[Feasibility of a three-sided encapsulation procedure based on fascia anatomy in laparoscopic lateral lymph node dissection for middle and low rectal cancer]

Objective: To explore the feasibility and value of performing a three-sided encapsulation procedure based on fascia anatomy in laparoscopic lateral lymph node dissection (LLND) for middle and low rectal cancer. Methods: This was a retrospective review. The study cohort comprised patients who met the diagnostic criteria for rectal cancer according to the Chinese Guidelines for the Diagnosis and Treatment of Colorectal Cancer, had a short lymph node diameter of >5 mm on the lateral side within the 15 days before surgery, were evaluated as feasible candidates for laparoscopic total mesorectal excision+LLND surgery, had been diagnosed with low or intermediate level rectal cancer, and whose tumor was less than 8 cm away from the anal verge according to pathological examination of the operative specimen. Patients with a history of other malignant tumors of the abdomen or with incomplete follow-up data were excluded. Forty-two patients with middle and low rectal cancer who had undergone lateral lymph node dissection in diagnosis and treatment center of Gastrointestinal Cancer of Guangdong Hospital of Chinese Medicine from Jan.2018 to Dec.2022 were enrolled. There were 24 men (57.1%) and 18 women (42.9%) aged 58.4±11.8 years and the median BMI was 22.5 (19.3-24.1) kg/m2. The main point of the three-sided encapsulation procedure is to expand the external side medial to the external iliac artery and vein, narrowing the range of exterior side dissection. The anterior-medial side is designed to expand the vesical fascia to define the range of anterior-medial side extension. The internal side is fully extended to the ureterohypogastric nerve fascia; the distal point of the caudal extension reaches the level of the Alcock canal and the bottom reaches the piriformis, enabling dissection of the obturator nerve and No.283 lymph nodes. No.263D lymph nodes are dissected by exposing the internal iliac artery and its branches, dissecting the group No.263P lymph nodes, and severing the inferior vesical artery. Finally, the lateral lymphatic tissue is completely resected. Relevant variables were recorded, including the number of lateral lymph nodes detected, the rate of lymph node metastasis, operation duration, intraoperative blood loss, postoperative complications, postoperative hospital stay, and 3-year overall survival rate. Results: Laparoscopic surgery was successfully completed in all patients with no conversions to open surgery and no intraoperative complications. Twenty-seven (64.3%) of the study patients underwent left-sided LLND, 10 (23.8%) right-sided LLND, and five (11.9%) bilateral LLND, with lymph nodes cleared on both sides. All patients' lymph nodes were examined pathologically. A median of 17.0 (11.7, 26.0) lymph nodes was detected, the median of lateral lymph nodes being 5.0 (2.0, 10.2). The median operation time was 254.5 (199.0, 325.2) minutes. The median intra-operative blood loss was 50.0 (30.0, 100.0) mL. All patients were diagnosed with adenocarcinoma by pathological examination of the operative specimen. Two patients developed postoperative intestinal obstruction, one lymphatic leakage, and one a perineal incision infection. There were no cases of anastomotic leakage. The median postoperative hospital stay was 6.0 (5.0, 7.0) days and the median follow-up time 23.5 (9.0, 36.7) months. During follow-up, three patients (7.1%) died of tumor recurrence and metastasis. Two (4.8%) experienced mild urinary dysfunction, and one (2.4%) had moderate postoperative erectile dysfunction. One patient (2.4%) was found to have prostate and lung metastases 3 month after surgery. The 3-year overall survival rate was 74.4%. Conclusions: Three sided encapsulation is a safe and feasible procedure for LLND, achieving accurate and complete clearance of lateral lymphatic tissue.

Dracorhodin perchlorate inhibits biofilm formation and virulence factors of Candida albicans

OBJECTIVE

The aim of this study was to investigate the antifungal activity of dracorhodin perchlorate (DP) against planktonic growth and virulence factors of Candida albicans.

METHODS

Microdilution method based on CLSI-M27-A3 was used to test the antifungal susceptibility of DP. The activity of DP against biofilm formation and development of C. albicans was quantified by XTT assay and visualized by confocal laser scanning microscope. The effect of DP on the morphological transition of C. albicans induced by four kinds of hyphal-inducing media at 37°C for 4hours was observed under microscope. The rescue experiment by adding exogenous cAMP analog was performed to investigate the involvement of cAMP in the yeast to hyphal transition and biofilm formation of C. albicans. Egg yolk emulsion agar was used to determine the inhibition of DP on the phospholipase production of C. albicans. Human JEG-3 and HUVEC cell lines, as well as the nematode Caenorhabditis elegans was used to assess the toxicity of DP.

RESULTS

The minimum inhibitory concentration (MIC) of DP is 64μM while the antifungal activity was fungistatic. As low as a concentration at 16μM, DP could inhibit the yeast to hyphal transition in liquid RPMI-1640, Spider, GlcNAc and 10% FBS-containing Sabouroud Dextrose medium, as well as on the solid spider agar. Exogenous cAMP analog could rescue part of biofilm viability of C. albicans. DP could inhibit the production of phospholipase. The toxicity of DP against human cells and C. elegans is low.

CONCLUSION

DP could inhibit the planktonic growth and virulent factors in multiple stages, such as yeast to hyphal transition, adhesion, biofilm formation and production of phospholipase of C. albicans.

Serum high-density lipoprotein cholesterol and progression to arterial stiffness in middle-aged and elderly Chinese

BACKGROUND AND AIMS

Low high-density lipoprotein cholesterol (HDL-c) is a risk factor for cardiovascular disease. Brachial-ankle pulse wave velocity (baPWV) is an indicator of arterial stiffness, which is recognized as a predictor of cardiovascular disease. The aim of this study was to investigate the association between HDL-c and baPWV among middle-aged and elderly Chinese.

METHODS

A total number of 1133 Chinese (430 men, 703 women) aged from 50 to 90 years old were recruited from Shanghai downtown district. The baPWV and major cardiovascular risk factors of the participants were measured.

RESULTS

Serum HDL-c was negatively correlated with baPWV (r = -0.143, P < 0.001) after adjustment for age and gender. Multivariate linear regression analysis demonstrated that age (P < 0.001), systolic blood pressure (P < 0.001), HDL-c (P < 0.001), smoking (P = 0.001), BMI (P = 0.002), fasting plasma glucose (P = 0.004), and white blood cell (P = 0.005) were independently associated with baPWV. After multiple adjustments, participants in the highest quartile of HDL-c had an odds ratio of 0.442 (95% CI 0.268-0.729) for developing high arterial stiffness compared with participants in the lowest quartile. The association remained significant after further adjustment for major cardiovascular risk factors.

CONCLUSION

HDL-c has an independent protective effect on arterial stiffness in middle-aged and elderly Chinese. Early detection of HDL-c level is important in high risk populations with arterial stiffness. Increasing HDL-c level may be an attractive therapeutic target for the prevention of arterial function and subsequent disease.

Localization of Toxoplasma gondii in feline intestinal tissue using PCR

Gametogony of Toxoplasma gondii occurs only in the epithelial cell layers within the intestine of the definitive feline host. Infected feline intestine is required in order to study the physiology, histology, and molecular biology of the gametogenic stages. Therefore, we set out to devise a rapid, conservative, and reproducible technique to determine which portions of the intestine were infected. Several methods of collecting and processing infected material were assessed for their ability to detect T. gondii. Infected and uninfected intestines from domestic cats were used to produce nitrocellulose lift impressions along the entire small intestine. The nitrocellulose was analyzed for the presence of T. gondii DNA using polymerase chain reaction (PCR) primers specific for the T. gondii alpha-tubulin gene. In addition, mucosal tissue scrapings, derived from segments of intestinal tissue, were used to isolate DNA and RNA for subsequent PCR and reverse transcriptase PCR analysis, respectively. The nitrocellulose impression lift method demonstrated distribution of parasite throughout the intestine. Histological staining and indirect immunofluorescence antibody analysis of sections obtained from the same infected tissue confirmed the presence of T. gondii intraepithelial stages. Comparison among the different techniques indicates that the nitrocellulose impression lift technique proved to be effective for easily and quickly assessing presence of T. gondii in infected tissue. This technique does not require a significant amount of the experimental material.

Intestinal first-pass metabolism of nitrosamines. 4. Metabolism of N-nitrosodibutylamine in vascularly autoperfused jejunal and ileal loops of rats

N-Nitrosodi-[1-14C]butylamine (NDBA) has been shown to undergo a high first-pass metabolism in isolated perfused rat small intestinal segments. Metabolites resulting from omega-hydroxylation of NDBA, the bladder carcinogens N-nitrosobutyl-(4-hydroxybutyl)amine (NB4HBA) and N-nitrosobutyl-(3-carboxypropyl)-amine (NB3CPA), accounted for greater than 90% of the total radioactivity absorbed. In the present study using vascularly perfused rat small intestinal segments, the high first-pass metabolism of NDBA could be confirmed under near in vivo conditions despite the much higher absorption rate. At the end of the 36 min experimental period 70-80% of the dose have been absorbed via the portal blood as opposed to 1-10% of the dose after 2 h in vitro perfusion. omega-Hydroxylation was again the most important metabolic pathway. However, the relationship of NB3CPA to NB4HBA was shifted in favor of NB4HBA, indicating a concentration and absorption rate dependency in the further metabolism of NB4HBA to NB3CPA.

Metabolism of T-2 toxin in vascularly autoperfused jejunal loops of rats

The intestinal metabolism of T-2 toxin, a major trichothecene mycotoxin, was investigated in rats using the method of the vascularly autoperfused jejunal loop in situ. Tritium-labeled T-2 toxin was injected into the tied-off intestinal segments at a dose of 5 or 500 nmol, respectively. T-2 toxin and its metabolites in the blood draining from the jejunal loops, in the intestinal lumen, and in the intestinal tissue were determined by HPLC and GLC-MS. There was an extensive metabolic degradation of T-2 toxin, the metabolite pattern being similar for the two dosage levels. During the experimental period of 50 min only some 2% of the total dose appeared in the effluent plasma as unchanged T-2 toxin. Likewise at the end of the experiments unchanged T-2 toxin in the intestinal lumen and tissue was present in minute amounts only (less than 1% of the dose). HT-2 toxin was the main metabolite. About 25% of the total radioactivity administered appeared in the effluent plasma as HT-2 toxin, 18% in the lumen and 10% in the tissue. 3'-OH-HT-2 toxin accounted for 4-7% (effluent plasma), 5% (lumen), and 2% (tissue) of the total dose. Furthermore small amounts (less than 2% of the dose) of 3'-OH-T-2 toxin, T-2 tetraol, and 4-deacetylneosolaniol were found. No glucuronide or sulfate conjugates could be detected. In the jejunal segments which had been exposed to the 5-nmol dose only minimal morphological alterations were observed. On the other hand, in jejunal segments exposed to the high dose marked tissue damage was present. Nevertheless the gut tissue retained its ability to metabolize T-2 toxin. From the present results it is concluded that T-2 toxin is subject to a marked presystemic first pass effect after oral ingestion in vivo.