Clinical analysis sciences

02/04/2025

MSH2 gene/protein in HNPCC

Mismatch repair gene MMR,




It's a mismatch repair gene( also known as mutS protein homolog 2, codes for a protein involved in the mismatch repair process after DNA replication) commonly associated with Hereditary Non-Polyposis Colorectal Cancer (HNPCC). HNPCC is a type of colorectal cancer caused by genetic changes (mutations) that run in families. These changes are part of a family cancer syndrome called Lynch syndrome, which may increase the risk of developing other cancers. Continue reading:

BioMed MD is about laboratory medicine, with all it's branches. Mainly we deal with biological sciences.

17/03/2025

In a recent study, researchers at NYU Langone Health have developed an ultra-fast genetic test, Ultra-Rapid droplet digital PCR (UR-ddPCR), that can identify brain cancer cells in real time during surgery. This test delivers results in just 15 minutes, significantly faster than traditional ddPCR, ............ continue into the comments

16/01/2025

| Karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities.
amniocentesis or chorionic villi sampling allows prenatal karyotyping, by isolation of amniotic fluid or chorion, containing fetal cells in mitosis, which are stained and paired
diagnosis of chromosomal abnormalities, such as Down syndrome, identifying extra chromosome 21 (trisomy 21)

يتم إجراء الفحص الوراثي (النمط النووي) باستخدام خلايا مأخوذة عبر بزل السائل الأمنيوسي أو أخذ عينات من الزغابات المشيمية، وذلك للتشخيص قبل الولادة لحالات الشذوذ الصبغي.
يتيح هذان الإجراءان عزل الخلايا الجنينية من السائل الأمنيوسي أو الزغابات المشيمية أثناء انقسامها، ثم يتم صبغها ودراستها لتحديد التغيرات الصبغية.
يساعد ذلك في تشخيص اضطرابات مثل متلازمة داون، التي تتميز بوجود كروموسوم 21 زائد (التثلث الصبغي 21).

| Karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities.

amniocentesis or chorionic villi sampling allows prenatal karyotyping, by isolation of amniotic fluid or chorion, containing fetal cells in mitosis, which are stained and paired
diagnosis of chromosomal abnormalities, such as Down syndrome, identifying extra chromosome 21 (trisomy 21)

16/01/2025

The role of C-reactive protein in atherogenesis

16/01/2025

| Vitamin B12

Vitamin B12 is the largest and most complex of all the vitamins. The name vitamin B12 is generic for a specific group of cobalt-containing corrinoids with biological activity in humans. Interestingly it is the only known metabolite to contain cobalt, which gives this water-soluble vitamin its red colour. This group of corrinoids is also known as cobalamins. The main cobalamins in humans and animals are hydroxocobalamin, adenosylcobalamin and methylcobalamin, the last two being the active coenzyme forms. Cyanocobalamin is a form of vitamin B12 that is widely used clinically due to its availability and stability. It is transformed into active factors in the body.

In 1934, three researchers won the Nobel prize in medicine for discovering the lifesaving properties of vitamin B12. They found that eating large amounts of raw liver, which contains high amounts of vitamin B12, could save the life of previously incurable patients with pernicious anaemia. This finding saves 10,000 lives a year in the US alone. Vitamin B12 was isolated from liver extract in 1948 and its structure was elucidated 7 years later.

Functions

Vitamin B12 is necessary for the formation of blood cells, nerve sheaths and various proteins. It is therefore, essential for the prevention of certain forms of anaemia and neurological disturbances. It is also involved in fat and carbohydrate metabolism and is essential for growth. In humans, vitamin B12 functions primarily as a coenzyme in intermediary metabolism. Two metabolic reactions are dependent on vitamin B12:

The methionine synthase reaction with methylcobalamin
The methylmalonyl CoA mutase reaction with adenosylcobalamin

In its methylcobalamin form vitamin B12 is the direct cofactor for methionine synthase, the enzyme that recycles homocysteine back to methionine. There is evidence that vitamin B12 is required in the synthesis of folate polyglutamates (active coenzymes required in the formation of nerve tissue) and in the regeneration of folic acid during red blood cell formation.

Methylmalonyl CoA mutase converts 1-methylmalonyl CoA to succinyl CoA (an important reaction in lipid and carbohydrate metabolism). Adenosylcobalamin is also the coenzyme in ribonucleotide reduction (which provides building blocks for DNA synthesis).



Main functions in a nutshell:

Essential growth factor
Formation of blood cells and nerve sheaths
Regeneration of folic acid
Coenzyme-function in the intermediary metabolism, especially in cells of the nervous tissue, bone marrow and gastrointestinal tract

Dietary sources

Vitamin B12 is produced exclusively by microbial synthesis in the digestive tract of animals. Therefore, animal protein products are the source of vitamin B12 in the human diet, in particular organ meats (liver, kidney). Other good sources are fish, eggs and dairy products. In foods, hydroxo-, methyl- and 5'-deoxyadenosyl-cobalamins are the main cobalamins present. Foods of plant origin contain no vitamin B12 beyond that derived from microbial contamination. Bacteria in the intestine synthesise vitamin B12, but under normal circumstances not in areas where absorption occurs.

Stability

Vitamin B12 is stable to heat, but slowly loses its activity when exposed to light, oxygen and acid or alkali-containing environments. Loss of activity during cooking is due to the water solubility of vitamin B12 (loss through meat juices or leaching into water) rather than to its destruction.

Safety

Large intakes of vitamin B12 from food or supplements have caused no toxicity in healthy people. No adverse effects have been reported from single oral doses as high as 100 mg and chronic administration of 1 mg (500 times the RDA) weekly for up to 5 years. Moreover, there have been no reports of carcinogenic or mutagenic properties, and studies to date indicate no teratogenic potential. The main food safety authorities have not set a tolerable upper intake level (UL) for vitamin B12 because of its low toxicity.

Industrial production

Vitamin B12 is produced commercially from bacterial fermentation, usually as cyanocobalamin.

27/06/2021

A Hematology reminder:

Myeloblasts, promyelocytes and myelocytes are all capable of cell division. However, metamyelocytes have indented nuclei and cannot undergo cell division.

02/05/2021

Think cultural change. Not incremental improvement!!

27/04/2021

الشرح الأول في سلسلة مخصصة عن الهماتولوجي.

هنا استعراض بسيط ومبدئي للمفاهيم المختلفة التي تربط البيولوجي بالهماتولوجي. Cell biologyعندما نربط العلوم ببعض نحصل على فهم اوسع واشمل للمادة.المصدرالاساسي...

19/03/2021

AstraZeneca vaccine
ما القصة وراء المخاوف من لقاح اكسفورد/استرازنيكا؟

هذا اللقاح مطور بشراكة بين الجامعة العريقة والمشهورة اكسفورد ممثلة بشركة فاكسيتيك والشركة العريقة استرازنيكا

منظمة الصحة العالمية وباختصار مهتمة بحدوث التطعيم وتحث عليه من باب التطعيم اي من حيث المبدأ
WHO calls for vaccinations to continue
Meanwhile, WHO has urged countries to continue using the AstraZeneca vaccine as part of their vaccination strategies.

"At this time, WHO considers that the benefits of the AstraZeneca vaccine outweigh its risks and recommends that vaccinations continue," the organization said in a statement on Wednesday.
هنا تؤكد منظمة الصحة العالمية ان عملية التطعيم اهم وان اهمية التطعيم بهذا اللقاح اهم من مخاطره ونلاحظ هنا انهم لم يتحفظوا على كلمة مخاطر! بمعنى ان له مخاطر (وهناك دليل اخر من الهيئة الاوروبية للادوية في اخر المقال)..
However, WHO also highlighted the importance of investigating the claims of side effects.
ولكن منظمة الصحة لاتنفي اهمية البحث في ادعاءات الاعراض الجانبية والمخاطر التابعة له بان دعمت اهمية الابحاث للتبين, وهنا استغرب سرعة رغبتهم بجعل الناس تاخذه رغم ان الابحاث ليست جاهزة % بخصوصه!

الاقتباسات هنا من موقع
DW

من ناحية اخرى ركزت ال
CNBC
على التقارير المتداولة بخصوص التجلطات
Reports of blood clots in some people who received the AstraZeneca-Oxford shot led several countries — many of them in Europe — to temporarily stop using the vaccine.
مما دفع عدد من الدول الاوروبية لايقاف استخدامه (اوروبية وغيرها وتاليا سنذكر عدد منها)

السويد ولاتفيا انضمتا لمخاوف المانيا وايطاليا وفرنسا
Sweden and Latvia on Tuesday joined a fast-growing list of European countries suspending the use of the vaccine as a precautionary measure following reports of blood clots.
Germany, France, Italy and Spain on Monday said they would all stop administering the shot.
The World Health Organization, Europe’s drug regulator and the International Society on Thrombosis and Hemostasis have all recommended that countries continue to use the Oxford-AstraZeneca vaccine.
مرة اخرى الجهات الدولية تحث الدول للعودة لاخذ اللقاح؟!

“Halting a vaccine roll out during a pandemic has consequences,” said Dr. Michael Head, senior research fellow in Global Health at the University of Southampton, U.K.
يبدو ان الفكرة تكمن في المبدأ انهم يريدون للناس اخذ اللقاح رغم المخاطر وليس على دراسات علمية بل لان المبدأ اهم..

Other countries, such as Austria, have temporarily paused the use of certain batches of the Oxford-AstraZeneca vaccine. Thailand on Friday became the first Asian nation to halt the use of the shot over safety concerns.
النمسا وتايلاند ودول اخرى منها افريقية توقفت عن استعماله للوقت الحالي
https://www.cnbc.com/2021/03/16/astrazeneca-covid-vaccine-doctors-react-as-eu-countries-suspend-shot.html?recirc=taboolainternal

تاليا مقارنة لل
BBC
بين لقاح فايزر واسترازنيكا, والغريب الفرق الشاسع في النتائج
Is the Oxford vaccine as good as the Pfizer?
Large trials showed the Pfizer vaccine was 95% effective, while the figure for the Oxford one was 62%.
فعالية اقل ولازال الاصرار عليه..
وبالطبع هناك مبررات منها صعوبة المقارنة لاختلاف الطرق! كيف نعتبر اختاف الطرق البحثية مصلحة هنا للدفاع عن هذا اللقاح بينما كانت نفسها وسيلة لتدعيم انه ليس خطر! اذا تمكنت من اثبات عدم خطورته فبنفس الطريقة يجب ان نتمكن من اثبات فائدته...
But directly comparing results is difficult because there are differences in the way the trials were carried out.

https://www.bbc.com/news/health-55302595

اعزائي المعلومة التالية من المصدر الاوروبي
ema
والتي تماثل ال
FDA
ولكن في اوروبا, تقول التالي:
COVID-19 Vaccine AstraZeneca offers a good level of protection against COVID-19 which is a critical need in the current pandemic. The main trials showed that the vaccine has around 60% efficacy. Most side effects are mild to moderate in severity and are gone within a few days.
فعالية 60% فقط!!! اعراضه من بسيطة لمتوسطة وتنسحب في ايام,

The European Medicines Agency decided that COVID-19 Vaccine AstraZeneca’s benefits are greater than its risks and it can be authorised for use in the EU.
مرة اخرى ارتأوا هنا ايضا ان فوائده اكبر من مضاره, ولكن !!
COVID-19 Vaccine AstraZeneca has been given ‘conditional authorisation’. This means that there is more evidence to come about the vaccine (see below), which the company is required to provide. The Agency will review any new information that becomes available and this overview will be updated as necessary.

هنا الملاحظة المهمة هذا اللقاح في اوروبا حصل على
‘conditional authorisation’
اي موافقة مشروطة وليست كاملة. وهذا مهم جدا بمعنى انه يجب على الشركة استرازنيكا الاستمرار بتزويد الادلة من التجارب السريرية المستمرة حاليا لمعرفة امور عديدة منها لمدى استمرار الفعالية واذا يفيد من الطفرات الجديدة وغيره ...
Since COVID-19 Vaccine AstraZeneca has been given conditional authorisation, the company that markets the vaccine will continue to provide results from the clinical trials, which are ongoing. These trials and additional studies will provide information on how long protection lasts, including against new variants of the virus, how well the vaccine prevents severe COVID-19, how well it protects older people, immunocompromised people, children and pregnant women, and whether it prevents asymptomatic cases.

وهناك دراسات مستمرة من قبل الاتحاد الاوروبي للتأكد من سلامته ..
In addition, independent studies of COVID-19 vaccines coordinated by EU authorities will also give more information on the vaccine’s long-term safety and benefit in the general population.

The company will also carry out studies to provide additional assurance on the pharmaceutical quality and testing of the vaccine as the manufacturing continues to be scaled up.

https://www.ema.europa.eu/en/medicines/human/EPAR/covid-19-vaccine-astrazeneca

وهناك الكثير من الملاحظات على خطورته على كبار السن.. ومن هنا و
بالنسبة لي اعتقد انه من المبكر اخذ هذا المطعوم, والله أعلم.

محمد الجده
اختصاصي مختبرات طبية/ ماجستير دم وبنك دم/ (MLS(ASCP

COVID-19 Vaccine AstraZeneca

12/03/2021