Is modified Carnoy’s solution as effective as Carnoy’s solution in terms of amount of bone necrosis and depth of penetration?

Carnoy's solution, a chemical cauterisation agent, has been indicated as one of the adjuvant treatment modalities for odontogenic keratocyst. In 2000, after the ban of chloroform many surgeons adopted the use of Modified Carnoy's solution. The purpose of this study is to compare the depth of penetration and amount of bone necrosis of Carnoy's versus Modified Carnoy's solution on the mandible of Wistar rats at different time intervals. Twenty-six male Wistar rats of six to eight weeks old, weighing approximately 150-200 grams, were allocated for this study. The predictor variables were type of solution and application time. The outcome variable was depth of penetration and amount of bone necrosis. Carnoy's solution was applied on the defect on the right side of the mandible and Modified Carnoy's solution on the left side for five minutes on eight rats, eight minutes on eight rats, and 10 minutes on eight rats. All specimens were subjected to histomorphometric analysis done using Mia image AR software. Univariate ANOVA test, and paired sample t test was done to compare the results. The depth of penetration for Carnoy's solution was more than Modified Carnoy's solution in the three different exposure times. Statistically significant results were observed at five minutes and eight minutes. The amount of bone necrosis was more in Modified Carnoy's solution. The results were not statistically significant at the three different exposure times. To conclude, when one wants to use Modified Carnoy's solution, the minimum exposure time should be 10 minutes to achieve similar results as those of Carnoy's solution.

CARNOY'S SOLUTION INCREASES LYMPH NODES COUNT IN COLON CANCER SPECIMENS WHEN COMPARED TO FORMALIN FIXATION: A RANDOMIZED TRIAL

AIM

At least 12 lymph nodes (LNs) should be examined following surgical resection of colon cancer. As it is difficult to find small LNs, fat clearing fixatives have been proposed, but there is no consensus about the best option. The objective of this study was to verify if Carnoy's solution (CS) increases the LN count in left colon cancer specimens.

METHODS

A prospective randomized trial (clinicaltrials.gov registration: NCT02629315) with 60 patients with left colon adenocarcinoma who underwent rectosigmoidectomy. Specimens were randomized for fixation with CS or 10% neutral buffered formalin (NBF). After dissection, the pericolic fat from the NBF group was immersed in CS and re-dissected (Revision). The primary endpoint was the total number of LNs retrieved.

RESULTS

Mean LN count was 36.6 and 26.8 for CS and NBF groups, respectively (p=0.004). The number of cases with <12 LNs was 0 (CS) and 3 (NBF, p=0.237). The duration of dissection was similar. LNs were retrieved in all cases during the revision (mean: 19, range: 4-37), accounting for nearly 40% of the LNs of this arm of the study. After the revision, no case was found in the NBF arm with <12 LNs. Two patients had metastatic LNs during the revision (no upstaging occurred).

CONCLUSION

Compared to NBF, CS increases LN count in colon cancer specimens. After conventional pathologic analysis, fixing the pericolic fat with CS and performing a second dissection substantially increased the number of LNs.

Cytotoxic T-lymphocyte-associated protein 4 in gastric cancer: Prognosis and association with PD-L1 expression

BACKGROUND

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is one of the most studied immune checkpoint in gastric cancer (GC). However, the prognostic role of CTLA-4 expression in GC is poorly described. This study aimed to evaluate CTLA-4 expression in GC and its impact on survival, including patients treated with standard platinum-based chemotherapy (CMT), and association with PD-L1 expression.

METHODS

All GC patients who underwent D2-gastrectomy were investigated retrospectively. Tumor samples were examined for CTLA-4 and PD-L1 by immunohistochemistry. Tumor-infiltrating inflammatory cells, including CD4 + and CD8 + , were also examined.

RESULTS

Among the 284 GC patients included, 159 (56%) were CTLA-4 positive and the remaining 125 (44%) were classified as negative. CTLA-4 positive GC was associated with increased inflammatory cell infiltration (p < 0.001), high CD8 + T cells (p = 0.016) and PD-L1 expression (p = 0.026). Considering GC referred for treatment, CTLA-4 negative patients who received CMT had a significant improvement in disease-free survival compared to untreated CLTA-4 negative (p = 0.028). In multivariate analysis, GC positive for both CTLA-4 and PD-L1 had a prognostic impact on survival.

CONCLUSION

CTLA-4 positive was associated with PD-L1 expression and a high tumor-infiltrating CD8 + T cells. Accordingly, positivity for both CTLA-4 and PD-L1 was an independent factor associated to better survival in GC patients.

Comparison of the Benzanthrone Luminophores: They Are Not Equal for Rapid Examination of Parafasciolopsis fasciolaemorpha (Trematoda: Digenea)

Luminescent derivatives of benzanthrone are becoming more useful based on their light-absorbing and fluorescent-emitting properties. Our previous studies showed that luminescent staining properties of the same benzanthrone dye differ for variable parasite samples. Therefore, two types of benzanthrone dyes were prepared. One has a strongly basic amidine group and a halogen atom, and the other has an amide moiety and a tertiary amine group. Trematoda Parafasciolopsis fasciolaemorpha is a liver fluke of a moose (Alces alces) and has a significant influence on the health and abundance of the moose population. Staining protocols for parasite P. fasciolaemorpha specific organ or organ systems imaging are mostly time-consuming and labor-intensive. The study aimed to compare the fixation technique and the staining protocol by synthesized benzanthrone luminescent dyes to determine detailed morphology, anatomical arrangement of the organ systems and gross organization of the muscle layers of P. fasciolaemorpha using confocal laser scanning microscopy. Luminophores were tested for samples fixed in different fixatives. Developed dyes and staining protocol resulting in imaging of all parts of trematode without additional sample preparation procedures, which usually are required for parasite examination. Obtained results confirmed that the most qualitative results could be reached using 3-N-(2-piperidinylacetamido)benzanthrone dye which has amide moiety and a tertiary amine group. Based on obtained results, 3-N-(2-piperidinylacetamido)benzanthrone gave more qualitative parasite visualization than 2-bromo-3-N-(N′,N′-dimethylformamidino)benzanthrone.

ROBOTIC GASTRECTOMY: TECHNIQUE STANDARDIZATION

BACKGROUND

Trocars position for the Si model (position is similar for the Xi, although trocars stay more in line). Robotic gastrectomy is gaining popularity worldwide. It allows reduced blood loss and lesser pain. However, it widespread use is limited by the extensive learning curve and costs.

AIM

To describe our standard technique with reduced use of robotic instruments.

METHODS

We detail the steps involved in the procedure, including trocar placement, necessary robotic instruments, and meticulous surgical description.

RESULTS

After standardizing the procedure, 28 patients were operated with this budget technique. For each procedure material used was: 1 (Xi model) or 2 disposable trocars (Si) and 4 robotic instruments. Stapling and clipping were performed by the assistant through an auxiliary port, limiting the use of robotic instruments and reducing the cost.

CONCLUSION

This standardization helps implementing a robotic program for gastrectomy in the daily practice or in one`s institution.

Prediction scores for complication and recurrence after multivisceral resection in gastric cancer

BACKGROUND

Multivisceral resection (MVR) is indicated in T4b gastric cancer (GC) when R0 can be achieved. Patient's selection for MVR is imperative, since it carries an increased risk for postoperative complications (POC) and disease recurrence. This study aims to elaborate prediction scores for POC and recurrence after MVR for cT4b GC.

METHODS

Patients who underwent MVR with curative intent due to cT4b gastric adenocarcinoma were selected from our prospective database. Scoring models were based on the variables identified as risk factors for the studied outcome. Through binary regression the model that best predicted the outcome was created.

RESULTS

From 237 MVRs, 58 fulfilled the inclusion criteria. Males were 70.7%, mean age was 61.8 years. A pT4b was confirmed in 34 patients, 29 had 2 or more adjacent organs removed. Major POC occurred in 25.9%, mortality was 8.6%. Overall survival (OS) and disease-free survival (DFS) were similar for pT4b and non-pT4b. DFS was worse for pN+ and when >2 adjacent organs were removed. Scoring models included 5 and 6 parameters for POC and recurrence, respectively, and their accuracy was 80.6% (95%CI = 0.69-0.92) and 78% (95%CI = 0.66-0.90). The POC and recurrence rates in low- and high-score groups were statistically different (p < 0.001 and p = 0.004, respectively). Patients with high-risk for POC had lower OS (p = 0.036) and DFS was worse in the high-recurrence risk group (p = 0.008).

CONCLUSION

The proposed scoring systems accurately predict POC and recurrence in GC patients undergoing MVR. These models are easy to use and can assist in the adoption of an individualized approach.

Multivisceral resection vs standard gastrectomy for gastric adenocarcinoma

INTRODUCTION

Multivisceral resection (MVR) is potentially curative for selected gastric cancer patients, supposedly at the cost of increased complications. However, current data comparing MVR to standard gastrectomy (SG) is lacking.

OBJECTIVES

Compare complications and survival after MVR and SG.

METHODS

In a retrospective cohort of 1015 patients with gastric adenocarcinoma, 58 underwent MVR and 466 SG. Groups were compared concerning their characteristics, complications, and survival.

RESULTS

One hundred seventy-six patients had postoperative complications. Major complications were more frequent after MVR (P = .002). Surgical mortality was 8.6% and 4.9% for MVR and SG (P = .221). Older age, higher morbidities, and MVR were independent risk factors for major complications. The odds ratio for major complications was 5.89 for MVR with one or two organs and 38.01 for MVR with three or more organs. The pancreas was the most commonly removed organ and pT4b disease were confirmed in 34 (58.6%) of the MVR cases. Disease-free survival (DFS) was lower in MVR patients (51% vs 77.8%; P < .001), being worse according to the number of organs resected. In pN+ patients, DFS was worse after MVR. DFS was equivalent to pT4b and non-pT4b in the MVR group.

CONCLUSIONS

Increased morbidity and lower survival are expected for gastric cancer patients undergoing MVR.

Expression Profile of Markers for Targeted Therapy in Gastric Cancer Patients: HER-2, Microsatellite Instability and PD-L1

BACKGROUND

The assessment of human epidermal growth factor receptor 2 (HER2), microsatellite instability (MSI) and programmed cell death-ligand 1 (PD-L1) expression is relevant for the selection and effectiveness of targeted therapy in gastric cancer (GC).

OBJECTIVE

We aimed to investigate the clinicopathological characteristics and prognosis of GC patients according to these profiles.

METHODS

GC patients who underwent gastrectomy with D2 lymphadenectomy were eligible. HER2, MSI status and PD-L1 expression were analyzed by immunohistochemistry (IHC). Patients were grouped as follows: HER2+ group, immunotherapy (IT) group (MSI and/or PD-L1+), and non-targeted therapy (NTT) group (stable microsatellite and HER2/PD-L1-).

RESULTS

Among 282 patients, 50 (17.7%) were HER2+ and 79 (28%) MSI/PD-L1+. Fifteen had HER2+ and MSI/PD-L1+, while 168 (59.6%) were in the NTT group. HER2+ GCs were related to male gender (p = 0.007), intestinal type (p = 0.001) and less advanced pTNM stage (p = 0.029). Older age (p = 0.003), subtotal gastrectomy (p = 0.025), intestinal type (p = 0.008), pN0 status (p = 0.002) and less advanced pTNM stage (p = 0.001) were associated with the IT group. IT GC had better disease-free survival (DFS) and overall survival than the NTT group (p = 0.015 and p = 0.027, respectively). Concerning patients eligible for the standard adjuvant therapy, the treatment impacted positively on DFS for HER2+ and NTT groups (p = 0.003 and p = 0.042, respectively). No difference in DFS was seen between IT patients who received perioperative/adjuvant therapy and those treated only with surgery (p = 0.160).

CONCLUSIONS

GC patients who exhibited markers that can serve as an indication for known targeted therapy represent 40.4% of cases. The IT group was associated with a better prognosis. No benefit with standard adjuvant treatment appears to be achieved in MSI/PD-L1+ GCs.

Laser-capture microdissection of murine lung for differential cellular RNA analysis

The lung tissue contains a heterogeneous milieu of bronchioles, epithelial, airway smooth muscle (ASM), alveolar, and immune cell types. Healthy bronchiole comprises epithelial cells surrounded by ASM cells and helps in normal respiration. In contrast, airway remodeling, or plasticity, increases surrounding of bronchial epithelium during inflammation, especially in asthmatic condition. Given the profound functional difference between ASM, epithelial, and other cell types in the lung, it is imperative to separate and isolate different cell types of lungs for genomics, proteomics, and molecular analysis, which will improve the diagnostic and therapeutic approach to treat cell-specific lung disorders. Laser capture microdissection (LCM) is the technique generally used for the isolation of specific cell populations under direct visual inspection, which plays a crucial role to evaluate cell-specific effect in clinical and preclinical setup. However, maintenance of tissue RNA quality and integrity in LCM studies are very challenging tasks. It is obvious to believe that the major factor affecting the RNA quality is tissue-fixation method. The prime focus of this study was to address the RNA quality factors within the lung tissue using the different solvent system to fix tissue sample to obtain high-quality RNA. Paraformaldehyde and Carnoy's solutions were used for fixing the lung tissue and compared RNA integrity in LCM captured lung tissue samples. To further confirm the quality of RNA, we measured cellular marker genes in collected lung tissue samples from control and mixed allergen (MA)-induced asthmatic mouse model using qRT-PCR technique. RNA integrity number showed a significantly better quality of RNA in lung tissue samples fixed with Carnoy's solution compared to paraformaldehyde solution. Isolated RNA from MA-induced asthmatic murine lung epithelium, smooth muscle, and granulomatous foci using LCM showed a significant increase in remodeling gene expression compared to control which confirm the quality and integrity of isolated RNA. Overall, the study concludes tissue fixation solvent can alter the quality of RNA in the lung and the outcome of the results.

Laparoscopic D2 Gastrectomy for Gastric Cancer: Mid-Term Results and Current Evidence

INTRODUCTION

Although the first laparoscopic gastrectomy was performed in 1991, there was a long delay until it was incorporated into the regular practice of western surgeons. In Brazil, there are only few case series reported and data on its safety and efficacy along with mid- and long-term results are desired.

OBJECTIVE

Present the mid-term results of laparoscopic gastrectomy with curative intent in the treatment of gastric adenocarcinoma and review the current evidence on the therapy of this neoplasia with the laparoscopic access.

METHODS

Patients who underwent D2 laparoscopic gastrectomy for gastric adenocarcinoma were retrospectively reviewed.

RESULTS

Sixty-nine patients met the inclusion criteria. The mean age was 59.2 years and the mean body mass index was 24.2 kg/m². Subtotal gastrectomy was performed in 73.9%. The mean number of harvested lymph nodes was 36.7, increased lymph node count and shorter operative time were observed in the last 34 cases. Median hospital stay was 8 days. Postoperative complications occurred in 22 (31.9%) cases. Surgical mortality was 4.3%.

CONCLUSION

Laparoscopic gastrectomy can be performed safely with excellent short- and mid-term results. As experience increases, surgical duration is reduced and lymph node count rises.

Surgical outcomes of gastrectomy with D1 lymph node dissection performed for patients with unfavorable clinical conditions

BACKGROUND

Gastric cancer (GC) patients with advanced age and/or multiple morbidities have limited expected survival and may not benefit from extended lymph node resection. The aim of this study was to evaluate the surgical outcomes of these GC patients who underwent gastrectomy with D1 dissection.

METHODS

We retrospectively reviewed all GC patients who underwent gastrectomy with curative intent from 2009 to 2017. The decision to perform D1 was based on preoperative multidisciplinary meeting, and/or intraoperative clinical judgment.

RESULTS

Among 460 enrolled patients, 73 (15.9%) underwent D1 lymphadenectomy and 387 (84.1%) D2 lymphadenectomy. Male gender, older age, American Society of Anesthesiologists score (ASA) III/IV, higher neutrophil-to-lymphocyte ratio (NLR) and higher Charlson Comorbidity Index (CCI) were more common in the D1 group. Postoperative major complications were significantly higher in D1 group (24.7% vs 12.4%, p < 0.001) and mostly related to clinical complications. Locoregional recurrence was higher in the D1 group (53.8% vs 39.5%, p = 0.330) however, without statistical significance. No difference was found in disease-free survival (DFS) between D1 and D2 patients with positive lymph nodes (p = 0.192), whereas overall survival was longer in the D2 group (p < 0.001). Multivariate analysis showed a statistically significant impact on survival of age ≥70 years, CCI ≥5, total gastrectomy, D1 lymphadenectomy and advanced stages (III/IV).

CONCLUSIONS

Frail patients had high surgical mortality even when submitted to D1 dissection. DFS was comparable to D2. Extent of lymphadenectomy in high-risk patients should take in account the expectation of a decrease in surgical risk with the possibility of impairment of long-term survival.

Carnoy's solution fixation with compression significantly increases the number of lymph nodes yielded from colorectal cancer specimens

BACKGROUND AND OBJECTIVES

Carnoy's fixation and compression represents a novel technique to enhance lymph node evaluation and accuracy of staging after colorectal cancer resection.

METHODS

This study was performed in all adults undergoing colorectal cancer operations by Kaiser Permanente surgeons at two separate facilities. Patients were assigned to either location based upon surgeon and patient availability. One group of patients had their lymph nodes examined with current standard manual technique (MT). The other group had their specimens fixed with Carnoy's solution and then compressed (CT) to assess for lymph nodes.

RESULTS

A total of 157 patients were enrolled. Seventy-eight patient specimens underwent MT and 79 patient specimens underwent the new compression technique (CT). CT resulted in a significant increase in total lymph node yield per specimen (37.6 ± 18.5 nodes with CT vs 18.9 ± 8.8 nodes with MT; P < 0.0001). CT also resulted in sufficient lymph node sampling (>12 nodes) in all 79 patients in the group compared with 13 of 78 patients (17%) with an insufficient lymph node evaluation in the MT group ( P = 0.0002).

CONCLUSION

This study demonstrated that Carnoy's fixation with compression can significantly increase lymph node yields in colorectal cancer specimens and allow for a higher rate of adequate lymph node sampling.

Lymph Node Yield After Neoadjuvant Chemoradiotherapy in Rectal Cancer Specimens: A Randomized Trial Comparing Two Fixatives

BACKGROUND

It is widely reported that neoadjuvant chemoradiation reduces lymph node yield in rectal cancer specimens. Some have questioned the adequacy of finding ≥12 lymph nodes for accurate staging, and fewer nodes were correlated with good response. Others reported that low lymph node count raises the chance for understaging and correlates with worse survival. In addition, a few studies demonstrated that diligent specimen analysis increases lymph node count.

OBJECTIVE

The aim of this study was to compare Carnoy's solution and formalin concerning lymph node yield in specimens of patients with rectal cancer after neoadjuvant chemoradiation.

DESIGN

This is a prospective randomized trial that was conducted from 2012 to 2015.

SETTINGS

This study was performed in a reference cancer center in Brazil.

PATIENTS

Patients who underwent low anterior resection with total mesorectal excision after neoadjuvant chemoradiation for rectal adenocarcinoma were included.

INTERVENTION

Rectosigmoid specimens were randomized for fixation with Carnoy's solution or formalin.

MAIN OUTCOME MEASURES

A total of 130 specimens were randomized. After dissection, the residual fat from the formalin group was immersed in Carnoy's solution in search for missed lymph nodes (Revision).

RESULTS

The Carnoy's solution group had superior lymph node count (24.0 vs 16.3, p < 0.01) and fewer cases with <12 lymph nodes (6 vs 22, p = 0.001). The Revision group found lymph nodes in all cases (mean, 11.1), retrieving metastatic lymph nodes in 6 patients. It reduced the formalin cases with <12 lymph nodes from 33.8% to 4.6% and upstaged 2 patients. Tumor response to neoadjuvant chemoradiotherapy was not associated with lymph node count.

LIMITATIONS

This was a unicentric study.

CONCLUSIONS

Compared with formalin, the Carnoy's solution increases lymph node count and reduces the cases with <12 lymph nodes. Harvested lymph nodes are missed following routine analysis and this is clinically relevant. Finding <12 lymph nodes is not a sign of good response to neoadjuvant chemoradiation (www.clinicaltrials.gov. Unique identifier: NCT02629315). See Video Abstract at http://links.lww.com/DCR/A694.

Clinicopathological and prognostic features of Epstein-Barr virus infection, microsatellite instability, and PD-L1 expression in gastric cancer

BACKGROUND AND OBJECTIVES

Gastric cancer (GC) has recently been categorized in molecular subtypes, which include Epstein-Barr (EBV)-positive and microsatellite instability (MSI) tumors. This distinction may provide prognostic information and identifies therapeutic targets. The aim of this study was to evaluate EBV, MSI, and PD-L1 immunoexpression in GC and its relationship with clinicopathological characteristics and patient's prognosis.

METHODS

We evaluated 287 GC patients who underwent D2-gastrectomy through immunohistochemistry for DNA mismatch repair proteins and PD-L1, and in situ hybridization for EBV detection utilizing tissue microarray.

RESULTS

EBV-positive and MSI were identified in 10.5% and 27% of the GCs, respectively. EBV positivity was associated to male gender (P = 0.032), proximal location (P < 0.001), undetermined Lauren type (P < 0.001), poorly differentiated histology (P = 0.043) and severe inflammatory infiltrate (P < 0.001). MSI-tumors were associated to older age (P = 0.002), subtotal gastrectomy (P = 0.004), pN0 (P = 0.024) and earlier TNM stage (P = 0.020). PD-L1-positive was seen in 8.8% of cases, with predominant expression in EBV-positive GC (P < 0.001). MSI was associated to better survival outcomes.

CONCLUSION

EBV-positive GCs had increased PD-L1 expression, while MSI GC had better survival outcome. EBV and MSI subgroups are distinct GC entities, their recognition is feasible by conventional techniques, and it may help individualize follow-up and guide adjuvant therapy.

Risk Factors for Lymph Node Metastasis in Western Early Gastric Cancer After Optimal Surgical Treatment

BACKGROUND

Lymph node metastasis (LNM) has a strong influence on the prognosis of patients with early gastric cancer (EGC). As minimally invasive treatments are considered appropriate for EGC, and lymphadenectomy may be restricted or even eliminated in some cases; it is imperative to identify the main risk factors for LNM to individualize the therapeutic approach. This study aims to evaluate the risk factors for LNM in EGC and to determine the adequacy of the endoscopic resection criteria in a western population.

METHODS

EGC patients who underwent gastrectomy with lymphadenectomy were retrospectively analyzed utilizing a prospective database. The clinicopathological variables were assessed to determine which factors were associated to LNM.

RESULTS

Among 474 enrolled patients, 105 had EGC (22.1%). LNM occurred in 13.3% of all EGC (10% T1a; 15.4% T1b). Tumor size, venous, lymphatic, and perineural invasions were confirmed as independent predictors of LNM by multivariate analysis. Expanded criteria were safely adopted only in selected cases, and 13.6% of patients who matched expanded indication had LNM.

CONCLUSIONS

Tumor size, venous, lymphatic, and perineural invasions were associated with LNM and should be considered as surrogate markers for surgical treatment of EGC. Expanded criteria for endoscopic resection can be safely adopted only in selected cases.

Immunohistochemical expression of thymidylate synthase and prognosis in gastric cancer patients submitted to fluoropyrimidine-based chemotherapy

Objective

Adjuvant chemotherapy with 5-fluorouracil (5-FU) has been widely used in gastric cancer (GC) patients to prevent relapse after curative resection. 5-FU acts by inhibiting thymidylate synthase (TS), and high levels of TS correlate with resistance to treatment with fluoropyrimidines. The aim of this study was to evaluate the expression of TS in GC patients, and its relation with clinicopathological characteristics and prognosis in adjuvant chemotherapy with 5-FU.

Methods

We retrospectively evaluated 285 patients who underwent D2-gastrectomy with curative intent. TS expression was determined by immunohistochemistry (IHC) in tumor cells by tissue microarray (TMA). TS level was evaluated according to the intensity and percentage of cells marked by a score system. Patients were divided in three groups according to their TS-score: negative, low and high.

Results

TS expression was positive in 92.3% of GC. TS-high, TS-low and TS-negative were observed in 46.3%, 46.0% and 7.7% of patients, respectively. High-TS GC were associated with older age (P=0.007), high neutrophil/lymphocyte ratio (P=0.048), well/moderately differentiated histology (P=0.001), intestinal Lauren type (P<0.001) and absence of perineural invasion (P=0.003). Among 285 patients, 133 stage II/III patients (46.7%) received chemotherapy with 5-FU. In survival analysis, TS-high was associated with worse disease-free survival (DFS) in stage III GC patients who received 5-FU-based chemotherapy (P=0.007). Multivariate analysis revealed that total gastrectomy, poorly differentiated tumors and high TS-score were associated with worse DFS in stage III GC patients.

Conclusions

High TS-score in stage III GC was associated with poor DFS in patients treated with fluoropyrimidine-based chemotherapy.

Histomorphological and Molecular Assessments of the Fixation Times Comparing Formalin and Ethanol-Based Fixatives

The lack of standardization of tissue handling and processing hinders the development and validation of new biomarkers in research and clinical settings. We compared the histomorphology and the quality and quantity of biomolecules in paraffin-embedded mouse tissues, followed by fixation with neutral buffered formalin (NBF), 70% ethanol, and buffered ethanol (BE70) fixative. The quality of the histomorphology and immunohistochemistry in BE70 was relatively time-independent, whereas those in NBF rapidly decreased after 1 week of fixation. Protein recovered from tissue fixed in 70% ethanol and BE70 was compatible with Western blot and protein array using AKT and GAPDH antibodies, regardless of the fixation time. In addition, the quality and quantity of RNA extracted from tissue in ethanol-based fixative showed minimal changes from 4 hr to 6 months, whereas NBF had a dramatic detrimental change in RNA quality after 1 week of fixation. Furthermore, ethanol-based fixative offers a superior DNA template for PCR amplification-based molecular assays than NBF. In conclusion, coagulative, ethanol-based fixatives show a broader time spectrum than the aldehyde crosslinking fixative NBF in their histomorphological features and the quantity and quality of the biomolecules from paraffin-embedded tissue, and they may facilitate the use of fixative-fixed paraffin-embedded tissues in research and clinical laboratories, avoiding overfixation.

An optimized swine dysentery murine model to characterize shedding and clinical disease associated with "Brachyspira hampsonii" infection

Background

The development of a mouse model as an in vivo pathogenicity screening tool for Brachyspira spp. has advanced the study of these economically important pathogens in recent years. However, none of the murine models published to date have been used to characterize the clinical signs of disease in mice, instead focusing on pathology following oral inoculation with various Brachyspira spp. The experiments described herein explore modifications of published models to characterize faecal consistency, faecal shedding and pathology in mice challenged with “Brachyspira hampsonii” clade II (Bhamp).

Methods and results

In Experiment 1, 24 CF-1 mice were randomly allocated to one of three inoculation groups: sham (Ctrl), Bhamp, or B. hyodysenteriae (Bhyo; positive control). Half of each group was fed normal mouse chow (RMH) while the other received a low-zinc diet (TD85420). In Experiment 2, eight CF-1 mice and nine C3H/HeN mice were divided into Ctrl or Bhamp inoculation groups, and all fed TD85420. In Experiment 1, mice fed TD85420 demonstrated more severe mucoid faeces (P = 0.001; Kruskal Wallis) and faecal shedding for a significantly greater number of days (P = 0.005; Kruskal Wallis). Mean faecal scores of Bhamp inoculated mice trended higher than Ctrl (P = 0.06; Wilcoxon rank-sum) as did those of Bhyo mice (P = 0.0; Wilcoxon rank-sum). In Experiment 2, mean faecal scores of inoculated CF-1 mice were significantly greater than in C3H mice (P = 0.049; Kruskal Wallis) but no group differences in faecal shedding were observed. In both experiments, mice clustered based on the severity of colonic and caecal histopathology but high lesion scores were not always concurrent with high fecal scores.

Conclusion

In our laboratory, CF-1 mice and the lower-zinc TD85420 diet provide a superior murine challenge model of “Brachyspira hampsonii” clade II.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-017-1166-5) contains supplementary material, which is available to authorized users.

GASTRIC NEUROENDOCRINE TUMOR: REVIEW AND UPDATE

INTRODUCTION

The frequency of gastric neuroendocrine tumors is increasing. Reasons are the popularization of endoscopy and its technical refinements. Despite this, they are still poorly understood and have complex management.

AIM

Update the knowledge on gastric neuroendocrine tumor and expose the future perspectives on the diagnosis and treatment of this disease.

METHOD

Literature review using the following databases: Medline/PubMed, Cochrane Library and SciELO. Search terms were: gastric carcinoid, gastric neuroendocrine tumor, treatment. From the selected articles, 38 were included in this review.

RESULTS

Gastric neuroendocrine tumors are classified in four clinical types. Correct identification of the clinical type and histological grade is fundamental, since treatment varies accordingly and defines survival.

CONCLUSION

Gastric neuroendocrine tumors comprise different subtypes with distinct management and prognosis. Correct identification allows for a tailored therapy. Further studies will clarify the diseases biology and improve its treatment.

Avaliação de diferentes fixadores na preservação das características histológicas de pele de orelha de cães

RESUMO Os fixadores biológicos desempenham um papel importante na qualidade final da histologia. Na rotina veterinária, a biópsia de pele é um procedimento comum e a escolha do fixador é primordial para resultado final adequado. Os fixadores mais usados são à base de formalina, ainda que sejam tóxicos, cancerígenos, de baixa penetração e de fixação lenta. Mesmo assim, não existe um fixador ideal que substitua as suas qualidades. O objetivo deste trabalho foi avaliar qualitativamente a preservação das características histológicas de pele de cão utilizando diferentes fixadores de tecidos incluídos em parafina, cortados e corados pela hematoxilina-eosina. Utilizou-se uma caneta Punch de 4 milímetros para coletar amostras de pele de orelha em seis cadáveres de cães. Após coleta, os tecidos foram fixados em: (1) Bouin, durante seis horas; (2) Carnoy, durante quatro horas; (3) formaldeído tamponado 10% durante 24 horas, todos sob refrigeração (4ºC). Posteriormente, os tecidos foram processados, cortados e corados em hematoxilina e eosina. As lâminas foram avaliadas, às cegas, por quatro patologistas diferentes, que consideraram aspectos qualitativos a seguir: (1) qualidade da coloração; (2) preservação das características histológicas; e (3) preservação dos limites citoplasmáticos utilizando a escala de LIKERT de pontuação para cada lâmina. O fixador com a maior média de pontuação em todos os itens foi o formol tamponado com 3,76 pontos, seguido pelo Bouin (3,39) e pelo Carnoy (2,52). O formol pode trazer riscos à saúde do profissional que rotineiramente o manuseia, portanto se faz necessária a busca por fixadores com as mesmas qualidades, mas menos nocivos à saúde.

A Buffered Alcohol-Based Fixative for Histomorphologic and Molecular Applications

Formalin-fixed paraffin-embedded (FFPE) tissue is the predominant preparation for diagnostic histopathological evaluation and increasingly the biospecimen on which molecular diagnostics are performed. However, formalin is carcinogenic and results in cross-linking of proteins and nicking and alterations of nucleic acids. Alternative fixatives, including 70% ethanol, improved biomolecular integrity; however, they have yet to replace neutral-buffered formalin (NBF). Herein, we describe the phosphate-buffered ethanol 70% (BE70) fixative. The histomorphology of BE70-fixed tissue is very similar to that of NBF; however, it is a non-cross-linking fixative and lacks the carcinogenic profile of formaldehyde-based fixatives. RNA isolated from tissue fixed in BE70 was of substantially higher quality and quantity than that was recovered from formalin-fixed tissue. Furthermore, the BE70 fixative showed excellent RNA and DNA integrity compared with that of NBF fixative based on real-time polymerase chain reaction analysis results. Immunohistochemical staining was similar for the antigen tested. In conclusion, BE70 is a non-cross-linking fixative that is superior to NBF and 70% ethanol with reference to biomolecule recovery and quality from paraffin-embedded tissue. Additional studies to compare the histomorphologic and immunohistochemical performance and utility in a clinical setting are required.

Carnoy's solution increases the number of examined lymph nodes following gastrectomy for adenocarcinoma: a randomized trial

BACKGROUND

Pathological examination of a minimum of 16 lymph nodes is recommended following surgery for gastric adenocarcinoma, despite this a longer survival is expected when 30 or more lymph nodes are examined. Small lymph nodes are difficult to identify, and fat-clearing solutions have been proposed to improve this, but there is no evidence of their clinical benefit.

METHODS

Fifty D2 subtotal gastrectomy specimens were randomized for fixation in Carnoy's solution (CS) or 10% neutral buffered formalin (NBF), with subsequent fat dissection. After dissection, the residual fat from the NBF group, instead of being discarded, was immersed in CS and dissected again. Data from 25 D2 subtotal gastrectomies performed before the study were also analyzed.

RESULTS

The mean number of examined lymph nodes was 50.4 and 34.8 for CS and NBF, respectively (p < 0.001). Missing lymph nodes were found in all cases from the residual fat group (mean of 16.9), and in eight of them (32%) metastatic lymph nodes were present; this allowed the upstaging of two patients. Lymph nodes in the CS group were smaller than those in the NBF group (p = 0.01). The number of retrieved lymph nodes was similar among the NBF and Retrospective groups (p = 0.802).

CONCLUSIONS

Compared with NBF, CS increases lymph node detection following gastrectomy and allows a more accurate pathological staging. No influence of the research protocol on the number of examined lymph nodes was observed.