Cerebral blood flow

Cerebral blood flow (CBF) is the supply of blood  to the brain over a  period of time. For adults, CBF is typically 750 milliliters per minute, or 15% of  cardiac output. This corresponds to an average perfusion of 50-54 milliliters of blood per 100 grams of brain tissue per minute. CBF is tightly regulated to meet the  metabolic requirements of the brain. Too much blood (clinical state of  normal homeostatic response to hyperemia) increases intracranial pressure (ICP), which can compress and damage delicate brain tissue. .. Low blood flow (ischemia) occurs when blood flow to the brain falls below 18-20 ml per 100 g / min, and tissue death occurs when blood flow falls below 8-10 ml per 100 g / min. increase. The biochemical cascade, known as the ischemic cascade, is triggered in brain tissue when the tissue becomes ischemic, which can lead to brain cell damage  and death. Physicians should take steps to maintain proper CBF for patients with conditions such as shock, stroke, cerebral edema, and traumatic brain injury.

 

Cerebral blood flow is determined by many factors, including: B. Blood viscosity, vasodilators, and  net pressure of blood flow to the brain. This is known as cerebral perfusion pressure, which is determined by the body's blood pressure. Cerebral perfusion pressure (CPP) is defined as  mean arterial pressure (MAP) minus  intracranial pressure (ICP). For the average person, it should be at least 50mmHg. Intracranial pressure should not exceed 15 mm Hg (20 mm Hg ICP is considered to be intracranial hypertension). Cerebral blood vessels can change blood flow  through them by changing their diameter in a process called cerebral autoregulation. When systemic blood pressure rises, it contracts, and  when it falls, it expands.  Arterioles also contract and dilate in response to different chemical concentrations. For example, it expands when the carbon dioxide level in the blood is high, and contracts when the carbon dioxide level is low. Assume a person with a arterial partial pressure  of 40 mmHg (normal range 38-42 mmHg) and a CBF of 50 ml per 100 g / min. If  PaCO2 is reduced to 30 mmHg, this corresponds to a 10 mmHg reduction from the initial PaCO2 value. As a result, for every 1 mmHg reduction in PaCO2, the CBF is reduced by 1 mL per 100 g / min, resulting in a new CBF of 40 mL per 100 g / min of brain tissue. In fact, for every 1 mmHg increase or decrease in PaCO2 in the 20-60 mmHg range, there is a corresponding CBF change of approximately 1-2 mL / 100 g / min, or 2-5% of CBF, in the same direction. [14] Therefore, small changes in respiratory patterns can cause large changes in global CBF, especially from PaCO2 fluctuations. 

A bleeding Blalock–Taussig shunt

 

Since birth, an 8-month-old child has had truncus arteriosus, a left pulmonary artery sling (Panel A), and tracheal stenosis. She received an operation for main pulmonary artery division from truncus, right modified Blalock-Taussig (mBT) shunt, and sliding tracheoplasty at the age of 13 days due to complex pulmonary artery anatomy and bilateral pulmonary artery hypoplasia. Cardiogenic shock due to blockage of the mBT shunt occurred two weeks after surgery. Right mBT shunt revision and fresh left mBT shunt implantation were conducted after extracorporeal cardiopulmonary resuscitation. She was discharged home with a tracheostomy at the age of 7 months after an extended stay in the hospital for post-resuscitation complications. After a month, the patient was readmitted due to respiratory discomfort and a high temperature. At the time of admission, the patient was moderately anaemic (haemoglobin was 11.3 g/dL), and his blood pressure was 94/40 mmHg. Bacteremia caused by Burkholderia cepacia was later proven. Surprisingly, a continuous colour flow jet was discovered at the confluence of the left subclavian artery and the left mBT shunt on follow-up echocardiography. Around the left mBT shunt, the swirling jet flowed into an aneurysm-like area (Panel B, Supplementary material online, Videos S1 and S2; star indicates pseudoaneurysm; arrow indicates flow jet of the bleeding site; arrowhead indicates the mBT shunt). 

The patient had a ruptured left mBT shunt with ongoing bleeding and pseudoaneurysm development. The filling contrast in a partially thrombosed huge pseudoaneurysm around the left mBT shunt was seen on computed tomography (Panel C, Supplementary material online, Video S3; star indicates pseudoaneurysm; arrow indicates flow jet of the bleeding site; arrowhead indicates the mBT shunt) and 3D reconstruction (Panel D, Supplementary material online, Video S4). Surprisingly, despite the fact that active bleeding remained for more than a month in subsequent follow-up, it appeared to be effectively contained inside the pseudoaneurysm with no major haemodynamic damage. We decided on palliative care after consulting with her family.

CRISPR-Cas9 In Vivo Gene Editing for Transthyretin Amyloidosis

 

 

Transthyretin amyloidosis, also known as ATTR amyloidosis, is a life-threatening condition marked by the accumulation of misfolded transthyretin (TTR) protein in tissues, primarily the nerves and heart. NTLA-2001 is a gene-editing therapeutic drug that works in vivo to cure ATTR amyloidosis by lowering TTR levels in the blood. It is based on a clustered model. CRISPR-Cas9 is an acronym for regularly interspaced short palindromic repeats and associated Cas9 endonuclease, and it consists of a lipid nanoparticle encasing Cas9 protein messenger RNA and a single guide RNA targeting TTR.

TTR knockdown was shown to be persistent after a single dosage in preclinical investigations. During the first 28 days following infusion, serial safety assessments in patients revealed few adverse events, and those that did occur were minor in severity. Pharmaco dynamic effects were shown to be dose-dependent. The mean reduction in serum TTR protein concentration from baseline was 52 percent (range, 47 to 56) in the group that got a 0.1 mg per kilogramme dosage and 87 percent (range, 80 to 96) in the group that received a 0.3 mg per kilogramme dose at day 28.

Administration of NTLA-2001 to a small sample of patients with hereditary ATTR amyloidosis and polyneuropathy was accompanied with fairly minor side effects and resulted in lower serum TTR protein concentrations due to targeted TTR deletion.

25th International Conference on Cardiology and Vascular Imaging

On behalf of the Conference series Ltd, it is our deep pleasure to invite all the Great Scientists, Academicians, young researchers, Professors, Doctors, Business persons, Cardiologist, Delegates and Students 

moreover Who are the front line of warriors in this pandemic situation from all over the world to attend the October 29-30, Webinar over the subject Cardiology and Vascular Imaging. The main theme of the conference is  "Outreaching the Rhythm for a Healthy Heart"

Cardiology and vascular Imaging shares an insight into the recent research and cutting edge technologies, which gains immense interest with the colossal and exuberant presence of adepts, young and brilliant researchers, Professors, Doctors, and talented student communities.

Cardiology and vascular Imaging meeting’s goal is to bring together, a multi-disciplinary group of Scientists and Researchers, Professors, Doctors from all over the world are invited cordially to present and exchange break-through ideas relating to the Cardiology and vascular Imaging promotes top level research and to globalize the quality research in general, thus making discussions, presentations more internationally competitive and focusing attention on the recent outstanding breakthroughs in the field of Cardiology and vascular Imaging , and future trends and needs.

We’re looking forward to an excellent meeting of all dignitaries from different countries all around the world to share innovative ideas and exciting trends in Cardiology and vascular Imaging which will be held on October 29-30, 2021.