Diabetes and Oxytocin // Katrina Dombovári // S6EN

In the last two weeks, we have been learning about type one and type two diabetes, and a bit about oxytocin. 

Starting off with diabetes, type one diabetes is the worst form of diabetes. Type one diabetes effects mainly younger people. When someone has type one diabetes it means that the beta cells are destroyed and the levels of glucose in the person’s blood is too high. Someone with type one diabetes needs to have insulin injected in them every so often (around twice a day), to insure that the glucose levels don’t get too high. Someone with type one diabetes also needs to watch their diet closely. 

The other form of diabetes is type two (diabetes). Type two diabetes mainly affects overweight and older people. Someone with type two diabetes has an impaired insulin secretion, insulin resistance and their level of glucose in the blood is too high. What that means is that the body (pancreas) of someone with type two diabetes can make insulin properly (unlike someone with type one diabetes), however either that person’s pancreas doesn’t make enough insulin to keep the glucose level stable, or the body can’t use the insulin well enough. Just like people with type one diabetes, people with type two also need to monitor their diet closely. 

For a long while, there wasn’t any form of treatment for type one diabetes. However around the 20th century, a Canadian scientist, by the name of Frederick Banting, decided that he would remove the pancreas of a dog, since that’s where diabetes is effected, and see what happens. To do this he needed financial support, which he got, by a Canadian biochemist, McCloud. Banting was also assisted by Best, a scientist.

After they extracted the pancreas from the dog, the blood sugar of the dog rose, the dog became more thirsty, it drank a lot of water, urinated more often, and all in all, the dog became much more weaker. In conclusion, they found out that the dog had developed diabetes. The scientists managed to save the dog though! To save the dog, the scientists injected a healthy version of the extracted pancreas (also known as insulin). This causes the previous effects on the dog to be reversed, meaning it became stronger, the blood sugar stayed level and it wasn’t as thirsty as it was before. To keep the dog healthy, and to insure that the previous effects wouldn’t return, they needed to continue to inject the dog with insulin everyday. 

Banting and McCloud then won the noble prize to figuring out a treatment for type one diabetes. 

In class we had to do a article about the history of diabetes. This is my article:

History of Diabetes

Diabetes mellitus was found around the Egyptian time. For a long period of time it was known as a disease of the kidneys from around the 19^th century. It was recognized by it's excessive amount of urine output. Observations were made by Areteus of Cappadocia, which show that it effects the kidneys. Someone took their urine and tasted it, which helped them tell if they had type one diabetes or not. This person who tested their urine in 1674, recognized that the urine had a sweet taste to it, which is how diabetes mellitus got it's name (diabetes meaning 'to run through'; mellitus meaning 'sweet like honey'). The sweet taste of the urine was caused because of the high glucose levels in the blood. 

For a long period of time no one was able to find a treatment. In 1869 a German medical student, Paul Langerhans, found out that in the tissues of the pancreas produces digestive juices in a cell with an unknown function. These cells were found to be the beta cells, which produce insulin. 

In 1923, Banting, a Canadian scientist, decide to try to extract the pancreas of a dog to see what would happen to that dog- would this dog get diabetes or not? Banting was supported by another Canadian biochemist, McCloud, and was assisted by a scientist by the last name of Best.

What they did was extract the pancreas of a dog. The removal of the pancreas caused it's blood sugar to rise and caused the dog to become weaker and weaker. Due to the removal of the pancreas, the dog got diabetes. They continued to try this on other dogs, and the same thing happened. What they then did was sliced up the pancreas into pieces and froze all the pieces in water and salt. After the pieces were half frozen, they were filtered, which then produced 'isletin'. The extract was injected back into a diabetic dog, and they observed that the blood glucose levels dropped and the dog became healthier once again. They gave the diabetic dog injections everyday to keep its blood glucose level stable, and the dog remained healthy and happy. 

In 1922, a 14 year old Canadian boy by the name of Leonard Thompson, was the first human being tested on with the insulin. Luckily, the test was very successful.

Due to the success of finding out how to treat type one diabetes, Banting and McCloud were rewarded a noble prize in Medicine and Physiology in 1923. 

After learning about diabetes, we began to talk a bit about oxytocin. Oxytocin is a hormone, that is made in the brain, in the hypothalamus and it gets transported to the pituitary gland. The release of oxytocin acts to regulate two female reproductive functions: childbirth and breast-feeding. Oxytocin is an important hormone for milk ejection. Its release is stimulated by seeing or hearing a stimulus, for example, the most intense release is triggered by the baby suckling on the mother’s breast. The first release is within a minute of suckling and continuously releases in spurts. It peaks and levels off about every six to ten minutes after nipple stimulation has stopped.

Sources of images:

 http://www.mchip.net/sites/default/files/mchipfiles/Oxytocin%20reflex.JPG

http://projects.cbe.ab.ca/Diefenbaker/Biology/Bio%20Website%20Final/notes/reproductive/Image72.gif

- Katrina Dombovári 

Wirkung von Alkohol auf unser Nervensystem / Anna Biermann S6DE

Wirkung von Alkohol auf unser Nervensystem

Der Konsum von Alkohol hat Einfluss auf unser Verhalten: schon nach kleinen Mengen fühlen wir uns selbstbewusster, haben verstärkten Tatendrang, reden mehr, bekommen Glücksgefühle. Je mehr Alkohol man zu sich nimmt desto stärker sind allerdings die Auswirkungen: Gleichgewichtsstörung, Verlangsamung der Reaktionsfähigkeit, Probleme beim Sprechen bis hin zur Bewusstlosigkeit.

Das heißt also, dass die Reizübertragung durch das zentrale Nervensystem unter dem Einfluss von Alkohol nicht mehr gut funktioniert.

WIESO?

Alkohol gelangt über die Blutbahn in den gesamten Körper und ist in ca. 2 Minuten auf diesem Weg im Gehirn. In kleineren Mengen wirken alkoholische Getränke anregend, in größeren Mengen dagegen berauschend. Die dafür verantwortliche Substanz im Alkohol heißt Ethanol (C₂H₆O). Alkohol löst eine biochemische Kettenreaktion in unserem Körper aus.

Der Alkohol verteilt sich im ganzen Körper und beeinflusst alle Transmittersysteme im Nervensystem.

Neurotransmitter sind nichts anderes als Botenstoffe, die an den Synapsen Informationen zwischen den Nervenzellen übertragen.

https://www.youtube.com/watch?v=BEglM5JehY4

Glutamat, Gaba, Serotonin, Dopamin, Acetylcholin sind solche Neurotransmitter.   

Wenn nun Alkoholmoleküle sich an die Rezeptoren der Nervenzellen binden, verändern sie die Informationsübertragung zwischen den Nervenzellen. Das heißt, die Funktionsweise der Neurotransmitter wird gestört. 

Wenn wir uns schon nach einem Glas Wein enthemmter, lustiger, zufriedener fühlen, dann sind dafür die Neurotransmitter Serotonin und Dopamin verantwortlich, die sogenannten Glückshormone. Serotonin gilt als zentraler Stimmungsmacher und beeinflusst unter anderem Appetit, Sexualtrieb und das psychische Wohlbefinden. 

Dopamin ist für Aufmerksamkeit, Wohlbefinden, Lernfähigkeit und motorische Aktivitäten zuständig. Die von den Alkoholmolekülen angegriffenen Nervenzellen schütten nun vermehrt Serotonin und Dopamin aus, die vom Belohnungszentrum im Gehirn über spezielle Rezeptoren aufgenommen wird.

Die Transmittersysteme, Gaba und Glutamat sorgen für das Gleichgewicht der Gehirnaktivität. Glutamat ist für die Gehirnaktivität zuständig, für die Übermittlung von Sinneswahrnehmungen, Bewegungssteuerung sowie für das Lernen und das Gedächtnis. Im Gehirn ist Glutamat der häufigste erregende Neurotransmitter. Gaba ist der Transmitter für die Dämpfung der Gehirnaktivität und somit gewissermaßen der Gegenspieler von Glutamat. Gaba ist der wichtigste hemmende Neurotransmitter im Gehirn, also  der wichtigste hemmende Botenstoff von Nerv zu Nerv.

Der Alkohol bringt das Gleichgewicht von Gaba und Glutamate durcheinander. Alkohol hat eine dämpfende Wirkung auf das Gehirn. Der aktivierende Botenstoff Glutamat wird gedämpft und die hemmende Wirkung von Gaba durch den Alkohol verstärkt.

So erklären sich also die oben genannten Symptome wie Gleichgewichtsstörung, Verlangsamung der Reaktionsfähigkeit, Probleme beim Sprechen bis hin zur Bewusstlosigkeit in Folge von Alkoholkonsum.

Alkohol ist ein gefährliches Nervengift und kann süchtig machen.

Quellen:

http://www.wdr.de/tv/applications/fernsehen/wissen/quarks/pdf/Q_Alkohol.pdf

http://www.a-connect.de/namalk.php

http://www.suchtschweiz.ch/fileadmin/user_upload/DocUpload/alkohol_koerper.pdf

http://dasgehirn.info/entdecken/kommunikation-der-zellen/neurotransmitter-2013-botenmolekuele-im-gehirn-5880/

http://www.doping-prevention.sp.tum.de/de/human-body/psychological-effects-and-addicition/psychological-effects-and-addicition/alcohol.html

http://www.netdoktor.at/laborwerte/neurotransmitter-8379

Vaskuläre Demenz

VASKULÄRE DEMENZ

Heute möchte ich euch eine andere Form der Demenzerkrankung vorstellen. Die vaskuläre Demenz ist nach Alzheimer die verbreitetste Demenzkrankheit.

Was ist die VASKULÄRE DEMENZ?

Die vaskuläre Demenz zählt zu den Demenzkrankheiten. Oft kann es passieren, dass sie mit Alzheimer verwechselt wird. Dem ist aber nicht so, da diese Form der Demenz eine ganz andere Ursache hat. Man bezeichnet sie eben als vaskulär (vaskuläre=Blut/Blutgefäße), da sie sich aufgrund von Durchblutungsstörungen im Gehirn entwickelt. Die große Eigenart an dieser Krankheit sind ihre unterschiedlichen Symptome die nicht vorhersehbar sind. Wie Alzheimer auch ist die vaskuläre Demenz nicht heilbar.

                                                                      Ursachen:

Die Ursachen einer vaskulären Demenz sind auf Durchblutungsstörungen zurückzuführen. Sie lösen im Gehirn eine Kettenreaktion aus. Eine verengte Arterie wird durch eine kleine Kruste verstopft. Dadurch steigt der Druck in der Arterie und sie platzt. Jetzt werden manche Teile des Gehirns nicht mehr mit Sauerstoff versorgt und sie fangen langsam an abzusterben. Man nennt das auch einen Schlaganfall. Da unser ganzes Gehirn mit Arterien verbunden ist, ist es reiner Zufall welche Hirnregionen betroffen werden, denn entsprechend sind die Symptome jedes Mal etwas anders. Die Stärke der Erkrankung ist davon abhängig ob es ein großer oder mehrere kleine Hirnschläge waren. Gefährlicher sind oft viele kleine, da hier besonders viele Regionen betroffen sind.

Symptome:

Die meisten Patienten wirken verwirrt, weil es ihnen immer schwerer fällt aufmerksam zuzuhören, sich zu orientieren und zusammenhängend zu reden. Diese Symptome treten meist früher und heftiger auf als bei Alzheimer. Dennoch behält der Betroffene oft meist noch sehr viel länger sein Gedächtnis. Andere Symptome können Persönlichkeitsveränderungen, nachlassendes Urteilvermögen und Probleme beim Alltag sein z.B weiß man nicht mehr wie der Fernseher angehet usw…

Therapie:

Wie Alzheimer ist auch diese Krankheit nicht heilbar. In der Regel gilt, ist das Gehirn einmal geschädigt ist es nicht mehr rückgängig zu machen. Es ist aber trotzdem wichtig die Krankheit frühzeitig zuerkennen um dem Patienten ein besseres Wohlbefinden für die Zukunft zu ermöglichen und um den Verlauf der Krankheit zu verlangsamen. Man kann dieser Demenz Erkrankung aber vorbeugen in dem man sich gesund ernährt und viel Sport macht.   

   

QUELLEN:

- http://www.deutsche-alzheimer.de/die-krankheit/andere-demenzformen/vaskulaere-demenz.html

-http://www.alzheimer.de/alzheimer/alzheimer/weiteredemenzformen/vaskulaeredemenz.html

- http://www.wegweiser-demenz.de/vaskulaere-demenz.html

- http://www.apotheken-umschau.de/Gehirn/Vaskulaere-Demenz-Vorbeugung--101481_8.html

Diseases of the Nervous System - Stefanie Matei S6EN

In week 41 in biology 2p we started learning about hormones.

The course started off with a song by Frank Sinatra, which, by looking at the lyrics, we decided was about a certain hormone called oxytocin.

So what is oxytocin? Oxytocin is one of the most interesting hormones, which is centered in the brain. It deals with maternal instincts, love impulses, orgasms, but also anxiety and social recognition. When there is a lack of oxytocin, the individual may go through stages of depression, but if oxytocin is in abundance, then the individual is considered to have a higher and sharper sense of instinct -- some would go as far as saying it can give them unnatural attributes. 

Now that we learned what oxytocin is, we can go ahead and start with the basics of hormones. 

What is a hormone? A hormone is a messenger molecule that is transported by the circulatory system to get to organs in order to regulate the person's behaviour. Hormones work slowly, traveling through your bloodstream. They affect many processes such as metabolism, sexual function, mood, growth and physical development, which is why during your teenage years hormones are most at work.

The endocrine system is made of glands and organs, and is where hormones are produced, stored and released. The glands are stimulated by the nervous system. 

Hormones can come from three different origins: peptide, amine or steroid. 

A steroid hormone is derived from cholesterol and deals with a lot of aspects, though mainly it regulates your metabolism and controls your sexual characteristics. Examples of steroid hormones are 

An amine hormone mostly deals with digestion, and is mostly found in the intestinal or pancreas tissues.

A peptide hormone is made of protein. An example of a peptide hormone is actually one we saw earlier, which is oxytocin.

In week 42 each student of the course presented a disease of their choice that affected the brain or the nervous system. Here is the list:

Alzheimer's Disease

Alzheimer's is the most common version of dementia and usually comes with old age, patients diagnosed with it almost always being over 65 (though there are rare cases for younger patients). Alzheimer's is a disease that causes memory dissipation, starting out in stages of short term memory loss, then progresses into long term.

It was discovered in 1906 by Alois Alzheimer, a psychiatrist who first noticed it on one of his patients called Auguste D who had been suffering of it since 1901. It was made an official disease by Emile Kraepelin later on after more patients were discovered to have the same symptoms as Auguste D.

Usually, AD patients have a loss of function in the temporal lobe, the part of the brain that deals with memory. Here is a photo of how the brain deteriorates itself, to the left being a healthy brain, and to the right a case of alzheimer's:

(http://www.neurology.org/content/71/24/1986/F1.large.jpg)

There has so far been no discovered cure.

Mad Cow Disease

Bovine Spongiform Encephalopathy, otherwise known as mad cow disease is a neurodegenerative disease that can be caught by eating cow meat. It was named Mad cow disease because when cows got infected with it, their behavior changed, and they went crazy -- or mad. The human version is called Creutzfeldt-Jakob disease, and it affects the humans brain.

This disease is not contagious, and can only be caught if the person eats cow meat that contains contaminated central nerve tissues. The disease can't be transmitted from human to human, only by eating contaminated meat.

The disease is fatal. Once a patient is infected with it, their lifespan shrinks to more or less 13 months. 

There was a big Mad cow outbreak in the UK back in 2009, when 177 were killed by it. Since then, the US developed a law that stated that all brain and spinal cattle and cow meat is forbidden from being sold.

Epilepsy

Epilepsy is a general disorder, most common between teenagers and elders. 

Epilepsy happens when the brain recieves too many light and color signals that flash too fast, then becomes confused and triggers seizures. 

Here is an example of something that would induce epilepsy (open at your own risk):

 http://media.tumblr.com/tumblr_ma3s80ynoJ1qg7p8h.gif

So far, there has been no cure for epilepsy, only drugs that make the seizures stop but cannot prevent new ones from happening in the future.

Congenital indifference to pain

Congenital indifference to pain is a rare disorder that consists of the individual being able to feel touch or temperature, but not any physical pain.

How this happens: when a normal person gets hurt, the pain receptors (nociceptors) transmit a message through the nervous system (peripheral nerve) to the brain in order to tell that you're hurt. Here is a photo oh how it works:

(https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhenutu7O53gYDf6d1qdbjqhZv7hLbhdiBlvef4BJ11-vHa6slKgciRmYtVgK7wYqZUYNCFK5Ql4wZd-hs3Fw__fiOpp_fRxusaaFTbnIeHhcAT487luUlOgL99mdwR3nist7YpvW0f7D8/s400/nociceptor.jpg)

For patients suffering from congenital indifference, the problem isn't that the brain doesn't recognize the pain, it's that the nerve tissues are either weakened or non existent, meaning that in the brain never gets any pain message since there's nobody sending them. 

Congenital indifference to pain is not something contagious, it is actually very rare, and can only be transmitted if both parents have a copy of the specific chromosome, making it a genetic disease.

Broca's aphasia

Broca's aphasia, otherwise known as expression aphasia, is a disorder that is characterized by the loss of being able to talk.

The most common cause of this disorder is a stroke, which is caused by a lack of brain oxygenation. The part of the brain usually affected and damaged is the bronca, hence the name of this aphasia. 

Brian's aphasia cannot be fully cured, but can become better with speech therapy and other expressive activities depending on how severe the case is.

Here is a video of how patients with Broca's aphasia speak:

https://www.youtube.com/watch?v=f2IiMEbMnPM