oxidative stress is an imbalance between free oxygen radicals and antioxidants. what are free oxygen radicals? they means free electrons which were bounded in chemical compound befoe.they cause damage on cell membranes, nucleus and other organels membranes. ıt leads to cell apoptosise. some effects triggers for seperating of bounded electrons like heat, toxins or drugs. we can give example of divorced pairs for this issue. in degenerated societies weakness wedlock permits to many factor to seperate with each other. and after marriage the singles with more energy seeking for a new relationship. most of the time ıt results with a releationship with a married person and this releationship leads to e new divorced person. that reveals to chains of divorced pairs. like in this example, free radicalls cause more free radicals. for preventing oxidative stress some substances referred to antioxidants can be used but true agent for true target is very important.

embriyoid body formation is used for embriyo generated in vitro situation. it is grown in vitro and in the stage of blastocyste inner cell mass isolated and it is grown in medium for providing ıts immortal division. after it is providen it is exposed to some growth factors and others respectively for obtaining differantation to which cell we want. there are more signaling factors which triggers a cell for differantiating and they are waiting for to be explored.

degenerated pancreas beta cells.ıs it possible replace them via stem cells.recent studies show that adult stem cells can not replace them but embryonic stem cells or adult beta cells replication is thought can replace.on the other hand dediferantation of cells for example pancreatic exocrine cells to pancreatic beta cells.ıt must be known which signaling mechamisms effects them to dedifferantie.ıt is releated with molecular biology.after dediferantation what must be done ı am interest with it deeper.maybe duplication of beta cells can be triggered in vivo but how it will be done.

what are the the caharacteristic figures of neuron? answer:the eurochromatine,spherical nucleus and the distinctive nucleolus.some times there are two nucleolus.the barr apparatus can be seen.we can't see centriole near the nucleus because the neurons do not divide. we see the centrioles at the periphere of perikaryon near the cilia.the function of cilia is not known excatly. it is known that it gets lost by the time except the neurons' have modified ciliaes rod and coni cells in the retina.the neurons have numerous mitochondrias which have spherical or flat shapes and their cristas are vertical or longitudinal.the nissl apparatus are characteristic figure of these cells and ıt is supposed that they protect neurones after travma or damaging events.ıt was seen when neurons were damaged the nissl aparatus dissolved and scattered everywhere of the some.the dendrites have the nissl apparatus,too but axons do not have for this reason it is an advantage for histologists to distinct axons from dentrites.all the neurons have only one axon but the number of dendrites can be changed.the microtubules and microfilamentes are very important for conducting organals,vesicles and metabolites.the protoplasma is syntesized in the soma and conducts to dentrites and axon.it is seen in the soma there are developet granular endoplasmic reticulum and golgi apparatus.the nissl apparatus are thought that they are consist of some granular endoplazmic retuculm cisternaes,free ribosomes and poliribosomes.these all the features of organels say that neurons are very productive cells.they syntesize protein and they are anabolic cells.

brain and oxidative stress

Hystopatalogical alterations in brain causes oxidativa stres.Mental distress is an important result of oxidative stress and you know bipolar disorders is one of the mental disorders.recently studies indicated that lithium which treats bipolar disorders decrease oxidative stress in the brain.but this positive effects of lithium can't be seen in other organs.why?what is the mechanism for lithium which working in brain positive contrary to the other organs?

discussing liver and blood testis barrier:we know some cells have duplicated nucleus like liver or muscle cells.but some of us know the liver cells nucleus have 4n,8n.12n e.g chromosomes.we think their nucleus have 2n chromosomes(46) but that is not.you know sperm has n(23) chromosomes and that is advocated that blood testis barrier is protecting sperms from immun system cells.ıf ıt is like that wyh there isn't a system protecting hepatocytes from immun system cells and when we research we see there are fenestreated capilleries not continous capilleries between hepatic cords.the hepatocytes are close to blood for this reason ı think the purpose of blood testis barrier must be for differen cause.

ı haven't written for a long time because ı was on holiday.ı want to give information about pancreas b cells and stem cells.(you know ı am interest in stem cell and ı want my workings to be releated with it.) diabettus mellitus type 1 is widespread dissease in the world.it is an outcome of degenerating b cells in pancreas with auto immun attack.there are many methods applied for treating.one of them is langerhans islets transplantation from cadavra's donor but it has not conclusive solution.ıt provides solution for a period longer than three years indepence of insulin.at the present time the stem cell treatment is promising.there are three ways.one of them is using embryonic stem cell or human stem cell for obtaining insulin secreting cells,the other is reprogramming somatic cells to convert b cells and the other is replication of b cells in vivo or in vitro conditions.