NICOTINE

INTRODUCTION:  Nicotine is sometimes considered a CNS stimulant, and although it does increase alertness, its actions and long-term consequences place it in a class by itself. Nicotine is unique among abused substances in that it is legal, strongly addictive, and highly carcinogenic. Furthermore, use of tobacco can cause harmful effects to those in the immediate area who breathe secondhand smoke.  Patients often do not consider tobacco use as substance abuse. 

Tobacco Use and Nicotine: The most common method by which nicotine enters the body is through the inhalation of cigarette, pipe, or cigar smoke. Tobacco smoke contains more than 1,000 chemicals, a significant number of which are carcinogens. The primary addictive substance present in cigarette smoke is nicotine. Effects of inhaled nicotine may last from 30 minutes to several hours. Nicotine affects many body systems including the nervous, cardiovascular, and endocrine systems. 

Pharmacodynamics:  Nicotine stimulates the CNS directly, causing increased alertness and ability to focus, feelings of relaxation, and light-headedness. The cardiovascular effects of nicotine include an accelerated heart rate and increased blood pressure, caused by activation of nicotinic receptors located throughout the autonomic nervous system.

These cardiovascular effects can be particularly serious in patients taking oral contraceptives: The risk of a fatal heart attack is five times greater in smokers than in nonsmokers. Muscular tremors may occur with moderate doses of nicotine, and convulsions may result from very high doses. Nicotine affects the endocrine system by increasing the basal metabolic rate, leading to weight loss. Nicotine also reduces appetite. Chronic smoking leads to bronchitis, emphysema, and lung cancer. Both psychological and physical dependence occur relatively quickly with nicotine. Dependence

Once started on tobacco, patient tend to continue their drug use for many years, despite overwhelming medical evidence that the quality of life will be adversely affected and their life span shortened. Discontinuation results in agitation, weight gain, anxiety, headache, and an extreme craving for the drug.  Although nicotine replacement patches and gum assist patients in dealing with the unpleasant withdrawal symptoms, only 25% of patients who attempt to stop smoking remain tobacco-free a year later.

RELATED;

1.  CAFFEINE  

2.  DEPENDENCE AND WITHDRAWAL SYNDROME

3.  BIOCHEMISTRY

REFERENCES

MILK THISTLE FOR ALCOHOL LIVER DAMAGE

Milk thistle is a plant found growing in North America that has been used as an herbal medicine for centuries. The active ingredient in the milk thistle plant (Silybum marianum), silymarin, has been confirmed to exhibit hepatoprotective qualities by different research studies. Studies have shown that silymarin is able to neutralize the effects of alcohol and actually stimulate liver regeneration. It acts as an antioxidant and free-radical scavenger. It is typically taken for liver cirrhosis, chronic hepatitis, and gallbladder disorders. The herb has few side effects, other than mild diarrhea, bloating, and upset stomach.

RELATED;

1.  HEPATITIS  

2.  VITAMIN A  

3.  GINGER

REFERENCES

PARTURITION AND LABOR

INTRODUCTION: Parturition is the formal term for birth, and labor is the sequence of events that occur during birth. The average gestation period is 40 weeks equivalent to 280days, with a range of 37 to 42 weeks. Toward the end of gestation, the placental secretion of progesterone decreases while the estrogen level remains high, and the myometrium begins to contract weakly at irregular intervals. At this time the fetus is often oriented head down within the uterus. Labor itself may be divided into three stages:

FIRST STAGE: Dilation of the cervix. As the uterus contracts, the amniotic sac is forced into the cervix, which dilates (widens) the cervical opening. At the end of this stage, the amniotic sac breaks sometimes referred to as, rupture of the “bag of waters” and the fluid leaves through the vagina, which may now be called the birth canal. This stage lasts an average of 8 to 12 hours but may vary considerably.

SECOND STAGE: Delivery of the infant. More powerful contractions of the uterus are brought about by oxytocin released by the posterior pituitary gland and perhaps by the placenta itself.  This stage may be prolonged by several factors. If the fetus is positioned other than head down, delivery may be difficult. This is called a breech birth and may necessitate a cesarean section (C-section), which is delivery of the fetus through a surgical incision in the abdominal wall and uterus. For some women, the central opening in the pelvic bone may be too small to permit a vaginal delivery. Fetal distress, as determined by fetal monitoring of heartbeat for example, may also require a cesarean section.

THIRD STAGE: Delivery of the placenta (afterbirth). Continued contractions of the uterus expel the placenta and membranes, usually within 10 minutes after delivery of the infant. There is some bleeding at this time, but the uterus rapidly decreases in size, and the contractions compress the endometrium to close the ruptured blood vessels at the former site of the placenta. This is important to prevent severe maternal hemorrhage.

RELATED;

1.  HEMOLYTIC DISEASE OF THE NEW BORN  

2.  THE BCG VACCINATION

3.  NORMAL LABOR AND VARGINAL DELIVERY

4.  FETAL CIRCULATION

5.  ECTOPIC PREGNANCY

REFERENCES

FISH OILS FOR INFLAMMATION

Fish oils, also known as marine oils, are lipids found primarily in coldwater fish. These oils are rich sources of long-chain polyunsaturated fatty acids of the omega-3 type. The two most studied fatty acids found in fish oils are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These fatty acids are known for their triglyceride-lowering activity. Several mechanisms are believed to account for the anti-inflammatory activity of EPA and DHA. The two competitively inhibit the conversion of arachidonic acid to the proinflammatory prostaglandins, thus reducing their synthesis.

RELATED;

1.  VITAMIN A  2.  GARLIC  3.  INFLAMMATION

REFERENCES

CATALASE

 

INTRODUCTION: Catalase is a common enzyme found in nearly all living organisms exposed to oxygen including but not limited to; bacteria, plants, and animals. It catalyzes the decomposition of hydrogen peroxide to water and oxygen. [water, the universal solvent] 

IMPORTANCE OF CATALASE:  Catalase is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS). Likewise, catalase has one of the highest turnover numbers of all enzymes. One catalase molecule can convert approximately 5 million molecules of hydrogen peroxide to water and oxygen each minute. [BIOCHEMISTRY OF ENZYMES]  

BIOCHEMICAL TESTS FOR CATALASE:  The presence of catalase in a microbial or tissue sample can be tested by adding a volume of hydrogen peroxide and observing the reaction. The formation of bubbles, oxygen, indicates a positive result. This easy assay, which can be seen with the naked eye, without the aid of instruments, is possible because catalase has a very high specific activity, which produces a detectable response. 

HYDROGEN PEROXIDE AND THE HUMAN BODY:  Hydrogen peroxide is a harmful byproduct of many normal metabolic processes. To prevent damage to cells and tissues, it must be quickly converted into other, less dangerous substances. To this end, catalase is frequently used by cells to rapidly catalyze the decomposition of hydrogen peroxide into less-reactive gaseous oxygen and water molecules.

RELATED.

1.  BACTERIA AND THEIR CELLULAR COMPONENTS

REFERENCES

WINDOWS BACKUP AND INSTALLATION MEDIA TOOLS

 

WINDOW INSTALLATION MEDIA:  Have ever wondered shifting from one operating system to another let's say from Windows 8 to Windows 10?  Some 5 years back of course the idea would most likely be, getting a windows installation DVD prepared.  With the increasing technology however, a CD/DVD is not a trustable media anymore by many users due to it's requirements to be used and possible risks of loosing the software burnt on it.  Using flash drives to install windows now days is one of the most common methods used where you have to build the windows installation media on that drive before the process of installation goes on.  On this page, get some of the most useful tools in making windows backups and installation media using Hard drives, USB flash discs and CD/DVD.  You will find these tools very handy in making Windows-to-USB packages.

1.  MINI TOOL SHADOW MAKER:  This is one of my favorite tools when it comes to crooning drives and creation of media installation files for windows.  If you have not been following us in media installation articles, follow the link below for details.

Creating windows installation media

2.  AOMEI BACKUPPER SETUP  

3. HOW TO MAKE A WINDOWS 10 INSTALLATION ISO FILE  

4.  MACRIUM REFLEX MEDIA CREATION TOOL  

5.  RUFUS V1.38 

6.  UNETBOOTIN SETUP

But of course everyone has a better choice for doing certain things.  So if you trust a DVD writer more than a flash disc, you can follow the link below to download some of the light weight burning software.

CD/DVD burning software

RELATED;  

1.  Windows software downloads  

2.  Ultimate software downloads

3.  Software download links and video demos

PHYSIOLOGICAL PROCESSES IN THE HUMAN BODY

PHYSIOLOGICAL PROCESSES IN THE HUMAN BODY

PNEUMOCOCCUS

HABITAT: Pneumococci are normally present in the nasopharynx of many healthy persons. Carriage rate may be up to 30% in some communities. The organism usually does not cause any illness itself unless a viral infection or some other predisposing factor provokes it to spread to lower respiratory tract, middle ear, sinuses and blood and cause a large number of clinical entities.

MORPHOLOGY: Pneumococci are gram-positive cocci which are usually seen in pairs and hence sometimes called as diplococci. These are oval or spherical in shape whereas when seen in clinical material these look like lancet shaped, in pairs or in short chains. They measure 0.5 to 1.25 μm, are non-motile and non-sporing.

CULTURAL CHARACTERS: These are facultative anaerobes and can grow at temperatures between 25 and 40°C (optimal: 37°C). Growth is better in an environment of 5-10% carbon dioxide and on media enriched with blood, serum or heated blood. These substances provide essential nutrients as well as enzymes such as catalase which can neutralise the toxic hydrogen peroxide liberated by pneumococci.

When incubated aerobically the colonies are surrounded by greenish (alpha) haemolysis. Under anaerobic incubation, the haemolysis is clear (beta). The beta haemolysis is due to the production of heat labile pneumolysin. Because of the production of hydrogen peroxide and autolytic enzymes such as amidase, the organisms tend to die quickly in cultures. This happens more so in cultures, in media without blood or blood products.

BIOCHEMICAL REACTIONS: Pneumococci are oxidase and catalase negative organisms; ferment glucose, lactose, sucrose with the production of acid alone. Since some other streptococci such as Strept. faecalis, Strept. Viridans, also produce greenish haemolysis on blood agar, help of certain tests is taken to differentiate them.

SUSCEPTIBILITY TO PHYSICAL AND CHEMICAL AGENTS: Pneumococci are extremely fragile organisms; readily killed by most disinfectants as well as moist heat at 55°C within 10 minutes. It is difficult to maintain the cultures of this organism in the laboratory. Long-term preservation is possible only with freeze drying method.

TREATMENT: For all practical purposes, pneumococci are sensitive to penicillin and chemotherapy should be started as early as possible. In persons allergic to penicillin, any broad spectrum antibiotic can be given.

IMMUNITY: Immunity to infection with pneumococci is type specific and depends both on the antibodies to capsular polysaccharide and on intact phagocytic function. Vaccines can induce production of antibodies against the serotypes used in the vaccine.

PREVENTION: Avoidance of predisposing factors and maintaining healthy dry lungs are the best preventive measures. A polyvalent pneumococcal vaccine having antigens from 23 of the most commonly occurring serotypes is available and is recommended for use in young children, elderly patients or persons with predisposing factors to this infection.

RELATED;

1. BACTERIAL TOXINS

2.  STREPTOCOCCUS

3.  STAPHYLOCOCCUS

References

HOW TO WRITE A RESEARCH PROPOSAL

RESEARCH PROPOSAL:  Research projects are conducted in partial fulfilment for the award of diplomas and degree in different specialties.  It is one course unit that lasts for at least a year and towards the end of the course.  In our discussion here, we are going to look at the steps taken to develop a medical research proposal, and also look at the components of the medical research proposal.  We will also get the details of each part as we go along, plus different tactics on how the proposal and reports can be handled without hassle.

Medical research is a pre-requisite for medical student starting from undergraduate level depending of the medical specialty.  It is therefore a must that towards the end of the course, one must develop a research report and be able to defend it.  But before the research report, a proposal must be developed and then later, once it is approved by the Faculty ethics research committee, data is collected and a report is compiled for submission.  Before we continue in case you are new to proposal development, follow the link below for components of a research proposal before we continue.

Components of a research proposal

THE RESEARCH TOPIC:  Before starting the research proposal, one must have a research topic.  It is like the key to open a padlock.  But getting a research problem has not always been easy for students.  In most cases you find student looking around previously research topics and they play around with such work.  But it must be clear that, there is a lot that can be research and in my own view, a good medical student would look forward to research on something new to gain higher credibility.

THE RESEARCH PROBLEM:  So before thinking about getting a research topic, get a research problem first.  This will help you to formulate a problem statement later in your chapter one of the research proposal.  A research problem will be something of a medical or social concern.  The next question now will be; where do I get a research problem from?  A research problem can be be got from media, newspapers, previous research studies, recommendations from other researchers and even just from individual observation during practice.  Follow the link below on how to formulate a research problem.

Formulating a research problem

It is worth noticing that without a problem, there would otherwise be no need to conduct a research study.  And so, prevalence of a problem or a phenomena is the trigger for conduction of research studies in order to draw conclusions.  Let's take some examples to understand the way problems can be generated.

Example 1:  You are working on the medical ward and you notice that every patient from the theatre, will suffer some form of sepsis before being discharged.  The whole idea will be either the surgical team does not sterilize instruments well, the surgeon does not employ sterile techniques during the procedures, or the bedside health practitioners and or the patients attendants have less or no knowledge about the care of a postsurgical wound.  At this point, we all know that sepsis is deadly and must not happen in such case and therefore, the problem will in that case be "High prevalence of sepsis on that specific medical ward".

Example 2:  The sustainable development goals 3.1, outlines a target to reduce the Maternal mortality rate to 70 per 100,000 live birth by the year 2030.  In Uganda according to UNFPA, the number was 336 per 100,000 live birth in 2016.  Therefore the problem in that case was "A higher that expected maternal mortality rate".

If you want more about generating research problems, follow the link below.

Prevailing research problems 2022

Now that you are done with a research problem, you can choose a study setting where you will be able you conduct your study but before that, you may also want to get some information concerning the problem you have identified.  It makes a lot of meaning when you really know about the problem you are talking about and actually when the people who will read your research paper will actually have an idea about the same problem.  We have talked about the research study setting in details and if you would like to read more about it, click on the link below.

The research study setting

When you are done with the research problem and you are finished with formulating a research topic, then you can start making your research writings.  Sometime it is OK that you have chosen a research topic well and you are ready to submit it to your supervisor and or the Research and Ethics committee, then you notes that someone else have the same topic and sometimes as students, you may not be allowed to do topics under the same theme.  In that case I would say in advance that, it is always good to formulate more than one research topics, and then let the supervisor choose or suggest for you what is best.  The research supervisor is one of the most important entity in your research project and without him/her, your research may not be valid.

RELATED;

1.  THE PROBLEM STATEMENT

2.  COMPONENTS OF A RESEARCH PROPOSAL

3.  HOW TO WRITE A RESEARCH REPORT

4.  RESEARCH METHODOLOGY

5.  COMPONENTS OF A MEDICAL RESEARCH REPORT

FUNGI

INTRODUCTION: Fungi may be unicellular, such as yeasts, or multicellular, such as the familiar molds and mushrooms. Most fungi are saprophytes; that is, they live on dead organic matter and decompose it to recycle the chemicals as nutrients. The pathogenic fungi cause infections that are called mycoses (singular: mycosis), which may be superficial or systemic.

YEASTS: Yeasts have been used by people for thousands of years in baking and brewing. In small numbers, yeasts such as Candida albicans are part of the resident flora of the skin, mouth, intestines, and vagina. Normal flora

In larger numbers, however, yeasts may cause superficial infections of mucous membranes or the skin, or very serious systemic infections of internal organs. An all-too-common trigger for oral or vaginal yeast infections is the use of an antibiotic to treat a bacterial infection. Antibiotics

The antibiotic diminishes the normal bacterial flora, thereby removing competition for the yeasts, which are then able to overgrow. Yeasts may also cause skin infections in diabetics, or in obese people who have skin folds that are always moist. Diabetes mellitus: Obesity

NOSOCOMIAL FUNGAL INFECTIONS: In recent years, Candida has become an important cause of nosocomial infections. The resistance of hospital patients is often lowered because of their diseases or treatments, and they are more susceptible to systemic yeast infections in the form of pneumonia or endocarditis. Pneumonia

Another superficial mycosis is ringworm (tinea), which may be caused by several species of fungi. The name ringworm is misleading, because there are no worms involved. It is believed to have come from the appearance of the lesions: circular, scaly patches with red dened edges; the center clears as the lesion grows. Athlete’s foot, which is probably a bacterial-fungal infection, is perhaps the most common form of ringworm.

SYSTEMIC MYCOSES: The systemic mycoses are more serious diseases that occur when spores of some fungi gain access to the interior of the body. Most of these fungi grow in a mold-like pattern. The molds we sometimes see on stale bread or overripe fruit look fluffy or fuzzy. The fluff is called a mycelium and is made of many threadlike cellular structures called hyphae. The color of a mold is due to the spore cases (sporangia) in which the reproductive spores are produced.

FUNGAL SPORES: Each spore may be carried by the air to another site, where it germinates and forms another mycelium. Because spores of these fungi are common in the environment, they are often inhaled. The immune responses are usually able to prevent infection and healthy people are usually not susceptible to systemic mycoses. Elderly people and those with chronic pulmonary diseases are much more susceptible, however, and they may develop lung infections. The importance of the immune system is clearly evident if we consider people with AIDS. HIV/AIDS

Without the normal immune responses, AIDS patients are very susceptible to invasive fungal diseases, including meningitis caused by Cryptococcus. Pneumocystis jiroveci (formerly P.carinii and classified with the protozoa, its DNA sequences suggest it is closer to the fungi) is an important cause of pneumonia in people with AIDS. This species is usually not pathogenic, because the healthy immune system can easily control it. For AIDS patients, however, this form of pneumonia is often the cause of death.

RELATED;

1.  OPPORTUNISTIC MYCOSES

REFERENCES

INNATE IMMUNE SYSTEM

 

Introduction: The innate immune system, also known as the nonspecific immune system or in-born immunity system, is an important subsystem of the overall immune system that comprises the cells and mechanisms that defend the host from infection by other organisms. The cells of the innate system recognize and respond to pathogens in a generic way, but, unlike the adaptive immune system, the system does not confer long-lasting or protective immunity to the host.

Innate immune systems provide immediate defense against infection, and are found in all classes of plant and animal life. The innate immune system is an evolutionarily older defense strategy, and is the dominant immune system found in plants, fungi, insects, and primitive multicellular organisms. The major functions of the vertebrate innate immune system include: 

(1) Recruiting immune cells to sites of infection, through the production of chemical factors, including specialized chemical mediators, called cytokines. 

(2) Activation of the complement cascade to identify bacteria, activate cells, and promote clearance of antibody complexes or dead cells. 

(3) Identification and removal of foreign substances present in organs, tissues, the blood and lymph, by specialized white blood cells. 

(4) Activation of the adaptive immune system through a process known as antigen presentation. 

(5) Acting as a physical and chemical barrier to infectious agents.

RELATED;

1.  ACTIVE IMMUNISATION

REFERENCES

CHAMBERS OF THE HEART AND ASSOCIATED STRUCTURES

INTRODUCTION: The walls of the four chambers of the heart are made of cardiac muscle called the myocardium. The chambers are lined with endocardium, simple squamous epithelium that also covers the valves of the heart and continues into the vessels as their lining also known as endothelium. Simple squamousepithelium

The important physical characteristic of the endocardium is not its thinness, but rather its smoothness. This very smooth tissue prevents abnormal blood clotting, because clotting would be initiated by contact of blood with a rough surface.

THE UPPER TWO CHAMBERS: The upper chambers of the heart are the right and left atria, which have relatively thin walls and are separated by a common wall of myocardium called the interatrial septum.

THE LOWER TWO CHAMBERS: The lower chambers are the right and left ventricles, which have thicker walls and are separated by the interventricular septum.

The atria receive blood, either from the body or the lungs, and the ventricles pump blood to either the lungs or the body.

RIGHT ATRIUM: The two large caval veins return blood from the body to the right atrium. The superior vena cava carries blood from the upper body, and the inferior vena cava carries blood from the lower body. From the right atrium, blood will flow through the right atrioventricular (AV) valve, or tricuspid valve, into the right ventricle. The tricuspid valve is made of three flaps (or cusps) of endocardium reinforced with connective tissue. The general purpose of all valves in the circulatory system is to prevent backflow of blood. The specific purpose of the tricuspid valve is to prevent backflow of blood from the right ventricle to the right atrium when the right ventricle contracts. As the ventricle contracts, blood is forced behind the three valve flaps, forcing them upward and together to close the valve.

LEFT ATRIUM: The left atrium receives blood from the lungs, by way of four pulmonary veins. This blood will then flow into the left ventricle through the left atrioventricular (AV) valve, also called the mitral valve or bicuspid (two flaps) valve. The mitral valve prevents backflow of blood from the left ventricle to the left atrium when the left ventricle contracts. Another function of the atria is the production of a hormone involved in blood pressure maintenance. When the walls of the atria are stretched by increased blood volume or blood pressure, the cells produce atrial natriuretic peptide (ANP), also called atrial natriuretic hormone (ANH).

RIGHT VENTRICLE: When the right ventricle contracts, the tricuspid valve closes and the blood is pumped to the lungs through the pulmonary artery (or trunk). At the junction of this large artery and the right ventricle is the pulmonary semilunar valve. Its three flaps are forced open when the right ventricle contracts and pumps blood into the pulmonary artery. When the right ventricle relaxes, blood tends to come back, but this fills the valve flaps and closes the pulmonary valve to prevent backflow of blood into the right ventricle. Projecting into the lower part of the right ventricle are columns of myocardium called papillary muscles.

LEFT VENTRICLE: The walls of the left ventricle are thicker than those of the right ventricle, which enables the left ventricle to contract more forcefully. The left ventricle pumps blood to the body through the aorta, the largest artery of the body. At the junction of the aorta and the left ventricle is the aortic semilunar valve (or aortic valve). This valve is opened by the force of contraction of the left ventricle, which also closes the mitral valve. The aortic valve closes when the left ventricle relaxes, to prevent backflow of blood from the aorta to the left ventricle. When the mitral (left AV) valve closes, it prevents backflow of blood to the left atrium; the flaps of the mitral valve are also anchored by chordae tendineae and papillary muscles. This is fibrous connective tissue that anchors the outer edges of the valve flaps and keeps the valve openings from stretching. It also separates the myocardium of the atria and ventricles and prevents the contraction of the atria from reaching the ventricles except by way of the normal conduction pathway.

THE HEART AS A TWO SIDED PUMP: From the description of the chambers and their vessels, the heart is really a double, or two-sided, pump. The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs to pick up oxygen and release carbon dioxide. The left side of the heart receives oxygenated blood from the lungs and pumps it to the body. Both pumps work simultaneously; that is, both atria contract together, followed by the contraction of both ventricles.

RELATED;

1. CARDIAC FUNCTIONING AND THE HEART SOUNDS

2. PHYSIOLOGY OF THE CHAMBERS AND CIRCULATION THROUGH THE HEART

3. HEART MURMURS

4.  ANATOMY AND PHYSIOLOGY

REFERENCES

ACYCLOVIR

INTRODUCTION: Acyclovir is an acyclic guanosine derivative with clinical activity against HSV-1, HSV-2, and VZV, but it is approximately 10 times more potent against HSV-1 and HSV-2 than against VZV. In vitro activity against Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpes virus-6 (HHV-6) is present but weaker.

PHARMACOKINETICS: Acyclovir requires three phosphorylation steps for activation. It is converted first to the monophosphate derivative by the virus pecified thymidine kinase and then to the di- and triphosphate compounds by host cell enzymes. Enzymes

Because it requires the viral kinase for initial phosphorylation, acyclovir is selectively activated and the active metabolite accumulates only in infected cells. Acyclovir triphosphate inhibits viral DNA synthesis by two mechanisms: competition with deoxyGTP for the viral DNA polymerase, resulting in binding to the DNA template as an irreversible complex; and chain termination following incorporation into the viral DNA. DNA the genetic material

The bioavailability of oral acyclovir is low (15–20%) and is unaffected by food. An intravenous formulation is available. Topical formulations produce high concentrations in herpetic lesions, but systemic concentrations are undetectable by this route. Acyclovir is cleared primarily by glomerular filtration and tubular secretion. The half-life is 2.5–3 hours in patients with normal renal function and 20 hours in patients with anuria.

RELATED;

1.  NEVIRAPINE  2.  ZIDOVUDINE

REFERENCES