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انجمن علوم آزمایشگاهیان

انجمن علوم آزمایشگاهیان

از همه بچه های آزمایشگاه دعوت میکنم که عضو شن

با سلام

از تمام دوستان آزمایشگاهی دعوت میشه جهت بالارفتن سطح علمی وارتقاء وضعیت آزمایشگاهای کشور با هم تبادل نظر داشته باشیم.

 دوستان عزیزی که مایل به  عضویت در این وبلاگ هستن توی همین پست نظر خصوصی بذارن و آدرس وبلاگ یا ایمیلشونو بدن تا نام کاربری و کد ورود رو واسشون بذارم.

باتشکر:مدیر وبلاگ

+ نوشته شده در  جمعه بیست و دوم مرداد 1389ساعت 19:27  توسط مدیر  | 

مشکلات آزمایشگاه

دوستان عزیز :

شما می تونید در مور مسائل  و مشکلات آزمایشگاه هایی رو که تا حالا توشون  کار کردید رو اینجا بنویسید تا همگی دنبال راهکارهایی برای بر طرف کردن این مشکلات باشیم و همچنین  اهمیت ایجاد نظام آزمایشگاهی برای همگی ما روشن تر بشه....

-دوستان خوبی که عضو شدید خواهش میکنم فعالیتتونو شروع کنید و این وبلاگو به همه ی علوم ازمایشگاهیا معرفی کنید و اونا رو به وبلاگ دعوت کنید 

با تشکر : مدیر

+ نوشته شده در  جمعه یکم مرداد 1389ساعت 6:3  توسط مدیر  | 

اطلاعیه

با سلام خدمت همه دوستان عزیز
وضعیت رشته علوم آزمایشگاهی در فضای مجازی کشور اصلاً‌ در جایگاه خوبی نیست . یعنی هیچ فضایی برای تبادل علمی موجود نیست ، اکثراً دانشجویانی که در این رشته فعالیت دارند اقدام به ایجاد وبلاگ های شخصی می کنند ، البته این کارها در مجموع این نتیجه رو می رساند که همگی خواهان ایجاد محیطی کامل و تخصصی برای این رشته هستند . به همین دلایلی که گفته شد در ماه اخیر طرحی برای ایجاد یک انجمن تخصصی رشته علوم آزمایشگاهی بیان شد ، که به لطف خدا این برنامه کامل شد و لینک انجمن وارد فضای مجازی کشور شد ، اما این انجمن به دلیل اینکه اولین انجمنی خواهد بود که در کشور به صورت کاملاً تخصصی فعالیت می کند ما نیاز به همکاری همه ی عزیزان جامعه ی مجازی علوم آزمایشگاهی داریم که همه ی عزیزان تمامی وبلاگ ها و مطالب خودشان را در این مکان متمرکز کنند .
لازم به ذکر است که اگر شما دوستان همکاری کنید این انجمن تغییرات کاربردی بسیاری خواهد کرد ، از جمله گرافیک ، هاست و دامنه و ..........................
تیم ما این امیدواری را دارد که همه ی شما دوستان که در این رشته فعالیت دارید اهمیت این موضوع را درک کرده و همه با هم در کامل کردن این مجموعه همکاری کنیم . این مجموعه برای کامل شدن نیاز به زمان و همکاری شما دارد .
آدرس : http://medicalglab.mihanbb.com/index.php
ما را از طریق ایمیل : R_m_genetic@live.com
مطلع و نظرات خود را بیان کنید .
با تشکر /

+ نوشته شده در  چهارشنبه شانزدهم تیر 1389ساعت 11:7  توسط reza mohammadizadeh  | 

انتقاد 2

با سلام .

نمی دونم اعضای این انجمن دارن چی کار می کنن .حتی از مدیریت هم چیزی نمی بینم .  هر چی نگاه می کنم می بینم دیگه انجمنی وجود نداره .  به هر حال تو این مدت به شخصه سعی کرد جدید ترین مقالات رو برای علاقمندان بزارم . ولی متاسفانه از نظرات (!!!!!) علاقه مندی هم نمی بینم .

این آخرین مطلبی هست که تو این به اصطلاح انجمن می زارم / به هر حال برای تمامی فعالان در عرصه علوم آزمایشگاهی و ژنتیک پزشکی آرزوی موفقیت می کنم . 

بدرود  .

+ نوشته شده در  سه شنبه چهارم اسفند 1388ساعت 11:56  توسط reza mohammadizadeh  | 

The liver - Part 1

The liver is the largest organ in the body. It is found high in the right upper abdomen, behind the ribs. It is a very complex organ and has many functions. They include:

Ø Storing energy in the form of sugar (glucose)

Ø Storing vitamins, iron, and other minerals

Ø Making proteins, including blood clotting factors, to keep the body healthy and help it grow

Ø Processing worn out red blood cells

Ø Making bile which is needed for food digestion

Ø Metabolizing or breaking down many medications and alcohol

Ø Killing germs that enter the body through the intestine

The liver shoulders a heavy work load for the body, and almost never complains. It even has a remarkable power to regenerate itself. Still, it should not be taken for granted. The liver is subject to illnesses that can lead to permanent damage. One example is autoimmune hepatitis, a condition in which the body fights against its own liver.

+ نوشته شده در  یکشنبه دوم اسفند 1388ساعت 0:13  توسط reza mohammadizadeh  | 

Who Discovered DNA

Who discovered DNA? Read on to find out the history of DNA discovery...

DNA was first isolated, analyzed and recognized as a unique macromolecule by Friedrich Miescher in 1869. Friedrich Mischer, who was an eminent physiological chemist from Switzerland, isolated this substance from the pus of discarded surgical bandages. Friedrich called it nuclein, since it was located in the nucleus of the cells. In 1919, Phoebus Levene identified the base, sugar and phosphate nucleotide unit in the structure. Further, in 1937, William Astbury produced the first X-ray diffraction patterns that proved that DNA had a regular structure.

In 1928, Frederick Griffith performed experiments to prove that DNA carried genetic information. Thereafter, Oswald Avery along with his co-workers identified DNA as the transforming principle in the year 1943. The role of DNA in heredity was confirmed in 1952, when Alfred Hershey and Martha Chase showed that DNA is the genetic material of the T2 phage. Finally in 1953, James D. Watson and Francis Crick suggested the first accurate model of DNA structure. It was the Meselson-Stahl experiment in1958, which led to the final confirmation of the replication mechanism that was implied by the double-helical structure.

The discovery of DNA was one of the major steps in the field of genetics. In case you don't know what DNA stands for, DNA stands for Deoxyribonucleic acid. DNA is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses as well. The main function of these DNA molecules is long-term storage of information. In addition to this, if you are looking for more related topics, you can also read about DNA fingerprinting, DNA research, DNA testing and other related issues like human cloning.


By Uttara Manohar
Published: 10/15/2008
+ نوشته شده در  جمعه دوم بهمن 1388ساعت 21:50  توسط reza mohammadizadeh  | 

FXIII Deficiency

Synonyms : Fibrin stabilizing factor deficiency.

Epidemiology : Very rare disorder, true incidence unknown since heterozygous carriers and patients with mild deficiency usually go undetected.


Pathogenesis : Factor XIII consists of two nonidentical-polypeptide subunits, the "a" chain and the "b" chain, that form a tetrameric molecule comprised of two a chains and two b chains (320,000 daltons). Activation of the factor XIII molecule by thrombin and calcium results in exposure of an active cysteine residue on the a chains, followed by dissociation of the b chain dimer. The activated form of factor XIII catalyzes the formation of covalent bonds between the gamma chains and alpha chains of fibrin, resulting in greatly increased mechanical stability and enhanced resistance of the fibrin clot to dissolution, fibrinolytic digestion by plasmin and non-specific proteolysis. Some of the inhibitors of fibrinolysis, such as alpha-2-plasmin inhibitor, are also stabilized by factor XIII. Only homozygous-recessive patients with severe deficiencies have clinical symptomatology, since plasma factor XIII levels of 1% to 2% or more are adequate for fibrin stabilization. Homozygous-recessive patients lack the a chains and have normal, reduced, or absent b chain antigenicity normally present in plasma. A specificfactor XIII mutation , Val34Leu, is present in many patients with symptomatic factor XIII deficiency. Patients with dysfunctional factor XIIImolecules have not been described.

Pattern of Inheritance : Usually inherited as an autosomal recessive trait, but rare families have been described in which only males are affected.

Clinical Presentation : Patients with homozygous recessive factor XIII deficiency are detected during the neonatal period due to umbilical cord bleeding. These patients also have an increased prevalence of primary intracranial hemorrhage, which is frequently fatal. Ecchymoses, hematomas, hemarthroses, and prolonged bleeding after superficial wounds, dental extractions orsurgery. Poor wound healing with excessive scar formation is seen in some patients but is not a consistent feature of the disease. In contrast, epistaxis, gingival bleeding, hematuria, and menorrhagia are not commonly seen. Spontaneous bleeding is not found in patients with a factor XIII level >3%. Clinical symptomatology is absent from individuals with heterozygous FXIII deficiency. Acquired decreases in factor XIII activity is seen in a few diseases, including the acute stages of Henoch Schonlein purpura (HSP) and the active stages of ulcerative colitis and Crohn’s disease. Inhibitors against factor XIII have rarely been described.

Laboratory Features : The platelet count, bleeding time, prothrombin time, aPTT, thrombin time, and whole blood clotting time are within normal limits. The diagnosis is usually based on the clot stability test, although specific immunoassays for factor XIII exist.
The clot stability test is based on the principle that the unstabilized clots in factor XIII patients are rapidly dissolved in 5 M urea or 1% monochloroacetic acid, while factor XIII-stabilized clots will be resistant to dissolution under these circumstances.
Since a factor XIII level of 1% will produce clot stabilization and a normal clot stability test, heterozygotes and patients with mild deficiency must be detected by quantitative (immunologic) assays. Dysfibrinogenernia, lead poisoning, mercury poisoning, and hyperfibrinolysis can prevent clot stabilization and must be excluded in patients with an abnormal clot stabilization assay.

Treatment : Factor XIII deficiency is treated with cryoprecipitate or fresh frozen plasma (FFP). Due to the low concentrations of factor XIII required for hemostasis, and the long half-life of factor XIII, prophylactic infusions are required at long (4-5 week) intervals.

+ نوشته شده در  پنجشنبه بیست و چهارم دی 1388ساعت 13:42  توسط reza mohammadizadeh  | 

Neurofibromatosis: Causes, Symptoms and Treatment

Neurofibromatosis causes tumor to grow on nerves and gives rise to many other abnormalities like skin changes and bone deformities. The tumor begins in the cells that make up the myelin sheath, which is a thin membrane that envelops and protects nerve fibers. The type of the tumor depends on its position in the body and the kind of cells involved. Neurofibromas is one of the most common tumor that develops in the tissue surrounding the peripheral nerves. The tumor is non-cancerous, but can become cancerous over time. This genetic disorder occurs in both sexes and in all races and ethnic groups.

Neurofibromatosis first appears in childhood, especially during puberty. The first observable sign is the presence of brown cafe-au-lait spots. These spots don't hurt or itch and can be found anywhere on the body, especially under the arms and groin areas. Scientists have categorized this disorder into two types: neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2).

Causes of Neurofibromatosis

Neurofibromatosis is an autosomal dominant genetic disorder, that is, an affected person has 50% chance of passing it on with each pregnancy. It can be the result of a mutation in the genetic material of the sperm or egg at conception in families having no previous history of neurofibromatosis. Nearly 50% of the cases are inherited and rest are due to spontaneous genetic mutation. NF1 and NF2 are linked to mutations in separate genes. The NF1 gene has been traced to chromosome 17 and the NF2 gene is located on chromosome 22. These findings are important, as it may help during a blood test or other genetic tests to know if a relative has NF.

Neurofibromatosis Type 1 (NF1)

NF1 is the most common type of the neurofibromatosis that occurs normally during adolescence. Earlier, NF1 was known as peripheral neurofibromatosis or von Recklinghausen's neurofibromatosis, as some of its symptoms like skin spots and tumors seemed to be restricted only to the outer nerves or peripheral nervous system of the affected person. But later the name was changed, as central nervous system tumors are known to occur in NF1. The benign tumor may originate on the skin (cutaneous), under the skin (subcutaneous) and in the connective nerve tissue (neurofibromas). It can be painful and in about 3-5% of cases, it becomes malignant.

Signs and Symptoms of NF1

Curvature of the spine (scoliosis)
More than five light brown skin spots about 5 millimeters in diameter in patients under the age of puberty or more than 15 millimeters in adults
Freckling in the armpit and groin areas
Benign growths on the iris of the eye known as lisch nodules or iris hamartomas
Tumor on the optic nerve called as optic glioma
Enlargement and deformity of the bones that may cause chronic pain
Hearing loss and learning disabilities

Neurofibromatosis Type 2 (NF2)

NF2 is less common type of neurofibromatoses which is characterized by bilateral tumors on the eighth cranial nerve. The tumor mainly occurs on the vestibular nerve (another branch of the eighth cranial nerve near the auditory nerve). It causes damage to the neighboring nerves and vital structures such as cranial nerves and the brainstem which can be life-threatening. It is also known as bilateral acoustic neurofibromatosis or central neurofibromatosis and is diagnosed during late teens and early twenties.

Signs and Symptoms of NF2


Hearing loss
Ringing in the ears
Headache
Facial pain or weakness
Feeling unsteady and off balance
Cataract at an early age
Glioma and meningioma

Diagnosis and Treatment for Neurofibromatosis

Diagnosis for neurofibromatosis involves several baseline studies like hearing and vision screening tests, psychologic testing to evaluate possible learning disorders, electroencephalogram (EEG), X-rays of the bones and head CT (computed tomography) or MRI (magnetic resonance imaging).

The treatment for NF1 includes removal of the neurofibromas for cosmetic purposes, getting intervention for children with learning disabilities and treating the complications like seizures, scoliosis, speech impairment, high blood pressure, optic nerve tumors and early or delayed onset of puberty. It's rare that neurofibromas become cancerous, but for such occurrences, surgery, chemotherapy or radiation treatment can be done. In 2000, the US Food and Drug Administration (FDA) approved an auditory brainstem implant which transmits sound signals directly to the brain for people with NF2 who have lost their hearing, and enables them to hear certain sounds and speech.

There is no specific treatment for NF, but genetic counseling and early detection of treatable conditions or complications can benefit people. The asymptomatic patient needs to be re-examined yearly and a symptomatic patient can be benefited from surgical treatment of tumors.

+ نوشته شده در  شنبه نوزدهم دی 1388ساعت 0:18  توسط reza mohammadizadeh  | 

Angelman Syndrome Symptoms

Angelman syndrome is a genetic disorder primarily affecting the nervous system. It was physician Harry Angelman who first described the syndrome in 1965 accurately. Angelman syndrome is believed to affect one in every 10,000-25,000 children across the globe. Children with this disorder feature overall development delay, difficult in speaking, balance and movement issues, hyperactive behavior and intellectual disability. Because of the jerky movements, cheery outlook and such other chirpy Angelman syndrome symptoms exhibited by children with this syndrome, this condition was also known as 'happy puppet syndrome'.

Angelman Syndrome Causes

When the egg gets fertilized by the sperm, the zygote formed contains two sets of chromosomes that have come from each parent. When the set of chromosome attained from the female parent lacks a copy of chromosome 15 due to chromosome deletion, the fetus developed has this Angelman syndrome. This is the most common reason for this condition and is seen in 68% of the Angelman syndrome cases.

If the zygote formed attains two copies of chromosome 15 from the male parent and none from the female parent, then also this condition can occur. However, this happens occasionally. Another scenario how this syndrome can occur is when the zygote attains chromosome 15 from each parent, however, the chromosome attained from the mother acts like that attained from the father. Yet another cause is mutation! When a gene called UBE3A on chromosome 15 mutates, it leads to Angelman syndrome in the fetus. Angelman syndrome cannot be not inherited, especially those which have been caused by chromosomal deletion or double chromosome set from father. Most of the people affected by this condition have not had others affected by this condition in the family. These genetic aberrations occur randomly during fertilization of the egg or during early embryonic development.

Symptoms of Angelman Syndrome

What are the symptoms of Angelman syndrome? Babies born with this disorder do not show any Angelman syndrome at birth. The signs of delayed growth and development are noticeable between 6-12 months of age. By the age of 2-3 years, children with Angelman syndrome often begin to experience seizures. Some of the other signs and symptoms of Angelman syndrome are as follows:

Speech impairments
Hyperactive behavior
Delayed mental and physical growth
Mental retardation
Delayed motor development
Walks in a stiff legged manner
Flapping of hands
Tongue thrusting
Occipital groove
Crossing of the eyes (strabismus)
Deep set eyes
Puppet like jerky or trembling movements
Unstable jerky gait
Intellectual disability
Feeding problems during infancy
Lower jaw jutting out
Frequent Drooling
Widely spaced teeth
Excessive chewing or mouthing behaviors
Can easily burst into laughter
Unusually happy demeanor
Wide, ever-smiling mouth
Hypopigmentation (light color hair, skin, eyes, etc.)
Happy go lucky, excitable, affectionate personality
Characteristic EEG (brainwave) abnormalities
Children with this syndrome have difficulty in sleeping, eating and toilet training. Moreover, some other symptoms of Angelman syndrome seen in children with this condition are flat heads with heads that are generally small in size. Around 80% of Angelman syndrome cases suffer from epilepsy.

Angelman Syndrome Treatments

DNA testing and careful observation of Angelman syndrome symptoms can help the doctor confirm the condition. As of today, there is no cure available for curing this nervous system disorder. Treatment is done to control only the symptoms of Angelman syndrome and includes physical therapies, occupational and speech therapies, behavioral modification techniques involving help with general behavior, communication, schooling, etc. Medical therapy is carried out to treat the seizures affecting the person.

People with this syndrome have normal life spans. Moreover, they do not feature developmental regression on aging. Early detection and appropriate treatment can help improve their quality of life. Hope these Angelman syndrome symptoms have given you a fair idea about this disorder.

+ نوشته شده در  سه شنبه هشتم دی 1388ساعت 12:47  توسط reza mohammadizadeh  | 

نانو حسگرهای مولکولی روشی برای تشخیص زودرس بیماریهای ژنتیکی و مارکرهای بیولوژیک سرطان در خون

 

نانوحسگرهای مولکولی می توانند با تشخیص زود هنگام بیماریهای ژنتیکی برای پیشگیری و شناسایی بیماریها کمک کند. طبق یک مطالعه که جدیدا منتشر شده است محققان برای اولین بار از نانوحسگرها برای اندازه گیری مارکرهای بیولوژیک سرطان در خون استفاده کرده اند. این سنسورها در مقیاس نانو یک مولکول منفرد با کمتر از ۲۰ نانومتر ضخامت دارند .این روش که در آمریکا ابداع شده است به دانشمندان اجازه می دهد تا تنها در عرض ۲۰ دقیقه مارکرهای بیولوژیک سرطان را در یک حجم کوچک خون اندازه گیری کنند. این یافته ها می تواند روش تشخیصی مارکرهای سرطانی و سایر بیماری ها را بطور چشمگیری آسان کند.
محققان برای این کار، ابزاری ابداع کرده اند که همانند یک فیلتر عمل می کند و مارکرهای سرطان را در یک تراشه گیر می اندازد. این روش تشخیص ذرات بسیار ریز سرطانی را در مقیاس پیکوگرم در هر میلی لیتر خون میسر می سازد.آزمایش هایی که در حال حاضر برای تشخیص سرطان وجود دارد چند روز طول می کشند اما این ابزار جدید می تواند تنها در عرض چند دقیقه غلظت مارکرهای بیولوژیک را اندازه گیری کند.این حسگرها در مقیاس نانو به روش تک مولکول می توانند به پیشرفت های قابل توجهی در تشخیص زودرس بیماری های ژنتیکی نیز منجر شوند. این پژوهش در مجله Nature Nanotechnology منتشر شده است.

+ نوشته شده در  دوشنبه هفتم دی 1388ساعت 11:1  توسط مدیر  |