The frontal cortex is activated during learning of endoscopic procedures

Background

To date, several training and evaluation systems for endoscopic surgery have been developed, such as virtual-reality simulators and box trainers. However, despite current advances in these objective assessments, no functional brain studies during learning of endoscopic surgical skills have been carried out. In the present study, we investigated cortical activation using near-infrared spectroscopy (NIRS) during endoscopic surgical tasks.

Study design

A total of 21 right-handed subjects, comprising 4 surgical experts, 4 trainees, and 13 novices, participated in the study. Suturing and knot-tying tasks were performed in a box trainer. Cortical activation was assessed in all subjects by task-related changes in hemoglobin (Hb) oxygenation using NIRS.

Results

In surgical experts and novices with no experience of endoscopic surgical training, we found no changes in oxy-Hb, deoxy-Hb or total-Hb levels in any of the frontal channels. In surgical trainees and one novice with experience of endoscopic surgical training, we found significant increases in oxy-Hb and total-Hb levels in most of the frontal channels. There were significant differences in oxy-Hb and total-Hb levels in CH-19 between surgical experts and trainees (p = 0.02 for both), and between surgical trainees and novices with no experience of endoscopic surgical training (p = 0.008 for both). Furthermore, additional training increased oxy-Hb levels in the frontal cortex of novices with no experience of endoscopic surgical training but had no such effect on surgical experts.

Conclusions

The present data suggest that NIRS is a feasible tool for assessing brain activation during endoscopic surgical tasks, and may have a large impact on the future development of teaching, training, and assessment methods for endoscopic surgical skills.     

Impaired cutaneous wound healing in mice lacking tetranectin

Tetranectin was originally purified from human serum on the basis of plasminogen kringle 4-binding properties. Tetranectin enhances plasminogen activation by a tissue-type plasminogen activator so that it has been suggested to play a role in tissue remodeling. We have generated mice with a targeted disruption of the tetranectin gene to elucidate the biological function of tetranectin. In this study, we showed that wound healing was markedly delayed in tetranectin-null mice compared with wild-type mice. A single full-thickness incision was made in the dorsal skin. By 14 days after the incision, the wounds fully healed in all wild-type mice based on the macroscopic closure; in contrast, the progress of wound healing in the tetranectin null mice appeared to be impaired. In histological analysis, wounds of wild-type mice showed complete reepithelialization and healed by 14 days after the incision. However, those of tetranectin-null mice never showed complete reepithelialization at 14 days. At 21 days after the injury, the wound healed and was covered with an epidermis. These results supported the fact that tetranectin may play a role in the wound healing process.     

Evaluation of video-assisted thoracoscopic surgery lobectomy requiring emergency conversion to thoracotomy

Objective: Video-assisted thoracoscopic surgery (VATS) lobectomy has been employed for the treatment of lung cancer. Many investigators have reported that the outcomes of VATS lobectomy for lung cancer are comparable to those of thoracotomy; however, several controversial issues remain. One of the critical concerns is the safety. VATS lobectomy often requires an emergency conversion to thoracotomy, for example, in the event of massive bleeding. In this study, cases in which VATS lobectomy for lung cancer was converted to thoracotomy intra-operatively (converted VATS lobectomy) were identified. The safety of the converted VATS lobectomy was evaluated. Methods: Between 2003 and 2007, VATS lobectomy was converted to thoracotomy in 24 out of 492 cases. Information regarding the patients’ characteristics, reasons for the conversion and perioperative complications as well as the recurrence and survival data were carefully reviewed. The reasons for the conversion were classified into two groups: (1) problems related to the VATS procedure (VATS-related problems) and (2) problems not related to the VATS procedure (non-VATS-related problems). Results: Of the 24 converted cases, 19 (79%) had a history of smoking. Nine patients (38%) had a history of lung disease. Left upper lobectomy was the most frequently associated with conversion (11/24, 46%), followed by right lower lobectomy and right upper lobectomy. The most frequent reasons for the conversion were hilar lymphadenopathy and bleeding (seven patients each), followed by fused fissure. Eight of the conversions were considered to be attributable to VATS-related problems. Perioperative complications were observed in four patients, consisting of prolonged air leak in three patients and transient recurrent laryngeal nerve palsy in one patient. However, there were no life-threatening complications. The median follow-up period was 26 months. Recurrence occurred in two patients: pleural dissemination in one and bone metastasis in the other. Two deaths were observed during the follow-up period: one related to lung cancer and another related to other type of cancer. Conclusions: The safety of the conversion was acceptable. Our findings suggest that VATS lobectomy for lung cancer is feasible from the viewpoint of safety, even after taking into account the potential need for conversion to thoracotomy in some patients.     

Relationship between pediatric sinusitis and middle turbinate pneumatization--ethmoidal sinus pyocele thought to be caused by middle turbinate pneumatization

OBJECTIVE: To investigate whether the presence of pediatric middle turbinate pneumatization causes narrowing of the ostiomeatal complex (OMC) and is associated with the development of paranasal sinusitis. METHODS: CT scans of 190 nasal sides of 95 children (1-15 years old) were analyzed for the presence of middle turbinate pneumatization and mucosal thickness in the paranasal sinus. RESULTS: Middle turbinate pneumatization was detected in nine (4.6%) of the nasal cavities. Only one of these sides was in a patient younger than 10 years of age, while the other eight sides were in patients at least 13 years old. In six of those nine sides with pneumatization, paranasal sinusitis was also found. However, the images showed that in five sides the middle turbinate pneumatization itself did not obstruct the OMC. In addition, the mean +/- standard deviation (S.D.) of the total score for the paranasal sinus opacification on the side which had the middle turbinate pneumatization was 5.67 +/- 2.95. The corresponding value for the 76 sides without pneumatization was 5.29 +/- 2.53, and the difference between these mean total scores was not statistically significant. However, in one side, the OMC was obstructed or narrowed due to the middle turbinate pneumatization, and an ethmoidal sinus pyocele formed on this side. CONCLUSION: A causal relationship was not found between middle turbinate pneumatization and the mechanism of development of paranasal sinusitis in children. However, in the event that the OMU becomes obstructed at some time, frequent cycles of improvement and aggravation of pediatric paranasal sinusitis may occur and lead to the development of a serious condition.     

Effect of mitomycin C dissolved in a reversible thermosetting gel on outcome of filtering surgery in the rabbit]

PURPOSE: Based on our previous report that showed enhanced transfer of mitomycin C to the sclera and the conjunctiva by dissolving the antiproliferative in a reversible thermo-setting gel, we conducted a study to investigate the efficacy of the mitomycin C-gel in the rabbit. METHODS: We subconjunctivally injected 0.1 ml of the mitomycin C-gel solution containing several amounts of the drug. Trephination was performed in the injected region 24 hours later. Intraocular pressure measurement, and photography and ultrasound biomicroscopic examination of the filtering bleb were done 1, 2, and 4 weeks postoperatively. RESULTS: The gel containing 3.0 micrograms or more mitomycin C significantly enhanced bleb formation in addition to reducing the intraocular pressure. CONCLUSION: The reversible thermo-setting gel seems to facilitate filtration following glaucoma filtering surgery in the rabbit and deserves further investigation as a new method of mitomycin C application.     

Bumetanide-induced enlargement of the intercellular space in the stria vascularis critically depends on Na+ transport

The intercellular space in the stria vascularis (intrastrial space) is a closed space and isolated from both the endolymph and the perilymph in normal tissue. Loop diuretics such as bumetanide and furosemide cause an acute enlargement of the intrastrial space in association with a decline in the endocochlear potential. It is known that bumetanide inhibits the Na+-K+-2Cl- cotransporter, which is expressed abundantly in the basolateral membrane of marginal cells. We studied ionic mechanisms underlying the bumetanide-induced enlargement of the intrastrial space using perilymphatic perfusion in guinea pigs. Perilymphatic perfusion with artificial perilymph containing 100 microM bumetanide caused marked enlargement of the intrastrial space, as reported previously. Removal of K+ from the perilymph did not affect the bumetanide-induced enlargement, whereas removal of Na+ from the perilymph inhibited it almost completely. Perilymph containing 1 mM amiloride also inhibited the enlargement of the intrastrial space almost completely. These results indicate that perilymphatic Na+, but not K+, and amiloride-sensitive pathways are essential to the bumetanide-induced enlargement of the intrastrial space. Two possible pathways could yield these results. Na+ in the perilymph could enter the endolymph via Reissner's membrane or the basilar membrane; Na+ in the endolymph would then be taken up by marginal cells via the apical membrane and secreted into the intrastrial space by Na+-K+-ATPase in the basolateral membrane of them. Another, less likely possibility is that Na+ in the perilymph is transported into basal cells or fibrocytes in the spiral ligament, then into intermediate cells via gap junctions, and finally secreted into the intrastrial space via Na+-K+-ATPase of intermediate cells.     

Evaluation of denture base resin after disinfection method using reactive oxygen species (ROS)

The effects of certain disinfectants on the stability of a polymethyl methacrylate denture base resin were investigated, including those of a novel disinfection method using reactive oxygen species (ROS). The surface roughness and flexural strength were analyzed to assess the effects of the disinfectants on material properties. The following disinfectants were tested: 5% sodium hypochlorite, 70% alcohol, and ROS. Furthermore, the attachment of Candida albicans to the resin surface was investigated. The disinfection method using sodium hypochlorite significantly increased the surface roughness and decreased flexural strength. The surface roughness and flexural strength of the ROS-treated specimens did not significantly differ from those of the control specimens, and the ROS-treated specimens exhibited diminished Candida attachment. These results demonstrate that the ROS disinfection method preserves acceptable material stability levels in polymethyl methacrylate resins.     

Long-term Therapeutic Outcome of Acute Primary Angle Closure in Japanese

Purpose

To investigate the long-term clinical course of acute primary angle closure (APAC) and acute primary angle-closure glaucoma (APACG) in Japanese patients.

Methods

We retrospectively reviewed our records of 66 consecutive APAC or APACG eyes observed between February 1992 and December 2003 (mean follow-up, 42.1 months). Immediately after the diagnosis, all patients had received similar medications to halt the acute attack. Subsequently, laser iridotomy or surgical peripheral iridectomy and/or laser iridoplasty were conducted. If intraocular pressure (IOP) control was poor under maximum tolerable ocular hypotensive agents, trabeculectomy with adjunctive mitomycin C (MMC) was undertaken.

Results

After laser therapy, the probability of success, defined as an IOP of <21?mmHg with or without medications, was 81.2% ± 6.2%. In the ten eyes that were trabeculectomized, the probability of success based on the same criterion was 40.0% ± 29.7%. Multivariate analysis revealed that the degree of synechial angle closure (P = 0.029) and the preexistence of chronic glaucomatous optic neuropathy (P = 0.015) significantly influenced the need for subsequent filtering surgery.

Conclusions

Without the intervention of filtering surgery, 84.6% of eyes with APAC or APACG maintained IOP control with or without antiglaucoma medications. However, APAC and APACG eyes that eventually received trabeculectomy were predisposed to an uncontrollable IOP, even with the intraoperative application of MMC. The severity of APAC or APACG in Japanese may be affected by an underlying creeping angle closure.?Jpn J Ophthalmol 2007;51:353–359 © Japanese Ophthalmological Society 2007

     

The time course of the change in antibody titres in herpes gestationis

The time course of the change in antibody titres was examined postpartum after treatment in two patients with herpes gestationis. The first patient, a 29-year-old woman seen first in the 32nd week of her first pregnancy, had an exudative erythema, and developed an itchy erythema with small tense vesicles on the trunk and legs after delivery in the 40th week of pregnancy. The second patient, a 28-year-old woman seen first in the 28th week of her first pregnancy, had an itchy exudative erythema, small tense vesicles and crusts on the legs. After a Caesarean section in the 40th week of pregnancy performed because of cardiac complications in the fetus, the skin lesions extended to the trunk and extremities. Direct immunofluorescence revealed linear depositions of IgG and C3 at the basement membrane zone (BMZ) and indirect immunofluorescence was positive at the epidermal side of the BMZ in 1 mol/L NaCl-split skin in both cases. In patient 1, prednisolone, 20 mg/day, administered 4 months after delivery, gave rapid improvement (within 1 week) of the skin lesions; in patient 2, minocycline, 200 mg/day, administered 2 weeks after delivery, gave improvement within 2 weeks. Immunoblotting against epidermal extracts revealed the presence of antibodies directed to the 180 kDa bullous pemphigoid antigen in both sera. Indirect immunofluorescence and immunoblot were positive for at least 2 months in patient 1 and for 5 months in patient 2 after disappearance of the skin lesions.     

Yo jyo hen shi ko, a novel Chinese herbal, prevents nonalcoholic steatohepatitis in ob/ob mice fed a high fat or methionine-choline-deficient diet.

BACKGROUND: Oxidative stress plays a role in the pathogenesis of nonalcoholic steatohepatitis (NASH). Yo jyo hen shi ko (YHK) is a complex compound purported to reduce reactive oxygen species (ROS) by blocking the propagation of radical-induced reactions. The aim of this study was to evaluate the role of the effect of YHK in experimental NASH. METHODS: NASH was induced in male ob/ob mice by a high-fat (HF) diet or methionine/choline-deficient (MCD) diet for 4 weeks. YHK-treated animals received YHK solution orally (20 mg/kg/day) in both experimental diets (n=6; each group) while control animals received only vehicle. RESULTS: The MCD and HF groups developed moderate diffuse macrosteatosis, hepatocellular ballooning, and a diffuse inflammatory infiltrate. With the addition of YHK, there was a marked reduction in macrosteatosis in both groups. This was associated with decreased lipoperoxide and reduced glutathione-GSH concentrations as well as reduced serum aminotransferases and improved histological markers of inflammation. These changes were also associated with weight loss in the MCD+YHK group and diminished weight gain in the HF+YHK group. CONCLUSION: YHK therapy blunts the development of macrosteatosis in these models of NASH and significantly reduces markers of oxidative stress. YHK also diminishes weight gain in this obesity prone model. Our findings warrant further study on the mechanisms involved with these effects.