT) in patients with normal glucose tolerance (NGT, n = 40). In the NGT patients, the insulinogenic index (r = 0.833), Matsuda index (r = 0.752), and disposition index (r = 0.845) calculated from the MTT data were each significantly (p < 0.001) correlated with those derived from the OGTT data. However, in patients with impaired glucose tolerance (IGT, n = 23) or diabetes mellitus (DM, n = 17), the postprandial glucose levels post-MTT were significantly lower than those post-OGTT, without increases in the postprandial insulin levels post-MTT. Thus, the severity of glucose intolerance measured by the MTT was milder than that indicated by the OGTT. Plasma levels of both glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were increased at the postprandial state, but only the GIP levels post-MTT were significantly higher than those post-OGTT. The enhancement of glucose disposal rates in patients with NGT or IGT after the MTT was associated with increased GIP levels. The postprandial hypertriglyceridemia induced by the MTT was associated with insulin resistance, but it was not associated with the impaired insulinogenic index or the disposition index. These results indicate that the new MTT is clinically useful to evaluate both abnormal glucose and triglyceride excursions caused by abnormal insulin sensitivity and secretions of insulin and gut hormones in morbidly obese patients.

The performance of heparin modified poly(ε-caprolactone) small diameter tissue engineering vascular graft in canine-A long-term pilot experiment in vivo.

Long-term in vivo observation in large animal model is critical for evaluating the potential of small diameter tissue engineering vascular graft (SDTEVG) in clinical application, but is rarely reported. In this study, a SDTEVG is fabricated by the electrospinning of poly(ε-caprolactone) and subsequent heparin modification. SDTEVG is implanted into canine's abdominal aorta for 511 days in order to investigate its clinical feasibility. An active and robust remodeling process was characterized by a confluent endothelium, macrophage infiltrate, extracellular matrix deposition and remodeling on the explanted graft. The immunohistochemical and immunofluorescence analysis further exhibit the regeneration of endothelium and smooth muscle layer on tunica intima and tunica media, respectively. Thus, long-term follow-up reveals viable neovessel formation beyond graft degradation. Furthermore, the von Kossa staining exhibits no occurrence of calcification. However, although no TEVG failure or rupture happens during the follow-up, the aneurysm is found by both Doppler ultrasonic and gross observation. Consequently, as-prepared TEVG shows promising potential in vascular tissue engineering if it can be appropriately strengthened to prevent the occurrence of aneurysm.

Effects of Fiber Diameter and Spacing Size of an Artificial Scaffold on the In Vivo Cellular Response and Tissue Remodeling.

By mimicking the extracellular matrix, nonwoven fabrics can function as scaffolds for tissue engineering application ideally, and they have been characterized regarding their fiber diameter and fiber spacing (spacing size) in vitro. We chronologically examined the in vivo effects of these fabrics on the cellular response and tissue remodeling. Four types of nonwoven polyglycolic acid fabrics (Fabric-0.7, Fabric-0.9, Fabric-3, and Fabric-16 with fiber diameters of 0.7, 0.9, 3.0, and 16.2 µm and spacing sizes of 2.0, 19.3, 19.0, and 825.4 µm, respectively) were implanted into the rat dorsum and subjected to histologic and immunohistochemical analyses from day 3 to 70. With Fabric-0.7, inflammatory cells (mainly M1 macrophages) and myofibroblasts with collagen type III accumulated mainly on the surface of the fabric and did not infiltrate inside the fabric initially, likely due to the narrow fiber space. Massive formation of collagen type I then appeared with the degradation of the fabrics, and finally, the remodeled tissue turned into a dense scar. With Fabric-0.9 and Fabric-3, inflammatory cells (predominantly M2 macrophages) were seen in all layers of the fabric initially. A mild increase in collagen type I was then seen, with few myofibroblasts, and the remodeled tissue ultimately showed a relatively little scar with an adequate thickness of the tissue induced by the fabrics. With Fabric-16, inflammatory cells (predominantly M1 macrophages) infiltrated into all layers of the fabric initially along with many myofibroblasts, especially in the hole. Lately, massive formation of collagen type I was noted due to the slow degradation of the fabric, with the shrinking of the fabric substantially, and the remodeled tissue finally turned to a dense scar. These findings suggest that optimizing the spacing size as well as the fiber diameter of artificial scaffolds may control the cellular response and tissue remodeling and facilitate favorable tissue regeneration without scar formation.

The usefulness of re-attachability of anti-adhesive cross-linked gelatin film and the required physical and biological properties.

BACKGROUND: To overcome the unfavorable issues associated with conventional anti-adhesive HA/CMC film, we developed an anti-adhesive thermally cross-linked gelatin film. OBJECTIVE: We tried to clarify the re-attachability of the film and the required properties concerning the film thickness, stiffness and anti-adhesion effect. METHODS: To determine the optimal thickness, 5 kinds of the thickness of gelatin film and the conventional film were analyzed by the tensile test, shearing test, buckling test and tissue injury test. Finally, using the optimal film thickness, we tried to clarify the anti-adhesion effect of the reattached film. RESULTS: The tensile and shearing test showed gelatin films ≥30 µm thick had greater tensile strength and a smaller number of film fractures, than the conventional film. The buckling and tissue injury test showed gelatin films ≥60 µm thick had higher buckling strength and worse injury scores than the conventional film. The anti-adhesive effect of re-attached gelatin film using optimal thickness (30-40 µm) found the anti-adhesion score was significantly better than that of the control. CONCLUSIONS: Provided it has an optimal thickness, gelatin film can be reattached with enough physical strength not to tear, safety stiffness not to induce tissue injury, and a sufficient anti-adhesion effect.

Thoracoscopic radical surgery for a morbidly obese patient with early lung cancer after laparoscopic sleeve gastrectomy: a case report.

BACKGROUND: We experienced a case of early stage lung cancer involving a morbidly obese patient. Obesity is associated with a higher incidence of surgical complications. We examined the effectiveness of laparoscopic sleeve gastrectomy as a primary weight loss procedure in a morbidly obese patient who required oncological surgery. CASE PRESENTATION: A 64-year-old morbidly obese female with a body mass index of 43.5 kg/m2 was referred to our hospital to undergo weight loss. A right-sided lung mass was found incidentally on computed tomography conducted in preparation for laparoscopic sleeve gastrectomy, which was performed prior to tumor surgery. As a result, weight loss was achieved within 2.5 months after the laparoscopic sleeve gastrectomy, and the patient's type-2 diabetes, hypertension, and dyslipidemia, which are linked to obesity, were markedly ameliorated. After a quick intraoperative pathological inspection revealed that the tumor was malignant, thoracoscopic right lung superior lobe resection was performed safely. CONCLUSIONS: Laparoscopic sleeve gastrectomy proved to be a powerful approach in a case in which a morbidly obese patient with early stage cancer needed to lose weight rapidly.

Newly Developed Polyglycolic Acid Reinforcement Unified with Sodium Alginate to Prevent Adhesion.

Polyglycolic acid (PGA) mesh fabric is widely used for reinforcing injured tissues during surgeries. However, PGA induces chronic inflammation and adhesion. The purpose of this study is to develop PGA reinforcement "without PGA-induced adhesion." We developed a reinforcement fabric unified with PGA mesh and alginate foam. The antiadhesive effects of sodium alginate foam and calcium alginate foam were evaluated in rats. Sodium alginate foam unified with PGA mesh fabric exhibited strong effects that limit the extent and severity of adhesion, whereas calcium alginate foam unified with PGA mesh was less effective in preventing adhesion. In the sodium alginate group, fibroblasts and collagen fibers around implanted sites were sparse and the material degraded rapidly by macrophage ingestion. Fibroblasts and collagen fibers play a major role in adhesion formation and their excessive proliferation results in postoperative adhesion. Thus, inhibiting their increase is the key in preventing PGA-induced adhesion. The reinforcement that is composed of PGA mesh unified with sodium alginate foam strongly inhibited PGA-induced adhesion and showed excellent handling during surgery and could be easily applied with a one-step procedure.

Reduction of Pulmonary Air Leaks with a Combination of Polyglycolic Acid Sheet and Alginate Gel in Rats.

Postoperative air leaks remain a major cause of morbidity after lung resection. This study evaluated the effect of a combination of polyglycolic acid (PGA) sheet and alginate gel on pulmonary air leaks in rats. Four pulmonary sealing materials were evaluated in lung injury: fibrin glue, combination of PGA sheet and fibrin glue, alginate gel, and combination of PGA sheet and alginate gel. With the airway pressure maintained at 20 cmH2O, a 2 mm deep puncture wound was created on the lung surface using a needle. Lowering the airway pressure to 5 cmH2O, each sealing material was applied. The lowest airway pressure that broke the seal was measured. The seal-breaking pressure in each experimental group was fibrin, 10.4 ± 6.8 cmH2O; PGA + fibrin, 13.5 ± 6.5 cmH2O; alginate gel, 10.3 ± 4.9 cmH2O; and PGA + alginate, 35.8 ± 11.9 cmH2O, respectively. The seal-breaking pressure was significantly greater in the PGA + alginate gel group than in the other groups (p < 0.01). There were no significant differences among the other three groups. Alginate gel combined with a PGA sheet is a promising alternative to fibrin glue as a safe and low-cost material for air leak prevention in pulmonary surgery.

Physical and biological properties of a novel anti-adhesion material made of thermally cross-linked gelatin film: Investigation of the usefulness as anti-adhesion material.

To create more useful, effective and safer anti-adhesion materials, we developed a thermally cross-linked gelatin film. In this study, we examined the physical properties of the film such as the physical strength and the adhesiveness to reveal the handling properties and biological properties, such as the anti-adhesion effect, the influence on cell proliferation, and the cytotoxicity to reveal the anti-adhesion mechanism, especially in comparison with the conventional hyaluronic acid and carboxymethylcellulose film (the conventional film). A tensile test under dry and wet conditions and shearing stress test showed that the gelatin film has significant higher maximum tensile stress and fracture strain than the conventional film. In the study using a rat model of cecum adhesion, the anti-adhesion effect of the gelatin film was significantly superior to that of the conventional film. In the cell proliferation test, the number of fibroblast cells on the gelatin film increased at each time point, while no cell proliferation was observed on the conventional film. Furthermore, in the cytotoxicity test using a colony assay and Live/Dead assay, the extract of the gelatin film had no cytotoxicity, while the extract of the conventional film had cytotoxicity considerably. These results suggest that the gelatin film provides better handling than the conventional film, due to better physical strength and ductility of the film. In addition, the gelatin film has a significantly greater anti-adhesion effect than the conventional film without any cytotoxicity. Therefore, the gelatin film is quite favorable as an anti-adhesion material. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 689-696, 2018.

Two-layer sheet of gelatin: A new topical hemostatic agent.

BACKGROUND/OBJECTIVE: Uncontrolled surgical bleeding is associated with increased morbidity, mortality, and hospital cost. Topical hemostatic agents available today have problems controlling hemostatic effects; furthermore, their handling is difficult and they are unsafe. METHODS: We devised a new hemostatic agent comprising gelatin sponge and film designed to be applied to the bleeding site, thereby creating a topical hemostatic agent made of gelatin alone. The gelatin was prepared by alkali treatment to eliminate viral activity. Hemostatic effects, surgical handling, and tissue reactions of the materials, namely a two-layer sheet of gelatin, TachoSil, and gelatin sponge, were evaluated using 21 dogs' spleens. RESULTS: The two-layer gelatin sheet and gelatin sponge exhibited superior hemostatic effects (100% hemostasis completed) compared with TachoSil (0-17% hemostasis). The gelatin matrix immediately absorbed blood flowing from wounds and activated the autologous components in the absorbed blood that promoted coagulation at the bleeding site. The two-layer gelatin sheet had the best surgical handling among the evaluated materials. Materials made of gelatin were associated with fewer inflammatory reactions compared with materials of TachoSil. CONCLUSION: The two-layer sheet of gelatin is a useful topical agent because of its superior hemostatic effects and usability, and is associated with a lower risk of transmitting diseases and inflammatory reactions.

The influences of a novel anti-adhesion device, thermally cross-linked gelatin film on peritoneal dissemination of tumor cells: The in vitro and in vivo experiments using murine carcinomatous peritonitis models.

To create anti-adhesive materials to be more effective and safer, we developed a thermally cross-linked gelatin film that showed superior anti-adhesive effects with excellent peritoneal regeneration. However, it may act as a convenient scaffold for tumor cell growth, thereby accelerating peritoneal dissemination when used in surgery for abdominal tumors. In this study, we tried to clarify this issue using mouse carcinomatous peritonitis models. First, we examined the in vitro tumor cell growth of mouse B16 melanoma or Colon26 cells on the gelatin film or the conventional hyarulonate/carboxymethylcellulose film. Tumor cell growth on each film was significantly lower than that of the control (no film). Next, we conducted the following in vivo experiments: After the parietal peritoneum was partially removed and covered with each film or without any film, mice were inoculated intraperitoneally with B16 melanoma or Colon26/Nluc cells expressing NanoLuc luciferase gene. At 7 days after the operation, we measured the weight of B16 melanoma tumors or the NanoLuc activity of Colon26/Nluc cells using in vivo imaging at the injured sites. There were no significant differences in the weight of the tumors and the NanoLuc activity among the three groups. We also observed the survival time of mice receiving the same operation and treatments. There was no significant difference in the survival time among the three groups. These results suggest that the gelatin film will likely not accelerate peritoneal dissemination as a convenient scaffold for tumor cell growth when used in surgery for abdominal tumors. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2122-2130, 2018.

New polyglycolic acid fabric for the prevention of postoperative pancreatic fistulas.

BACKGROUND: The incidence of postoperative pancreatic fistula (POPF) after distal pancreatectomy is approximately 30%. The most serious complications of pancreatic resection, such as mortality and prolonged hospitalization, are unresolved despite the proposal of various surgical procedures. We developed a new polyglycolic acid (PGA) fabric composed of fine diameter fibers to prevent POPF, and macroscopically and microscopically evaluated the effects of applying it to the pancreatic remnant. METHODS: The ventral pancreatic surface was cauterized to create the experimental model of POPF in 33 female Wistar/ST rats. The injured sites were wrapped with nonwoven PGA fabrics of different fiber diameters and porosities in the treated rats; one group of rats remained untreated. Survival, incidence of generalized peritonitis, and microscopic findings around the pancreas were investigated. RESULTS: The PGA fabrics acted as a scaffold for tissue repair and resulted in superior survival. Generalized peritonitis was milder in the PGA treated groups. With the new PGA fabric, abundant fibroblast infiltration and a uniformly-developed, self-organized barrier wall prevented both pancreatic leak and spread of inflammation. CONCLUSION: Application of the newly developed PGA fabric to the pancreatic remnant prevented POPF, and the essential factor for preventing pancreatic leak was the early formation of a self-organized barrier.

Preliminary Study of PGA Fabric for Seromas at Latissimus Dorsi Flap Donor Sites.

BACKGROUND: Seroma formation is a major complication following latissimus dorsi (LD) flap transfer for breast reconstruction. We implanted a nonwoven polyglycolic acid (PGA) fabric-a biodegradable polymer-in the LD flap donor site and examined its effect on postoperative seroma formation and resolution in a comparative study on 38 patients undergoing primary 1-stage breast reconstruction by LD flap. METHOD: A PGA treatment group had a PGA fabric placed in the donor wound (PGA group, n = 20), whereas a second group was treated with standard donor site closure (control group, n = 18). The incidence of seromas was comparable between the groups. RESULT: There was a significant reduction in aspiration volume by needle aspiration after drain removal (P < 0.05) and in the time until seroma resolution (P < 0.01) in the PGA group compared with the control group. CONCLUSION: These results indicate that application of PGA at the LD donor site is useful in controlling postoperative seromas.

Anti-adhesive effects of a newly developed two-layered gelatin sheet in dogs.

AIM: Adhesion after pelvic surgery causes infertility, ectopic pregnancy, and ileus or abdominal pain. The materials currently available for clinical use are insufficient. The purpose of this study was to develop an anti-adhesive material that overcomes the limitations of conventional anti-adhesive agents. METHODS: The adhesion prevention effects of three methods - a two-layered sheet composed of gelatin film and gelatin sponge, Seprafilm and INTERCEED - were evaluated in 37 dogs. Anti-adhesive effects were investigated macroscopically and microscopically in a cauterized uterus adhesion model. Cell growth on the materials in vitro using human peritoneal mesothelial cells, fibroblasts and uterine smooth muscle cells were also evaluated. RESULTS: The two-layered gelatin sheet had significantly superior anti-adhesive effects compared to the conventional materials (Seprafilm and INTERCEED). A single-cell layer of mature mesothelium formed three weeks after surgery in the gelatin group. Peritoneum regeneration in the Seprafilm and INTERCEED groups was delayed and incomplete in the early phase. Little inflammation around the materials occurred and cell growth was significantly proliferated with the gelatin sheet. CONCLUSION: The anti-adhesive effects of a two-layered gelatin sheet were superior to conventional agents in a cauterized canine uterus model, demonstrating early regeneration of the peritoneum, little inflammation and material endurance. The newly developed two-layered gelatin sheet is a useful option as an anti-adhesive agent for deeply injured and hemorrhagic sites.

Sialic acid level is significantly elevated in IgM enriched protein fraction in sera of cancer patients.

Serum sialic acid (SA) levels are important for diagnosis, follow-up, and mechanistic analysis of malignant diseases. However, little is known about the levels of SA bound to serum IgM. Here, we isolated IgM from sera of healthy individuals and patients with cancer using DEAE chromatography and 8% polyethylene glycol precipitation. In this fraction, which contained partially purified IgM (recovery; 52%; purity: 25%), SA was quantified with fluorescence detection-HPLC (detection limit: 0.08 µM). SA levels in the IgM-enriched fraction was significantly higher in cancer patients (104 ± 27 µM) than in healthy individuals (81 ± 11 µM; P = 0.003).

Filling and shielding for postoperative gastric perforations of endoscopic submucosal dissection using polyglycolic acid sheets and fibrin glue.

BACKGROUND AND STUDY AIMS: Many medical institutions in Japan perform endoscopic mucosal dissection (ESD) to treat early gastric cancer. Perforations can occur during ESD, and clipping has been reported as useful for treating small pinhole perforations. However, it is often difficult to close postoperative perforations because they usually have large diameters, and the muscle layer around the perforated region is often fragile, so additional open surgery is the only currently used method to treat large perforations and delayed perforations. Another method for large perforation is needed to treat perforations endoscopically. Ono et al. reported a case in which a postoperative perforation was closed using a polyglycolic acid (PGA) sheet and fibrin glue. In addition, it has been used by the authors' group to repair duodenal injuries that occur during ESD. We report 3 cases in which PGA sheets and fibrin glue were successfully used to repair postoperative gastric perforations endoscopically. This method is simple, safe, and effective, and is a new way to treat large perforations and delayed perforations that occur following ESD.

Prevention of Polyglycolic Acid-Induced Peritoneal Adhesions Using Alginate in a Rat Model.

Postoperative intra-abdominal or intrathoracic adhesions sometimes cause significant morbidity. We have designed three types of alginate-based treatments using strongly cross-linked (SL), weakly cross-linked (WL), and non-cross-linked (NL) alginate with calcium gluconate. In rat experiments, we compared the antiadhesive effects of the three types of alginate-based treatments, fibrin glue treatment (a standard treatment), and no treatment against adhesions caused by polyglycolic acid (PGA) mesh (PGA-induced adhesions). The antiadhesive materials were set on the PGA sheet fixed on the parietal peritoneum of the abdomen. Fifty-six days later, the adhesions were evaluated macroscopically by the adhesion scores and microscopically by hematoxylin-eosin staining and immunostaining. We also tested the fibroblast growth on the surface of the antiadhesive materials in vitro. The antiadhesive effects of WL and NL were superior to the no treatment and fibrin glue treatment. A microscopic evaluation confirmed that the PGA sheet was covered by a peritoneal layer constructed of well-differentiated mesothelial cells, and the inflammation was most improved in the NL and WL. The fibroblast growth was inhibited most on the surfaces of the NL and WL. These results suggest that either the WL or NL treatments are suitable for preventing PGA-induced adhesions compared to SL or the conventional treatment.

Emphasizing mesenteric blood vessels in laparoscopic colon cancer surgery video images.

This study aims to reduce surgeon burden by emphasising mesenteric blood vessels buried in the mesentery using image processing techniques.We have developed an image processing system that can be connected to a laparoscope. The first step of the method is superficial vessel deletion using an opening process. Next, the mesenteric blood vessels are extracted by multiple regression analysis using hue, saturation, and value color space information in the image. Finally, the enhanced regions are determined by areas obtained by a labeling process. Although examples with both true and false positives are observed, the proposed technique demonstrates sufficient accuracy.

Biological properties of a thermally crosslinked gelatin film as a novel anti-adhesive material: Relationship between the biological properties and the extent of thermal crosslinking.

In order to prevent postoperative adhesion and the related complications, a thermally crosslinked gelatin (TCG) film was developed and the basic biological properties were examined, paying special attention to the relationship between these properties and the extent of crosslinking of the film. The gelatin films crosslinked thermally for five different time periods (0, 1, 3, 8, and 14 hours) were developed and the following tests were performed. Regarding the material characterization of the films, the water content, the water solubility, and the enzymatic degradation for collagenase were found to be closely related to the duration of thermal crosslinking. In an in vitro study conducted to examine the cell growth of fibroblasts cultured on the films, the degree of cell growth, except no crosslinked film, was less than that observed in the control group, thus suggesting that such effects of the films on fibroblast cell growth may be related with their anti-adhesive effects. In in vivo tests, the films crosslinked for longer time periods (3, 8, and 14 hours) were retained for longer after being implanted into the abdominal cavity in rats and showed a significant anti-adhesive effect in the rat cecum adhesion models, indicating that the biodegradability and anti-adhesive effects of the TCG films depend on the duration of thermal crosslinking. In order to develop useful and effective anti-adhesive gelatin film, it is very important to optimize duration of the thermal crosslinking.