Cross-talk between Tor1 and Sch9 regulates hyphae-specific genes or ribosomal protein genes in a mutually exclusive manner in Candida albicans.

The human fungal pathogen Candida albicans switches its morphology from yeast to hyphal forms. The morphological transition may render C. albicans virulent. Several signaling cascades, including those of the cyclic AMP-protein kinase A and mitogen-activated protein kinase pathways, are responsible for morphogenesis. In this study, we observed a reduction in gene transcription of ribosomal proteins during true hyphae formation. Moreover, morphogenesis-dependent decrease in ribosomal protein gene transcription was confirmed in constitutive yeast or filamentous growing strains. We consistently observed that polysome and monosome levels were decreased by hyphal stimuli through TORC1 and Sch9 kinases. Taken together, these results provide several lines of evidence to show that the Tor1-Sch9 kinase cascade, which stimulates transcription of ribosomal protein genes, exists in C. albicans. Thus, the present study revealed a novel link between ribosome biogenesis and morphogenesis in C. albicans that is mediated by Tor1 and Sch9.

Longer coronary anastomosis provides lower energy loss in coronary artery bypass grafting.

Distal anastomosis technique affects graft patency and long-term outcomes in coronary artery bypass grafting, however, there is no standard for the appropriate length of distal anastomosis. The purpose of this study is to evaluate whether longer distal anastomosis provides higher quality of distal anastomosis and better hemodynamic patterns. Off pump CABG training simulator, YOUCAN (EBM Corporation, Japan), was used for distal anastomosis model. Two lengths of distal anastomosis model (10 versus 4 mm) were prepared by end-to-side anastomosis technique. After CT scan constructed three-dimensional inner shape of distal anastomosis, computational flow dynamics (CFD) was used to analyze hemodynamic patterns. The working flow was defined as Newtonian fluid with density of 1050 kg/m3 and viscosity of 4 mPa s. The boundary condition was set to 100 mmHg at inlet, 50 ml/min at outlet, and 100 % stenosis of proximal coronary artery. Three-dimensional CT imaging showed quality of distal anastomosis in 10 mm model was more uniform without vessel wall inversion or kinking compared to 4 mm model. Anastomotic flow area was significantly larger in 10 mm model than that in 4 mm model (28.67 ± 4.91 versus 8.89 ± 3.18 mm2, p < 0.0001). Anastomotic angle was significantly smaller in 10 mm model compared to 4 mm model (10.2 ± 5.65° versus 20.6 ± 3.31°, p < 0.0001). CFD analysis demonstrated 10 mm model had streamlined flow with smooth graft curvature, whereas 4 mm model had abrupt blood flow direction changes with flow separation at the toe. 10 mm model had significantly lower energy loss than 4 mm model (34.78 ± 6.90 versus 77.10 ± 21.47 µW, p < 0.0001). Longer distal anastomosis provided higher quality of distal anastomosis, larger anastomotic flow area, smaller anastomotic angle, and smoother graft curvatures. These factors yielded lower energy loss at distal anastomosis.

A Novel Method of Real-Time Assessment for Coronary Artery Anastomosis Skill.

PURPOSE: Coronary anastomosis is the most key factor to accomplish coronary artery bypass grafting, which is one of the largest areas in cardiovascular surgery. Although we have organized on-site simulator training courses of coronary anastomosis using BEAT YOUCAN, it became difficult to continue it because of COVID-19. Therefore, we established a real-time evaluation sheet instead of an Objective Structured Assessment of Technical Skills (OSATS) evaluation sheet. The purposes of this study was to develop the real-time assessment system and to prove the correlation between the score obtained by the OSATS and the score obtained by the real-time evaluation system. SUBJECTS AND METHODS: A total of 22 videos from the qualifying round of real-time coronary anastomosis competition evaluated by both the modified OSATS and the real-time evaluation system were utilized in this study. The global rating score of OSATS was compared with the global rating score of real-time evaluation system. RESULTS: When examined the relationship between the OSATS total score and the real-time total score, there was a significant correlation (R = 0.752, p <0.001). The OSATS general definition score and the real-time total score also showed a strong correlation (R = 0.733, p <0.001). CONCLUSIONS: We developed a real-time assessment sheet to evaluate coronary anastomosis. This assessment sheet had a good correlation with the OSATS evaluation sheet.

Novel connecting tube for saline chaser in contrast-enhanced CT: the effect of spiral flow of saline on contrast enhancement.

OBJECTIVE: To evaluate the effect of a newly developed connecting tube, which generates a spiral flow of saline, on aortic and hepatic contrast enhancement during hepatic-arterial phase (HAP) and portal venous phase (PVP) computed tomography (CT). METHODS: Eighty patients were randomly assigned to one of two protocols: with a new or a conventional tube. The contrast material (600 mgI/kg) was delivered over 30 s; this was followed by the administration of 25 ml saline solution delivered at the same injection rate as the contrast material. Unenhanced and contrast-enhanced CT images of the upper abdomen were obtained. We calculated the changes in the CT number (∆HU) for the aorta during HAP and PVP, and for the liver during PVP. We compared ∆HU between protocols. RESULTS: The mean ∆HU for the abdominal aorta during HAP was significantly higher with the new tube protocol than with the conventional tube protocol (322 ± 53 vs. 290 ± 53, P < 0.01). There were no significant differences in the mean ∆HU for the abdominal aorta and liver during PVP between the two protocols (P > 0.05). CONCLUSION: The new connecting tube increased the effect of a saline chaser and significantly improved aortic enhancement during HAP. KEY POINTS: • Optimal administration of intravenous contrast material is essential for optimal CT quality. • A new connecting tube can generate spiral flow, which improves intravenous administration. • The new connecting tube improved aortic contrast enhancement during the hepatic-arterial phase. • The new connecting tube increased the effect of a saline chaser.

A single surgeon's experience with 54 consecutive cases of multivisceral resection for locally advanced primary colorectal cancer: can the laparoscopic approach be performed safely?

BACKGROUND: Laparoscopic resection for colorectal cancer has become popular. However, no previous studies have compared the laparoscopic and open approaches for colorectal cancer adherent to adjacent organs. This study analyzed the short- and long-term survival outcomes after laparoscopic multivisceral resection of the locally advanced primary colorectal cancer compared with open procedure in an effort to address appropriate patient selection. METHODS: From a prospectively collected database, 54 patients with locally advanced primary colorectal cancer who had undergone multivisceral resection from March 2001 to September 2009 were identified. Laparoscopic and open surgeries were selectively performed for 38 and 16 patients, respectively. RESULTS: The two groups had similar demographics, with no differences in age, sex, and comorbidity. However, five emergency or urgency operations were included in the open group. No differences existed between the two groups in terms of tumor node metastasis (TNM) staging, histologic tumor infiltration rates, or curative resection rates. Three patients (7.9%) in the laparoscopic group required conversion to open procedure. In the laparoscopic group, the operation time was longer (330 vs. 257 min; p = 0.018), the volume of blood loss was less (269 vs. 638 ml; p = 0.000), and the time until return of bowel movement was shorter (3.7 vs. 4.7 days; p = 0.029) than in the open group. The perioperative morbidity rates were similar in the two groups (21.1% vs. 43.7%; p = 0.107), and no perioperative mortality occurred in either group. The mean follow-up period after curative resection was 40 months in the laparoscopic group and 35 months in the open group. The two groups showed similar rates for local recurrence (7.7% vs. 27.3%; p = 0.144) and distant metastasis (15.4% vs. 45.5%; p = 0.091). The overall 5-year survival rate was 60.5% for the laparoscopic group and 47.7% for the open group (p = 0.044, log-rank test). In terms of TNM stages, the overall 5-year survival rate for pathologic stage 3 disease was 58.3% for the laparoscopic group and 25% for the open group (p = 0.022, log rank test), but no difference was noted for the stage 2 patients (p = 0.384). CONCLUSIONS: No adverse long-term oncologic outcomes of laparoscopic resection were observed in this study. Although inherent limitations exist in this nonrandomized study, laparoscopic multivisceral resection seems to be a feasible and effective treatment option for colorectal cancer for carefully selected patients. Patients with colon cancer should be much more carefully selected for laparoscopic multivisceral resection than patients with rectal cancer because anatomic uncertainty can make oncologic en bloc resection incomplete.

Efficacy of simulation training for beating heart coronary anastomosis using BEAT + YOUCAN simulator.

BACKGROUND: We sought to evaluate our distributed practice program developed for training for beating heart anastomosis by employing a novel beating heart simulator. METHODS: Eleven trainees watched and reviewed instructional video recordings of coronary anastomosis methods with a BEAT + YOUCAN training device, then performed coronary anastomosis procedures under a beating condition. Next, they participated in a four-hour training program developed by faculty surgeons. Ten different anastomosis components were assessed on a five-point rating scale (5, good; 3, average; 1, poor). After finishing the training program, each trainee again performed a coronary anastomosis procedure. Component scores were then compared before and after the training program. RESULTS: The mean time to completion of the procedure improved from 1033 ± 424 to 795 ± 201 s (p < 0.05). Assessment scores improved from 1.88 ± 0.41 to 2.57 ± 0.30 (p < 0.05). Improvements in some technical components related to handling of instruments were noted (p < 0.05), whereas no significant improvement was seen with arteriotomy, graft orientation, suture management, or knot tying after finishing the training program. CONCLUSION: Trainees who participated in our four-hour focused training program for coronary anastomosis with a novel beating heart simulator showed improved ability under the beating condition in regard to technical skills related to handling instruments.

Development of Carbazole Derivatives Compounds against Candida albicans: Candidates to Prevent Hyphal Formation via the Ras1-MAPK Pathway.

Morphogenesis contributes to the virulence of the opportunistic human fungal pathogen Candida albicans. Ras1-MAPK pathways play a critical role in the virulence of C. albicans by regulating cell growth, morphogenesis, and biofilm formation. Ume6 acts as a transcription factor, and Nrg1 is a transcriptional repressor for the expression of hyphal-specific genes in morphogenesis. Azoles or echinocandin drugs have been extensively prescribed for C. albicans infections, which has led to the development of drug-resistant strains. Therefore, it is necessary to develop new molecules to effectively treat fungal infections. Here, we showed that Molecule B and Molecule C, which contained a carbazole structure, attenuated the pathogenicity of C. albicans through inhibition of the Ras1/MAPK pathway. We found that Molecule B and Molecule C inhibit morphogenesis through repressing protein and RNA levels of Ras/MAPK-related genes, including UME6 and NRG1. Furthermore, we determined the antifungal effects of Molecule B and Molecule C in vivo using a candidiasis murine model. We anticipate our findings are that Molecule B and Molecule C, which inhibits the Ras1/MAPK pathway, are promising compounds for the development of new antifungal agents for the treatment of systemic candidiasis and possibly for other fungal diseases.

Production, characterization, and epitope mapping of monoclonal antibodies of ribosomal protein S3 (rpS3).

Ribosomal protein S3 (rpS3), a member of 40S small ribosomal subunit, is a multifunctional protein with various extra-ribosomal functions including DNA repair endonuclease activity and is secreted from cancer cells. Therefore, antibodies with high specificity against rpS3 protein could be useful cancer biomarkers. In this study, polyclonal antibody (pAb) and monoclonal antibodies (mAbs) were raised against rpS3 protein and epitope mapping was performed for each antibody; the amino acid residues of rpS3 were scanned from amino acid 185 to 243 through peptide scanning to reveal the epitopes of each mAb. Results showed that pAb R2 has an epitope from amino acid 203 to 230, mAb M7 has an epitope from amino acid 213 to 221, and mAb M8 has an epitope from amino acid 197 to 219. Taken together, novel mAbs and pAb against rpS3 were raised and mapped against rpS3 with different specific epitopes.

Subunits of the vacuolar H+-ATPase complex, Vma4 and Vma10, are essential for virulence and represent potential drug targets in Candida albicans.

Hyphal morphogenesis of Candida albicans is important for its pathogenesis. Here, we showed that the filamentous growth of C. albicans requires vacuolar H+-ATPase function. Results showed that levels of Vma4 and Vma10 increased in cells undergoing hyphal growth compared to those undergoing yeast growth. Deleting VMA4 or VMA10 abolished vacuolar functions and hyphal morphogenesis. These deletion mutants were also characterized as avirulent in a mouse model of systemic infection. Furthermore, VMA4 and VMA10 deletion strains showed hypersensitivity to fluconazole, terbinafine, and amphotericin B. Based on these findings, Vma4 and Vma10 are not only involved in vacuole biogenesis and hyphal formation, but also are good targets for antifungal drug development in C. albicans.

Surgical training technology for cerebrovascular anastomosis.

Cerebrovascular anastomosis (for example in the management of Moyamoya disease or complex aneurysms) is a rarely performed but essential procedure in neurosurgery. Because of the complexity of this technique and the infrequent clinical opportunities to maintain skills relevant to this surgery, laboratory training is important to develop a consistent and competent performance of cerebrovascular anastomosis. We reviewed the literature pertaining to the training practices surrounding cerebrovascular anastomosis in order to understand the ways in which trainees should best develop these skills. A wide variety of training methods have been described. These may be classified into five general categories, according to training materials used, being synthetic material, living animal, animal carcass, human cadaver, and computer simulation. Ideally, a novice begins training with non-biological material. After gaining sufficient dexterity, the trainee will be able to practice using biological materials followed by high fidelity models prior to actual surgery. Unfortunately, the effectiveness of each model has generally, to our knowledge, only been judged subjectively. Objective quantification methods are necessary to accelerate the acquisition of competence.

Effective control of massive venous bleeding by "multioverlapping therapy" using polysaccharide nanosheets in a rabbit inferior vena cava injury model.

OBJECTIVE: To investigate the efficacy of multioverlapping therapy using a polysaccharide nanosheet having 75-nm thickness for sealing and stopping massive venous hemorrhage. METHODS: The hydrostatic durability of the polysaccharide nanosheet was evaluated in vitro when secured to an incised silicon tube. For in vivo studies, the inferior vena cava (IVC) of rabbits was cut longitudinally, and multiple polysaccharide nanosheets were overlapped onto the injured IVC. RESULTS: The mechanical hydrostatic durability of the nanosheets was gradually augmented by an increasing number of multilayered nanosheets in vitro. This durability was saturated at 80 ± 6 mm Hg by four layers of nanosheets, which was robust enough to seal injured vessel walls of the large IVC. Multioverlapping therapy using nanosheets effectively sealed and stopped bleeding from the injured IVC in vivo. One month later, no inflammatory tissue response was observed around the nanosheet attachment sites of the IVC, while conventional suturing repair in control rabbits showed a severe inflammatory response around the sutured area. CONCLUSIONS: The multioverlapping therapy using the polysaccharide nanosheets will effectively stop massive venous bleeding without adverse effects in the immediate or chronic postoperative setting.

Quantitative evaluation for anastomotic technique of coronary artery bypass grafting by using in-vitro mock circulatory system.

This study focuses on the development of self-training system for surgical operation and quantitative evaluation of the surgical skills. Our group has developed a self-training system for anastomotic technique in Coronary Artery Bypass Grafting (CABG) to contribute the education of cardiovascular surgery without a risk to patients. The self-training system consists of following portions, 1) "YOUCAN", coronary and graft vascular silicone model, 2) "BEAT", a device, simulating stabilized myocardial surface, and 3) Quantitative evaluation system based on in vitro mock circulatory system. The coronary and graft model has been anastomosed by expert and trainee cardiac surgeon. The anastomosed model was mounted onto test section of the in vitro mock circulatory system then identical waveforms of coronary artery was applied into the inlet of an anastomosis. The energy loss was quantified as a pressure difference between proximal and distal ends of anastomosis. The energy loss was obtained as 67.3+/-1.75 mJ (trainee) and 41.3+/-3.08 mJ (registered surgeon). It was founded that average energy loss by expert surgeon was lower by 38.6% than that by trainee surgeon. The major difference among the models of expert and trainee was the Effective Orifice Area (EOA) of the anastomosis. Through the experiment, EOA was confirmed by image analysis as 2.73 mm2 for an expert against 0.534 mm2 for a trainee. In conclusion, it was suggested that the anastomotic skill among expert and trainee surgeons could be hydrodynamically differentiated by using in vitro mock circulatory system.