Aggressiveness in Plasmopara halstedii (sunflower downy mildew)

Sakr, Nachaat The Korean Society of Plant Pathology 2011 Plant Pathology Journal Vol.27 No.2

Aggressiveness was studied in seven Plasmopara halstedii (sunflower downy mildew) pathotypes: 100, 300, 304, 314, 704, 710 and 714. Aggressiveness criteria including percentage infection, latent period, sporulation density and reduction of hypocotyl length (dwarfing) were analysed in one sunflower inbred line showing a high level of quantitative resistance. Genetic relationships were detected between the seven pathotypes using 12 EST-derived markers. Pathotypes 100, 300, 304 and 314 were characterized with shorter latent period and higher sporulation density than pathotypes 710, 704 and 714. All pathotypes showed high percentage infection values and caused a large reduction in seedling size except for pathotype 314 involved in dwarfing. Pathotypes 714, 704 and 314 had an intermediary genetic position between the pathotypes 100 and 710. No correlation was detected between aggressiveness traits and EST genotypes.

Cognitive spectrum access in device-to-device-enabled cellular networks

Sakr, Ahmed Hamdi,Tabassum, Hina,Hossain, Ekram,Dong In Kim IEEE 2015 IEEE communications magazine Vol.53 No.7

<P>Cognitive spectrum access (CSA) in in-band D2D-enabled cellular networks is a potential feature that can promote efficient resource utilization and interference management among coexisting cellular and D2D users. In this article, we first outline the challenges in resource allocation posed by the coexistence of cellular and D2D users. Next, we provide a qualitative overview of the existing resource allocation and interference management policies for in-band D2D-enabled cellular networks. We then demonstrate how cognition along with limited information exchange between D2D users and the core network can be used to mitigate interference and enhance spectral efficiency of both cellular and D2D users. In particular, we propose a CSA scheme that exploits channel sensing and interference- aware decision making at the D2D terminals. This CSA scheme at the D2D terminals is complemented by a D2D-aware channel access method at the cellular BSs. The performance gains of the proposed CSA scheme are characterized in terms of channel access probability for a typical D2D transmitter and spectral efficiencies for both cellular and D2D transmissions. Finally, potential research issues that require further investigation are highlighted.</P>

Gastric Adenocarcinoma Secondary to Primary Gastric Diffuse Large B-cell Lymphoma

Sakr, Riwa,Massoud, Marcel Antoine,Aftimos, Georges,Chahine, Georges The Korean Gastric Cancer Association 2017 Journal of gastric cancer Vol.17 No.2

Despite the decreasing incidence and mortality from gastric cancer, it remains a major health problem worldwide. Ninety percent of cases are adenocarcinomas. Here, we report a case of gastric adenocarcinoma developed after successful treatment of prior primary gastric diffuse large B-cell lymphoma (DLBCL). Our patient was an elderly man with primary gastric DLBCL in whom complete remission was achieved after R-CHOP (cyclophosphamide, adriamycin, vincristine, prednisolone plus rituximab) chemotherapy. Helicobacter pylori infection persisted despite adequate treatment leading to sustained chronic gastritis. The mean time to diagnose metachronous gastric carcinoma was seven years. We believe that a combination of many risk factors, of which chronic H. pylori infection the most important, led to the development of gastric carcinoma following primary gastric lymphoma. In summary, patients who have been successfully treated for primary gastric lymphoma should be followed up at regular short intervals. H. pylori infection should be diagnosed promptly and treated aggressively.

Long-term bowel functional outcomes following anal sphincter-preserving surgery for upper and middle rectal cancer: a single-center longitudinal study

Sakr Ahmad,양승윤,조민수,Hur Hyuk,Min Byung Soh,Lee Kang Young,김남규 대한대장항문학회 2024 Annals of Coloproctolgy Vol.40 No.1

Purpose: Despite advances in neoadjuvant chemoradiotherapy and anal sphincter-preserving surgery for rectal cancer, bowel dysfunction is still unavoidable and negatively affects patients’ quality of life. In this longitudinal study, we aimed to investigate the changes in bowel function with follow-up time and the effect of neoadjuvant chemoradiotherapy on bowel function following low anterior resection for rectal cancer.Methods: In this study, 171 patients with upper or middle rectal cancer who underwent low anterior resection between 2012 and 2018 were included. Bowel function was assessed longitudinally with Memorial Sloan Kettering Cancer Center Bowel Function Instrument and Wexner scores every 6 months after restoration of bowel continuity. Patients with at least 2 follow-up visits were included.Results: Overall, 100 patients received neoadjuvant chemoradiotherapy. Urgency, soilage, and fecal incontinence were noted within 24 months in the patients treated with neoadjuvant chemoradiotherapy. After 2 years of follow-up, significant bowel dysfunction and fecal incontinence were observed in the neoadjuvant chemoradiotherapy group. Low tumor level and neoadjuvant chemoradiotherapy were associated with delayed bowel dysfunction.Conclusion: Neoadjuvant chemoradiotherapy in combination with low tumor level was significantly associated with delayed bowel dysfunction even after 2 years of follow-up. Therefore, careful selection and discussion with patients are paramount.

Postoperative developed intra-abdominal desmoid tumor after surgical resection of gastrointestinal malignancy: A review of 10 cases

Ahmad Sakr,Jong Min Lee,Homoud Alawfi,Mohammed Alessa,Nam Kyu Kim 대한종양외과학회 2019 Korean Journal of Clinical Oncology Vol.15 No.2

Purpose: Desmoid tumors are locally aggressive tumors with no known potential for metastasis. They tend to recur even after complete excision. Sometimes it is not easy to differentiate between intra-abdominal desmoid and tumor recurrence, especially after gastrointestinal (GI) tumor resection. The current study aims to review the characteristics, management, and outcomes of patients with intra-abdominal desmoid tumor post GI resection. Methods: During the period between 2007 and 2018, after a retrospective review of patients’ clinical data, 10 patients were finally included. Medical records were screened for demographic, clinical, pathological data, management strategy, postoperative morbidity, mortality, recurrence rate and follow-up. Results: The study comprised 10 patients (8 males). The median age was 53.5 years (range, 35–68 years). Two patients diagnosed as familial adenomatous polyposis (FAP). All the patients underwent previous GI resection: three (30%) for colon cancer, three (30%) gastrectomy, two (20%) total proctocolectomy with ileal pouch-anal anastomosis (TPC+IPAA) for FAP, one (10%) low anterior resection (three rectal cancers) and one (10%) distal pancreatectomy. The tumor was found to be in bowel mesentery in eight cases (80%). The median tumor size was 5.3 cm (range, 2.6–19.0 cm). Six patients (60%) underwent open resection, while four patients (40%) underwent laparoscopic surgery. Complications occurred in five cases (50%) and ranged from Clavien-Dindo (II-III). The median follow-up period was 16.5 months (1.5–136.0 months) with recurrence in one case (10%). Pathology came out to be desmoid tumor fibromatosis in all cases. Conclusion: When a mass develops after surgical resection for abdominal GI malignancy and tends to be large in size, located in the bowel mesentery and away from previous primary tumor site, most probably it is desmoid rather than tumor recurrence

Impact of the type of Surgery And Preoperative Chemoradiotherapy On Bowel Function After Sphincter-Preserving Surgery for Rectal Cancer: A Single-Center Longitudinal Observational Study

Ahmad SAKR,Jae Hyun KANG,Seung Yoon YANG,Yoon Dae HAN,Min Soo CHO,Hyuk HUR,Byung Soh MIN,Kang Young LEE,Nam Kyu KIM 대한외과학회 2019 대한외과학회 학술대회 초록집 Vol.2019 No.10

Gastric Adenocarcinoma Secondary to Primary Gastric Diffuse Large B-cell Lymphoma

Riwa Sakr,Marcel Massoud,Georges Aftimos,Georges Chahine 대한위암학회 2017 Journal of gastric cancer Vol.17 No.2

Despite the decreasing incidence and mortality from gastric cancer, it remains a major health problem worldwide. Ninety percent of cases are adenocarcinomas. Here, we report a case of gastric adenocarcinoma developed after successful treatment of prior primary gastric diffuse large B-cell lymphoma (DLBCL). Our patient was an elderly man with primary gastric DLBCL in whom complete remission was achieved after R-CHOP (cyclophosphamide, adriamycin, vincristine, prednisolone plus rituximab) chemotherapy. Helicobacter pylori infection persisted despite adequate treatment leading to sustained chronic gastritis. The mean time to diagnose metachronous gastric carcinoma was seven years. We believe that a combination of many risk factors, of which chronic H. pylori infection the most important, led to the development of gastric carcinoma following primary gastric lymphoma. In summary, patients who have been successfully treated for primary gastric lymphoma should be followed up at regular short intervals. H. pylori infection should be diagnosed promptly and treated aggressively.

Aggressiveness in Plasmopara halstedii (sunflower downy mildew)

Nachaat Sakr 한국식물병리학회 2011 Plant Pathology Journal Vol.27 No.2

Aggressiveness was studied in seven Plasmopara halstedii (sunflower downy mildew) pathotypes: 100, 300, 304,314, 704, 710 and 714. Aggressiveness criteria including percentage infection, latent period, sporulation density and reduction of hypocotyl length (dwarfing) were analysed in one sunflower inbred line showing a high level of quantitative resistance. Genetic relationships were detected between the seven pathotypes using 12 ESTderived markers. Pathotypes 100, 300, 304 and 314 were characterized with shorter latent period and higher sporulation density than pathotypes 710, 704 and 714. All pathotypes showed high percentage infection values and caused a large reduction in seedling size except for pathotype 314 involved in dwarfing. Pathotypes 714,704 and 314 had an intermediary genetic position between the pathotypes 100 and 710. No correlation was detected between aggressiveness traits and EST genotypes.

Single-center Experience of 24 Cases of Tailgut Cyst

Ahmad Sakr,김호승,한윤대,조민수,허혁,민병소,이강영,김남규 대한대장항문학회 2019 Annals of Coloproctolgy Vol.35 No.5

Purpose: Tailgut cysts are rare congenital or developmental lesions that arise from vestiges of the embryological hindgut. They are usually present in the presacral space. We report our single-center experience with managing tailgut cysts. Methods: We conducted a retrospective analysis of 24 patients with tailgut cyst treated surgically at the Colorectal Surgery Department of Severance Hospital, Yonsei University, Seoul, South Korea, between 2007–2018. Results: This study included 24 patients (18 females) with a median age of 51.5 years (range, 21–68 years). Ten cases were symptomatic and 14 were asymptomatic. Cysts were retrorectal in 21 patients. Cysts were below the coccyx level in 16 patients, opposite the coccyx in 6, and above the coccyx in 2. Cysts were supralevator in 5 patients, had a supra- and infralevator extension in 18 patients, and were infralevator in 1. Ten patients were managed using an anterior laparoscopic approach, 11 using a posterior approach, and 3 using a combined approach. Mean cyst size was 5.5 ± 2.7 cm. Postoperative complications were Clavien-Dindo (CD) classification grade II in 9 patients (37.5%) and CD grade III in 1 (4.2%). The posterior approach group showed the highest rate of complications (P = 0.021). Patients managed using a combined approach showed a larger cyst size (P < 0.001), longer operation times (P < 0.001), and a greater likelihood of tumor level above the coccyx (P = 0.002) compared to other approaches. The tumors of 2 male patients were malignant: 1 was a neuroendocrine tumor treated with radiotherapy, while the other was a closely followed adenocarcinoma. Median follow-up was 12 months (range, 1–66 months) with no recurrence. Conclusion: Tailgut cysts are uncommon but can cause perineal or pelvic pain. Complete surgical excision via an appropriate approach according to tumor size, location, and correlation with adjacent pelvic floor muscles is the key treatment.

Review of Heterotopic Thyroid Autotransplantation

Mahmoud Sakr,Ahmed Mahmoud 대한이비인후과학회 2017 Clinical and Experimental Otorhinolaryngology Vol.10 No.4

Total thyroidectomy is increasingly accepted for the management of bilateral benign thyroid disorders. Postoperatively, patients require lifelong levothyroxine replacement therapy to avoid postoperative hypothyroidism, which besides the burden of compliance, has been proven to be associated with several long-term side effects. Heterotopic thyroid autotransplantation was proposed several decades ago to avoid the need for life-long postoperative replacement therapy with maintaining the autoregulatory mechanism of thyroxin production inside the body according to its needs. Available data regarding this topic in literature is relatively poor. Before applying thyroid autotransplantation on humans, several studies have been done on animals, where the autologous transplantations were found to be successful in almost all the cases, proved by follow up postoperative 8-week measurements of thyroid hormones and histopathological examination of the removed autografts. Regarding the clinical application, few trials have been done using cryopreserved in vivo, in vitro or immediately autotransplanted thyroid autografts. Satisfactory results were obtained, however, the number of these studies and the number of patients per each study was very low. Besides the study methodologies were not so consistent.