Experimental necrotizing enterocolitis using oral lipopolysaccharide and protective role of breastmilk. / Enterocolitis necrotizante experimental con lipopolisacárido oral y función protectora de la leche materna.

INTRODUCTION: Necrotizing enterocolitis (NEC) is a life-threatening condition that afflicts neonates. Breastfeeding has demonstrated to play a protective role against it. By administering lipopolysaccharides (LPS) orally in newborn rats (NBR), we have developed an experimental model to induce NEC-like gut damage. Our aim was to assess the macroscopic and microscopic appearance of the gut, to evaluate the presence of NEC and study the role of breast milk (BM). MATERIALS AND METHODS: NBR were divided into 3 groups: Group A (control, n= 10) remained with the mother, group B (LPS, n= 25) was isolated after birth, gavage-fed with special rat formula and oral LPS, then submitted to stress (hypoxia after gavage) and group c (BM, n= 12) was breastfed once after birth, then isolated, and submitted to stress like group B. On day 4, NBR were sacrificed, and intestine was harvested and assessed. RESULTS: In the control group NEC was not present either macroscopically or histologically. Both groups submitted to stress (B and C) presented a global incidence of NEC of 73%. Most of group B developed histologic signs of NEC (85%) and group C showed a statistically lower incidence of NEC (50%, p= 0.04), playing the BM a protective role against NEC (OR= 0.19; 95% CI: 0.40-0.904). CONCLUSION: Our model showed a significant incidence of NEC in NBR (73%) with the same protective role of BM as in newborn humans, achieving a reliable and reproducible experimental NEC model. This will allow us to investigate new potential therapeutic targets for a devastating disease that currently lacks treatment.

INTRODUCCION: La enterocolitis necrotizante (ECN) es una enfermedad potencialmente mortal que afecta a los neonatos, y frente a la que la leche materna ha demostrado tener un papel protector. Administrando lipopolisacáridos (LPS) por vía oral en ratas recién nacidas (RRN), hemos desarrollado un modelo experimental para inducir un daño intestinal similar al que provoca la ECN con objeto de evaluar el aspecto macroscópico y microscópico del intestino, y de ese modo, analizar la presencia de ECN y estudiar el papel que desempeña la leche materna (LM). MATERIAL Y METODOS: Las RRN se dividieron en tres grupos: el grupo A (control, n= 10) permaneció con su madre; el grupo B (LPS, n= 25) fue aislado tras el nacimiento, alimentado por sonda con una fórmula especial para ratas y LPS oral, y sometido a estrés (hipoxia tras sonda); y el grupo C (LM, n= 12) fue alimentado con leche materna tras el nacimiento y posteriormente aislado y sometido a estrés al igual que el grupo B. El día 4 se sacrificó a las RRN y se recuperaron sus intestinos para su posterior evaluación. RESULTADOS: En el grupo de control, no se observó ECN ni macroscópica ni histológicamente, mientras que los dos grupos sometidos a estrés (B y C) presentaron una incidencia global de la ECN del 73%. La mayoría de los sujetos del grupo B desarrollaron signos histológicos de ECN (85%), y los del grupo C registraron una incidencia de la ECN estadísticamente menor (50%, p= 0,04), lo que significa que la LM desempeña una función protectora frente a la ECN (OR= 0,19; IC 95%: 0,40-0,904). CONCLUSION: Nuestro modelo reveló una incidencia significativa de la ECN en RRN (73%), desempeñando la LM la misma función protectora que en el caso de los humanos recién nacidos, lo que significa que este modelo experimental de ECN es fiable y reproducible. Gracias a dicho logro, podremos investigar nuevos y potenciales objetivos terapéuticos para una peligrosa enfermedad que, a día de hoy, carece de tratamiento.

Enterocolitis necrotizante experimental con lipopolisacárido oral y función protectora de la lechematerna / Experimental necrotizing enterocolitis using oral lipopolysaccharide and protective role of breastmilk

Introducción: La enterocolitis necrotizante (ECN) es una enfermedad potencialmente mortal que afecta a los neonatos, y frente a laque la leche materna ha demostrado tener un papel protector. Administrando lipopolisacáridos (LPS) por vía oral en ratas recién nacidas(RRN), hemos desarrollado un modelo experimental para inducir undaño intestinal similar al que provoca la ECN con objeto de evaluarel aspecto macroscópico y microscópico del intestino, y de ese modo,analizar la presencia de ECN y estudiar el papel que desempeña laleche materna (LM). Material y métodos: Las RRN se dividieron en tres grupos: el grupoA (control, n= 10) permaneció con su madre; el grupo B (LPS, n=25)fue aislado tras el nacimiento, alimentado por sonda con una fórmulaespecial para ratas y LPS oral, y sometido a estrés (hipoxia tras sonda);y el grupo C (LM, n= 12) fue alimentado con leche materna tras elnacimiento y posteriormente aislado y sometido a estrés al igual que elgrupo B. El día 4 se sacrificó a las RRN y se recuperaron sus intestinospara su posterior evaluación. Resultados: En el grupo de control, no se observó ECN ni macroscópica ni histológicamente, mientras que los dos grupos sometidos aestrés (B y C) presentaron una incidencia global de la ECN del 73%.La mayoría de los sujetos del grupo B desarrollaron signos histológi-cos de ECN (85%), y los del grupo C registraron una incidencia de laECN estadísticamente menor (50%, p= 0,04), lo que significa que laLM desempeña una función protectora frente a la ECN (OR= 0,19; IC95%: 0,40-0,904). Conclusión: Nuestro modelo reveló una incidencia significativa dela ECN en RRN (73%), desempeñando la LM la misma función protectora que en el caso de los humanos recién nacidos, lo que significa que estemodelo experimental de ECN es fiable y reproducible. Gracias a dichologro, podremos investigar nuevos y potenciales objetivos terapéuticospara una peligrosa enfermedad que, a día de hoy, carece de tratamiento.(AU)

Introduction: Necrotizing enterocolitis (NEC) is a life-threateningcondition that afflicts neonates. Breastfeeding has demonstrated to playa protective role against it. By administering lipopolysaccharides (LPS)orally in newborn rats (NBR), we have developed an experimental modelto induce NEC-like gut damage. Our aim was to assess the macroscopicand microscopic appearance of the gut, to evaluate the presence of NECand study the role of breast milk (BM). Material and methods: NBR were divided into 3 groups: GroupA (control, n= 10) remained with the mother, group B (LPS, n= 25)was isolated after birth, gavage-fed with special rat formula and oralLPS, then submitted to stress (hypoxia after gavage) and group c (BM,n= 12) was breastfed once after birth, then isolated, and submitted tostress like group B. On day 4, NBR were sacrificed, and intestine washarvested and assessed. Results: In the control group NEC was not present either macroscopically or histologically. Both groups submitted to stress (B and C)presented a global incidence of NEC of 73%. Most of group B developedhistologic signs of NEC (85%) and group C showed a statistically lowerincidence of NEC (50%, p= 0.04), playing the BM a protective roleagainst NEC (OR= 0.19; 95% CI: 0.40- 0.904)Conclusion: Our model showed a significant incidence of NEC inNBR (73%) with the same protective role of BM as in newborn humans,achieving a reliable and reproducible experimental NEC model. This willallow us to investigate new potential therapeutic targets for a devastatingdisease that currently lacks treatment.(AU)

Positron Emission Tomography-Computed Tomography and Magnetic Resonance Imaging Assessments in a Mouse Model of Implant-Related Bone and Joint Staphylococcus aureus Infection.

Osteomyelitis is an infection of the bone, associated with an inflammatory process. Imaging plays an important role in establishing the diagnosis and the most appropriate patient management. However, data are lacking regarding the use of preclinical molecular imaging techniques to assess osteomyelitis progression in experimental models. This study aimed to compare structural and molecular imaging to assess disease progression in a mouse model of implant-related bone and joint infections caused by Staphylococcus aureus. In SWISS mice, the right femur was implanted with a resorbable filament impregnated with S. aureus (infected group, n = 10) or sterile culture medium (uninfected group, n = 6). Eight animals (5 infected, 3 uninfected) were analyzed with magnetic resonance imaging (MRI) at 1, 2, and 3 weeks postintervention, and 8 mice were analyzed with [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)-computed tomography (CT) at 48 h and at 1, 2, and 3 weeks postintervention. In infected animals, CT showed bone lesion progression, mainly in the distal epiphysis, although some uninfected animals presented evident bone sequestra at 3 weeks. MRI showed a lesion in the articular area that persisted for 3 weeks in infected animals. This lesion was smaller and less evident in the uninfected group. At 48 h postintervention, FDG-PET showed higher joint uptake in the infected group than in the uninfected group (P = 0.025). Over time, the difference between groups increased. These results indicate that FDG-PET imaging was much more sensitive than MRI and CT for differentiating between infection and inflammation at early stages. FDG-PET clearly distinguished between infection and postsurgical bone healing (in uninfected animals) from 48 h to 3 weeks after implantation. IMPORTANCE Our results encourage future investigations on the utility of the model for testing different therapeutic procedures for osteomyelitis.

Antibiotic delivery from bone-targeted mesoporous silica nanoparticles for the treatment of osteomyelitis caused by methicillin-resistant Staphylococcus aureus.

Osteomyelitis is a hard-to-treat infection of the bone and bone marrow that is mainly caused by Staphylococcus aureus, with an increasing incidence of methicillin-resistant S. aureus (MRSA). Owing to the aggressiveness of these bacteria in colonizing and destroying the bone, systemic antibiotic treatments fail to eradicate the infection. Instead, it normally entails surgery to remove the dead or infected bone. In this work, we report bone-targeted mesoporous silica nanoparticles for the treatment of osteomyelitis. The nanoparticles have been engineered with a functional gelatine/colistin coating able to hamper premature release from the mesopores while effectively disaggregating the bacterial biofilm. Because antibiotic resistance is a global emergency, we have designed two sets of identical nanoparticles, carrying each of them a clinically relevant antibiotic, that have demonstrated to have synergistic effect. The bone-targeted nanoparticles have been thoroughly evaluated in vitro and in vivo, obtaining a notable reduction of the amount of bacteria in the bone in just 24 h after only one dose, and paving the way for localized, nanoparticle-mediated treatment of MRSA-caused osteomyelitis. STATEMENT OF SIGNIFICANCE: In this work, we propose the use of bone-targeted mesoporous silica nanoparticles to address S. aureus-caused osteomyelitis that render synergistic therapeutic effect via multidrug delivery. Because the bacterial biofilm is responsible for an aggressive surgical approach and prolonged antibiotic treatment, the nanoparticles have been functionalized with a functional coating able to both disaggregate the biofilm, hamper premature antibiotic release and protect the intact bone. These engineered nanoparticles are able to effectively target bone tissue both in vitro and in vivo, showing high biocompatibility and elevated antibacterial effect.

Defining stage in mucinous tumours of the appendix with peritoneal dissemination: the importance of grading terminology: systematic review.

BACKGROUND: Mucinous appendiceal neoplasms with peritoneal dissemination (PD) show a wide spectrum of clinical behaviour. Histological grade has been correlated with prognosis, but no universally accepted histological grading has been established. The aim of this systematic review was to provide historical insight to understand current grading classifications, basic histopathological features of each category, and to define which classification correlates best with prognosis. METHODS: MEDLINE and the Cochrane Library were searched for studies that reported survival across different pathological grades in patients with mucinous neoplasm of the appendix with PD treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. PRISMA guidelines were followed. RESULTS: Thirty-eight studies were included. Ronnett's classification was the most common (9 studies). Classifications proposed by the Peritoneal Surface Oncology Group International (PSOGI) (6 studies) and the seventh or eighth edition of the AJCC (7 studies) are gaining in popularity. Nine studies supported a two-tier, 12 a three-tier, and two a four-tier classification system. Three studies demonstrated that acellular mucin had a better prognosis than low-grade pseudomyxoma peritonei in the PSOGI classification or M1bG1 in the eighth edition of the AJCC classification. Four studies demonstrated that the presence of signet ring cells was associated with a worse outcome than high-grade pseudomyxoma peritonei in the PSOGI classification and M1bG2 in the eighth edition of the AJCC. CONCLUSION: There is a great need for a common language in describing mucinous neoplasms of the appendix with PD. Evolution in terminology as a result of pathological insight turns the four-tiered PSOGI classification system into a coherent classification option.

Preoperative management of obese patients undergoing bariatric surgery: Role of endoscopy and Helicobacter eradication.

BACKGROUND: Obesity is a pandemic disease associated to severe health problems. Management is usually multimodal, but many patients eventually need surgery to reduce weight. Many guidelines recommend endoscopy prior to surgery. This study reviews a series of patients undergoing sleeve gastrectomy to see whether endoscopy performance and histopathological findings influence surgery outcome. MATERIAL AND METHODS: Retrospective series of patients undergoing sleeve gastrectomy as bariatric procedure at a single institution. We have reviewed the demographic data, the associated pathologies, endoscopic findings prior to surgery, histopathological findings in the surgical resection specimen and postoperative complication rate. RESULTS: 259 patients fulfilled criteria for the study. Over 70% were women and the mean age was 46.9 (SD 9.8). Preoperative endoscopy was performed in 28.9% of the patients and biopsy only in 19.3%. Helicobacter pylori was detected in 28% of the patients undergoing endoscopy (either in the biopsy or the urease test) and eradicated before surgery in all the patients. Helicobacter pylori was present in 9.7% of the surgical resection specimens and its presence was significantly associated with the development of postoperative complications, mostly staple line leaks (p = 0.01). CONCLUSION: Our study confirms that Helicobacter infection is significantly associated with postoperative complications after sleeve gastrectomy. It is therefore important to detect its presence and eradicate it before surgery.

Aryl hydrocarbon receptor interacting protein (AIP) significantly influences prognosis of pancreatic carcinoma.

INTRODUCTION: Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor. Aryl hydrocarbon receptor interacting protein (AIP) in one of AHR ligands. The aim of this study is to analyze the prognostic influence of AIP in pancreatic carcinoma. MATERIAL AND METHODS: Retrospective case series with immunohistochemical analysis of AIP. We have estimated a multivariate Cox's model for the outcome (progression free and overall survival). RESULTS: 204 patients were included in the study. As expected prognosis was poor and 67.8% died of disease. As for AIP 9.8% of the cases showed nuclear staining of the epithelial tumor cells and 59.4% a cytoplasmic one. Stroma was stained in 53.1% of the cases. Univariate survival analysis revealed a significantly worse prognosis of patients with cytoplasmic AIP expression (stroma and epithelium), but nuclear expression was associated to a better prognosis. In the multivariate analysis stromal AIP expression was an independent prognosticator of progression free survival, together with pT stage, histological grade and history of diabetes. DISCUSSION: AIP Is a conserved cochaperone protein binding to many proteins. AIP has been proposed as a potential tumor suppressor gene. To date, no study has analyzed the immunohistochemical expression of AIP in pancreatic carcinoma. Our results indicate that both epithelial and stromal cytoplasmic expression of AIP is associated to bad prognosis, while nuclear translocation seems to improve prognosis. CONCLUSION: Although we must deepen into the complex signaling pathways underlying this potential association, our results open a way to inhibiting AHR as a potential target against pancreatic carcinoma.

TRIM72 Immunohistochemical Expression Can Predict Relapse in Colorectal Carcinoma.

Large bowel adenocarcinoma is one of the most frequent human neoplasms and despite recent insights into the pathophysiology and molecular basis of this disease, mortality remains high in advanced and metastatic cases. Most guidelines recommend adjuvant chemotherapy for tumours involving lymph nodes, but not for patients with localized stage I or II disease. However, it is well known that approximately 20% of stage II colorectal carcinoma patients eventually recur, mainly with distant or peritoneal involvement and show bad prognosis. It would be important to predict which patients are at increased risk of recurrence to guide potential adjuvant therapy use in this controversial setting. In this sense, only microsatellite stability has been proposed as a predictive tool in some guidelines. The tripartite motif family protein 72 (TRIM72) is a ubiquitin ligase, involved in the cell membrane repair machinery and known to be associated to insulin resistance. Its potential role in colon cancer has recently been proposed. The aim of this study is to determine the potential predictive value of TRIM72 immunohistochemical expression in stage II colon carcinoma. We have retrospectively reviewed a series of 95 patients with stage II colon microsatellite stable carcinomas operated with a curative intent at a single large tertiary hospital in Madrid (Spain) between 2006 and 2012. None of the patients received adjuvant chemotherapy. We reviewed the histopathological slides and constructed a tissue microarray (TMA) of three representative areas to perform immunohistochemical staining for TRIM72. In our series 30 patients (31.7%) recurred after a median follow-up of 17.5 months. Lack of immunohistochemical expression of TRIM72 in the tumor was significantly and independently associated to recurrence. A recent report by Chen et al. has shown that TRIM72 can be measured in plasma for colon carcinoma detection as an alternative to CEA or CA19.9, with lower levels in patients with carcinoma. Our report is the first one to show that lower immunohistochemical expression of TRIM72 predicts recurrence in colon stage II carcinoma. We feel this predictive influence can be related to its crucial role as a central regulator in many signaling pathways (PI3K-AKT, ERK). As an ubiquitin ligase, the lack of TRIM72 could increase the levels of several potential oncogenic molecules and therefore lead to a more aggressive phenotype. It remains to be shown whether chemotherapy could change the clinical behaviour of this bad prognosis group. We propose TRIM72 immunohistochemical analysis as a potential tool to predict recurrence risk in stage II colon carcinoma patients. Our results should be confirmed in larger series, but could open the way to management strategies refinement in this early stage group of patients.

Colorectal cribriform comedo-type adenocarcinoma: a distinct subtype with poor prognosis?

Colorectal cancer is one of the most commonly diagnosed cancers in the world. It is a heterogeneous disease with several histologic subtypes, and some of them are associated with adverse prognostic factors. Cribriform comedo-type adenocarcinoma (CCA) has been included as a colorectal adenocarcinoma subtype in the last World Health Organization (WHO) classification of gastrointestinal system tumors. Some authors have linked this subtype to an adverse prognosis, but to the best of our knowledge there is only one previous report assessing its histologic and prognostic features. We herein review a series of CCA of the colon, emphasizing its clinical and morphological features.

Anal cytology in women: Experience from a single tertiary center.

INTRODUCTION: Anal cytology (AC) can be used as a screening tool for detection of anal HPV associated lesions, mainly in men who have sex with men and in immunosuppressed patients. Our aim is to review our experience with AC in women. MATERIAL & METHODS: We have retrospectively reviewed all AC diagnosed between 2010-2017 in a single tertiary hospital (n = 644) and selected those performed in women (n = 158). RESULTS: 24.53% of AC were performed in women. 14.7% of all women were HIV positive and 56.7% referred anal intercourse. Squamous lesions were found in 27.2% of women, most of them ASCUS and LSIL (14% and 11.5%). HPV DNA was detected in 38.6% of patients, and 63.9% of them showed positivity for multiple high-risk types. Anal biopsy showed high grade lesions in 20% of biopsied patients. We observed a significant relationship between HPV status and receptive anal sex, and the association between HPV status and anal histological diagnosis tended to significance. Sensitivity, specificity, negative predictive value and positive predictive value for anal cytology were 57%; 83%; 28% and 94%, respectively. 70.9% of women had synchronous cervical cytology, and squamous cervical lesions were detected in 46.4% of the cases, most of them LSIL or ASCUS (21.4% and 15.2%). We did not confirm a significant association between cytological diagnosis of cervical and anal samples. CONCLUSIONS: AC is less widely used in women than in homosexual men. However, women show important rates of anal lesions, regardless of their HIV status. More studies should be performed to assess the potential impact of screening protocols in this population.

Still a place for conventional histopathological analysis in the era of molecular medicine: predicting prognosis of resectable ductal pancreatic adenocarcinoma.

INTRODUCTION: Our aim is to find features that define prognosis in surgically resected ductal pancreatic adenocarcinoma readily accessible in everyday practice. MATERIALS AND METHODS: Longitudinal retrospective case series of pancreatic adenocarcinoma operated with a curative intent in a large tertiary hospital in Madrid between 2009 and 2015. RESULTS: 162 were enrolled. 40.8% survived less than 1 year. Multivariate Cox's regression model revealed that gender, presence of symptoms, T and N stage independently influenced progression-free survival, while overall survival was determined by gender, smoking, presence of symptoms and N stage. Logistic regression analysis revealed that only symptoms at diagnosis could predict death, while gender, symptoms, histopathological type, vessel invasion, T stage and necrosis could independently predict recurrence. DISCUSSION: Our series show that patients with symptomatic disease at the time of diagnosis and females showed a shorter progression-free and overall survival. We herein propose a regression model to predict outcome.

Globular amyloidosis of the colon.

Gastrointestinal involvement is frequent in systemic amyloidosis. However, amyloidosis can rarely be confined to the gastrointestinal tract or appear as a tumour mass. There have been few reports describing amyloid globular deposits in a variety of locations, as opposed to the usual linear ones. We herein report a rare case of globular amyloidosis involving the large bowel, which to the best of our knowledge is the second reported in the world literature. A 74-year-old man consulted on anaemia. Endoscopy showed ulcerative lesions in the left colon, which were biopsied and diagnosed as ischemic colitis. Under light microscopy, we found globular discrete deposits in the lamina propria which were Congo red-positive and resistant to permanganate digestion. Histopathological diagnosis was globular amyloidosis with AL deposits. The patient underwent further studies, including a haematologic evaluation that discarded systemic involvement. Globular amyloidosis seems to be a rare morphologic type of amyloidosis, but not a distinct entity. Its etiology, pathogenesis and relationship with patient prognosis and disease severity remain largely unknown. When amyloid deposits are confined to the gastrointestinal tract, systemic therapy can be avoided and patients should only be followed periodically. Immunohistochemical classification and clinical correlation are essential to rule out systemic amyloidosis.

The potential predictive value of DEK expression for neoadjuvant chemoradiotherapy response in locally advanced rectal cancer.

BACKGROUND: Limited data are available regarding the ability of biomarkers to predict complete pathological response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer. Complete response translates to better patient survival. DEK is a transcription factor involved not only in development and progression of different types of cancer, but is also associated with treatment response. This study aims to analyze the role of DEK in complete pathological response following chemoradiotherapy for locally advanced rectal cancer. METHODS: Pre-treated tumour samples from 74 locally advanced rectal-cancer patients who received chemoradiation therapy prior to total mesorectal excision were recruited for construction of a tissue microarray. DEK immunoreactivity from all samples was quantified by immunohistochemistry. Then, association between positive stained tumour cells and pathologic response to neoadjuvant treatment was measured to determine optimal predictive power. RESULTS: DEK expression was limited to tumour cells located in the rectum. Interestingly, high percentage of tumour cells with DEK positiveness was statistically associated with complete pathological response to neoadjuvant treatment based on radiotherapy and fluoropyrimidine-based chemotherapy and a marked trend toward significance between DEK positiveness and absence of treatment toxicity. Further analysis revealed an association between DEK and the pro-apoptotic factor P38 in the pre-treated rectal cancer biopsies. CONCLUSIONS: These data suggest DEK as a potential biomarker of complete pathological response to treatment in locally advanced rectal cancer.

Histopathological changes associated to an absorbable fibrin patch (Tachosil®) covering in an experimental model of high-risk colonic anastomoses.

BACKGROUND: TachoSil® is a fibrin sponge that contains fibrinogen and thrombin and is a useful adjuvant to enhance control of air leaks in thoracic surgery and to control bleeding in vascular and general surgery. Its use in intestinal surgery to prevent suture dehiscence is currently under investigation. MATERIAL AND METHODS: We report the results of a prospective randomized experimental study on 33 large white pigs in which a high-risk suture was created by induction of ischemia. We randomly employed TachoSil® to cover the anastomosis in half of the animals compared to a control group of uncovered anastomosis. After euthanasia, postmortem analysis was performed describing the findings related to anastomotic leakage, peritonitis and grade of adhesions. The entire anastomosis was resected in bloc and sent for histopathological analysis. A single blinded-pathologist evaluated the histopathological features of the specimens. RESULTS: We found statistically significant differences favouring the patch in decreasing leakage in the covered group. The healing process did not show significant differences between groups, although a higher rate of microscopic abscess was observed in the covered group. CONCLUSION: The use of fibrin sealants covering high-risk intestinal sutures has a positive effect in avoiding macroscopic anastomotic leakage. The patch did not have any influence in the anastomotic healing process, however, as a result of the effect in containing the inflammatory response, it may increase the rate of abscess.

Histopathological factors predicting response to neoadjuvant therapy in gastric carcinoma.

BACKGROUND: Neoadjuvant therapy (NAT) is a useful therapeutic option. However, some patients respond poorly to it and can even show tumor progression. It is important to define factors that can predict response to NAT. MATERIALS AND METHODS: This is a retrospective cohort study to define histopathological factors predicting response to NAT in gastric tubular carcinoma. This study has enrolled 80 patients receiving chemotherapy for locally advanced gastric carcinoma. RESULTS: 44.5% of the patients were men; mean age was 64.49 years. Only 5.7% of the patients showed a complete response to therapy, 10% had grade 1, 21.4% grade 2, and 62.9% grade 3 regression. On follow-up, 43.8% of the patients showed recurrence of disease (57.1% distant metastasis) and 33.8% eventually died of it. We found a statistically significant association between response and prognosis. We found a statistically significant association between regression and perineural, vascular, and lymph vessel invasion. Logistic regression model showed that only lymph vessel invasion had independent influence. Lymph vessel invasion not only indicated lack of response to therapy, but also higher incidence of lymph node involvement in the gastrectomy specimen. DISCUSSION: Our study indicates that the presence of vascular or perineural invasion in the endoscopic biopsies and high histopathological grade predict poor response to therapy. This seems peculiar, for undifferentiated tumors are supposed to have better response to therapy. CONCLUSION: Our study indicates that undifferentiated tumors respond worse to therapy. Furthermore, studies are necessary to define lack of response, to help avoid neoadjuvant therapy in unfavorable cases.

CPEB4 immunohistochemical expression is associated to prognosis in stage IV colorectal carcinoma.

The cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a RNA binding protein and translational regulator. It has been associated with tumor growth, vascularization and invasion and with tumor progression in breast, pancreas and lung carcinomas. To the best of our knowledge only one previous report has analyzed the prognostic value of CPEB4 in an experimental model of colorectal carcinoma. We have reviewed the files of patients with stage IV colorectal carcinoma metastatic to the liver. All the patients had received chemotherapy followed by hepatic metastasis resection and subsequent resection of the colon (liver-first approach). We have gathered demographic, analytical and morphological data of the primary tumors. We have performed immunohistochemical analysis of CPEB4 expression in these tumors and analyzed the potential prognostic value of this protein. 50 patients fulfilled inclusion criteria for the present study. All of them received preoperative chemotherapy based on platinum and also postoperative chemotherapy, with or without targeted drugs (18% received anti-epidermal growth factor receptor (EGFR) drugs and 24% anti-vascular endothelial growth factor receptor (VEGFR) drugs. 66% of the primaries were of sigmoid-rectal origin. CPEB4 expression was mainly cytoplasmic and it was scored as intense in 46% of the patients. Survival analysis revealed a significant association between progression free survival (PFS) and overall survival (OS) and CPEB4 immunohistochemical expression, which was independent in the multivariate analysis. CPEB4 behaves as a significant predictor of prognosis in stage IV colorectal carcinoma. The existence of CPEB4 specific inhibitors can open a new way for targeted therapy. Larger prospective studies are needed to confirm our promising results.

Prognostic significance of tumor regression in lymph nodes after neoadjuvant therapy for rectal carcinoma.

Neoadjuvant therapy (NAT) is mainly indicated for locally advanced rectal carcinoma. Many reports have shown that regression of the primary tumor is a prognostic factor. However, few reports to date have analyzed the potential prognostic significance of lymph node regression in rectal carcinoma. The aim of the present study is to describe the pattern of tumor regression in lymph nodes after NAT for rectal carcinoma and its potential prognostic significance. We have retrospectively reviewed 106 cases of rectal carcinoma treated at a single institution. We have retrieved data from the patients and reviewed the histopathological slides to evaluate tumor regression both of the primary tumor and of LN metastases. Prognosis has been defined both in terms of disease-free survival (DFS) and disease-specific survival (DSS). Of the patients, 16% showed complete response of the primary tumor, while 24% showed poor response, according to the CAP regression grading system. Absence of lymph node involvement after therapy was found in 80% of the patients (ypN0 cases), while 20% were ypN+. We reviewed 639 LN; 85 were involved by tumor, and 170 showed histological signs of tumor regression. The main pattern of tumor regression in lymph nodes was fibrosis (66.3%), followed by hystiocytosis (29.1%) and mucin pools (4.6%). We found histological signs of regression in 57% of ypN0 cases and 76% of ypN+ cases. We found a significant association between regression grade of the primary tumor and of lymph node metastases. For ypN0 patients with persistence of the primary tumor after NAT, the median DFS was significantly shorter in patients showing tumor regression in the LN. In a Cox multivariate survival model for DFS, this prognostic influence was independent of the regression grade of the primary tumor and also of the ypTNM stage. We found no significant association between any factor and DSS. The pattern of tumor regression in lymph nodes was not significantly associated with prognosis. Tumor regression in lymph nodes is an important prognostic factor in rectal carcinoma after NAT and should be specifically looked for and included in pathology reports.

PLK-1 Expression is Associated with Histopathological Response to Neoadjuvant Therapy of Hepatic Metastasis of Colorectal Carcinoma.

Polo-like kinase 1 (PLK1) is a serine/threonine-protein kinase expressed during mitosis and overexpressed in multiple human cancers, including leukemia and also many solid tumors. PLK1 knockdown has been shown to block proliferation of leukemic cell lines and the clonogenic potential of tumor cells grown from patients with cancer. PLK1 inhibition is a promising strategy for the treatment of some tumors. We aim to analyze expression of PLK1 in metastatic colorectal carcinoma. Retrospective analysis of colorectal carcinomas with hepatic metastasis during follow-up receiving neoadjuvant chemotherapy (NAC), based on oxaliplatin. Immunohistochemistry for PLK-1 in paraffin-embedded tissue from the primary and also from the metastasis. 50 patients. 32% showed good histopathological response. 43% of the primaries were positive for PLK1, as opposed to 23.5% of the metastasis. Expression of PLK1 was significantly reduced in metastasis compared with the primaries (p = 0.05), what could be due to therapy or to a phenotypic change of the metastatic nodule. Analysis of the prognostic influence of PLK1 expression showed significant association between PLK1 expression in metastasis and lower overall survival (p = 0.000). We have also found a significant association between PLK1 expression and histopathological response (p = 0.02). All the tumors with high expression of PLK1 showed minor response (11/11). This study shows the association between survival and poor histopathological response to therapy and high expression of PLK1 in metastasis. Our results could open a new therapeutic approach through the inhibition of PLK1.

Meniscal degeneration in human knee osteoarthritis: in situ hybridization and immunohistochemistry study.

OBJECTIVE: Meniscus injury is one of the causes of secondary osteoarthritis (OA). However, the role of meniscus is still unclear. Human meniscal distribution of cells and cartilage oligomeric matrix protein (COMP) and their changes in advanced OA were analyzed. PATIENTS AND METHODS: Thirty-one medial menisci from patients with knee OA that underwent a total knee arthroplasty were studied. Normal meniscal tissue was obtained from partial arthroscopic meniscectomy. Meniscal samples were processed for histology, immunohistochemistry and in situ hybridization, for cell assessment including density, active divisions, apoptosis, COMP distribution and proteoglycan content. RESULTS: Osteoarthritic menisci demonstrated areas of cell depletion and significant decrease in COMP immunostaining. Actively dividing cells were only found in the meniscectomy group, but not in the osteoarthritic group. Proteoglycan staining was less prominent in menisci from the osteoarthritis group. CONCLUSIONS: Our results show a decreased cell population, with low COMP and altered matrix organization in osteoarthritis menisci that suggest an altered meniscal scaffold and potential impairment of meniscal function. These meniscal changes may be associated with the development of knee osteoarthritis.