Dear Colleagues
Hello
I wish you all happy new year. I wish to say you that we are reaching 5000 gynecologist every month. You can very well use this newsletter for your opinions and adverts. I welcome you.
This news letter I make it more towards the basics of oocyte maturation. This topic comes in mind because , when we stimulate the female partner for IVF, we make more eggs and when there are more eggs ,there are ample chance to get eggs at different stages of maturity.
During IVF we do down regulation of the ovaries and then stimulate the ovary to get the cohort of follicles in the same stage of maturity. But sometimes the oocytes we get are not in the same stage. We try to judge them by corona cumulus complex ( CCC ) morphology .But when they are denuded ( for ICSI ) we see that few of the Oocytes did not release there first polar body ,but their CCC were mature. It is a case of mismatch between cellular and nuclear maturity, and more common with hyper-stimulation.
We are at a fix ,we can not do ICSI because they have not released the first polar body ,and conventional IVF is usually poor with denuded Oocytes. We have no other chance to wait for first polar body release. Gene therapy is an upcoming technique to treat genetic disorders .RNA interference is one of the promising one.
I wish you all the best
Dr.D’Pankar Banerji
Maturation of Mammalian Oocytes
Mammalian Oocytes are unique in nature. In humans they are maximum in female ovaries when the girl is in her mother’s womb at around 20 weeks of gestation. From that age she starts loosing her eggs (Menopause starts in females when she is in-utero!!!!).
Germ cells are diploid (46 chromosomes). Reduction of the chromosome to its half is required for formation of gamete (oocyte/eggs). The reduction division (meiosis) has two stages,Meiosis I and II .First is actual reduction of chromosome number to its half along with reshuffling of genetic contents between the corresponding pairs.
Human germ cells are fixed in first meiotic division stage and chromosomes are entangled at reshuffling (intact nuclear membrane is present and nucleus is called Germinal vesicle,Prophase I ),till it is released during ovulation. At ovulation first stage completes, first by breaking down of Germinal Vesicle (Metaphase I) and then release of first polar body (Metaphase II).
At the time of entry of sperm the second stage completes ( second polar body is released ). During conventional IVF we retrieve the eggs after an artificial LH surge by hCG injection. It is very important to know whether the first polar body is released or not ( nuclear maturity ) to decide the time interval between retrieval and insemination. Entry of the sperm after the first polar body is released, makes a so-called zygote of 46 chromosomes. (Entry of sperms before this may create triploidy, 3 PN ) Eggs are covered by corona cumulus cells at the time of retrieval, then it is very difficult to see the polar body by microscope. Hence, to a great extent ,nuclear maturity is assessed by morphology of corona cumulus cells (ovarian hyper-stimulation with gonadotrophins may disturb this relationship !!!! )
A tightly packed cumulus and corona radiata is classified as very immature ( Prophase –I ).When corona radiata is compacted but still distinct from the cumulus it is usually associated with Metaphase I. A sunburst like corona and a well expanded cumulus ( more than twice the diameter of oocyte ) is usually associated with mature oocyte ( Metaphase II ),here the corona cumulus may be stringy and propensity to attach to culture dish
2.RNA Interference ( RNAi) : Gene silencing technique
It is a novel way of gene therapy We know that, good genes ( called wild ) make good proteins (functional ones, and they help us). Bad genes ( called mutants ) make bad proteins and they may destroy us if they overpower the good ones. Genes are like masters in there den (nucleus ),they do not come out.
They have their own dedicated messengers. Messengers take the information from the masters and they come out from the den and goes in to the jungle (cytoplasm ), to get the work done, by local workers. Messengers are mRNA and the local workers are t RNA .If information is correct the output ( protein ) will be good. If information is incorrect then proteins will be damaging.
Creation of a messenger from the master gene is called Transcription and when this goes to cytoplasm and make proteins, process is called Translation If we can destroy the messenger from a mutant master then we can prevent the bad work done in cytoplasm hence we can prevent the bad protein formation and can limit a genetic disease to a great extent.
Messenger RNA is middle man in this transaction. Iatrogenic interference in the functioning of mRNA is called RNA interference (RNAi) Scientists can tailor make the pieces of mRNA which are complementary to specific strands of mRNA. This small pieces are called short interference RNA (siRNA). When these small pieces of RNA match with the cell’s own mRNA they cut the mRNA into small fragments. The cell recognize these fragments as wastes and degrades them, and proteins never form.
Training in IVF and Embryology
Module I : Ovulation induction and Intra Uterine Insemination ( One day ),Rs.2000
Module II : Conventional IVF and fundamentals of Embryology( Two days ), Rs.20,000
Module III : Intra cytoplasmic sperm injection, Micromanipulation ( Two days ) Rs.50,000
For details contact ,two participants per batch
Dates :
Throughout the year
Drafts should be in favor of Dr.D’Pankar Banerji, payable at Jabalpur.
Stay can be arranged in nearby hotels at an extra cost Rs.250-1000 per day
Lunch will be served during the training session.
Faculty :
Dr.D’Pankar Banerji ,Consulting Gynecologist and Infertility specialist
Dr.Mrs.Rinku Banerji,Embryologist
Certificate will be issued after the course to participants
Sale and purchase of the used equipments
* Ultrasonography machine for schimadzu SDU 350- convex & vaginal probe 2000 make. with probe converter contact +91-9998968631." Dr.kalpana khandheria
Letters to the editor:
I welcome your views and comments in this column and will be published in the forthcoming publications
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