Vinyl polymerization by metal complexes. VI. On the initiation mechanism of vinyl polymerization by the α-amino acid ester/copper(II) system

Polymerization of acrylonitrile and methyl methacrylate was studied in the presence of an α-amino acid ester and copper(II) ion in dimethyl sulfoxide solution. The initiation mechanism of the polymerization by the α-amino acid ester/copper(II) system was refered to the complex forming properties of the system, confirmed by spectroscopic measurements. The polymerization of both monomers was influenced by the kind of the α-alkyl group of the α-amino acid esters, but it was not affected by the kind of the ester groups. The carboxylic group of the esters was found to affect only the polymerization of methyl methacrylate. Based on the results, the character of the free radicals was discussed.     

Objective evaluation of cerebrovascular reactivity for acetazolamide predicts cerebral hyperperfusion after carotid artery stenting: Comparison with region of interest methods

Background and purpose

Hemodynamic impairments are considered risk factors of cerebral hyperperfusion after carotid artery stenting (CAS); measurement by Single-photon emission computed tomography (SPECT) using a subjective region of interest (ROI) method lacks consistency and reproducibility.

Preoperative High Visceral Fat Increases Severe Complications but Improves Long-Term Prognosis after Gastrectomy for Patients with Advanced Gastric Cancer: A Propensity Score Matching Analysis

This study investigated the paradox of high visceral fat mass increasing severe complications but improving long-term prognosis after radical gastrectomy for gastric cancer. This was a retrospective cohort study of consecutive patients with primary stage I–III gastric cancer who underwent gastrectomy between April 2008 and June 2018. The visceral adipose tissue index (VAI) was calculated by dividing the visceral fat mass preoperatively measured on computed tomography by the square of the height. Patients with VAIs below the median cut-off value were classified as low-VAI, while those above it were classified as high-VAI. We compared the postoperative complication rate and overall survival (OS) in the low- and high-VAI groups after adjusting patient characteristics using propensity score matching (PSM). There were 155 patients in both groups after PSM. After matching, there was no significant difference in factors other than BMI and VAI that were not adjusted. The high-VAI group had more severe postoperative complications (p = 0.018), but the OS was significantly better in the high-VAI group (hazard ratio 0.611, 95%CI 0.403–0.928, p = 0.021). Preoperative high visceral fat mass not only increased severe complications, but also improved OS after gastrectomy in patients with advanced gastric cancer.     

Suppression of galectin-4 attenuates peritoneal metastasis of poorly differentiated gastric cancer cells

Gastric Cancer - Peritoneal dissemination, most often seen in metastatic and/or recurrent gastric cancer, is an inoperable condition that lacks effective treatment. The use of molecular targeted...     

Indocyanine green fluorescence imaging-guided laparoscopy-assisted distal gastrectomy for early gastric cancer in a patient with situs inversus totalis: A case report with video

Situs inversus totalis is a rare congenital anomaly. Most surgeons have seldom performed laparoscopy-assisted distal gastrectomy for situs inversus totalis. Inadequate knowledge regarding the anatomy of situs inversus totalis can result in increased intraoperative bleeding and prolonged operative time. A 74-year-old man was diagnosed with early gastric cancer with situs inversus totalis. We performed laparoscopy-assisted distal gastrectomy with D1+ lymphadenectomy and Billroth-I reconstruction by reversing the standard laparoscopy-assisted distal gastrectomy setup. Mirror images of the operative video of the standardized laparoscopy-assisted distal gastrectomy were created using video editing software. Lymphadenectomy was performed by indocyanine green fluorescence imaging of the lymphatic flow with operative time of 220 minutes and 100 mL intraoperative bleeding. The patient was discharged on postoperative day 10, without postoperative complications. Laparoscopy-assisted distal gastrectomy with indocyanine green navigation is safe and effective in patients with situs inversus totalis and is comparable with standard laparoscopy-assisted distal gastrectomy.     

Thallium-201 scintigraphy for the assessment of long-term prognosis in patients with osteosarcoma

Objective

The aim of this study was to confirm the prognostic value of ²⁰¹Tl scintigraphy in the midcourse of preoperative chemotherapy in patients with osteosarcoma.

Methods

The 28 patients with biopsy-proven osteosarcoma were enrolled retrospectively in this study. Planar scintigraphy was performed 15?min after injection of 111?MBq ²⁰¹Tl before preoperative chemotherapy and after third course (midcourse) of chemotherapy in all patients. The ²⁰¹Tl uptake ratio was calculated by dividing the count density of the lesion by that of the contralateral normal area. The percentage reduction of the ²⁰¹Tl uptake ratio calculated by 100?×?[(pre-chemotherapy ratio??C?mid-chemotherapy ratio)/pre-chemotherapy ratio] was compared with the histopathological response and long-term survival rate.

Results

Good histopathological response was observed in 16 patients. Mean follow-up period was 58.0?±?41?months. Both overall and event-free survival rates of histopathologically good responders were significantly higher than that of poor responders (P?=?0.018 and P?=?0.0076). There was also significant correlation between pre-chemotherapeutic effect evaluated with ²⁰¹Tl scintigraphy and overall and event-free survival rate in all patients (P?=?0.045 and P?=?0.017, respectively), and in patients without metastasis at initial diagnosis (P?=?0.043 and P?=?0.031, respectively).

Conclusion

²⁰¹Tl scintigraphy performed in the middle of neoadjuvant chemotherapy can predict overall survival and event-free survival in patients with osteosarcoma.     

Robot-assisted surgery for rectal cancer with solitary sacrococcygeal metastasis after neoadjuvant chemoradiotherapy: A case report

An 81-year-old man was referred to our hospital for anal bleeding. Colonoscopy revealed a type 3 tumor at the upper rectum and biopsy showed adenocarcinoma. An enhanced circumferential lesion at the upper rectum and a solitary soft-tissue shadow at the fifth sacral vertebra to the coccyx were detected on abdominal magnetic resonance imaging. Fluorodeoxyglucose uptake was observed at the same sites on positron emission tomography. The patient was diagnosed with rectal cancer with isolated sacrococcygeal metastasis and was treated with neoadjuvant chemoradiotherapy followed by robotic surgery. Hartmann's operation was performed in the lithotomy position. The left internal iliac artery and vein were then divided. The internal pudendal artery and vein, the piriformis muscle, and sacrospinous ligament were also divided while preserving the lumbosacral trunk. The scheduled transection line of the sacral surface was fully exposed to prevent massive bleeding during sacrectomy. The dorsal surface of the sacrum was then exposed in the prone position and communicated with the pelvic space. The sacrum was transected at the superior margin of S3 and a specimen was extracted. Pathological findings revealed the infiltration of cancer cells in the sacrococcygeal specimen. The postoperative course was uneventful and the patient was discharged on postoperative day 13.     

A comparative study between the clinical and autoptic findings in cases with malignant tumor in the head and neck]

In 106 autopsies of patients in Kitasato University Hospital from 1974 to 1989, who had died of malignant tumor in the head and neck, the relationship between the clinical diagnosis and its autoptic finding was retrospectively investigated. The result was summarized as follows. 1. Characteristics in 98 cases other than malignant lymphoma: 1) Local recurrence was detected by autopsy in 60 cases (61%) among 98. Discrepancy between clinical diagnosis and autoptic findings was recognized in 10 cases (10%), in whom 4 false positive cases by clinical diagnosis were included and it was considered that the rate was relatively high. 2) The metastatic lymph nodes were demonstrated by autopsy in 50 cases (51%). Discrepancy between clinical diagnosis and autoptic findings was found in 37 (38%), 35 of them were clinically diagnosed to be negative. However, in 35 of them it was considered that the discrepancy had not influenced their fatal courses. 3) Metastases to distant organs were demonstrated by autopsy in 49 (50%). Discrepancy between clinical diagnosis and autoptic findings was found in 39 (40%). 33 of them were clinically diagnosed to be negative. The discrepancy concerned with the causes of death was shown in 5 cases. 2. Characteristics in 8 cases of malignant lymphoma: Discrepancy between clinical diagnosis and autoptic findings of distant metastases was frequently observed but the discrepancy concerned with the causes of death was not shown. There were 2 cases in which side effect of chemotherapy may cause poor prognosis.     

Transrectal robotic natural orifice translumenal endoscopic surgery (NOTES) applied to intestinal anastomosis in a porcine intestine model

Background

Natural orifice translumenal endoscopic surgery (NOTES) is a minimally invasive operation using devices such as flexible endoscopes and linear or circular staplers. Nevertheless, hand-sewn anastomosis in NOTES remains challenging. This study aimed to investigate the feasibility of transrectal robotic NOTES requiring intracorporeal small intestinal anastomosis and closure of the rectal anterior wall incision in a relevant human model.

Methods

The authors developed a flexible rectal proctoscope with a diameter of 43 mm for transrectal robotic NOTES. Small intestinal anastomosis was performed in a porcine intestinal transrectal NOTES model using two robotic arms and a camera inserted through the proctoscope and a rectal anterior wall incision. The quality of transrectal small intestinal anastomosis using the da Vinci surgical system (transrectal robotic NOTES group) was compared with that of transabdominal anastomosis using the da Vinci surgical system (transabdominal robot-assisted surgery group) and transrectal anastomosis using traditional transanal endoscopic microsurgery (TEM) instruments (TEM NOTES group). The quality of transrectal rectal anterior wall suturing in the transrectal robotic NOTES group was compared with that of the TEM NOTES group and the open surgical instruments group (open group).

Results

Robotic intracorporeal suturing was performed successfully in the porcine intestine model. During small intestinal anastomosis, burst pressure in the transrectal robotic NOTES group (67.7 ± 29.3 mmHg) was similar to that in the transabdominal robot-assisted surgery group (73.3 ± 18.2 mmHg) but significantly higher than in the TEM NOTES group (20.3 ± 24.0 mmHg; p < 0.01). During rectal anterior wall suturing, the burst pressure did not differ significantly between the transrectal robotic NOTES group (149.9 ± 81.1 mmHg) and the open group (195.0 ± 60.5 mmHg).

Conclusions

The preliminary safety and efficacy of transrectal robotic NOTES was established. Further studies are required to determine the practical feasibility of this procedure.