Editorial: Evolving roles of piRNAs in solid tumors

According to Global Cancer Statistics 2020, an estimated 19.3 million new cancer cases and almost 10 million cancer deaths occurred in 2020. Solid tumors represent approximately 90% of adult human cancers, hence they warrant significant attention from the research fraternity to improve upon the existing platforms of treatment and management of the malignancy. Only by a better understanding of the biology associated with cancer development and progression can we identify clinically relevant novel molecular targets that can not only improve upon the risk stratification of the patients, but also assist in overall disease management. PIWI-interacting RNA (piRNA) is a class of small non-coding RNA (26-31nt) that interacts with PIWI proteins to form the piRNA silencing complex (piRISC). PIWI is a subfamily of Argonaute, and piRNA must bind to PIWI to exert its regulatory role, although have been also described PIWI independent functions for piRNAs. Nearly 10 million unique piRNA sequences (2) have now been identified in humans alone that have been recognized to play a wide variety of roles including germline development, maintenance, and protection of the genome integrity by repressing the activity of transposons through post-transcriptional silencing or other epigenetic mechanisms. Emerging data suggests that piRNAs also have strong regulatory roles within the somatic tissues where they regulate gene expression by inducing histone modification and DNA methylation. Owing to their remarkable roles in maintaining cellular homeostasis, it is not surprising that the expression of piRNAs is reported to be frequently deregulated in several cancers. Current studies indicated that piRNAs are significantly abnormally expressed and are involved in the initiation, progression, and metastasis of different solid tumors, which may be the potential diagnostic tools, prognostic markers, and therapeutic targets for cancers. This special issue is a collection of original research and review articles on this topic

A Comparative Study of Routine Laparoscopic Versus Open Appendectomy

Scientific PapersOBJECTIVE: We evaluated the outcomes of routine laparoscopy and laparoscopic appendectomy (LA) in patients with suspected appendicitis. This is a retrospective study of the outcomes of patients undergoing laparoscopic appendectomy compared with outcomes for patients undergoing open appendectomy (OA) during the time that LA came into use. METHOD: Results of patients managed with routine laparoscopy and LA for suspected acute appendicitis were reviewed and analyzed. The preoperative and intraoperative findings were recorded. The clinical outcomes were compared with those of patients undergoing OA in the preceding 10 months. RESULTS: During the LA study period, 97 patients (47 men) with the median age of 34 years (range, 18 to 79) presented with clinical features of acute appendicitis. With the exclusion of 5 patients with open operations and 10 patients with other pathologies, 82 patients underwent laparoscopic appendectomy (Group A) for appendicitis. Thirty-one (37.8%) patients had complicated appendicitis (perforated or gangrenous appendicitis). Conversions were required in 6 patients (7.3%). During the OA period, 125 patients (57 men) with the median age of 42 (range, 19 to 79) years were operated on. With the exclusion of 6 patients with other pathologies, 119 underwent OA for acute appendicitis (Group B). Fifty-one (42.9%) had either perforated or gangrenous appendicitis. The median durations of surgery in Group A and Group B were 80 minutes (range, 40 to 195) and 60 minutes (range, 25 to 260), respectively (P < 0.005). Postoperative complication rates were comparable between the 2 groups (13.4% in Group A versus 15.8% in Group B). The median hospital stay for patients in Group A and Group B were 3.0 days (range, 1 to 47) and 4.0 days (range, 1 to 47), respectively (P = 0.037). CONCLUSIONS: We conclude that routine laparoscopy and LA for suspected acute appendicitis is safe and is associated with a significantly shorter hospital stay. Other intra-abdominal pathologies can also be diagnosed more accurately with the laparoscopic approach.link_to_OA_fulltex

Reply: The Impact of the Standardized Medial-to-lateral Approach on Outcome of Laparoscopic Colorectal Resection

Reply to World J Surg. 2010 May;34(5):1146-7published_or_final_versionSpringer Open Choice, 01 Dec 201

Surgical management and outcome of rectal carcinoids in a university hospital

Abstract Background: Rectal carcinoids are an uncommon entity comprising only 1%-2% of all rectal tumors. Rectal carcinoids are frequently diagnosed during colonoscopy, but management after polypectomy is still controversial. The aims of this study were to review the surgical procedures for rectal carcinoids and to compare the outcomes of patients after different treatment modalities in a university hospital in Hong Kong. Methods: All rectal carcinoids diagnosed between January 2003 and September 2012 were reviewed retrospectively, including clinicopathological characteristics, their management, and surgical outcomes. Results: There were 54 patients with a median age of 60 years, and 32 were males (59.3%). All patients underwent colonoscopy, and the most had rectal bleeding (53.7%). Two patients were diagnosed incidentally in the surgical specimens of rectal tissues. Eighteen patients were diagnosed to have rectal carcinoids after snaring polypectomy, and no further intervention was required. Twenty-five patients had local resection either by means of transanal resection or transanal endoscopic operation. Radical resection was performed in seven patients in which one had T3N1 disease and the others did not have any lymph node metastasis. In the median follow-up of 30 months (10-108 months), there was no recurrence in the &quot;incidental&quot; or post-polypectomy group. However, two patients with transanal resection and two patients with radical resection developed hepatic metastases after 13-24 months post-treatment. The 5-year overall survival was 100% in patients having snaring polypectomy only, 83% for those with local resection, and 63% in patients who underwent radical surgery (p = 0.04)

Impact of neoadjuvant treatment on total mesorectal excision for ultra-low rectal cancers

<p>Abstract</p> <p>Background</p> <p>This study reviewed the impact of pre-operative chemoradiotherapy or post-operative chemotherapy and/or radiotherapy on total mesorectal excision (TME) for ultralow rectal cancers that required either low anterior resection with peranal coloanal anastomosis or abdomino-perineal resection (APR). We examined surgical complications, local recurrence and survival.</p> <p>Methods</p> <p>Of the 1270 patients who underwent radical resection for rectal cancer from 1994 till 2007, 180 with tumors within 4 cm with either peranal coloanal anastomosis or APR were analyzed. Patients were compared in groups that had surgery only (Group A), pre-operative chemoradiotherapy (Group B), and post-operative therapy (Group C).</p> <p>Results</p> <p>There were 115 males and the mean age was 65.43 years (range 30-89). APR was performed in 134 patients while 46 had a sphincter-preserving resection with peranal coloanal anastomosis. The mean follow-up period was 52.98 months (range: 0.57 to 178.9). There were 69, 58 and 53 patients in Groups A, B, and C, respectively. Nine patients in Group B could go on to have sphincter-saving rectal resection. The overall peri-operative complication rate was 43.4% in Group A vs. 29.3% in Group B vs. 39.6% in Group C, respectively. The local recurrence rate was significantly lower in Group B (8.6.9% vs. 21.7% in Group A vs. 33.9% in Group C) <it>p < 0.05</it>. The 5-year cancer-specific survival rates for Group A was 49.3%, Group B was 69.9% and Group C was 38.8% (<it>p </it>= 0.14).</p> <p>Conclusion</p> <p>Pre-operative chemoradiation in low rectal cancer is not associated with a higher incidence of peri-operative complications and its benefits may include reduction local recurrence.</p

Rates of metachronous adenoma after curative resection for left-sided or right-sided colon cancer

Background/Aims We determined the rates of metachronous colorectal neoplasm in colorectal cancer (CRC) patients after resection for right (R)-sided or left (L)-sided cancer. Methods Consecutive CRC patients who had undergone surgical resection for curative intent in our hospital between 2001 and 2004 were identified. R-sided colonic cancers refer to cancer proximal to splenic flexure whereas L-sided cancers include rectal cancers. Patients were included only if they had a clearing colonoscopy performed either before or within 6 months after the operation. Findings of surveillance colonoscopy performed up to 5 years after colonic resection were included in the analysis. Results Eight hundred and sixty-three CRC patients underwent curative surgical resection during the study period. Three hundred and twenty-seven patients (107 R-sided and 220 L-sided) fulfilled the inclusion criteria and had at least 1 postoperative surveillance colonoscopy performed. The proportion of patients who had polyp and adenoma on surveillance colonoscopy was significantly higher among patients with L-sided than R-sided cancers (polyps: 30.9% vs. 19.6%, P=0.03; adenomas: 25.5% vs. 13.1%, P=0.01). The mean number of adenoma per patient on surveillance colonoscopy was also higher for patients with L-sided than R-sided tumors (0.52; 95% confidence interval [CI], 0.37–0.68 vs. 0.22; 95% CI, 0.08–0.35; P<0.01). Multivariate analysis showed that L-sided cancers, age, male gender and longer follow-up were independent predictors of adenoma detection on surveillance colonoscopy. Conclusions Patients with Lsided cancer had a higher rate of metachronous polyps and adenoma than those with R-sided cancer on surveillance colonoscopy

Measurement invariance of the Functional Assessment of Cancer Therapy—Colorectal quality-of-life instrument among modes of administration

OBJECTIVES: To test for the measurement invariance of the Functional Assessment of Cancer Therapy—Colorectal (FACT-C) in patients with colorectal neoplasms between two modes of administration (self- and interviewer administrations). It is important to establish the measurement invariance of the FACT-C across different modes of administration to ascertain whether it is valid to pool FACT-C data collected by different modes or to assess each group separately. METHODS: A cross-sectional sample of 391 Chinese patients with colorectal neoplasms was recruited from specialist outpatient clinics between September 2009 and July 2010. Confirmatory factor analysis (CFA) was used to test the original five-factor model of the FACT-C on data collected by self- and interviewer administrations in single-group analysis. Multiple-group CFA was then used to compare the factor structure between the two modes of administration using chi-square tests and other goodness-of-fit statistics. RESULTS: The hypothesized five-factor model of FACT-C demonstrated good fit in each group. Configural invariance and metric invariance were fully supported in multiple-group CFA. Some item intercepts and their corresponding error variances were not identical between administration groups, suggesting evidence of partial strict factorial invariance. CONCLUSIONS: Our results confirmed that the five-factor structure of FACT-C was invariant in Chinese patients using both self- and interviewer administrations. It is appropriate to pool or compare data in the emotional well-being and colorectal cancer subscale scores collected by both administrations. Measurement invariance in three items, one from each of the other subscales, may be contaminated by response bias between modes of administration

A Gramaticalização do Verbo Ir e a Variação de Formas para Expressar o Futuro do Presente: uma Fotografia Capixaba

Esta pesquisa verifica o estágio do processo de gramaticalização do verbo IR, que tem assumido a função de auxiliar em construções perifrásticas para expressar tempo. Para isso, investiga-se a variação entre as formas sintética e perifrástica com IR para expressão do futuro do presente. Temos por hipótese que a forma perifrástica já atinge todos os gêneros das duas modalidades da língua, uma vez que já se especializou para codificar tempo. São examinados dois gêneros, tomando-os como prototípicos do continuun oral/escrito: entrevistas com informantes universitários e editoriais de jornal. Partindo de uma orientação teórica Funcionalista, num quadro mais geral, concebe-se a língua como flexível ao uso, passível de influências cognitivas, sociais e também individuais, embora haja nela forças que atuam no sentido de regularizar a estrutura. Seguindo algumas pesquisas que têm se mostrado frutíferas, o modelo funcionalista estará em diálogo com outro modelo que procura dar conta da heterogeneidade estruturada da língua e de seus processos de mudança: a Teoria Variacionista. Num quadro mais específico, os fundamentos que orientam a pesquisa são os da Gramaticalização. Os dados extraídos dos gêneros selecionados serão submetidos ao programa computacional GOLDVARB 2001 e, em seguida, interpretados à luz das teorias lingüísticas que fundamentam esta pesquisa

Proximity-induced quasi-one-dimensional superconducting quantum anomalous Hall state: a promising scalable top-down approach towards localized Majorana modes

In this work, ~100 nm wide quantum anomalous Hall insulator (QAHI) nanoribbons are etched from a two-dimensional QAHI film. One part of the nanoribbon is covered with superconducting Nb, while the other part is connected to an Au lead via two-dimensional QAHI regions. Andreev reflection spectroscopy measurements were performed, and multiple in-gap conductance peaks were observed in three different devices. In the presence of an increasing magnetic field perpendicular to the QAHI film, the multiple in-gap peak structure evolves into a single zero-bias conductance peak (ZBCP). Theoretical simulations suggest that the measurements are consistent with the scenario that the increasing magnetic field drives the nanoribbons from a multi-channel occupied regime to a single channel occupied regime, and that the ZBCP may be induced by zero energy Majorana modes as previously predicted [24]. Although further experiments are needed to clarify the nature of the ZBCP, we provide initial evidence that quasi-1D QAHI nanoribbon/superconductor heterostructures are new and promising platforms for realizing zero-energy Majorana modes