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Dive into the research topics where Ibrahim Alkatout is active.

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Featured researches published by Ibrahim Alkatout.


Jsls-journal of The Society of Laparoendoscopic Surgeons | 2012

Principles and safety measures of electrosurgery in laparoscopy.

Ibrahim Alkatout; Thoralf Schollmeyer; Nusrat A. Hawaldar; Nidhi Sharma; Liselotte Mettler

This report stresses that a thorough knowledge of electrosurgical fundamentals by the entire operative team is essential for patient safety and recognizing potential complications.


Obstetrical & Gynecological Survey | 2013

Clinical diagnosis and treatment of ectopic pregnancy.

Ibrahim Alkatout; Ulrich Honemeyer; Alexander Strauss; Andrea Tinelli; Antonio Malvasi; Walter Jonat; Liselotte Mettler; Thoralf Schollmeyer

Background Implantation of the zygote outside the uterine cavity occurs in 2% of all pregnancies. The product of conception can be removed safely by laparoscopic surgery and be submitted for histological examination. The rate of ectopic pregnancies has increased from 0.5% in 1970 to 2% today. The prevalence of ectopic pregnancy in all women presenting to an emergency department with first-trimester bleeding, lower abdominal pain, or a combination of the 2 is between 6% and 16%. Designation Workup of all localizations of ectopic pregnancies at a university department of obstetrics and gynecology. Methods Comparison of diagnostic and therapeutic modalities from the surgical laparoscopic approach to nonsurgical, medical options. Findings Surgical treatment: Tubal pregnancies: (1) to preserve tubal function, salpingotomy, partial salpingectomy followed by laparoscopic anastomosis, or fimbrial milking is performed. (2) Tubectomy or salpingectomy is performed only in severely damaged or ruptured tubes or if the patient does not desire further pregnancies. Nontubal ectopic pregnancies (ovarian pregnancy, ectopic abdominal pregnancy, interstitial or cornual pregnancy/rudimentary horn, intraligamental and cervical pregnancies) all require their own specific treatment. Medical treatment The predominant drug is methotrexate, but other systemic drugs, such as actinomycin D, prostaglandins, and RU 486, can also be applied. Complications Tubal rupture is a complication of late diagnosed tubal pregnancy that is more difficult to treat conservatively and often indicates tubectomy or segmental resection. In 5% to 15% of treated ectopic pregnancy cases, remnant conception product parts may require a final methotrexate injection. Conclusions This article is a review to aid clinical diagnosis of ectopic pregnancies that now can be diagnosed earlier and treated effectively by laparoscopic surgery. Target Audience Obstetricians and gynecologists, family physicians Learning Objectives After completing this CME activity, obstetricians and gynecologists should be better able to diagnose ectopic pregnancy in its early stages to provide safe treatment, choose the appropriate treatment for patients with ectopic pregnancy, and identify the role that human chorionic gonadotropin plays in ectopic pregnancy.


The American Journal of Surgical Pathology | 2009

Insulinomatosis: a multicentric insulinoma disease that frequently causes early recurrent hyperinsulinemic hypoglycemia.

Martin Anlauf; Juliane Bauersfeld; Andreas Raffel; Christian A. Koch; Tobias Henopp; Ibrahim Alkatout; Anja Schmitt; Achim Weber; Marie L. Kruse; Stefan Braunstein; Klaus Kaserer; Michael Brauckhoff; Henning Dralle; Holger Moch; Philipp U. Heitz; Paul Komminoth; Wolfram T. Knoefel; Aurel Perren; Günter Klöppel

Background Multicentric insulinoma disease was characterized with regard to its histopathology, multiple endocrine neoplasia type 1 (MEN1) status, precursor lesions, and the risk of hyperinsulinemic hypoglycemia recurrence. Methods Fourteen patients with multicentric insulinoma disease were compared with 267 patients with sporadic and familial insulinomas. The tumors were classified according to the World Health Organization (WHO) criteria. The MEN1 status was defined clinically and by germline mutation analysis. Detection of the MEN1 gene locus was performed using fluorescence in situ hybridization. The surgical interventions and the duration of disease-free survival were recorded. Results Fourteen patients (5%) without evidence of MEN1 showed 53 macrotumors and 285 microtumors expressing exclusively insulin. In addition, they had small proliferative insulin-expressing monohormonal endocrine cell clusters (IMECCs). No allelic loss of the MEN1 locus was detected in 64 tumors. All but one patient had benign disease. Recurrent hypoglycemia occurred in 6/14 patients (11 recurrences; mean time to relapse 8.4 y). Thirteen patients with MEN1 (4.6%) showed 41 insulinomas and 133 tumors expressing islet hormones other than insulin. IMECCs were not detected. Allelic loss of the MEN1 locus was found in 17/19 insulinomas. Recurrent hypoglycemia occurred in 4/13 patients (4 recurrences; mean time to relapse 14.5 y). Solitary insulinomas were found in 254/281 patients (90.4%). IMECCs were absent. There was no recurrent hypoglycemia in 84 patients with benign insulinomas. Conclusions Insulinomatosis is characterized by the synchronous and metachronous occurrence of insulinomas, multiple insulinoma precursor lesions, and rare development of metastases, but common recurrent hypoglycemia. This disease differs from solitary sporadic and MEN1-associated insulinomas.


International Journal of Women's Health | 2015

Vulvar cancer: epidemiology, clinical presentation, and management options

Ibrahim Alkatout; Schubert M; Garbrecht N; Weigel Mt; Jonat W; Mundhenke C; Günther

Epidemiology Vulvar cancer can be classified into two groups according to predisposing factors: the first type correlates with a HPV infection and occurs mostly in younger patients. The second group is not HPV associated and occurs often in elderly women without neoplastic epithelial disorders. Histology Squamous cell carcinoma (SCC) is the most common malignant tumor of the vulva (95%). Clinical features Pruritus is the most common and long-lasting reported symptom of vulvar cancer, followed by vulvar bleeding, discharge, dysuria, and pain. Therapy The gold standard for even a small invasive carcinoma of the vulva was historically radical vulvectomy with removal of the tumor with a wide margin followed by an en bloc resection of the inguinal and often the pelvic lymph nodes. Currently, a more individualized and less radical treatment is suggested: a radical wide local excision is possible in the case of localized lesions (T1). A sentinel lymph node (SLN) biopsy may be performed to reduce wound complications and lymphedema. Prognosis The survival of patients with vulvar cancer is good when convenient therapy is arranged quickly after initial diagnosis. Inguinal and/or femoral node involvement is the most significant prognostic factor for survival.


Journal of Minimally Invasive Gynecology | 2013

Combined Surgical and Hormone Therapy for Endometriosis is the Most Effective Treatment: Prospective, Randomized, Controlled Trial

Ibrahim Alkatout; Liselotte Mettler; Carmen Beteta; Jürgen Hedderich; Walter Jonat; Thoralf Schollmeyer; Ali Salmassi

STUDY OBJECTIVE To evaluate 3 therapy strategies: hormone therapy, surgery, and combined treatment. DESIGN Prospective, randomized, controlled study (Canadian Task Force classification I). SETTING University-based teaching hospital. PATIENTS Four hundred fifty patients with genital endometriosis, aged 18 to 44 years, before first laparoscopy. INTERVENTIONS Patients were randomly assigned to 1 of 3 treatment groups: hormone therapy, surgery, or combined treatment. Patients were reevaluated at second-look laparoscopy, at 2 to 2 months after 3-month hormone therapy in groups 1 and 3 and at 5 to 6 months in group 2 (surgical treatment alone). Outcome data were focussed on the endometriosis stage, recurrence of symptoms, and pregnancy rate. MEASUREMENTS AND MAIN RESULTS All treatment options, independent of the initial Endoscopic Endometriosis Classification stage, achieved an overall cure rate of ≥50%. A cure rate of 60% was achieved with the combined treatment, 55% with exclusively hormone therapy, and 50% with exclusively surgical treatment. Recurrence of symptoms was lowest in patients who received combined treatment. Significant benefit was achieved for dysmenorrhea and dyspareunia. An overall pregnancy rate of 55% to 65% was achieved, with no significant difference between the therapeutic options. CONCLUSION In the quest to find the most effective treatment of genital endometriosis, this clinical randomized study shows the lowest incidence of recurrence with combined surgical and medical treatment and improved pregnancy rate in any medically treated patients with or without surgery. The highest cure rate (Endoscopic Endometriosis Classification stage 0) for endometriosis was also achieved in the combined treatment group.


Obstetrics and Gynecology International | 2012

Complications of Uterine Fibroids and Their Management, Surgical Management of Fibroids, Laparoscopy and Hysteroscopy versus Hysterectomy, Haemorrhage, Adhesions, and Complications

Liselotte Mettler; Thoralf Schollmeyer; Andrea Tinelli; Antonio Malvasi; Ibrahim Alkatout

A critical analysis of the surgical treatment of fibroids compares all available techniques of myomectomy. Different statistical analyses reveal the advantages of the laparoscopic and hysteroscopic approach. Complications can arise from the location of the fibroids. They range from intermittent bleedings to continuous bleedings over several weeks, from single pain episodes to severe pain, from dysuria and constipation to chronic bladder and bowel spasms. Very seldom does peritonitis occur. Infertility may result from continuous metro and menorrhagia. The difficulty of the laparoscopic and hysteroscopic myomectomy lies in achieving satisfactory haemostasis using the appropriate sutures. The hysteroscopic myomectomy requires an operative hysteroscope and a well-experienced gynaecologic surgeon.


Journal of the National Cancer Institute | 2015

Role of Cannabinoid Receptor CB2 in HER2 Pro-oncogenic Signaling in Breast Cancer

Eduardo Pérez-Gómez; Clara Andradas; Sandra Blasco-Benito; María M. Caffarel; Elena García-Taboada; María Villa-Morales; Estefanía Moreno; Sigrid Hamann; Ester Martín-Villar; Juana M. Flores; Antonia Wenners; Ibrahim Alkatout; Wolfram Klapper; Christoph Röcken; Peter Bronsert; Elmar Stickeler; Annette Staebler; Maret Bauer; Norbert Arnold; Joaquim Soriano; Manuel Pérez-Martínez; Diego Megías; Gema Moreno-Bueno; Silvia Ortega-Gutiérrez; Marta Artola; Henar Vázquez-Villa; Miguel Quintanilla; José Fernández-Piqueras; Enric I. Canela; Peter J. McCormick

BACKGROUND Pharmacological activation of cannabinoid receptors elicits antitumoral responses in different cancer models. However, the biological role of these receptors in tumor physio-pathology is still unknown. METHODS We analyzed CB2 cannabinoid receptor protein expression in two series of 166 and 483 breast tumor samples operated in the University Hospitals of Kiel, Tübingen, and Freiburg between 1997 and 2010 and CB2 mRNA expression in previously published DNA microarray datasets. The role of CB2 in oncogenesis was studied by generating a mouse line that expresses the human V-Erb-B2 Avian Erythroblastic Leukemia Viral Oncogene Homolog 2 (HER2) rat ortholog (neu) and lacks CB2 and by a variety of biochemical and cell biology approaches in human breast cancer cells in culture and in vivo, upon modulation of CB2 expression by si/shRNAs and overexpression plasmids. CB2-HER2 molecular interaction was studied by colocalization, coimmunoprecipitation, and proximity ligation assays. Statistical tests were two-sided. RESULTS We show an association between elevated CB2 expression in HER2+ breast tumors and poor patient prognosis (decreased overall survival, hazard ratio [HR] = 0.29, 95% confidence interval [CI] = 0.09 to 0.71, P = .009) and higher probability to suffer local recurrence (HR = 0.09, 95% CI = 0.049 to 0.54, P = .003) and to develop distant metastases (HR = 0.33, 95% CI = 0.13 to 0.75, P = .009). We also demonstrate that genetic inactivation of CB2 impairs tumor generation and progression in MMTV-neu mice. Moreover, we show that HER2 upregulates CB2 expression by activating the transcription factor ELK1 via the ERK cascade and that an increased CB2 expression activates the HER2 pro-oncogenic signaling at the level of the tyrosine kinase c-SRC. Finally, we show HER2 and CB2 form heteromers in cancer cells. CONCLUSIONS Our findings reveal an unprecedented role of CB2 as a pivotal regulator of HER2 pro-oncogenic signaling in breast cancer, and they suggest that CB2 may be a biomarker with prognostic value in these tumors.


BJUI | 2009

Interobserver variation in grading and staging of squamous cell carcinoma of the penis in relation to the clinical outcome.

C.M. Naumann; Ibrahim Alkatout; M.F. Hamann; Amr Al-Najar; A. Hegele; Joanna Beate Korda; Christian Bolenz; Günter Klöppel; K.P. Jünemann; Christof van der Horst

To examine interobserver variations in assessing grade and stage of penile squamous cell carcinoma (SCC).


Melanoma Research | 2014

Melanomas of unknown primary frequently harbor TERT-promoter mutations.

Friederike Egberts; Sandra Krüger; Hans M. Behrens; Inka Bergner; Giorgios Papaspyrou; Jochen A. Werner; Ibrahim Alkatout; Jochen Haag; Axel Hauschild; Christoph Röcken

Commonly, in patients with melanoma metastases of an unknown primary tumor (MUP), an extensive search for the primary tumor is carried out. Recently, highly recurrent telomerase reverse transcriptase (TERT)-promoter mutations were found in malignant melanomas, which may function as driver mutations of skin cancer. The aim of this study was to test the hypothesis that MUP and mucosal melanomas harbor different prevalences of TERT-promoter mutations. Thirty-nine patients with MUP and 53 patients with mucosal melanomas were retrieved. In total, 152 paraffin samples of 92 patients were analyzed, and in 38 patients, multiple samples were tested. Mutational analysis of the TERT-promoter, BRAF, NRAS, and KIT genes was carried out. In total, 92 patients were eligible for mutational analysis. TERT-promoter mutations were found in 33 patients (35.9%): chr5, 1,295,228 C>T (18 patients); chr5, 1,295,250 C>T (11 patients); chr5, 1,295,228–229 CC>TT (three patients); chr5, 1,295,242–243 CC>TT (one patient). The mutations were significantly more prevalent in MUP [26 (66.7%)] than in mucosal melanomas [seven patients (13.2%); P<0.001]. In MUP, BRAF mutations were found in 46.2% of patients (18 patients) and NRAS mutations in 28.2% of patients (11 patients). In mucosal melanoma, NRAS mutations were found in 18.9% of patients (10), and BRAF and KIT mutations in 7.5% of patients (four patients), respectively. The prevalence of TERT-promoter mutations was associated with the patients sex [23 (51.1%) men, 10 (21.3%) women; P=0.004]. No significant correlation was found between TERT-mutation and patient survival. The TERT-promoter genotype of MUP points toward a cutaneous and not mucosal origin. The significant sex differences merit further attention in having putative therapeutic implications.


Experimental and Molecular Pathology | 2013

Transcription factors associated with epithelial–mesenchymal transition and cancer stem cells in the tumor centre and margin of invasive breast cancer

Ibrahim Alkatout; Meike Wiedermann; Maret Bauer; Antonia Wenners; Walter Jonat; Wolfram Klapper

Although tumor surgery aims for a complete resection respecting tumor-specific safety distance, in many cases the most peripheral part, the invasion front, remains in situ. Tumor cells at the tumor margin lose epithelial properties and acquire features of mesenchymal cells. The process of epithelial-to-mesenchymal transition (EMT) has been suggested to be of prime importance for tissue and vessel invasion. Recently, features of EMT were shown to be linked to cells with tumor-founding capability, so- called cancer stem cells (CSC). In this study we show that transcription factors associated with EMT markers Snail, Slug, Twist and Zeb1 are differentially expressed between normal breast epithelium, ductal carcinoma in situ and invasive breast cancer. Both invasive and in situ carcinoma expressed less Slug and Twist and more Zeb1 compared to normal epithelium. Using fluorescence multi-staining the number of potential CSC among invasive cancer cells varied dramatically depending on the staining combination used (18.5% for CD44(+)/CD24(-) and 2.4% for CD49f(+)/CD24(+)). Interestingly, neither transcription factors associated with EMT nor potential CSC counts varied between tumor centre and invasion front. No association of these features with clinical outcome was detected. Our results suggest that reliable in situ markers for EMT are missing for invasive breast cancer. Alternatively, the process of EMT might be activated in tumor cells at the margin as well as the centre. Furthermore, our data show that the bio-markers of CSC detect very variable cell populations within breast cancer, challenging the assumption of a hierarchical organization of CSC in these tumors.

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