1. The document discusses measuring creatine kinase (CK) levels in the blood of a healthy person and a cardiac patient to detect muscle damage.
2. CK levels were higher in the cardiac patient (214.7 U/L) compared to the healthy person (97.62 U/L), indicating possible myocardial infarction in the patient.
3. CK is released into the blood from damaged muscle tissue and can be used as a biomarker for detecting cardiac muscle damage like heart attacks.
Dr. Barry Sears discusses inflammation and its direct relationship to concussions. His labs have developed a test for the detection of inflammation and related symptoms of concussion
Cardiac biomarkers are of great importance in the timely, accurate diagnosis and management of acute coronary syndrome as well as the prognosis. Diagnosis in the golden period is of utmost importance to institute therapy at the earliest and possibly reverse the myocardial damage. Cardiac biomarkers are also a powerful tool for triaging. Among the many biomarkers, the earliest examined were the myocardial enzymes, several myocardial proteins, peptides, and many other molecules.
Dr. Barry Sears discusses inflammation and its direct relationship to concussions. His labs have developed a test for the detection of inflammation and related symptoms of concussion
Cardiac biomarkers are of great importance in the timely, accurate diagnosis and management of acute coronary syndrome as well as the prognosis. Diagnosis in the golden period is of utmost importance to institute therapy at the earliest and possibly reverse the myocardial damage. Cardiac biomarkers are also a powerful tool for triaging. Among the many biomarkers, the earliest examined were the myocardial enzymes, several myocardial proteins, peptides, and many other molecules.
Cardiac Inflammation and Repair Following Myocardial InfarctionInsideScientific
Join Dr. Merry Lindsey as she discusses her research involving the physiology of recovery from cardiac events.
Age plays a pivotal role in the deterioration of cardiovascular functionality, resulting in an increased risk of cardiovascular disease in older adults. The prevalence of cardiovascular disease has also been shown to increase with age, in both men and women, including the prevalence of atherosclerosis, stroke and, myocardial infarction.
Following myocardial infarction (MI), the left ventricle (LV) undergoes a series of cardiac wound healing responses that involve both the stimulation of robust inflammation to clear necrotic myocytes and tissue debris and the induction of extracellular matrix (ECM) protein synthesis to generate an infarct scar. Collectively, this process in known as LV remodeling. Matrix metalloproteinase-9 (MMP-9) is a key regulator of LV remodeling post-MI, through direct effects on ECM turnover as well as indirect effects on the regulation of the major cell types that coordinate cardiac wound healing- namely the infiltrating leukocytes and the cardiac fibroblasts. We will discuss recent research that has expanded our understanding of MI LV remodeling, including recent proteomic advances focused on the ECM compartment to provide novel functional and translational insights. In summary, this webinar will provide an overview of how cardiac ECM research has evolved over the last decade and will provide insight into future directions that will drive further understanding of MMP directed cardiac ECM turnover after MI.
Cardiac Inflammation and Repair Following Myocardial InfarctionInsideScientific
Join Dr. Merry Lindsey as she discusses her research involving the physiology of recovery from cardiac events.
Age plays a pivotal role in the deterioration of cardiovascular functionality, resulting in an increased risk of cardiovascular disease in older adults. The prevalence of cardiovascular disease has also been shown to increase with age, in both men and women, including the prevalence of atherosclerosis, stroke and, myocardial infarction.
Following myocardial infarction (MI), the left ventricle (LV) undergoes a series of cardiac wound healing responses that involve both the stimulation of robust inflammation to clear necrotic myocytes and tissue debris and the induction of extracellular matrix (ECM) protein synthesis to generate an infarct scar. Collectively, this process in known as LV remodeling. Matrix metalloproteinase-9 (MMP-9) is a key regulator of LV remodeling post-MI, through direct effects on ECM turnover as well as indirect effects on the regulation of the major cell types that coordinate cardiac wound healing- namely the infiltrating leukocytes and the cardiac fibroblasts. We will discuss recent research that has expanded our understanding of MI LV remodeling, including recent proteomic advances focused on the ECM compartment to provide novel functional and translational insights. In summary, this webinar will provide an overview of how cardiac ECM research has evolved over the last decade and will provide insight into future directions that will drive further understanding of MMP directed cardiac ECM turnover after MI.
Startups aren't a goal unto themselves. They're a means of finding a company worth building. They should offer a coherent, focused product or service that solves a real, existing problem.
MI is one of the CVS complication leading to mortality whose diagnosis is mainly dependent on clinical presentation and other supportive investigation. clinical laboratory plays crucial role in its diagnosis, prognosis and monitoring therapy.
Immunoassay is a biochemical test that estimate or asses the presence or concentration of a macromolecule (antigen) in a solution (eg-blood) through the use of an antibody or immunoglobulin(Ig). The macromolecule called "analyte". Analytes in biological liquids such as blooed serum, biological fuid and urine are frequently measured using immunoassays ( for medical and research purposes).
Identification of the positively selected genes governing host-pathogen arm r...Atai Rabby
Bacterial evolution is due to the adaptive nature of the core bacterial genomes that plays critical role in diversification, fitness and adaptation of the species to different environment and host. Since Vibrio cholerae represents an appropriate model organism for studying the interplay of environment and host driven factors shaping the microbial genome structure and function, the current study aims to identify genes that are under these strong forces in V. cholerae. Here, we employed a comparative genomics approach to identify genes that are under positive selection in ten strains of Vibrio sp. including four pathogenic V. cholerae strains. From the available genome sequence data, a total of 422 orthologous genes were identified by reciprocal BLAST best-hit method, recombination breakpoint frequency analysis and tree comparison method. These 422 genes, representing the core genome of Vibrio sp., constituted the dataset to be analyzed for evolutionary selections. The analysis of natural selection, based on Maximum Likelihood method on synonymous and non-synonymous substitution rate, confirms the hypothesis that the bacterial core genomes are mostly under purifying selection with a few positively selected regions. However, our finding also reveals that positively selected sites in the Vibrio genome occur in a wide range of different genes encompassing diverse functional pathways including cell surface proteins (e.g. outer membrane-specific lipoprotein transporter/assembly proteins etc.), cell motility proteins (e.g. flagellar motor switch proteins, flagellar hook and assembly proteins), nutrient acquisition (e.g. amino acid, carbohydrate and phosphate ABC transporters), DNA repair and transcription related proteins. Interestingly, these positively selected gene products are directly involved with host-pathogen interactions and fitness in gastrointestinal environment. Therefore, the collective evidences of these positively selected genes spanning several pathways raise the possibility of their involvement in evolutionary arms races with other bacteria, phages, and/or the host immune system. This finding points to the natural selections which is the responsible factor for the diversification of Vibrio genus.
D4476, a cell-permeant inhibitor of CK1, potentiates the action of Bromodeoxy...Atai Rabby
To elucidate the mechanism of bromodeoxyuridine (BrdU) induced cellular senescence, we treated HeLa cells with D4476, a potent and specific inhibitor of casein kinase 1(CK1). We found that D4476 (10µM) treatment could arrest cell growth at G1 stage and induced cellular senescence when treated together with BrdU (10µM). However neither D4476 nor BrdU can induce cellular senescence alone, at a concentration of 10µM. These results suggest that the targets of CK1 may be involved in maintaining normal cellular process and their inactivation potentiates BrdU to induce senescence like phenomena.
Identifying Antibiotics posing potential Health Risk: Microbial Resistance Sc...Atai Rabby
The present study was undertaken to investigate the trends of antimicrobial resistance and identify antibiotics that are posing public health risk due to resistant microbes in Bangladesh. Antimicrobial resistance data of Bangladesh for last 10 years were searched out and compared with corresponding antibiotic consumption rates. In this study, a factor is introduced to identify the therapeutic sub-class of antibiotics that are mostly threatened by growing antimicrobial resistance. Highly resistance trend against several antibiotics such as cloxacillin, ampicillin, metronidazole, oxacillin, amoxicillin, tetracycline, cotrimoxazole, penicillin etc. were also indentified. Heat map analysis of this study revealed that nine antimicrobial agents: metronidazole, amoxicillin, tetracycline, cotrimoxazole, cephadine, penicillin, ciprofloxacin, doxycycline and nalidixic acid are associated with public health risk due to growing bacterial resistance. This study would significantly contribute in minimizing development and spread of antibiotic resistance by revealing the microbial resistance scenario and aid the effective antibiotic treatment options in Bangladesh.
Antiviral drugs are a class of medication used specifically for treating viral infections.Like antibiotics for bacteria, specific antivirals are used for specific viruses. Unlike most antibiotics, antiviral drugs do not destroy their target pathogen; instead they inhibit their development.
Actin filaments, usually in association with myosin, are responsible for many types of cell movements. Myosin is the prototype of a molecular motor—a protein that converts chemical energy in the form of ATP to mechanical energy, thus generating force and movement. The most striking variety of such movement is muscle contraction, which has provided the model for understanding actin-myosin interactions and the motor activity of myosin molecules. However, interactions of actin and myosin are responsible not only for muscle contraction but also for a variety of movements of nonmuscle cells, including cell division, so these interactions play a central role in cell biology. Moreover, the actin cytoskeleton is responsible for the crawling movements of cells across a surface, which appear to be driven directly by actin polymerization as well as actin-myosin interactions.
The thyroid hormones, triiodothyronine (T3) and its prohormone, thyroxine (T4), are tyrosine-based hormones produced by the thyroid gland that are primarily responsible for regulation of metabolism. Iodine is necessary for the production of T3 and T4. A deficiency of iodine leads to decreased production of T3 and T4, enlarges the thyroid tissue and will cause the disease known as simple goitre. The major form of thyroid hormone in the blood is thyroxine (T4), which has a longer half-life than T3.The ratio of T4 to T3 released into the blood is roughly 20 to 1. T4 is converted to the active T3 (three to four times more potent than T4) within cells by deiodinases (5'-iodinase). These are further processed by decarboxylation and deiodination to produce iodothyronamine (T1a) and thyronamine (T0a). All three isoforms of the deiodinases are selenium-containing enzymes, thus dietary selenium is essential for T3 production.
Parathyroid hormone (PTH), parathormone or parathyrin, is secreted by the chief cells of the parathyroid glands as a polypeptide containing 84 amino acids. It acts to increase the concentration of calcium (Ca2+) in the blood, whereas calcitonin (a hormone produced by the parafollicular cells (C cells) of the thyroid gland) acts to decrease calcium concentration. PTH acts to increase the concentration of calcium in the blood by acting upon the parathyroid hormone 1 receptor (high levels in bone and kidney) and the parathyroid hormone 2 receptor (high levels in the central nervous system, pancreas, testis, and placenta).PTH half-life is approximately 4 minutes. It has a molecular mass of 9.4 kDa.
As a component of the endocrine system, both male and female gonads produce sex hormones. Male and female sex hormones are steroid hormones and as such, can pass through the cell membrane of their target cells to influence gene expression within cells. Gonadal hormone production is regulated by hormones secreted by the anterior pituitary in the brain. Hormones that stimulate the gonads to produce sex hormones are known as gonadotropins. The pituitary secretes the gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These protein hormones influence reproductive organs in various ways. LH stimulates the testes to secrete the sex hormone testosterone and the ovaries to secrete progesterone and estrogens. FSH aids in the maturation of ovarian follicles (sacs containing ova) in females and sperm production in males.
The classical GI hormones are secreted by epithelial cells lining the lumen of the stomach and small intestine. These hormone-secreting cells - endocrinocytes - are interspersed among a much larger number of epithelial cells that secrete their products (acid, mucus, etc.) into the lumen or take up nutrients from the lumen. GI hormones are secreted into blood, and hence circulate systemically, where they affect function of other parts of the digestive tube, liver, pancreas, brain and a variety of other targets.
In mammals, the adrenal glands (also known as suprarenal glands) are endocrine glands that sit at the top of the kidneys. They are chiefly responsible for releasing hormones in response to stress through the synthesis of corticosteroids such as cortisol and catecholamines such as adrenaline (epinephrine) and noradrenaline. They also produce androgens in their innermost cortical layer. The adrenal glands affect kidney function through the secretion of aldosterone, and recent data (1998) suggest that adrenocortical cells under pathological as well as under physiological conditions show neuroendocrine properties; within normal adrenal glands, this neuroendocrine differentiation seems to be restricted to cells of the zona glomerulosa and might be important for an autocrine regulation of adrenocortical function.
DNA extraction is an important step in molecular assays and plays a vital role in obtaining highresolution results in gel-based systems, particularly in the case of cereals with high content of interfering components in the early steps of DNA extraction.This is a rapid miniprep DNA extraction method, optimized for rice, which was achieved via creating some modifications in present DNA extraction methods, especially in first step of breaking down and lyses of cell wall, and the use of cheap and frequent chemicals, found in every lab, in the next steps. The normal quality and quantity was obtained by the method. The PCR based assays also revealed the efficiency of the method.
The advantages of this method are: 1- it is applicable with both dry and fresh samples, 2- no need to large weight samples, 3- no need to liquid nitrogen and 4- easy, rapid and applicable in every laboratory.
A restriction map is a map of known restriction sites within a sequence of DNA. Restriction mapping requires the use of restriction enzymes. In molecular biology, restriction maps are used as a reference to engineer plasmids or other relatively short pieces of DNA, and sometimes for longer genomic DNA. There are other ways of mapping features on DNA for longer length DNA molecules, such as mapping by transduction (Bitner, Kuempel 1981).
Restriction mapping is a useful way to characterise a particular DNA molecule. It enables us to locate and isolate DNA fragments for further study and manipulation. The relative location of different restriction enzyme sites to each other are determined by enzymatic digest of the DNA with different restriction enzymes, alone and in various combinations.The digested DNA is separated by gel electrophoresis and the fragment sizes that have been generated are used to build the 'map' of sites of the fragment. The map lets us know 'where we are' in the linear DNA macromolecule.
MATATAG CURRICULUM: ASSESSING THE READINESS OF ELEM. PUBLIC SCHOOL TEACHERS I...NelTorrente
In this research, it concludes that while the readiness of teachers in Caloocan City to implement the MATATAG Curriculum is generally positive, targeted efforts in professional development, resource distribution, support networks, and comprehensive preparation can address the existing gaps and ensure successful curriculum implementation.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Mesurement of cretinine kinase from blood of a cardiac patient
1. Department of Biochemistry and Molecular Biology
University of Dhaka
MS Practical
Mesurement of Cretinine Kinase from Blood of a Cardiac patient
Submitted by
Md. Atai rabby
MS
2. Priciple
The development of sensitive spectrophotometers able to measure a wide range of wavelengths has
allowed natural substrates and measurements in the ultraviolet region of the spectrum to be used in
clinical tests. Assays using natural substrates and measurements in the ultraviolet region are the
basis of most of the commonly used methods to determine enzyme activities in clinical
biochemistry. Typically, they continuously measure the absorbances of NAD+ or NADP+ at 340
nm. Figure shows the reactions used to monitor the activities of creatine kinase (CK) in clinical
laboratories by measuring changes in the absorbance of NAD+ or NADP+. Clinical investigations
using this enzyme can be used to detect muscle damage..
4. Result
Cretine Kinase Activity in healthy person = 97.62 U/L
Cretine Kinase Activity Cardiac Patient = 214.7 U/L
Comment
1. The CK activity of healthy person lies in normal range [ 24-190 U/L at 370
C ]
2. The CK activity of the patient is High than reference value indicating possible Miocardial
Infraction But further diagnosis in necessary for conformation.
Discussion
A biomarker is a biological molecule whose concentration in the blood changes in response to a
specific disease. Biomarkers are normally considered in relation to a specific type of tissue damage.
Biomarkers that indicate muscle damage,in particular damage to cardiac muscle, which can lead to
heart disease are usually referred to as cardiac biomarkers.
A number of different types of molecules have been exploited as biomarkers. These include:
enzymes and their associated coenzymes or cofactors
structural tissue proteins
intermediates of metabolic pathways
messenger molecules
Creatine kinase transfers a phosphate from creatine phosphate to adenosine diphosphate (ADP) to
form adenosine triphosphate (ATP) . When muscle tissue contracts it consumes ATP; however, in
some conditions muscles can potentially run out of ATP. Should this happen, the muscles would
then stop working. However, muscles have stores of creatine phosphate that in the short term can be
5. used to phosphorylate the ADP to ATP. The released creatine is subsequently broken down to
creatinine, whichis used to test for renal function.
The level of CK activity in the blood is due to leakage from muscle tissues. This means that its
activity in the blood will be affected by muscle mass and muscle composition. This is the reason
that the reference value for CK activities in the blood of men is higher than that of women, who on
average have less muscle mass. Slightly different types of muscle fibres are found in the muscles of
different ethnic groups, which explains, for example, why CK levels are higher in Afro-Caribbeans
than Caucasians.
Creatine kinase is found in all the muscles of the body. Its activity in the blood begins to increase
about 4–6 hours following an AMI and peaks at 24 hours. However, there is much more skeletal
muscle than cardiac muscle in the body. Consider someone involved in a road traffic accident who
has a crushed chest and thus a damaged heart. There is also skeletal muscle damage, so the increase
in CK from the damaged muscles may mask the increase resulting from the damaged heart.
However, CK activity can be due to one of three isoenzymes.
CK1 or CKMM, found mostly in skeletal muscle
CK2 or CKMB, found predominately in cardiac muscle
CK3 or CKBB, found in smooth muscle
Assaying the individual isoenzymes can help in distinguishing between the CK activities from
cardiac muscle and skeletal muscle damage. Thus, measuring CKMB activity is a more sensitive
method of detecting an AMI, especially if there has been damage to skeletal muscle.Creatine kinase
MB activity starts to increase slightly earlier than the overall CK levels and peaks 21 hours after a
MI. To better distinguish between cardiac and skeletal muscle damage the amount of CKMB can be
expressed as the ratio CKMB/total CK. The theory is that if the ratio increases it is more likely to be
cardiac than skeletal muscle damage.
The usefulness of CKMB in detecting AMIs has led to the development of immunoassays for its
measurement. However, there is a drawback to the use of CKMB in detecting AMI.
6. Although cardiac muscle contains more of the MB than other isoenzymes of CK it also contains
significant amounts of CKMM. Similarly, although skeletal muscle also contains mostly CKMM, it
does have significant amounts of CKMB. Crucially, this means that an increase in CKMB is not
absolutely specific for cardiac damage, although for many years it was the best available test.
In addition to the isoenzymes of CK, there are also isoforms of CKMM and CKMB. Isoforms of a
protein differ from one another due to post-translational modifications. Post-translational
modifications include chemical modifications, such as glycosylation and phosphorylation, and, as is
the case here, the removal of certain amino acid residues. Isoforms of CKMM and CKMB are
formed by a deaminase in the bloodstream that removes the carboxy terminal amino acid residue
from the M subunit of CK molecules. This means that there are potentially two isoforms of CKMB,
called MB1 and MB2, and three isoforms of CKMM, called MM1, MM2, and MM3. There was
initial interest in using the ratio of MB1 to MB2 as a very early test for AMI although this has been
replaced by assays for cardiac troponin. However, measuring isoforms of CKMM is potentially a
useful way of determining whether there has been recent skeletal muscle damage. The common
form of CKMM is MM3, so an increased amount of MM1 would suggest that there has been recent
skeletal muscle damage. This test is not yet used in routine clinical practice.
Heart disease occurs due to blockage of the blood vessels supplying oxygen to the heart muscle. In
any tissue where the need for oxygen from the blood exceeds the rate at which it can be supplied, a
deficiency of oxygen or ischaemia occurs. However, ischaemia is reversible provided it is not
unduly prolonged. When the ischaemia is prolonged, irreversible cell damage and cell death can
occur; this is known as infarction, and is followed by cellular breakdown and necrosis. Thus,
infarction is irreversible.
In the heart, ischaemia of cardiac muscle will occur if the artery supplying blood to an area of
cardiac muscle becomes partially or totally blocked. The reason that a partial blockage can also
cause ischaemia is that some areas of cardiac muscle are on the borders of the area supplied with
blood by the arteries, areas called watersheds. In a normal state they receive just enough blood to
survive, but should one of the arteries become even partially blocked then the already barely
adequate supply to this muscle slips below the minimum level; thus the muscle becomes
inadequately supplied with oxygen and slides into a state of ischaemia. The ischaemia will be
7. exacerbated if the need for oxygen increases at the same time, for example if heavy exercise is
being undertaken.
A number of terms are used to describe patients with a real or suspected heart attack, which is a
myocardial infarction (MI). Myocardial infarction and acute myocardial infarction (AMI) are
associated with cardiac pain and the death of cardiac tissue (myocardial cell necrosis). In some
patients, such as diabetics, an infarction can occur without pain. It is then referred to as a silent MI.
Angina is often confused with MI but the term simply means heart pain. The difference between
angina and MI is that damage to cardiac muscle does not occur in the former. Angina occurs in two
principal forms: stable and unstable anginas. In stable angina, the cardiac pain occurs predictably
and gradually and can be controlled by actions as simple as physically resting or by using
appropriate drugs. Cardiac pain or breathlessness that is associated with exercise and relieved by
rest is also stable angina. In contrast, in unstable angina the cardiac pain comes on unpredictably
and is not relieved, or only partially, by rest or by drugs.