Impact of Sleep Apnea on Nocturnal Parasympathetic Activity in Atrial Fibrillation Patients After Catheter Ablation　- Implications for Heart Rate Variability Analysis.

BACKGROUND: The impact of sleep apnea (SA) on heart rate variability (HRV) in atrial fibrillation (AF) patients has not been investigated.Methods and Results: Of 94 patients who underwent AF ablation between January 2021 and September 2022, 76 patients who had a nocturnal Holter electrocardiography and polysomnography conducted simultaneously were included in the analysis. A 15-min duration of HRV, as determined by an electrocardiogram during apnea and non-apnea time, were compared between patients with and without AF recurrence at 12 months' postoperatively. Patients had a mean age of 63.4±11.6 years, 14 were female, and 20 had AF recurrence at 12 months' follow-up. The root mean square of the difference between consecutive normal-to-normal intervals (RMSSD, ms) an indicator of a parasympathetic nervous system, was more highly increased in patients with AF recurrence than those without, during both apnea and non-apnea time (apnea time: 16.7±4.5 vs. 13.5±3.3, P=0.03; non-apnea time: 20.9±9.5 vs. 15.5±5.9, P<0.01). However, RMSSD during an apneic state was decreased more than that in a non-apneic state in both groups of patients with and without AF recurrence (AF recurrence group: 16.7±4.5 vs. 20.9±9.5, P<0.01; non-AF recurrence group; 13.5±3.3 vs. 15.5±5.9, P=0.03). Consequently, the effect of AF recurrence on parasympathetic activity was offset by SA. Similar trends were observed for other parasympathetic activity indices; high frequency (HF), logarithm of HF (lnHF) and the percentage of normal-to-normal intervals >50 ms (pNN50). CONCLUSIONS: Without considering the influence of SA, the results of nocturnal HRV analysis might be misinterpreted. Caution should be taken when using nocturnal HRV as a predictor of AF recurrence.

[Axillary Lymph Node Recurrence after Curative Surgery for Transverse Colon Cancer-A Case Report].

We report the rare case of an 89-year-old female with axillary lymph node recurrence after curative surgery for transverse colon cancer who had undergone right hemicolectomy with D3 lymphadenectomy with an uneventful postoperative course. Pathological examination confirmed the tumor's status as tub2>sig, T4aN3M0, and pStage Ⅲc, and signet-ring cell carcinoma was remarkably found in the metastatic lymph node. Genetic testing revealed wild-type RAS, a BRAF mutation, and a high MSI. After 9 months of follow-up without adjuvant chemotherapy, CEA increased sharply to 41.3 ng/mL by 9 months postoperatively, and CT showed nodules in the right axilla, adrenal gland, and retroperitoneum. PET-CT showed abnormal fluorodeoxyglucose uptake in the same regions. A core needle biopsy of the axillary lymph node revealed signet-ring cell carcinoma, which was diagnosed as a recurrence of transverse colon cancer. Although we suggested chemotherapy due to the unresectable recurrence of colorectal cancer, she preferred to receive supportive care instead. Three months after the recurrence was diagnosed, CEA increased to 248.4 ng/mL, and CT showed enlargement of the axillary lesion and a new lesion in the hilum of the lung.

[Brain Metastasis Following Conversion Surgery for Sigmoid Colon Cancer-A Case Report].

A 64-year-old man was diagnosed with KRAS-mutant type sigmoid colon cancer with metastasis in the lung, liver, left adrenal gland, and para-aortic lymph node(T3N1M1b, Stage ⅣB[Union for International Cancer Control 8th edition]). Laparoscopic transverse colostomy was performed to treat colonic obstruction. Subsequently, a combination regimen of capecitabine plus oxaliplatin plus bevacizumab was administered. After 5 courses of chemotherapy, the S8 liver tumor disappeared completely. Sigmoidectomy, para-aortic lymph node dissection, and left adrenal gland resection were performed. After 3 months, right S3 segmental pneumonectomy and right S8 and S10 partial pneumonectomy were performed. R0 resection for the primary lesion and metastatic lesions of the chest and abdomen was achieved. Following the conversion surgery, he was administered the adjuvant chemotherapy regimen of uracil-tegafur plus Leucovorin. After 2 courses of chemotherapy, he presented to our hospital complaining of vomiting and dizziness. Contrast-enhanced magnetic resonance imaging revealed multiple brain metastases. Thus, we should be mindful of the possibility of brain metastasis in cases of unresectable colon cancer showing satisfactory response to chemotherapy with an indication of conversion surgery.

[Laparoscopic Abdominoperineal Resection of the Rectum in a Case with Pagetoid Spread of Anal Canal Carcinoma].

The patient, a man in his 60s, first noticed an elevated lesion around the anus 3 years ago. The lesion failed to subside with the topical drug preparations prescribed at a local clinic, and the patient was referred to the Department of Dermatology of our hospital for further workup and treatment. The findings of biopsy from the lesion suggested skin infiltration of anal canal carcinoma, and the patient was referred to the Department of Surgery. Examination here revealed only induration of the anal canal, with no abnormality of the rectal mucosa even when the endoscope was reversed to visualize the rectum. Examination by various imaging modalities failed to reveal any metastases to the lymph nodes or distant organs, and the primary lesion remained unidentified. Laparoscopic abdominoperineal excision of the rectum was performed, beginning with anal manipulation. First, a 15-mm margin was set on the skin from the tumor edge, and the skin stump was divided into 4 equal portions. After confirming by rapid intraoperative frozen-section examination that the margin was negative along the full circumference, anal manipulation was performed, leaving a distance in the vertical direction immediately below the tumor. Upon completion of the anal manipulation, intraperitoneal manipulation was performed in a routine manner. The anal skin was relaxed subcutaneously, as done during mastectomy, and the subsequent suture closure could be done smoothly. The tumor was classified as pT1bN0M0, pStage Ⅰ. The experience with this case indicates that biopsy should be proactively employed for the diagnosis in such cases, and that proactive skin biopsy is useful when dealing with intractable anal skin lesions.

[A Case of Recurrent Gastric GIST Who Survived for Long after Laparoscopic Resection and Imatinib Therapy].

A man patient in his 70s underwent left nephrectomy and laparoscopic partial gastrectomy for the treatment of a left renal cell carcinoma and gastrointestinal stromal tumor(GIST)arising from the stomach. Histopathologically, both the renal cell carcinoma and GIST were kit-positive, CD34-positive, and S-100 protein-negative, and the Ki-67 index was about 40% as determined by the hot spot method, so that it was diagnosed as an intermediate-group GIST. After surgery, the patient was followed without adjuvant therapy, as he did not wish to receive postoperative chemotherapy. A computed tomography(CT)conducted 3 years after the surgery revealed tumorous shadows in the abdominal wall, inferior periesophageal region, and dorsal aspect of the pancreas. Positron emission tomography(PET)-CT showed fluorodeoxyglucose(FDG) accumulation in these lesions. Therefore, based on a suspicion of recurrent renal cell carcinoma or GIST, we carried out abdominal wall tumor resection for both exploratory and diagnostic purposes, which yielded histopathological diagnosis of GIST, with features similar to those observed at the time of the initial operation. Because the number of tumors remained unchanged during the subsequent follow-up period, the tumorous lesions in the periesophageal region and on the dorsal aspect of the pancreas were resected laparoscopically. Each of the resected tumors showed histological features consistent with GIST. The patient was started on oral imatinib therapy after this operation. To date(5 years after the surgery for the recurrent tumors and 8 years after the initial operation), the patient has remained free of recurrence. The pattern of tumor recurrence noted in the present case(ie, metastasis/dissemination to the skeletal muscles)is relatively rare, and few reports have been published concerning long-term survivors through multidisciplinary treatment (surgical treatment and others). We report this case with a review of the literature.

[A Case of Unresectable Advanced Gastric Cancer Successfully Treated with Conversion Surgery].

A man in his 70s consulted a local clinic with a chief complaint of difficulty eating. Upper gastrointestinal endoscopy revealed a type 4 tumor spreading irregularly from immediately below the esophageal cardia to the lower gastric body. The patient was referred to our hospital with a diagnosis of advanced gastric cancer(human epidermal growth factor receptor 2 [HER2]-positive moderately-differentiated adenocarcinoma)accompanied by lymph node enlargement. We planned an open total gastrectomy after staging laparoscopy to rule out dissemination because peritoneal dissemination could not be ruled out using computed tomography(CT). To perform a total gastrectomy, a celiotomy was done after staging laparoscopy results suggested that dissemination was unlikely. However, the border between the pericardial lymph nodes and the pancreas or peritoneal artery was not visible, forcing us to terminate the staging laparotomy based on a judgment of unresectable locally advanced gastric cancer. Therefore, the patient was administered 6 cycles of combined S-1/CDDP plus trastuzumab as the primary therapy. The response to therapy was favorable, and we scheduled a surgical resection. However, the scheduled surgery was rescheduled because of COVID-19 pneumonia, and R0 resection was finally performed after the 7th cycle of S-1/CDDP plus trastuzumab therapy. Histopathologically, the regional lymph node metastasis had disappeared, the viable tumor remained within the mucosal layer, and scarring was evident from the submucosal layer to the serosa. In recent years, conversion surgery for unresectable gastric cancer has been sporadically reported. However, we are unable to definitively opine on whether this kind of surgery may contribute to improving the prognosis, resection remains indispensable for radical treatment. We report this case along with a review of the literature.

Intramural cancer recurrence in the rectum after curative surgery for proximal sigmoid colon cancer: a case report.

BACKGROUND: Intramural metastasis distant from the primary tumor is rare in colorectal cancer. Here, we present a notably rare and probably the first case of asynchronous intramural recurrence in the rectum after curative surgery for proximal sigmoid colon cancer. CASE PRESENTATION: A 44-year-old man underwent curative sigmoidectomy for proximal sigmoid colon cancer with T3N0M0, Stage IIA tubular adenocarcinomas. After 15 months, the tumor marker level had increased, and positron emission tomography-computed tomography (PET-CT) revealed abnormal fluorodeoxyglucose uptake in the rectum; colonoscopy revealed a submucosal tumor (SMT)-like lesion in the upper rectum, and biopsy revealed a tubular adenocarcinoma. We performed curative low anterior resection with tumor-specific mesorectal excision (TSME). The SMT-like tumor was located approximately 20 cm from the initial sigmoid colon anastomosis (i.e., at least 20 cm distal to the initial sigmoid colon cancer). The pathological findings revealed cancer cells with the same features as the initial sigmoid colon cancer, only in the intestinal wall but not in the mucosa and extramural tissue. Therefore, the lesion was determined to be an intramural recurrence. After 24 months, lung recurrence, and local recurrence, which might have involved the lymph nodes in the preserved mesorectum after TSME at the bottom of the pelvis was detected on PET-CT. Hence, we started systemic chemotherapy. CONCLUSIONS: This case report suggests that PET-CT and short-interval repeat colonoscopy may help detect a rare intramural recurrence. A long distal margin may be necessary to achieve local control in the rectal resection for intramural recurrence.

[Rectal Neuroendocrine Tumor G2 of Measuring Less Than 1 cm in Diameter with Lymph Node Metastases-A Case Report].

A 40-year-old man visited our hospital with rectal submucosal tumors measuring 5 mm and the 7 mm as detected by colonoscopy, following which an endoscopic submucosal resection was performed. Pathological examination revealed that the tumors was neuroendocrine tumor(NET); the tumor measuring 5 mm was NET G1 without lymphatic and venous invasion, while the 7 mm size was NET G2 with venous invasion but without lymphatic invasion. Lymph node and distant metastasis were not observed by computed tomography. Informed consent was obtained and he agreed to undergo additional rectal resection. Laparoscopic low anterior resection was performed and pathological examination enabled a diagnosis of rectal neuroendocrine tumor with regional lymph node metastases(T1a, N1, M0, Stage ⅢB[Union for International Cancer Control 8th edition]). Post-surgery, he was followed up for 3 years, without recurrence. This report suggests that the determination of treatment plan for rectal neuroendocrine tumor measuring less than 1 cm in diameter should be done carefully.

[R0 Resection following Chemotherapy for Colon Cancer Liver Metastasis Close to the Inferior Vena Cava and Hepatic Vein Confluence-A Case Report].

A 78-year-old man was diagnosed with sigmoid colon cancer, and laparoscopic sigmoidectomy was performed. On pathological examination, he was diagnosed with RAS-wild type sigmoid colon cancer with regional lymph node metastasis (T3, N1, M0, Stage ⅢB[Union for International Cancer Control 8th edition]). Computed tomography revealed S8 and S7 liver metastasis, 3 months after the initial surgery. The location of the S8 tumor was close to the inferior vena cava(IVC), right hepatic vein(RHV)and segment Ⅷ hepatic vein(V8). He was administered cetuximab plus modified FOLFOX6. After 6 courses of chemotherapy, the S8 and S7 liver tumor shrank. S8 plus 4 plus 1 and S7 partial hepatectomy was performed and R0 resection was achieved. The RHV and V8 were resected, while right superficial and middle hepatic veins were preserved. An IVC invasion was not observed. He was administered 12 courses of adjuvant modified FOLFOX6. After the partial hepatectomy, he has been followed up for 1.5 years with no recurrence.

[A Case of Colorectal Cancer with Asymptomatic Idiopathic Pneumatosis Intestinalis during Bevacizumab Administration].

We present the case of a 75-year-old woman who received CapeOX plus Bmab therapy(capecitabine, oxaliplatin, and bevacizumab)after primary excision for an unresectable advanced sigmoid colon cancer with remote metastasis. Pneumatosis intestinalis(i.e., the presence of isolated gas in the abdominal cavity)was revealed accidentally during a periodical imaging examination in the small intestine and transverse colon, albeit no subjective symptoms were reported. Owing to the absence of definitive evidence of pneumatosis intestinalis and gastrointestinal perforation, the patient was diagnosed with idiopathic pneumatosis intestinalis. Bmab was discontinued, and CapeOX therapy alone was continued after follow-up. Approximately 4 months later, pneumatosis intestinalis had completely disappeared. Bmab is a vascular endothelial growth factor antibody with well-known side effect of gastrointestinal-perforation. However, there have been few reports on pneumatosis intestinalis; to our knowledge, there have been no reports on pneumatosis intestinalis associated with colorectal cancer in Japan. Further, the report suggests the need for appropriate and immediate management of pneumatosis intestinalis following diagnosis.

The impact of the mesorectal apparent diffusion coefficient value on surgical difficulty in laparoscopic anterior resection for rectal cancer.

PURPOSE: We aimed to clarify the impact of the apparent diffusion coefficient (ADC) value of the mesorectum from preoperative magnetic resonance imaging (MRI) on surgical difficulty in laparoscopic anterior resection (Lap-AR) for rectal cancer. METHODS: In total, 67 patients who had undergone curative Lap-AR for rectal cancer in our hospital from January 2008 to March 2015 and had preoperative MRI findings available were included. We randomly calculated the average ADC in three regions of the mesorectum at the level of the upper edge of the superior border of the femur. Univariate and multivariate analyses were performed to evaluate the correlation between the patients' clinicopathological characteristics, including the ADC value and short-term surgical outcomes. RESULTS: The univariate analysis revealed that a lower ADC value was associated with a significantly increased operative blood loss (p = 0.008) and prolonged operative time (p < 0.001). The multivariate analysis adjusted for the body mass index, anal verge, tumor location, covering stoma, clinical T factor and conversion revealed that the ADC value was an independent risk factor for a prolonged operative time (R2 = 0.6003, p < 0.001). Furthermore, the multivariate analysis adjusted for the body mass index, anal verge, covering stoma, clinical T factor and conversion revealed that the ADC value was an independent risk factor for an increased blood loss (R2 = 0.4345, p = 0.008). CONCLUSION: A lower ADC value of the mesorectum might be a predictor of surgical difficulty in Lap-AR for rectal cancer.

Pelvic inlet shape measured by three-dimensional pelvimetry is a predictor of the operative time in the anterior resection of rectal cancer.

PURPOSE: We evaluated pelvic shape as a predictor of the surgical outcome of anterior resection in patients with rectal cancer. METHODS: In total, 228 patients who had undergone anterior resection (R0 resection and double-stapling anastomosis) for rectal cancer from 2005 to 2014 were included in this study. The anteroposterior (AP) and transverse (T) diameters of the pelvic inlet and outlet and pelvic depth were analyzed on three-dimensional volume-rendered images, and the AP/T ratio was calculated. Univariate and multivariate analyses were performed to determine the predictive significance of the operative time and intraoperative blood loss as surgical outcomes. RESULTS: No difference was observed between the inlet AP/T and patient sex ratios, but the other pelvic dimensions were significantly shorter in males than in females. The univariate analysis revealed that the operative time was significantly correlated with the inlet T diameter and that it tended to be correlated with the outlet T diameter and the inlet AP/T ratio. A multivariate analysis adjusted for operation-related factors revealed that the inlet AP/T ratio was the only independent risk factor for an extended operative time (p = 0.036). None of the pelvic dimensions were independent risk factors for increased blood loss. CONCLUSION: The shape of the pelvic inlet may be useful for predicting the operative time.

Curative resection after percutaneous drainage followed by preoperative panitumumab monotherapy for locally advanced sigmoid colon cancer with intra-abdominal abscess: a case report.

BACKGROUND: The gold standard treatment for locally advanced colon cancer is curative surgery followed by adjuvant chemotherapy, although this approach is associated with serious concerns, such as high recurrence rates and occasionally unnecessary oversurgery. Neoadjuvant chemotherapy may be a promising strategy for overcoming these issues. This study reports a case of a recurrence-free patient who underwent curative resection without significant organ dysfunction after preoperative chemotherapy for locally advanced sigmoid colon cancer. The tumor coexisted with a large intra-abdominal abscess, and the patient was quite frail at the first visit. We performed percutaneous drainage followed by preoperative panitumumab monotherapy, which yielded favorable outcomes. CASE PRESENTATION: A 78-year-old frail woman was emergently transferred to our hospital with fever and abdominal pain. The diagnosis was locally advanced sigmoid colon cancer stage IIIC (T4bN2aM0) with a large intra-abdominal abscess. Immediate curative surgery was inappropriate, considering both tumor progression and the patient's frailty. We performed percutaneous drainage and colostomy construction, which was followed by seven cycles of preoperative panitumumab monotherapy without significant adverse events. After these treatments, inflammation was well controlled, and the tumor shrank remarkably. Furthermore, the patient recovered well from frailty; therefore, curative sigmoidectomy combined with resection of the left ovary and stoma closure was possible without any postoperative complications. The final pathological finding was T3N0M0, stage IIA disease. The patient was recurrence-free and had no significant organ dysfunction 21 months after the curative surgery. CONCLUSIONS: The management of intra-abdominal abscesses and tailor-made preoperative chemotherapy based on the patient's frailty may have been the key factors responsible for the favorable course of this patient. Although further research is needed on the appropriateness of percutaneous drainage for malignancies related to intra-abdominal abscesses and preoperative panitumumab use for locally advanced colon cancer, the study findings can serve as reference for managing similar cases in an aging society.

Molecular cloning and characterization of the repetitive DNA sequences that comprise the constitutive heterochromatin of the W chromosomes of medaka fishes.

Among the medaka fishes of the genus Oryzias, most species have homomorphic sex chromosomes, while some species, such as Oryzias hubbsi and Oryzias javanicus, have heteromorphic ZW sex chromosomes. In this study, a novel family of repetitive sequence was molecularly cloned from O. hubbsi and characterized by chromosome in situ and filter hybridization, respectively. This repetitive element, which we designated as a BstNI family element, localized at heterochromatin regions on the W chromosome, as well as on two pairs of autosomes. Homologous sequences to this element were found only in O. javanicus, which is a sister species of O. hubbsi, suggesting that this repeated element originated in the common ancestor of these two species. However, the intensity of the hybridization signals was lower in O. javanicus than in O. hubbsi, and the chromosomal location of this element in O. javanicus was confined to heterochromatin regions on one pair of autosomes. Thus, we hypothesize that this repetitive element was extensively amplified in the O. hubbsi lineage, especially on its W chromosome, after the separation of the O. javanicus lineage. In addition, we also found the W chromosomal location of the 18S-28S ribosomal RNA genes in both O. hubbsi and O. javanicus. Our previous studies showed no linkage homology of the sex chromosomes in these species, indicating that the RNA genes were shared between W chromosomes of different origins. This situation may be explained by a translocation of the sex-determining region with the ribosomal RNA genes in either species or an independent accumulation of the RNA genes as a convergent process during W chromosome degeneration.

Pathological complete response after neoadjuvant chemotherapy with FOLFOX for locally advanced sigmoid colon cancer with diverticulitis: A case report.

INTRODUCTION AND IMPORTANCE: The standard treatment for locally advanced colon cancer (LACC) without distant metastasis is curative surgery followed by adjuvant chemotherapy, but the long-term outcomes of this strategy are not satisfactory. Neoadjuvant chemotherapy (NAC) is a promising novel option to overcome this issue. Tumor regression is an expected effect of NAC for LACC, but pathological complete response (pCR) is rare. In this report, we present a rare case of pCR after NAC with FOLFOX for LACC in the sigmoid colon. PRESENTATION OF CASE: A 66-year-old woman presented to our hospital with fever and abdominal pain. The diagnosis was LACC in the sigmoid colon with possible invasion of the uterus and pelvic wall, stage IIIC (T4bN1bM0). Furthermore, the tumor was complicated by diverticulitis. A colostomy was performed, followed by NAC with FOLFOX. Six cycles were completed without significant adverse events, and the lesion shrunk remarkably. We performed a curative sigmoidectomy without any postoperative complications. Pathological examination revealed no viable cancer cells, indicating pCR. DISCUSSION: To the best of our knowledge, this is the first report of pCR after NAC for LACC complicated by diverticulitis. Colostomy before NAC, regimen, and cycle of NAC may be the key to this favorable course. CONCLUSION: We present a rare case of pathological complete after neoadjuvant chemotherapy with FOLFOX for locally advanced colon cancer in the sigmoid colon complicated by diverticulitis. Our experience may be valuable in determining the optimal treatment strategy for LACC complicated by diverticulitis.

Inhibition of Heat-shock Protein 27 Reduces 5-Fluorouracil-acquired Resistance in Human Colon Cancer Cells.

BACKGROUND/AIM: In previous work we showed that expression of heat-shock protein 27 (HSP27; encoded by HSPB1) was associated with inherent resistance to 5-fluorouracil (5-FU). However, the relationship between HSP27 and acquired resistance remains unknown. MATERIALS AND METHODS: We generated an acquired resistance model (WiDr-R) of a colon cancer cell line by exposing WiDr cells to 5-FU. Cell viability assays under treatment with 5-FU, as well as down-regulation of HSP27 using small interfering HSP27 RNA, were performed. HSP27 mRNA and protein expression was analyzed using real-time polymerase chain reaction and western blotting. RESULTS: 5-FU-acquired resistance induced overexpression of HSP27 mRNA and protein levels in WiDr-R cells. Furthermore, siRNA knockdown of HSP27 in WiDr-R cells reduced 5-FU-acquired resistance. CONCLUSION: These findings demonstrate that HSP27 is associated with 5-FU resistance in human colon cancer cell cells and suggest that HSP27 regulation represents a novel approach to overcoming chemoresistance in colorectal cancer.

BAF57 Is a Potential Determinant of Colorectal Cancer Malignancy.

BACKGROUND/AIM: The role of brahma-related gene 1 (BRG1)-associated factor 57 (BAF57), a transcription factor, has been determined in prostate, breast, and ovarian cancer. However, the relationship between BAF57 and colorectal cancer (CRC) is obscure. Thus, we examined the functional correlation between BAF57 expression and oncological malignancy in CRC in vitro. MATERIALS AND METHODS: BAF57 expression in WiDr and HT29 CRC cell lines and clinical specimens from CRC patients was analysed by western blotting and/or RT-PCR. BAF57 expression was down-regulated in WiDr cells through siRNA transfection. An invasion assay was also performed to assess malignancy. RESULTS: BAF57 was expressed in both human CRC cell lines. Overall survival and recurrence-free survival rates were significantly reduced in high BAF57-expressing specimens. BAF57 expression was an independent predictive factor for long-term survival. CONCLUSION: BAF57 correlates with oncological malignancy and may be a novel therapeutic target in CRC.

Heat shock protein 27 knockdown using nucleotide­based therapies enhances sensitivity to 5-FU chemotherapy in SW480 human colon cancer cells.

Heat shock protein 27 (Hsp27) is a chaperone protein of low molecular weight that is produced in response to various stresses and has a cytoprotective function. In the present study we found that there is a strong correlation between sensitivity to 5-fluorouracil (5-FU) and the expression of Hsp27 in colorectal cancer. Apatorsen is an antisense oligonucleotide that targets Hsp27 and has various antitumor effects in some types of cancer, such as bladder and prostate. Although several clinical studies are currently studying apatorsen in many malignancies, to date no promising results have been reported for colorectal cancer. In the present study, we examined the impact of Hsp27 downregulation (via apatorsen) on 5-FU sensitivity in colon cancer both in vitro and in vivo. In vitro, apatorsen significantly decreased the levels of Hsp27 in a dose-dependent manner in human colon cancer SW480 cells. A cell proliferation assay revealed that although apatorsen did not inhibit tumor growth, it resulted in greater 5-FU sensitivity in comparison with treatment with OGX-411 (control). In vivo, intraperitoneal injection of apatorsen decreased the levels of Hsp27 in subcutaneous tumors in a xenograft mouse model using SW480 cells and enhanced 5-FU sensitivity, compared to controls. Although further research is warranted, the present study confirmed that concurrent treatment with Hsp27 knockdown using apatorsen and 5-FU could be a promising therapy for colon cancer.

Supranormal orientation selectivity of visual neurons in orientation-restricted animals.

Altered sensory experience in early life often leads to remarkable adaptations so that humans and animals can make the best use of the available information in a particular environment. By restricting visual input to a limited range of orientations in young animals, this investigation shows that stimulus selectivity, e.g., the sharpness of tuning of single neurons in the primary visual cortex, is modified to match a particular environment. Specifically, neurons tuned to an experienced orientation in orientation-restricted animals show sharper orientation tuning than neurons in normal animals, whereas the opposite was true for neurons tuned to non-experienced orientations. This sharpened tuning appears to be due to elongated receptive fields. Our results demonstrate that restricted sensory experiences can sculpt the supranormal functions of single neurons tailored for a particular environment. The above findings, in addition to the minimal population response to orientations close to the experienced one, agree with the predictions of a sparse coding hypothesis in which information is represented efficiently by a small number of activated neurons. This suggests that early brain areas adopt an efficient strategy for coding information even when animals are raised in a severely limited visual environment where sensory inputs have an unnatural statistical structure.