Role of machine learning algorithms in predicting the treatment outcome of uterine fibroids using high-intensity focused ultrasound ablation with an immediate nonperfused volume ratio of at least 90.

OBJECTIVE: This study aimed to investigate the role of machine learning (ML) classifiers to determine the most informative multiparametric (mp) magnetic resonance imaging (MRI) features in predicting the treatment outcome of high-intensity focused ultrasound (HIFU) ablation with an immediate nonperfused volume (NPV) ratio of at least 90%. PATIENTS AND METHODS: Seventy-three women who underwent HIFU treatment were divided into groups A (n=47) and B (n=26), comprising patients with an NPV ratio of at least 90% and <90%, respectively. An ensemble feature ranking model was introduced based on the score values assigned to the features by five different ML classifiers to determine the most informative mpMRI features. The relationship between the mpMRI features and the immediate NPV ratio of 90% was evaluated using Pearson's correlation coefficients. The diagnostic ability of the ML classifiers was evaluated using standard performance metrics, including the area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity in eight folds cross-validation. RESULTS: For all the 12 most informative features, the area under receiver operating characteristic curve (AUROC), accuracy, specificity, and sensitivity ranged from 0.5 to 0.97, 0.34 to 0.97, 0.56 to 1.0, and 0.87 to 1.0, respectively. The gradient boosting (GBM) classifier demonstrated the best predictive performance with an AUROC of 0.95 and accuracy of 0.92, followed by the random forest, AdaBoost, logistic regression, and support vector classifiers, which yielded an AUROC of 0.92, 0.92, 0.83, and 0.78 and accuracy of 0.96, 0.88, 0.84, and 0.84, respectively. GBM had the best classifier performance with the best performing features from each mpMRI group, Ktrans ratio of the fibroid to the myometrium, the ratio of area under the curve of the fibroid to the myometrium, subcutaneous fat thickness, the ratio of apparent diffusion coefficient value of fibroid to the myometrium, and T2-signal intensity of the fibroid. CONCLUSIONS: The preliminary findings of this study suggest that the most informative and best performing features from each mpMRI group should be considered for predicting the treatment outcome of HIFU ablation to achieve an immediate NPV ratio of 90%.

Favorable outcome with sentinel lymph node biopsy alone after neoadjuvant chemotherapy in clinically node positive breast cancer at diagnosis: Turkish Multicentric NEOSENTI-TURK MF-18-02-study.

PURPOSE: Factors affecting local outcome were evaluated in patients with clinically node-positive (cN+) breast cancer at diagnosis, who underwent sentinel lymph node biopsy (SLNB) alone after neoadjuvant chemotherapy (NAC). METHODS: Between 2004 and 2018, 303 cytopathology-proven cN (+) patients in a multicentric registry, who received NAC and underwent SLNB alone were analysed. All patients had regional nodal irradiation. RESULTS: Median age was 46 (23-70). Of those, 211 patients had ypN0 disease (69.6%), whereas 92 patients had ypN (+) disease including 19 (20.6%) isolated tumor cells (ITC), 33 micrometastases (35.9%) and 40 macrometastases (43.5%). At a median follow-up of 36 months (24-172), one patient (0.3%) with macrometastatic SLN was found to have locoregional recurrence as chest wall and supraclavicular LN metastases at the 60th month. Five-year disease-free survival (DFS) and disease specific survival (DSS) rates were 87% and 95%, respectively. Patients with cT3/4 (HR = 2.41, 95% CI; 1.14-5.07), non-luminal molecular pathology (HR = 2.60, 95% CI, 1.16-5.82), and non-pCR in the breast (HR = 2.11, 95% CI, 0.89-5.01) were found to have an increased HR compared to others in 5-year DFS. However, no difference could be found between ypN0 and ypN ITC and micrometastasis (HR = 1.23, 95% CI, 0.44-3.47), whereas there was a slight increase in HR of patients with ypN macrometastasis versus ypN0 (HR = 1.91, 95% CI, 0.63-5.79). CONCLUSION: ALND could be avoided in meticulously selected cN (+) patients who underwent SLNB after NAC having breast and/or nodal pCR, cT1-2, or low volume residual nodal disease with luminal pathology, as long as axillary radiotherapy is provided.

TWIST1 Gene Expression as a Biomarker for Predicting Primary Doxorubicin Resistance in Breast Cancer.

Doxorubicin is one of the most commonly used chemotherapeutic agents for adjuvant chemotherapy of breast cancer. In the studies focused on finding biomarkers to predict the response of the patients and tumors to the drugs used, the Twist transcription factor has been suggested as a candidate biomarker for predicting chemo-resistance of breast tumors. In this study, we aimed to investigate the relationship between TWIST transcription factor expression and the effectiveness of doxorubicin treatment on directly taken primary tumor samples from chemotherapy-naive breast cancer patients. Twenty-six primary breast tumor samples taken from 26 different breast cancer patients were included in this study. Adenosine triphosphate tumor chemo-sensitivity assay (ATP-TCA) has been used to determine tumor response to doxorubicin and real-time reverse-transcription polymerase chain reaction (RT-PCR) was used for analyzing the TWIST1 gene expression of tumors. There was a significant difference in TWIST gene expression between responder and non responder tumors (p <0.05). The TWIST gene expression of the drug-resistant group was higher than the responsive group. This difference was not dependent on the histopathological features of tumors. In conclusion, compatible with earlier studies that have been performed with cell lines, the current study supports the role of higher TWIST gene expression as a biomarker for predicting the response of breast tumors to chemo-therapeutic agent doxorubicin.

The use of Ligasure vessel sealing system in axillary dissection; effect on seroma formation.

BACKGROUND: Seroma formation is the most frequent postoperative complication after axillary dissection for breast surgery with an incidence of 10 - 50 %. This prospective clinical randomized study was carried out to evaluate the Ligasure vessel sealing system and its effect on seromaformation and other complications for axillary dissection. METHODS: Between January 2006 and November 2007, the patients with histopathological diagnosis of breast cancer were analysed prospectively. The patients with positive sentinel lymph node biopsy or clinical axillary involvement were included in the study, and the patients who underwent neoadjuvant therapy or using anticoagulants have been excluded from the study. Patients were divided into two study groups.Axillary dissection was performed in the first group by LigaSure and in the second group by linking and electrocautery. RESULTS: There were a total of thirty three patients with a mean age of 51.4 +- 13.7. In group one, mean age of patients was 54.1 +- 13.2 and 48.68 +- 14.1 in group two. There was no significant statistical difference between the groups regarding age, body mass index, excised tissue weight,tumour size and number of excised lymph nodes. The use of Ligasure reduced drainage amount and duration of drain till removal, but increased operative time. CONCLUSION: There were no significant differences between study groups regarding the complications. LigaSure electrothermal bipolar vessel sealing system can be safely used in axillary dissection as an alternative to traditional methods.

Laparoscopic versus open appendectomy: where are we now?

PURPOSE: Although the advantages of laparoscopic procedures has been well studied over the last two decade, laparoscopic appendectomy could not to be a standard therapy due to some disadvantages such as longer operative time and higher cost.The objective of our study is to re-evaluate the outcomes of laparoscopic versus open appendectomy with current data. METHODS: Between January 2012 and July 2012, the data of the patients who had appendectomy were recorded prospectively. Patients' demographics, duration of procedure, length of hospital stay, need of analgesics, postoperative visual analogue scale scores and morbidity were assessed. RESULTS: Of 241 patients, 120 (49.8%) underwent open and 121(50.2%) laparoscopic appendectomy. The operating time was similar for both groups (p=0.855). The visual analog scale scores of 1st (p=0.001), 6th (p=0.001) and 12th (p=0.028) hours were higher in open the appendectomy group. The total need of analgesics significantly was higher in open group (p=0.001).There was no statistical difference in terms of total morbidity rate between open and laparoscopic appendectomy groups (p=0.617). CONCLUSION: Two operative techniques are similar in terms of length of hospital stay, operative time, and postoperative complications. Laparoscopic appendectomy reduces the need for analgesics and visual analog scale scores; therefore,it should be considered as the gold standard for surgical treatment of acute appendicitis.

A reliable pancreaticojejunal anastomosis with V-Loc 180 wound closure device for soft pancreatic stump.

BACKGROUND/AIMS: Although mortality rates decreased in recent years, pancreaticoduodenectomy is still associated with high morbidity rates. Pancreatic fistula is the leading cause of morbidity after pancreaticojejunal anastomosis and commonly occurs in soft pancreas. The objective of this study is to compare outcomes of conventional modified invaginated end to side pancreaticojejunostomy with a new practical method using V-Loc 'rM 180 wound closure device in soft pancreas. METHODOLOGY: Between December 2011 and August 2013, a total of 90 pancreaticoduodenectomy procedures were performed in our hospital. 28 of them were defined as soft pancreas according to attending surgeon and included in this study. Patients were divided into two groups consecutively and analysed for postoperative pancreatic fistula (POPF) rate, length of stay, operation time, cost and particular duration of anastomosis. Pancreatic fistulas were classified according to International Study Group on Pancreatic Fistula (ISGPF) definition. RESULTS: 1 grade A and 2 grade B fistulas appeared in V-Loc group (Group 1), whereas 1 grade A, 2 grade B and 1 grade C fistulas appeared in conventional anastomosis group (Group 2). CONCLUSIONS: Pancreaticojejunostomy with V-Loc suture is a convenient method in soft pancreas and can be performed safely.

Appendiceal mucocele: clinical and imaging features of 14 cases.

PURPOSE: Appendiceal mucocele as a cystic dilatation filled with mucinous material is a very rare disease of the appendix vermiformis. Its preoperative diagnosis is still acking behind common use of imaging techniques. METHODS: Retrospective analysis of the patients with a pathological diagnosis of appendiceal mucocele with regard to clinical and imaging features. RESULTS: The study group included 14 patients with a mean age of 51 years (range from 17 to 82 years). Predominant symptoms were pain and feeling of fullness in the right iliac fossa in 9(64%) and 5 (36%) patients, respectively. For imaging purposes, use of computed tomography resulted in preoperative diagnosis of appendiceal mucocele in half of the patients(50%). 93% of the cases underwent appendectomy, and righth emicolectomy was performed in one patient (7%). Mucocele and cystadenoma were detected in 11 (79%) and 3 (21%)patients, respectively. Presence of acute appendicitis and coloncarcinoma were confirmed afterwards histologically in 4 (29%)and one (7%) patients, respectively. CONCLUSIONS: Despite the common use of imaging studies,preoperative diagnosis of appendiceal mucocele is still not possible in most of the cases. During surgical treatment,which is tailored according to imaging and intraoperative findings, precautionary measures to avoid intraperitoneal rupture and dissemination should be taken.

Male breast cancer: a retrospective study of 15 years.

PURPOSE: To retrospectively evaluate the 15-year experience with breast cancer in males at a single institution. METHODS: The data from 25 male patients who had undergone surgery for breast cancer at a single center were retrospectively analysed. Their medical records were studied for clinical characteristics, therapeutic modalities used and factors associated with disease free (DFS) and overall survival (OS), like local recurrence/distant metastasis. RESULTS: The median patient age was 67 years (range 38-83). The most frequent presenting symptom was a palpable lump. Eighteen (72%) patients underwent modified radical mastectomy (MRM), while sentinel lymph node biopsy (SLNB) was performed in 14 (56%) cases. Of 25 patients, 21 (84%) underwent axillary lymph node dissection (ALND) and 15 (71.4%) of them had pathological axillary lymph node involvement. Two of 25 (8%) patients with bone and liver metastases underwent toilet mastectomy due to breast ulceration. Estrogen receptor (ER) was positive in 15 (60%) patients, while progesterone receptor (PR) and C-erbB2 (HER-2) were positive in 10 (40%) and 2 (8%) patients, respectively. Ten patients (40%) had both ER(+) and PR(+). The median follow-up period was 19 months (range 3-102). Local recurrence developed in one (4%) patient and distant metastasis in 4 (16%). Five-year OS and DFS were 53 and 49%, respectively. In univariate and multivariate analysis, pathological tumor size (<2 vs. >2 cm), pathological lymph node involvement and preoperative skin involvement over the breast were not associated with breast recurrence. Only in univariate analysis local recurrence/distant metastasis were associated with poor OS. CONCLUSION: Large cooperative studies are needed using strict clinical and laboratory criteria to advance the understanding of this disease and to identify the most effective treatment approaches.

Breast conserving surgery in patients with multifocal/multicentric breast cancer.

PURPOSE: To retrospectively evaluate the outcome of patients with multifocal (MF) and multicentric (MC) breast cancer treated with conservative surgery. METHODS: We evaluated 59 patients who had undergone breast conserving surgery (BCS) for MF/MC cancer between 1998-2008. We used sentinel lymph node (SLN) biopsy for all 59 patients and we performed axillary lymph node dissection in those with positive SLN. Local control, overall survival (OS), disease-free survival (DFS) and identification of predictive factors for recurrence were evaluated. RESULTS: Twenty patients with modified radical mastectomy because of persistent positive margins were excluded from the study. Evaluated were 55 patients with MF (93.2%) and 4 (6.8%) with MC disease. Thirty-four patients (57.6%) had 2, 20 patients (33.9%) had 3 and 5 (8.5%) had 4 or more tumor foci. Median follow up time was 20 months (range 2- 97). The projected 5- and 8-year OS were 95% and 89% respectively, and DFS 92.3%. At multivariate analysis, overexpression of human epidermal growth factor receptor 2 (HER-2) was associated with a higher ipsilateral breast cancer recurrence. Menopausal status, MF/MC disease, number of tumor foci (2 vs. ≥3), histological grade, extracapsular extension (ECE), lymphovascular invasion (LVI), and hormone receptor status were not associated with ipsilateral breast cancer recurrence. CONCLUSION: Our study demonstrates that in selected patients with MF/MC breast cancer, wide conservative surgery is a safe therapy.

Axillary sentinel node biopsy after neoadjuvant chemotherapy.

INTRODUCTION: The role of sentinel lymph node biopsy (SLNB) in patients with locally advanced breast cancer (LABC) with potentially sterilized axillary lymph nodes after neoadjuvant chemotherapy (NAC) remains unclear. PATIENTS AND METHODS: Between 2002 and 2008, SLNB with both blue-dye and radioisotope injection was performed in 77 patients with LABC whose cytopathologically confirmed positive axillary node(s) became clinically negative after NAC. Factors associated with SLN identification and false-negative rates, presence of non-sentinel lymph node (non-SLN) metastasis were analyzed retrospectively. RESULTS: SLNB was successful in 92% of the patients. Axillary status was predicted with 90% accuracy and a false-negative rate of 13.7%. Patients with residual tumor size >2 cm had a decreased SLN identification rate (p=0.002). Axillary nodal status before NAC (N2 versus N1) was associated with higher false-negative rates (p=0.04). Positive non-SLN(s) were more frequent in patients with multifocal/multicentric tumors (versus unifocal; p=0.003) and positive lymphovascular invasion (versus negative; p=0.0001). SLN(s) positive patients with pathologic tumor size >2 cm (versus 2 cm, and extra-sentinel node extension.

MAPK overexpression is associated with anthracycline resistance and increased risk for recurrence in patients with triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer is estimated to account for 15%-20% of all patients with breast cancer and is considered as a prognostically unfavorable subset. The aim of this study is to evaluate the prognostic impact of various molecular factors in patients with triple-negative breast cancer. PATIENTS AND METHODS: Tumor specimens from 109 patients with receptor-negative (estrogen receptor and progesterone receptor) breast cancer were analyzed for mitogen-activated protein kinase (MAPK), epidermal growth factor receptor (EGFR) and phosphoinositol-3-kinase (PI3K) expression by immunohistochemistry. The prognostic significance of these molecular factors, in addition to various prognostic variables, was investigated. RESULTS: Fifteen (13.8%), 38 (34.9%) and 33 patients (30.3%) had positive staining for EGFR, MAPK and PI3K, respectively. MAPK was associated with anthracycline resistance (P = 0.008) and lower MAPK score was significantly associated with shorter disease-free survival (P = 0.029). Survival following relapse was significantly worse for those with a higher MAPK score (P = 0.03). CONCLUSION: MAPK is a significant prognostic and predictive factor in patients with triple-negative breast cancer. Furthermore, the level of staining among those with a positive MAPK expression may play a prognostic role at different stages of relapse. Further translational research is required to elucidate molecular mechanisms of tumor proliferation in this subset of patients.

Prognostic and predictive factors after surgical treatment for locally recurrent rectal cancer: a single institute experience.

OBJECTIVE: Resection of locally recurrent rectal cancer (LRRC) after curative resection represents a difficult problem and a surgical challenge. The aim of this study was to evaluate the results of resecting the local recurrence of rectal cancer and to analyze factors that might predict curative resection and those that affect survival. PATIENTS AND METHODS: A retrospective review was performed in 50 patients who underwent surgical exploration with intent to cure LRRC between April 1998 and April 2005. All of the patients had previously undergone resection of primary rectal adenocarcinoma. Of these patients' charts, operation and pathology reports were reviewed. Primary tumor and treatment details, hospital of initial treatment and TNM stage were registered. The following data were collected concerning the detection of the local recurrence; date of recurrence, symptoms at the time of presentation and diagnostic work-up. Perioperative complication and date of discharge were also gathered. The recurrent tumors were classified as not fixed (F0), fixed at one site (F1) and fixed to two or more sites (F2) according to the preoperative and peroperative findings. Microscopic involvement of surgical margins and localization of recurrence were noted based on pathology reports. RESULTS: The median time interval between resection of primary tumor and surgery for locally recurrent disease was 24 (4-113) months. In a statistical analysis, initial surgery, complaints of patients, increasing number of sites of the recurrent tumor fixation in the pelvis, location of the recurrent tumor were associated with curative surgery. Curative, negative resection margins were obtained in 24 (48%) of patients; in these patients a median survival of 28 months was achieved, compared to 12 months (p=0.01) in patients with either microscopic or gross residual disease. Primary operation and CEA level at recurrence were also found to be important factors associated with improved survival. There was no operative mortality and, the complication rate was 24%. CONCLUSIONS: This study demonstrated that many patients with LRRC can be resected with negative margins. The type of primary surgery, symptoms, location, and fixity of recurrent tumor are associated with the increased possibility of carrying out curative resection. Previous surgery and curative surgery are significant predictors of both disease-specific survival and overall survival.

Genomic alterations in low-grade, anaplastic astrocytomas and glioblastomas.

To extend our understanding of potential stepwise genetic alterations that may underlie tumor progression from low-grade astrocytomas to glioblastomas, histopathologic and comparative genomic hybridization analyses were performed on tumor specimens from 68 primary lesions, including 40 glioblastomas, 10 anaplastic and 18 low-grade astrocytomas. The number of aberrations per case increased towards the higher grade tumors (grade II: 1.66+/-1.49; grade III: 2.80+/-1.68; grade IV: 3.02+/-1.07; F=6.955, p=0.002). A gain of 7/7q was common and the most frequently seen aberration in low-grade astrocytomas, whereas loss of 10q was the most frequently seen anomaly in anaplastic astrocytomas and glioblastomas. Chromosome 7p amplification was only detected in glioblastomas. Chromosome 10/10q deletion and combination of 1p, 19q and 17p deletions were specific to high-grade astrocytic tumors. Sequences of chromosome 7 and 10 seem to have pivotal roles in the biology of human gliomas. The genomic copy deletions of chromosomes 1p and 19q might provide an alternative mechanism in the genesis of astrocytomas.

Relation of glutathione S-transferase genotypes (GSTM1 and GSTT1) to laryngeal squamous cell carcinoma risk.

The purpose of the present study was to investigate GSTM1 and GSTT1 genotypes by using multiplex polymerase chain reaction (PCR) in patients with laryngeal squamous cell carcinoma (LSCC). The genotypes of 110 patients with LSCC and of 197 healthy subjects as the control group were determined by PCR analysis for GSTM1 and GSTT1 genes. Results showed that frequencies of GSTM1-null, GSTT1-null, and both GSTs-null genotypes were 51.8, 30, and 16.4%, respectively, in the patients with LSCC and 37.6, 15.7, and 5.6% in the control group. There was a significant difference between the genotype distributions of all GSTs in patients and in control groups (P < 0.05). The results support the hypothesis that null genotypes of GSTM1 and GSTT1 can reduce detoxification capacity of GSTs as members of the xenobiotic enzyme system. GSTM1-null, GSTT1-null, and both GSTs-null genotypes were more common in the patients with LSCC than in the control group. Patients with both GSTs-null genotypes had the highest risk for supraglottic LSCC in the early period, even if they were light-to-medium smokers. Investigation and determination of the genetic basis of LSCC may contribute to detection of risk groups and to prevent LSCC in the population.

Breast conserving surgery after primary chemotherapy in locally advanced breast cancer.

PURPOSE: Primary chemotherapy is being given in the treatment of locally advanced breast cancers (LABC), but a major concern is local recurrence after therapy. The aim of this study was to assess the role of breast conserving surgery (BCS) in patients with locally advanced breast cancer. MATERIAL AND METHODS: Twenty-eight patients, presenting LABC (T any, N 012, M0) were treated with primary chemotherapy comprising of cyclophosphamide, doxorubicin and fluorouracil and then BCS followed by radiotherapy were examined between the years 1992-2002 retrospectively. Before neoadjuvant chemotherapy, seven patients (25%) were Stage IIB, 19 patients (68%) Stage IIIA and two patients (7%) Stage IIIB. Survival times and curves were established according to the Kaplan-Meier method and compared by means of the log-rank test. The chi-square test and log rank test were performed for univariate statistical analysis of each prognostic factor. P values in multivariate analysis were carried out by the Cox's proportional hazards regression model. All p values were two-sided in tests and p values <0.05 were considered significant. RESULTS: Clinical down staging was obtained in 25 (89%) of patients. Three (11%) patients had complete clinical response, 22 (78%) patients with partial response and 3 (11%) had stable disease. The primary tumour could not be palpated after chemotherapy in 6 (21%) of 28 patients presenting with palpable mass, therefore needle localization was performed for BCS. Median follow-up was 51.9 months (ranging 10 to 118 months). Local recurrence was detected in 4 (14%) patients. Distant metastasis developed in 5 (18%) patients. Three of the patients died of distant metastases and two of them are alive at 49 months. Five-year survival rate was 66%. Statistically, there were no significant factors in terms of local recurrence. Histological grade and menopause status were significantly associated with overall survival (p = 0.018) and nuclear grade was the one significant factor on distant disease-free survival in univariate analysis (p = 0.006). In multivariate analysis, there were no significant factors in terms of overall and distant disease-free survival CONCLUSIONS: Negative margin is more important than the clinical and histological parameters, such as pretreatment stage, clinical response rate, ER and PR in terms of local recurrence. BCS can be performed safely by achieving free surgical margin in patients who have small sized tumour and with either N2 axillary involvement or skin invasion.

Comparison of subdermal and peritumoral injection techniques of lymphoscintigraphy to determine the sentinel lymph node in breast cancer.

PURPOSE: The purpose of this study was to evaluate 2 different injection techniques for lymphoscintigraphy to determine the axillary sentinel lymph node (SLN) in patients with breast cancer. METHODS: Thirty-six patients with early breast cancer were studied prospectively. Both peritumoral (PT) and subdermal (SD) injections were performed on each patient with Tc-99m rhenium sulfide colloid. PT injections were done 1 to 8 days before surgery and SD injections were done on the day of operation. An intraoperative gamma probe was used to explore the axillary SLNs prior to tumor excision and axillary dissection. All surgical specimens were evaluated histopathologically. RESULTS: In 19 of 36 patients, the same lymphatic drainage sites were observed with both techniques. Of these, 17 patients showed only axillary, 1 showed axillary and internal mammary (IM), and 1 showed axillary and subclavicular drainage sites. With PT injections 26 of 36 patients (72%), and with SD injections 33 of 36 patients (92%), showed axillary drainage and axillary SLNs. With PT injections 9 patients, and with SD injections only 2 patients, did not show any drainage site. During the operation with a gamma probe, axillary SLNs were excised in 35 patients (success rate, 97%). IM drainage was seen in 8 of 36 patients who underwent PT injections and in 3 of 36 with SD injections. CONCLUSION: The success rate was found to be higher with the SD injection technique than with PT injections to visualize the axillary SLN. To increase the visualization of both axillary and IM SLNs, it may be useful to perform lymphoscintigraphy with SD and PT injections together.

Mutations in human complement regulator, membrane cofactor protein (CD46), predispose to development of familial hemolytic uremic syndrome.

Membrane cofactor protein (MCP; CD46) is a widely expressed transmembrane complement regulator. Like factor H it inhibits complement activation by regulating C3b deposition on targets. Factor H mutations occur in 10-20% of patients with hemolytic uremic syndrome (HUS). We hypothesized that MCP mutations could predispose to HUS, and we sequenced MCP coding exons in affected individuals from 30 families. MCP mutations were detected in affected individuals of three families: a deletion of two amino acids (D237/S238) in family 1 (heterozygous) and a substitution, S206P, in families 2 (heterozygous) and 3 (homozygous). We evaluated protein expression and function in peripheral blood mononuclear cells from these individuals. An individual with the D237/S238 deletion had reduced MCP levels and approximately 50% C3b binding compared with normal controls. Individuals with the S206P change expressed normal quantities of protein, but demonstrated approximately 50% reduction in C3b binding in heterozygotes and complete lack of C3b binding in homozygotes. MCP expression and function was evaluated in transfectants reproducing these mutations. The deletion mutant was retained intracellularly. S206P protein was expressed on the cell surface but had a reduced ability to prevent complement activation, consistent with its reduced C3b binding and cofactor activity. This study presents further evidence that complement dysregulation predisposes to development of thrombotic microangiopathy and that screening patients for such defects could provide informed treatment strategies.

Laparoscopic treatment of mesenteric cysts.

Mesenteric cysts are rare intraabdominal tumors. We review the diagnosis, laparoscopic management, patient's outcome and follow-up of evaluation for three cases of mesenteric cyst that presented to Istanbul University, Istanbul Medical School, Department of Surgery, from 1999 to 2002. All of the patients presented with nonspecific abdominal symptoms such as constipation, abdominal discomfort, and anorexia. Preoperative evaluation for differentiating mesenteric cyst from malignancy is made by abdominal ultrasound and computed tomography. The procedure was completed laparoscopically using three trocars in three patients. In one patient retroperitoneal resection was performed. There were no intraoperative or postoperative complications. The follow-up periods ranged from 6 to 36 months, and there were no recurrences. Currently, the surgical treatment of mesenteric cyst should be performed by laparoscopy, which offers significant advantages in terms of reduced morbidity and hospital stay. For appropriate cases in which cyst arises from mesenterium of colon, the retroperitoneal approach should be applied.

Endoscopic sphincterotomy in the management of postoperative biliary fistula A complication of hepatic hydatid disease.

BACKGROUND: Intrabiliary rupture is the most common complication of hepatic hydatid disease (HHD), and persistent biliary leakage is the most frequent complication after surgery for HHD. In this study, we evaluated the outcome of endoscopic sphincterotomy (ES) performed in the management of postoperative biliary fistula in 33 patients with HHD and investigated the effects of the daily output of the fistula and the timing of the ES on the duration of the fistula. METHODS: Between January 1994 and April 2000, 33 patients (20 female, 13 male; median age, 44 years; range, 17-72) underwent ES at our clinics. The daily output of the biliary fistula ranged from 100 ml to 1000 ml (mean, 430 ml; in 18 patients < or = 400 ml; in 15 patients, >400 ml). The interval between the occurrence of the fistula and the performance of the ES ranged from 7 days to 5 months (median, 20 days; in 12 patients, < or = 2 weeks; in 21 patients >2 weeks). RESULTS: In patients with fistula output 400 ml (n = 18) and >400 ml (n = 15), the average closure times for the fistula after ES were 10.7 +/- 4.5 and 10.4 +/- 4.9 days, respectively (t-test: p = 0.847, t = 0.195). In patients (n = 2) with a short interval between the occurrence of the fistula and ES (<2 weeks), the average closure time for the fistula was 11.6 +/- 5.6 days, whereas for the patients (n = 15) with longer intervals (>2 weeks) it was 9.4 +/- 3.9 days (t = test: p = 0.254, t = 1.180). The drainage from the fistula stopped after an average of 9.88 +/- 4.83 days in all patients who underwent ES, and there were no any complications. Pearson's correlation test (PC) showed no significant relationship between the time for the complete closure time of the fistula after ES and the fistula output (PC=-0.253, p=0.155) or for the duration of the fistula before endoscopic retrograde cholangio pancreatography (ERCP) (PC = -0.333, p = 0.058). CONCLUSIONS: Endoscopic sphincterotomy is safe and effective and should be considered the minimally invasive procedure of choice for the management of postoperative biliary fistula due to HHD because it obviates the need for reoperation. If the sphincterotomy is successful, neither the daily output not the duration of the fistula has any influence on the time required for complete closure of the fistula.