The molecular mechanisms of mitosis and meiosis: Review

WOS: 000254582800014In order to understand the function of the cell, which is the basic unit of human organism, the fundamentals of cell replication should be elucidated. Cell cycle checkpoints work in balance during the cell division process. The most important step in cell replication is to copy its own genetic material. During replication, mitosis lasts only I hour whereas 95% of the cell cycle process comprises the interphase. G1, S, G2 and M phases of the cell cycle are strictly controlled by the cell itself. Cell cycle checkpoints are sensitive to and control the errors that occur during the replication process, misegregation of the chromosomes, errors in DNA replication and any other errors that can occur during replication, thus maintaining the cell cycle. The molecules that have a role in the cell cycle and mitosis such as MPF (maturation promoting factor), cyclines and cell cycle inhibitors have very important functions, and proper maintenance of the cell cycle depends on the interaction between them. On the other hand, interaction between the different growth factors and cyclins during the switch to silent phase, the cell cycle inhibitors (p21 and TGF-beta) during the termination of the cell cycle, and the tumor suppressor genes (p53 and Rb) have major roles in the maintenance of the cell cycle. DNA packaging, chromosome condensation, formation of mitotic spindle and cytokinesis are under control during mitosis. In this review, the steps in mitosis and meiosis, the control points and the functions of major modulator molecules during the cell cycle are broadly reviewed with referral to recent findings

Genetik danışmanlık ve önemi

Genetic diseases occur due to abnormalities consisting in the genomic material of the living beings. It may transmit from one generation to the other but it may also be limited only in the affected individual. Everyone carries a risk for a particular genetic disease but a greater risk is observed in some families. Today, in parallel with the development in genetics, an increasing demand from the public and medical field is present. This situation brings importance of informing individuals, their families and their children of their present or future genetic conditions, a process called genetic counseling. Although there is no treatment for most of the genetic diseases, genetic counseling has an important role in conditions such as family planning, diagnosis of genetic diseases and possible novel treatment protocols. In our country, there are genetic centers based in the university hospitals, state hospitals and private medical centers. The importance of genetics and genetic counseling is gradually being understood by the people who have been referred for genetic counseling, and by the physicians and other health care workers who refer those providers to the genetic centers. They ensure more individuals receive this service as well. In this review, genetic counseling, its status in our country and in the world is presented widely with up-to-date literature.Genetik hastalıklar, canlıların genomik materyallerinde oluşan anormallikler nedeniyle meydana gelen hastalıklardır. Kuşaktan kuşağa aktarılabileceği gibi, sadece ortaya çıktığı bireyle de sınırlı kalabilir. Her insan belli bir genetik hastalık riski taşımakla birlikte bazı ailelerde bu risk daha fazla olarak gözlenmektedir. Günümüzde genetik biliminde sağlanan gelişmelere paralel olarak bu alana talep, hem toplumsal hem de tıp alanında gittikçe artış göstermektedir. Bu durum genetik danışmanlık olarak adlandırılan, bireylerin kendilerinde, ailelerinde, ileride doğacak çocuklarında mevcut veya ortaya çıkabilecek genetik hastalıklar hakkında her türlü bilgi verme işlemini çok önemli hale getirmektedir. Genetik danışmanlık, genetik hastalıkların tanınması ortaya çıkabilecek tedavi yöntemlerinin uygulanması, aile planlaması gibi durumlarda önemli bir yere sahiptir. Ülkemizde üniversite hastaneleri, devlet hastaneleri ve bazı özel merkezler dahilinde genetik tanı merkezleri bulunmaktadır. Genetik danışmanlık hizmeti almak üzere merkezlere başvuran bireyler, bu bireyleri yönlendiren doktorlar ve diğer sağlık hizmeti görevlileri gün geçtikçe genetik ve genetik danışmanlık sürecinin önemini anlamakta ve daha çok kişinin bu hizmeti almasını sağlamaktadırlar. Bu derlemede genetik danışmanlık konusu, ülkemiz ve dünyadaki durumu güncel literatür bilgileri ışığında sunulmaktadır

Evaluation of the SMN and NAIP Genes in a Family: Homozygous Deletion of the SMN2 Gene in the Fetus and Outcome of the Pregnancy

WOS: 000266407800002PubMed ID: 1939740

A case of acute lymphoblastic leukemia with additional chromosomes X and 5 associated with a Philadelphia chromosome in the bone marrow

WOS: 000286303200012PubMed ID: 27263746We report herein a very rare case of acute lymphoblastic leukemia having a chromosomal constitution of 48,XY,+X,+5,t(9;22)(q34;q11) in the bone marrow. A patient with additional chromosomes X and 5 with a Philadelphia chromosome has not been reported previously. However, no abnormal karyotype was obtained from the lymphocytes in our patient, and he did not have the characteristics of Klinefelter syndrome. He achieved a complete remission with IDA-FLAG and dasatinib therapy. The mechanism of trisomy 5 or any other chromosomal aneuploidy in the pathogenesis of leukemogenesis remains unclear. Further studies involving the genes affected by this karyotype and their products may lead to strategies to further increase the understanding of drug-resistant acute lymphoblastic leukemia and may represent the next frontier in the targeted therapy of those patients. (Turk J Hematol 2010; 27: 299-302

Böbrek tümörlü hastalarda VHL gen mutasyonu - Üroonkoloji

Objective: This study aimed to determine VHL gene mutations and the relation of these mutations to type and pathological stage of renal tumors. Materials and methods: Forty patients (20 males, 20 females; mean age 59 years) who underwent ablative surgery for renal tumor prediagnosis between February 2009-November 2009 in of Ege University School of Medicine, Department of Urology were randomly selected. Twenty-nine of the patients underwent radical nephrectomy, 5 underwent partial nephrectomy, and 2 patients underwent laparoscopic radical nephrectomy. Four patients whose pathological outcome was not malign kidney tumor have been excluded from the study. Thirty-eight patients (21 males, 16 females; mean age 61 years) who underwent any surgeries in Department of Urology and showed no malignance suspicion in the same time period were included in control group. VHL gen mutations were analyzed preoperatively. Results: According to 2002 TNM staging, 8 (22%) patients were T1a, 11 (31%) patients were T1b, 3 (8%) patients were T2, 9 (25%) patients were T3a, 3 (8%) patients were T3b, and 2 (6%) patients were T4 stage. Twenty-eight (78%) patients were N0, 5 (14%) patients were N1, and 3 (8%) patients were N2. Five (14%) patients was at M1 stage. Histologically, 18 (50%) patients had clear cell carcinoma, 3 (8.3%) patients had chromofob cell carcinoma, and 3 (8.3%) patients had papillary cell type 1 carcinoma. Genetic analysis showed that 6 individuals had heterozygote change described previously as mutation (Q167Q and V181V linked heterozygote in 2 patients, P61P heterozygote in 2 patients, L129L heterozygote in 1 patient, and P61P heterozygote in 1 patient). None of these changes resulted in the change of aminoacids. Conclusion: VHL gene mutation was not detected in our study population, which may be result of the genetical characteristics of Turkish population or small sample size. The present study would be a pioneer for future studies on tumor tissue and VHL gene polymorphism in Turkish population.Amaç: Bu çalışma ile böbrek tümöründe VHL geninde mutasyonların ve bu mutasyonlar ile tümör tipi ve patolojik evre arasındaki ilişkinin belirlenmesi amaçlanmıştır. Gereç ve yöntem: Şubat 2009-Kasım 2009 tarihleri arasında Ege Üniversitesi Tıp Fakültesi Hastanesi Üroloji Anabilim Dalı’nda böbrek tümörü ön tanısıyla ablatif cerrahi uygulanan 40 hasta (20 erkek, 20 kadın; yaş ortalaması 59) rastgele seçildi. Hastaların 29’una açık radikal nefrektomi, 5’ine açık parsiyel nefrektomi, 2’sine ise laparoskopik radikal nefrektomi yapıldı. Patoloji sonucu malign böbrek tümörü gelmeyen 4 hasta çalışma dışı bırakıldı. Aynı dönemde üroloji kliniğinde opere edilen ve malignite kuşkusu uyandıracak bulgusu olmayan 37 hasta (21 erkek, 16 kadın; yaş ortalaması 61) kontrol grubu olarak belirlendi. Preoperatif dönemde VHL gen mutasyonları incelendi. Bulgular: Tümörlerin 2002 TNM evrelemesi; 8 (%22) hastada T1a, 11 (%31) hastada T1b, 3 (%8) hastada T2, 9 (%25) hastada T3a, 3 (%8) hastada T3b, 2 (%6) hastada ise T4 idi. Hastaların 28’i (%78) N0, 5’i (%14) N1, 3’ü (%8) ise N2 olarak değerlendirilirken, 5 (%14) hasta M1 olarak tespit edildi. Histolojik olarak 18 (%50) hastada şeffaf hücreli karsinom, 3 (%8.3) hastada kromofob hücreli karsinom, 3 (%8.3) hastada papiller tip 1 karsinom saptandı. Genetik olarak 6 hastada daha önce mutasyon olarak tanımlanmamış heterozigot değişiklik (2 hastada Q167Q ve V181V birleşik heterozigotluğu, 2 hastada P61P heterozigotluğu, 1 hastada L129L heterozigotluğu, 1 hastada P61P heterozigotluğu) görüldü. Bu değişikliklerin hiçbirisi aminoasit değişikliğine neden olmadı. Sonuç: Çalışmamızda hiçbir hastada VHL mutasyonu saptanmadı. Bu durum Türklerin genetik yapısındaki farklılığa ya da hasta sayısının az olmasına bağlanabilir. Sunulan çalışma, ilerde yapılacak tümör dokusu ve Türk popülasyonunda VHL gen polimorfizmi çalışmaları için öncü olacaktır