Anatomy of the smooth muscle structure in the female anorectal anterior wall: convergence and anterior extension of the internal anal sphincter and longitudinal muscle

AIM

The anatomy of the region between the vagina and anal canal plays an essential role when performing a proctectomy for low-lying tumours. However, the anatomical characteristics of this area remain unclear. The purpose of the present study was to clarify the configuration, and both lateral and inferior extensions, of the muscle bundles in the anorectal anterior wall in females.

METHODS

Using cadaveric specimens, macroscopic anatomical and histological evaluations were conducted at the anatomy department of our institute. Macroscopic anatomical specimens were obtained from six female cadavers. Histological specimens were obtained from eight female cadavers.

RESULTS

The smooth muscle fibres of the internal anal sphincter and longitudinal muscle extended anteriorly in the anorectal anterior wall of females and the muscle bundles showed a convergent structure. The anterior extending smooth muscle fibres merged into the vaginal smooth muscle layer, distributed subcutaneously in the vaginal vestibule and perineum and spread to cover the anterior surface of the external anal sphincter and the levator ani muscle. Relatively sparse space was observed in the region anterolateral to the rectum on histological analysis.

CONCLUSION

Smooth muscle fibres of the rectum and vagina are intermingled in the median plane, and there is relatively sparse space in the region anterolateral to the rectum. Therefore, when detaching the anorectal canal from the vagina during proctectomy, an approach from both the lateral sides should be used.

Abstract P4-06-28: Doxorubicin induces cellular senescence in human breast cancer cells and sensitizes them to cytotoxic T-lymphocytes

[Background]“Cellular senescence” is a state in which cells undergo irreversible cell cycle arrest in response to various cellular stresses. Senescence is induced in not only normal cells but also cancer cells when anti-cancer agents trigger DNA damage. Recent studies have revealed additional feature of senescent cells: increased secretion of various secretory proteins, such as inflammatory cytokines, chemokines, growth factors, and MMPs. This newly recognized senescent phenotype, termed senescence-associated secretory phenotype (SASP), reportedly contribute to tumor recurrence and promotion. Alternatively, senescent cancer cells could be good targets in anti-cancer immunotherapy because they are cell cycle-arrested.

[Objective]In this study, we determined whether ”cellular senescence” could be induced by a chemotherapeutic drug doxorubicin (DXR) and whether senescent cancer cells might increase their susceptibility to cytotoxic T-lymphocytes using human breast cancer cells.

[Methods and Results]A triple-negative (negative for ER, PR, and HER2) human breast cancer cell line (MDA-MB-231) was used. This cell line was treated with DXR for 2 days and examined for their appearance microscopically. The DXR treatment (500 nM) decreased their proliferating ability and increased their cell size. Colony formation assay revealed that cancer cells significantly decreased the number of colonies even with lower doses (3 nM) of DXR. In immunoblot assay, the DXR treatment increased the protein expression of p21, which inhibits cell cycle. In a flow cytometric assay after staining with SPIDER-β-gal, the DXR treatment (500 nM) increased the expression of β-gal in MDA-MB-231 cells. The induction of SA-β-gal in DXR-treated cancer cells were also confirmed by confocal imaging. In addition, the DXR treatment (500 nM) for 2 days beforehand increased their subsequent ability to produce IL-6 and IL-8. Although the DXR treatment (500 nM) decreased the expression of epidermal growth factor receptor (EGFR) on cancer cells, this treatment sensitized them to anti-EGFR chimeric antigen receptor (CAR) T-lymphocytes in apoptosis assay.

[Conclusion]These results suggest that a chemotherapeutic drug DXR can render MDA-MB-231 cells to be senescent and increase their sensitivity to antigen-specific cytotoxic T-lymphocytes. These findings may provide a rationale of combination of chemotherapy and T cell-based anti-cancer immunotherapy.

Citation Format: Inao T, Iida Y, Kotani H, Harada M. Doxorubicin induces cellular senescence in human breast cancer cells and sensitizes them to cytotoxic T-lymphocytes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-06-28.

Network meta-analysis of the relative efficacy of bariatric surgeries for diabetes remission

BACKGROUND

Bariatric surgery leads to a higher remission rate for type 2 diabetes mellitus than non-surgical treatment. However, it remains unsolved which surgical procedure is the most efficacious. This network meta-analysis aimed to rank surgical procedures in terms of diabetes remission.

METHODS AND FINDINGS

We electronically searched for randomized controlled trials in which at least one surgical treatment was included among multiple arms and the diabetes remission rate was included in study outcomes. A random-effects network meta-analysis was performed within a frequentist framework. The hierarchy of treatments was expressed as the surface under the cumulative ranking curve value. Results of the analysis of 25 eligible randomized controlled trials that covered non-surgical treatments and eight surgical procedures (biliopancreatic diversion [BPD], BPD with duodenal switch, Roux-en Y gastric bypass, mini gastric bypass [mini-GBP], laparoscopic adjustable gastric banding, laparoscopic sleeve gastrectomy, greater curvature plication and duodenal-jejunal bypass) showed that BPD and mini-GBP had the highest surface under the cumulative ranking curve values among the eight surgical treatments.

CONCLUSION

Current network meta-analysis indicated that BPD or mini-GBP achieved higher diabetes remission rates than the other procedures. However, the result needs to be interpreted with caution considering that these procedures were in the minority of bariatric surgeries.

Immunohistochemical Analysis of Human Lung Cancers with Anti-ras p21 Monoclonal Antibodies

The expression of ras oncogene product p21 in human malignant pleurisy and primary lung cancer was studied immunocyto-histochemically with monoclonal antibodies (MoAbs) rp-28 and rp-35 against ras p21. In pleural effusion cells, cancer cells revealed more intensively positive reaction with MoAb rp-35 than with MoAb rp-28, especially in the plasma membrane, and no positive reaction was obtained in any kind of inflammation cells with the exception of faintly positive reaction in the cytoplasm of macrophages.

In primary lung cancers, well or moderately differentiated adenocarcinoma tissues showed higher reactivity with MoAb rp-28 than those of poorly differentiated adenocarcinoma or any other histological subtype of lung cancer. With MoAb rp-35, intensively positive reaction was obtained in most of cases with all different histological subtypes of lung cancer. The staining in cancer cells was usually localized intensively to the plasma membrane and weakly to the cytoplasm with both MoAbs. Normal bronchial epithelial and glandular tissues showed only cytoplasmic staining. These two MoAbs, especially MoAb rp-35, may be useful in clinicopathological applications for the diagnosis of malignant pleurisy and primary lung cancer.

Predictors of inhalation burn injury using fire site information

Inhalation burn injury (IBI) is a risk factor for mortality in burn patients. However, it is difficult to diagnose IBI using traditional physical examination alone, especially in prehospital settings. Therefore, facial burn patients are usually treated for suspected IBI. In the present study, we investigated whether fire site information could predict IBI as an alternative to traditional physical examination. This retrospective single-centre analysis involved 27 facial burn patients with suspected IBI who were admitted between 2014 and 2016. The patients were divided into two groups (IBI and non-IBI) according to bronchoscopy findings. Fire site information was compared between the two groups. The IBI (n = 13) and non-IBI (n = 14) groups were compared. Domestic fire was more frequent in the IBI group (69% vs. 29%, P = 0.035). The IBI group included one patient with carboxyhemoglobin ≥10% on admission. Prehospitalization fire site information, particularly domestic fires, might predict IBI in facial burn patients..

A randomized, open-label, phase III trial comparing amrubicin versus docetaxel in patients with previously treated non-small-cell lung cancer

Background

Amrubicin is approved for treating non-small-cell lung cancer (NSCLC) and small-cell lung cancer. However, no direct comparisons between amrubicin and docetaxel, a standard treatment for NSCLC, have been reported.

Patients and methods

We conducted a randomized phase III trial of Japanese NSCLC patients after one or two chemotherapy regimens. Patients were randomized to amrubicin (35 mg/m2 on days 1-3 every 3 weeks) or docetaxel (60 mg/m2 on day 1 every 3 weeks). Outcomes included progression-free survival, overall survival, tumor responses, and safety.

Results

Between October 2010 and June 2012, 202 patients were enrolled across 32 institutions. Median progression-free survival (3.6 versus 3.0 months; P = 0.54) and overall survival (14.6 versus 13.5 months; P = 0.86) were comparable in the amrubicin and docetaxel groups, respectively. The overall response rate was 14.4% (14/97) and 19.6% (19/97) in the amrubicin and docetaxel groups, respectively (P = 0.45). The disease control rate was 55.7% in both groups. Adverse events occurred in all patients, and included grade ≥3 neutropenia occurred in 82.7% and 78.8% of patients in the amrubicin and docetaxel groups, respectively, grade ≥3 leukopenia occurred in 63.3% and 70.7%, and grade ≥3 febrile neutropenia occurred in 13.3% and 18.2% of patients in the amrubicin and docetaxel groups, respectively. Of eight cardiac-related events in the amrubicin group, three were considered related to amrubicin and resolved without treatment discontinuation.

Conclusions

This was the first phase III study to compare amrubicin and docetaxel in patients with pretreated NSCLC. Amrubicin did not significantly improve the primary endpoint of PFS compared with docetaxel.

Clinical trial registration

NCT01207011 (ClinicalTrials.gov).

High serum dihydrotestosterone examined by ultrasensitive LC-MS/MS as a predictor of benign prostatic hyperplasia or Gleason score 6 cancer in men with prostate-specific antigen levels of 3-10 ng/mL

There has been no consensus on the role of serum androgen concentrations in prostate cancer detection in men with prostate-specific antigen levels of 3-10 ng/mL. In this study, testosterone and dihydrotestosterone concentrations in blood were examined by a newly developed method using ultrasensitive liquid chromatography with two serially linked mass spectrometers (LC-MS/MS). We investigated the correlation between serum androgen levels and Gleason scores at biopsy. We analyzed data of 157 men with a total prostate-specific antigen range of 3-10 ng/mL who underwent initial systematic prostate needle biopsy for suspected prostate cancer between April 2000 and July 2003. Peripheral blood testosterone and dihydrotestosterone concentrations were determined by LC-MS/MS. Blood levels of testosterone and dihydrotestosterone were compared with pathological findings by multivariate analyses. Median values of prostate-specific antigen and prostate volume measured by ultrasound were 5.7 ng/mL and 31.4 cm³ , respectively. Benign prostatic hyperplasia was diagnosed in 97 patients (61.8%), and prostate cancer was diagnosed in 60 (38.2%) patients, including 31 (19.7%) patients with a Gleason score of 6 and 29 (18.5%) patients with a Gleason score of 7-10. Median values of testosterone and dihydrotestosterone in blood were 3798.7 and 371.7 pg/mL, respectively. There was a strong correlation between serum testosterone and dihydrotestosterone. In multivariate analysis, age, prostate volume, and serum dihydrotestosterone were significant predictors of benign prostatic hyperplasia or prostate cancer with a Gleason score of 6. The area under the receiver operating characteristics curve for age, prostate volume, and serum dihydrotestosterone were 0.67, 0.67, and 0.67, respectively . We confirmed that high dihydrotestosterone blood levels can predict benign prostatic hyperplasia or prostate cancer with a Gleason score of 6 in men with prostate-specific antigen levels of 3-10 ng/mL.

Dynamic MR Imaging of Hepatoma Treated by Transcatheter Arterial Embolization Therapy

The effect of transcatheter arterial chemo-embolization therapy (TACE) for hepatoma was evaluated with dynamic MR imaging with Gd-DTPA in 37 patients (44 tumors). TACE was performed using Lipiodol/cis-platinum and gelatin sponge (or microspheres) as an embolic material. All patients were examined with dynamic CT and MR imaging before and after treatment. On conventional spin echo images, changes of signal intensity after treatment varied regardless of presence of Lipiodol. Dynamic MR imaging revealed changes of tumor vascularity before and after treatment. On histologic correlation, areas of persistent tumor enhancement on dynamic MR imaging corresponded to areas of viable tumor cells while areas of nonenhancement corresponded to areas of necrosis. Dynamic MR imaging was superior in contrast resolution and was not influenced by the presence of Lipiodol compared with dynamic CT, and therefore residual viable tumors were better defined by dynamic MR imaging.

In Vivo 19F Mr Spectroscopic Study of Metabolism of 5-Fluorotryptophan in Rat Liver

The metabolism of 5-fluorotryptophan in rat liver was examined by in vivo 19F MR spectroscopy. After i.v. injection of 200 mg/kg b.w. of 5-fluorotryptophan the substance was noted immediately as a strong peak, which decreased gradually. Another peak appeared about 40 min after the injection. The chemical shift value of this peak was 1.6 ppm from that of 5-fluorotryptophan. Kynurenine is known to be a major metabolite of tryptophan in the liver. We synthesized 5-fluorokynurenine from 5-fluorotryptophan by ozonolysis. The chemical shift value of 5-fluorokynurenine was confirmed to be coincident with that of the metabolite peak. This strongly suggests that the metabolite peak of 5-fluorotryptophan observed in this study was the 5-fluorokyrurenine signal. We also applied this method for the CCl4-injured liver. In the liver injury group, the metabolite peak appeared slowly and the intensity was low compared to that of the normal group, though the peak of 5-fluorotryptophan decreased similarly as in the normal liver. These results suggest that the decrease of 5-fluorotryptophan is due mainly to the renal excretion, as the injured liver could not metabolize 5-fluorotryptophan.