Zvika Vaknin
Tel Aviv University
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Featured researches published by Zvika Vaknin.
Gynecologic and Obstetric Investigation | 2005
Reuvit Halperin; Sergei Zehavi; Zvika Vaknin; Ido Ben-Ami; Moty Pansky; David Schneider
Objective: In order to better understand the etiology of the vulvar vestibulitis syndrome, we examined the histopathologic parameters in vestibular mucosa, and compared the findings in specimens obtained from women with vulvar vestibulitis with those obtained from the control group. Study Design: Specimens of vestibulitis were obtained from 24 patients, undergoing circumferential vestibulectomy under general anesthesia due to the symptoms and signs consistent with vulvar vestibulitis. Control specimens were obtained from 16 women, without symptoms or signs of vulvar vestibulitis, undergoing reconstructive introital surgery due to roomy vagina, rectocele or painful episiotomy. All vestibular tissue specimens were examined for intensity of inflammation, extension of inflammatory cells into the epithelium, vascular proliferation, the presence of mast cells and proliferation of peripheral nerve bundles. Results: No significant difference was found regarding the degree of inflammation, the extension of inflammatory cells into the epithelium, the vascular proliferation and the presence of mast cells while comparing the study and the control groups. The only histopathologic feature, differentiating the patients with vulvar vestibulitis from the control group, was the proliferation of peripheral nerve bundles found in 19 out of 24 (79.1%) specimens expressing vestibulitis and in none of 16 control specimens (p < 0.0001). Conclusion: Our results, therefore, support the existence of peripheral nerve hyperplasia in vestibular tissue obtained from patients with vulvar vestibulitis, and exclude the role of active inflammation or mast cells as probable etiologies for the vulvar vestibulitis syndrome.
European Journal of Obstetrics & Gynecology and Reproductive Biology | 2003
Reuvit Halperin; Moty Pansky; Zvika Vaknin; S Zehavi; Ian Bukovsky; David Schneider
OBJECTIVE The aim of this study was to define the role of luteinizing hormone (LH) as a tumor marker, specific for ovarian cancer. METHODS The study included 34 women with functional and benign ovarian cysts, 11 women with borderline ovarian tumors, 22 patients with advanced ovarian cancer and 15 patients with non-ovarian intraperitoneal malignancies. Serum, peritoneal fluid and ovarian cyst aspirates were obtained intraoperatively (laparoscopy or laparotomy) and were subjected to the LH analysis. RESULTS Peritoneal fluid LH levels were significantly increased in patients with ovarian cancer and those with borderline ovarian tumors as compared to patients with functional and benign ovarian cysts (P=0.005 and P=0.007, respectively). The patients with non-ovarian malignancies demonstrated the same peritoneal fluid LH levels as patients with benign ovarian tumors. There was no significant difference in the level of peritoneal fluid LH between ovarian cancer patients with and without ascites. The patients with functional and benign ovarian cysts demonstrated also significantly lower cyst fluid LH levels as compared to patients with malignant and borderline ovarian cysts (P=0.01 and P=0.03, respectively). Peritoneal and ovarian cyst fluid levels of LH were significantly increased in patients with fibrothecomas as compared to patients with other benign ovarian cysts. There were no significant differences in the serum LH levels comparing patients from all study groups. CONCLUSION LH, detectable in peritoneal and ovarian cyst fluids, can be used as a tumor marker for identification of patients with borderline and malignant ovarian tumors.
Gynecologic and Obstetric Investigation | 2003
Reuvit Halperin; Zvika Vaknin; David Schneider; Michal Yaron; Arie Herman
Objective: To evaluate the efficacy of conservative management of ectopic pregnancy with fetal cardiac activity by combined local sonographically guided and systemic injection of methotrexate. Study Design: The study group included 12 patients with ectopic pregnancy and fetal cardiac activity, treated by combined local and systemic injection of methotrexate in the period from January 1, 2000 to July 1, 2002. The outcome of these patients was compared with the outcome of 53 patients who had ectopic pregnancy without fetal cardiac activity and were being treated only by systemic injection of methotrexate during the same period of time. Results: The success rate was 91.6% (11 out of 12) in the group of patients with ectopic fetal cardiac activity and 90.5% (48 out of 53) in the group of patients with ectopic pregnancy, but without fetal cardiac activity. There was also no significant difference between the two groups comparing the percentage of cases treated by an additional dose of methotrexate (8.3 and 13.2%, respectively), nor comparing the number of days to resolution of β-human chorionic gonadotrophin (BHCG; 40 ± 2 and 34 ± 10 days, respectively). Conversely, there was a significant difference in the initial BHCG level comparing the group of patients treated by combined local and systemic injection of methotrexate (12,616 ± 9,585 mIU/ml) and the group of patients treated by systemic injection of methotrexate (1,499 ± 2,065 mIU/ml) (p < 0.00001). Seventy-five percent of patients (6 out of 8) diagnosed with ectopic fetal cardiac activity, who desired to become pregnant, succeeded to conceive within 6 months following the combined local and systemic injection of methotrexate. Conclusion: The combined local sonographically guided and systemic injection of methotrexate is associated with a successful outcome in asymptomatic patients presenting with ectopic pregnancy and fetal cardiac activity.
Human Reproduction | 2011
Ido Ben-Ami; Y. Edel; Oshri Barel; Zvika Vaknin; A. Herman; Ron Maymon
BACKGROUND The incidence rates of anterior neural tube defects, anencephaly and encephalocele appear increased among twins compared with singletons. The current study aimed to evaluate whether the etiology of this phenomenon is related to twinning, assisted reproductive technology (ART), or both. METHODS The study cohort consisted of parturient women who were referred to our ultrasonography unit between January 1998 and December 2009 due to suspicion of severe fetal abnormality. The study cohort was divided into two subgroups based on mode of conception: spontaneous and ART (including IVF and ICSI). The subgroups were further subdivided into singleton and multiple pregnancies. We also compared pregnancies diagnosed with anencephaly in the study group to all live births in the Department of Obstetrics and Gynecology. RESULTS Anencephaly was diagnosed in 43 fetuses out of 1154 (3.7%) pregnancies diagnosed with severe fetal anomaly. Anencephaly was diagnosed in 9 out of 78 twin pregnancies (11.5%); of these, 8 of 45 (17.8%) were ART conceived and 1 of 33 (3%) spontaneously conceived. A significant correlation was found between twinning and anencephaly, with an odds ratio (OR) of 3.4 [confidence interval (CI) = 1.3-8.9, P= 0.011], while no significant correlation was found between ART and anencephaly. A significant correlation was found between anencephaly and the combination of ART conception and twinning (OR of 6.6, CI = 2.8-15.3, P< 0.01). Analyzing the distribution of pregnancies diagnosed with anencephaly in the study group compared with the total number of live births in the department revealed a significant correlation between twinning and anencephaly, with an OR of 11.4 (CI = 4.9-26.5, P< 0.01), with no significant correlation between ART and anencephaly. Among all live births, a significant correlation was found between anencephaly and the combination of ART conception and twinning (OR of 24.6, CI = 11.4-53.2, P< 0.01). CONCLUSIONS Our data suggest that twin pregnancies conceived by ART constitute a high-risk group for anencephaly, due to a possible synergistic effect of twinning and ART.
Prenatal Diagnosis | 2014
Oshri Barel; Ron Maymon; U. Barak; Noam Smorgick; Josef Tovbin; Zvika Vaknin
The aim of this study was to assess the effect of fetal sex on the accuracy of multiple formulas for sonographic estimation fetal weight (SEFW).
Human Reproduction | 2004
Ron Maymon; Reuvit Halperin; S. Mendlovic; David Schneider; Zvika Vaknin; A. Herman; Moty Pansky
International Journal of Gynecological Cancer | 2006
Ido Ben-Ami; Zvika Vaknin; David Schneider; Reuvit Halperin
Human Reproduction | 2005
Ido Ben-Ami; David Schneider; Ron Maymon; Zvika Vaknin; Arie Herman; Reuvit Halperin
Journal of Reproductive Medicine | 2003
Reuvit Halperin; Zvika Vaknin; Rami Langer; Ian Bukovsky; David Schneider
Journal of Reproductive Medicine | 2004
Reuvit Halperin; Zvika Vaknin; Ido Ben-Ami; Ian Bukovsky; David Schneider