Proteomic analysis to identify biomarker proteins in pancreatic ductal adenocarcinoma

Background: Pancreatic ductal adenocarcinoma (PDAC) is the fifth most common cause of death from cancer in Korea. PDAC is difficult to diagnose at an early stage and even more difficult to cure. Thus, there is an urgent need to identify molecular targets for early diagnosis and effective treatment. The objectives of this study were to identify differentially expressed biomarker proteins of PDAC using proteomic analysis, to validate the identified biomarker proteins associated with carcinogenesis using western blot analysis and to evaluate clinical factors influencing expression of candidate biomarker proteins. Methods: In the present study, we carried out proteomic analysis in 10 pairs of PDAC specimens with matching adjacent normal tissues to clarify the different patterns of protein expression. The proteins were separated by high‐resolution 2‐D polyacrylamide gel electrophoresis (2D PAGE) and the differentially expressed proteins were identified by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). Differential expression of candidate biomarker proteins associated with carcinogenesis was further validated using western blot analysis. Standard statistical analysis was carried out in an attempt to establish a correlation between clinical variables and expression of candidate biomarker proteins. Results: Analysis of PDAC and the adjacent normal tissues showed reproducibly similar proteomic patterns for each group. Approximately 700 spots each were seen by silver‐stained gels from both PDAC and normal tissues. Differentially expressed protein spots were gel digested and identified by MALDI‐TOF MS. Twenty‐five proteins were identified, of which five proteins (galectin‐1, enolase‐2, α‐1‐antitrypsin, N‐myc interactor, peroxiredoxin‐4) were previously reported as being differentially expressed either at the mRNA level or protein level in human cancer. The five proteins were selected for candidate biomarker proteins related to carcinogenesis. These proteins were further validated by western blot analysis. Among the candidate biomarker proteins, galectin‐1 expression was highly correlated to histology (P = 0.019), T stage (P = 0.047), N stage (P = 0.033) and American Joint Committee on Cancer stage (P = 0.011). Conclusion: Differentially expressed 25 proteins in PDAC were identified using proteomic analysis and five proteins related to carcinogenesis were validated by western blot analysis. galectin‐1 expression was highly correlated to tumour histology and stage.     

In vitro investigation of pig cells for resistance to human antibody‐mediated rejection

Although human complement‐dependent cytotoxicity (CDC) of α1,3‐galactosyltransferase gene‐knockout (GTKO) pig cells is significantly weaker than that of wild‐type (WT) cells, successful xenotransplantation will require pigs with multiple genetic modifications. Sera from healthy humans were tested by (i) flow cytometry for binding of IgM/IgG, and (ii) CDC assay against peripheral blood mononuclear cells and porcine aortic endothelial cells from five types of pig – WT, GTKO, GTKO transgenic for H‐transferase (GTKO/HT), WT transgenic for human complement regulatory protein CD46 (CD46) and GTKO/CD46. There was significantly higher mean IgM/IgG binding to WT and CD46 cells than to GTKO, GTKO/HT, and GTKO/CD46, but no difference between GTKO, GTKO/HT, and GTKO/CD46 cells. There was significantly higher mean CDC to WT than to GTKO, GTKO/HT, CD46, and GTKO/CD46 cells, but no difference between GTKO and GTKO/HT. Lysis of GTKO/CD46 cells was significantly lower than that of GTKO or CD46 cells. CD46 expression provided partial protection against serum from a baboon sensitized to a GTKO pig heart. GTKO/CD46 cells were significantly resistant to lysis by human serum and sensitized baboon serum. In conclusion, the greatest protection from CDC was obtained by the combination of an absence of Gal expression and the presence of CD46 expression, but the expression of HT appeared to offer no advantage over GTKO. Organs from GTKO/CD46 pigs are likely to be significantly less susceptible to CDC.     

Selective parathyroid auto‐transplantation during thyroidectomy

Aim: Permanent hypoparathyroidism is a debilitating morbidity following thyroidectomy and parathyroid auto‐transplantation has been shown to be effective in preventing permanent hypoparathyroidism. Controversy exists regarding the benefit of routine versus selective auto‐transplantation. We evaluate the outcome of selective parathyroid auto‐transplantation in our hospital. Methods: A retrospective study was conducted to assess the incidence of postoperative hypocalcaemia. Indication for parathyroid auto‐transplant was doubtful viability of parathyroid gland during thyroidectomy. From 1 July 2000 to 30 June 2005, all patients who underwent total, subtotal and completion thyroidectomy were included. Other outcome measures including recurrent laryngeal nerve injury and operative time were also analyzed. Results: A total of 170 bilateral or completion thyroidectomies were performed within this period. Total, subtotal, and completion total thyroidectomies were performed in 103 (60.6%), 62 (36.5%), and five (2.9%) patients, respectively. Median age was 45 years (range 19–82). One hundred and twenty‐four patients (73%) had benign thyroid disease, and 46 patients (27%) had thyroid carcinoma. Parathyroid auto‐transplant was performed in 35 patients (20.6%). Mean operation time was 204 min (range 95–510 min). There was no difference in the operation time between the patients with parathyroid auto‐transplant and those without auto‐transplant (217 vs 200 min, P = 0.229). Transient hypocalcaemia occurred in 31 patients (18.2%) whereas two patients had permanent hypocalcaemia (1.2%). Permanent recurrent laryngeal nerve injury occurred in one patient (0.6%). Conclusions: The adoption of selective parathyroid auto‐transplant during thyroidectomy achieves an extremely low incidence of permanent hypoparathyroidism without excessive transient hypoparathyroidism.     

Postmastectomy reconstruction with extended latissimus dorsi myocutaneous flap for Hong Kong Chinese

Objective: Because of the smaller breast size of Chinese women, postmastectomy reconstruction without prosthesis by extended latissimus dorsi (LD) flap is potentially more applicable in the Chinese population. Methods: Patients who had undergone immediate postmastectomy breast reconstruction by extended latissimus dorsi flap without prosthesis were retrospectively studied. Surgical complications, aesthetic result and patient satisfaction were evaluated. Results: Ten Asian patients (nine Chinese and one Filipino) underwent extended LD flap for breast reconstruction after mastectomy. There was no total or partial flap failure. Operative complications included seroma in one patient and minor wound edge slough at back wounds in two patients. Simultaneous seroma and minor donor wound slough occurred in another patient. Aesthetic outcome was excellent (n = 5), good (n = 4) and poor (n = 1). Patient satisfaction with the procedure was very satisfied in four, satisfied in four and dissatisfied in two, respectively. All but two patients would recommend the same procedure to their friends or relatives. Conclusion: Extended LD flap can reliably achieve pleasing results with low morbidity. It has more potential to become a competitive alternative to transverse abdominis myocutaneous flap in most Chinese women for postmastectomy reconstruction.     

Case report of post-traumatic arterial high-flow priapism

Priapism is rare and usually unpredictable. High-flow priapism is caused by unregulated arterial inflow. Antecedent trauma is the most commonly described etiology. This condition does not require emergent treatment. The initial management of high-flow priapism should be observation, because treatment-related erectile dysfunction may appear. We report a case of high-flow priapism by perineal trauma in a 27-year-old man. His corpora were typically tumescent, but not completely rigid. He could not have sexual intercourse. Blood from the corpus cavernosum was normally oxygenated. Color duplex ultrasonography was performed in the lithotomy position, scanned at the perineum, showed pseudoaneurysmal appearance. Selective internal pudendal arteriography showed a right cavernous arterial extravasation. Superselective embolization of right internal pudendal arteries was performed with an autologous clot. After the procedure, detumescence was achieved as well as erectile function. We recommend superselective arterial embolization as the management of high flow priapism to patients who request treatment.     

Main traumatic events in Europe: PTSD in the European study of the epidemiology of mental disorders survey

A potentially traumatic event (PTE) contributes to trauma through its frequency, conditional probability of posttraumatic stress disorder (PTSD), and experience of other PTEs. A cross-sectional survey was conducted, enrolling 21,425 adults nationally representative of six European countries. Using the WHO-Composite International Diagnostic Interview, 8,797 were interviewed on 28 PTEs and PTSD. Prevalence of 12-month PTSD was 1.1%. When PTSD was present, the mean number of PTEs experienced was 3.2. In a multivariate analysis on PTEs and gender, six PTEs were found to be more traumatic, and to explain a large percentage of PTSD, as estimated by their attributable risk of PTSD: rape, undisclosed private event, having a child with serious illness, beaten by partner, stalked, beaten by caregiver.     

Factors Influencing Pathologic Results after Total Mesorectal Excision for Rectal Cancer: Analysis of Consecutive 100 Cases

Background The aim of this study was to analyze clinical and anatomical factors affecting the pathologic quality of the resected specimen after total mesorectal excision (TME) for rectal cancer. Methods A total of 100 patients who underwent TME for mid or low rectal cancer were evaluated prospectively. MRI pelvimetry data (transverse diameter, obstetric conjugate, interspinous distance, sacrum length, and sacrum depth) were analyzed as anatomically affecting factors to postoperative specimen quality. Sex, body mass index (BMI), type of surgery, tumor size, and tumor distance from the anal verge were analyzed as clinically affecting factors. The gross judgment of resected specimen, circumferential resection margin and the number of harvested lymph nodes were used to access postoperative specimen quality. Results The univariate and multivariate analysis showed that narrow obstetric conjugate and shorter interspinous distance were related to the inadequate quality of the mesorectum in the specimen (P = 0.022, P = 0.030). Interspinous distance was a predicting factor of a positive circumferential resection margin (P = 0.007). There were no clinical factors affecting the inadequate quality of the mesorectum or positive circumferential resection margin. Moreover, there were no clinico-anatomical factors affecting the number of harvested lymph nodes after TME. Conclusion Narrow obstetric conjugate and shorter interspinous distance were factors leading to poor postoperative specimen quality. Rectal cancer patients with narrow obstetric conjugate or shorter interspinous distance should be considered as high-risk patients with regard to specimen quality, which is in turn related to oncological outcome.     

Solitary Lymph Node Metastasis in Gastric Cancer

The feasibility and diagnostic reliability of sentinel node (SN) biopsy for gastric cancer are still controversial. We studied the clinicopathological features and localization of solitary lymph node metastasis (SLM) in gastric cancer to provide useful information for use of the SN concept in gastric cancer. From 2000 to 2004, 3,267 patients with gastric cancer underwent D2 radical gastrectomy. The clinicopathological features of 195 patients with histologically proven SLM and the distribution of metastasized nodes were assessed. The incidence of SLM was 6.0% in all cases. Compared with the node-negative patients, significant differences were observed in age, tumor size, depth of invasion, and surgical type. The cumulative 5-year survival rate of patients with SLM was 80.5%, which was significantly lower than 90.2% for node-negative patients (P < 0.001). Of patients with SLM, 82.6% had it in the perigastric node area (N1), and the other 17.4% patients had skip metastasis in the N2-N3 nodes. Perigastric nodes were the most common first sites of drainage from the tumor, making them the main targets of the operative SN mapping procedure. Due to the higher than expected incidence of skip metastasis in gastric cancer, D2 lymphadenectomy should be performed until the reliability of SN navigation surgery is validated in multicenter prospective clinical trials.     

A Significant Correlation between Nuclear CXCR4 Expression and Axillary Lymph Node Metastasis in Hormonal Receptor Negative Breast Cancer

Background and objectives In breast cancer, the expression pattern of CXCR4 may be correlated with the degree of axillary lymph node involvement. The aim of this study was to evaluate the contributing factors that contribute to the correlation between CXCR4 expression and axillary lymph node metastasis in breast cancer. Methods Between August 1997 and August 2002, sections of paraffin-embedded tissue were obtained from 107 patients who received optimal treatment for breast cancer. The expression of CXCR4 was evaluated by immunohistochemical staining. Results A significant correlation was found in the expression of nuclear CXCR4 and lymph node metastasis (P = 0.03). We found a significant correlation between a high nuclear expression of CXCR4 and axillary lymphatic metastasis in estrogen and progesterone receptor negative breast cancer (P = 0.01 and P = 0.01). There was a significant correlation between the high expression of nuclear CXCR4 and axillary lymphatic metastasis in comparisons between positive estrogen and/or progesterone receptor expression and negative expression (P = 0.02). Conclusions Our results showed that high expression of nuclear CXCR4 was significantly correlated with lymph node metastasis in breast cancer. The high expression of nuclear CXCR4 in hormone receptor negative breast cancer was associated with a high possibility of lymph node metastasis.     

Treatment Guidelines for Branch Duct Type Intraductal Papillary Mucinous Neoplasms of the Pancreas: When Can We Operate or Observe?

Background The objectives of this study were to investigate the clinicopathological features of branch intraductal papillary mucinous neoplasm (IPMN) and to determine safe criteria for its observation. Most clinicians agree that surgical resection is required to treat main duct-type IPMN because of its high malignancy rate. However, no definite treatment guideline (with respect to surgery or observation) has been issued on the management of branch duct type IPMN. Methods We retrospectively reviewed the clinicopathological data of 138 patients who underwent operations for IPMN between 1993 and 2006 at five institutes in Korea. Results Of 138 patients (mean age, 60.6 years; 87 men, 51 women), 76 underwent pancreatoduodenectomy, 39 distal pancreatectomy, 4 total pancreatectomy, and 20 limited pancreatic resection. There were 112 benign cases: 47 adenoma, 63 borderline cases, and 26 malignant cases, with 9 of these being noninvasive and 17 invasive. By univariate analysis, tumor size and the presence of a mural nodule were identified as meaningful predictors of malignancy. By receiver operating characteristic curve analysis, a tumor size of >2 cm was found to be the most valuable predictor of malignancy. When cases were classified according to tumor size and the presence of a mural nodule, the malignancy rate for a tumor ≤2 cm without a mural nodule was 9.2%, for a tumor of ≤2 cm plus a mural nodule was 25%, and for other conditions such as tumor >2 cm, >25%. Conclusions Many branch duct IPMNs are malignant. Surgical treatment is recommended, except in cases that are strongly suspected to be benign or cases that present a high operative risk. Observation is only recommended in patients with a tumor size of ≤2 cm without a mural nodule.