CARBOHYDRATES: These are some of the most important biomolecules in nature and the human body needs a lot of them. Carbohydrates are some of the most abundant chemicals of life in nature and we need them for provision of energy. they are the universal sources of energy in the human body. Carbohydrates are of different chemical structure and composition but in our discussion here, we shall be looking at starch and glycogen.
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2. Starch
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
ELECTRICALLY ACTIVE CELL MEMBRANES: Most cells in the body make use of charged particles, ions, to build up a charge across the cell membrane. Previously, this was shown to be a part of how muscle cells work. For skeletal muscles to contract, based on excitation–contraction coupling, requires input from a neuron. Both of the cells make use of the cell membrane to regulate ion movement between the extracellular fluid and cytosol. The cell membrane is primarily responsible for regulating what can cross the membrane and what stays on only one side. The cell membrane is a phospholipid bilayer, so only substances that can pass directly through the hydrophobic core can diffuse through unaided. Solubility of compounds
Charged particles, which are hydrophilic by definition, cannot pass through the cell membrane without assistance. Transmembrane proteins, specifically channel proteins, make this possible. Several channels, as well as specialized energy dependent ion-pumps, are necessary to generate a transmembrane potential and to generate an action potential.
RELATED;
1. PROPAGATION OF A NERVE IMPULSE
2. DIVISIONS OF THE NERVOUS SYSTEM
3. THE SYNAPSE
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
ULBUM OF OBSTETRICS AND GYNECOLOGY
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
SOURCE AND RESERVOIR: The source of infection is the person, animal, object or substance from which an infectious agent passes or disseminates to the host whereas a reservoir is defined as any person, animal, arthropod, plant, soil or substance (or combination of these) in which an infectious agent lives and multiplies. These can be of three types: 1) Humans 2) Animals 3) Non-living substances. Humans For infectious diseases of human beings, man is the most important reservoir. He may be a case or a carrier.
HUMAN CASE: A case may be having a clinical disease or subclinical infection which remains unmanifested or abortive. In latter, the disease agent may multiply in the host but does not manifest itself by signs and symptoms.
Though carriers are less infectious than cases, they carry greater epidemiological importance because of the prolonged duration for which they can silently excrete organisms. The carriers can be: 1) incubatory 2) convalescent or 3) healthy. Depending upon the duration of excretion of microorganisms they can be designated as: 1) temporary (acute) or 2) chronic carriers.
The incubatory and convalescent carriers are usually temporary whereas chronic carriers are otherwise healthy individuals. Chronic carrier state occurs in various diseases notably typhoid fever and hepatitis B. Hepatitis B
ANIMALS: Animals and birds can also pass on microorganisms to man. These may also manifest as case or exist as carriers. The diseases which are naturally transmissible between man and animals are called as zoonoses. These diseases are of great importance in countries where a close contact between man and animals is inevitable such as occurs in rural areas of India and Sub-Saharan Africa. Some of the important zoonotic infections are rabies; plague, brucellosis, leptospirosis, hydatidosis. Brucellosis
NON-LIVING SUBSTANCES: Soil and inanimate objects can also occur as reservoir of some microorganisms such as causative agents of infectious tetanus, anthrax, hookworm disease and mycetoma.
The indirect transmission is possible by any of the following mechanisms; 1) Vehicles (water, food etc.). 2) Vectors (mechanical or biological). 3) Air (droplet or dust). 4) Fomites. 5) Unclean hands and fingers.
MECHANISM OF INFECTION: To produce infection in man a microbe has to gain entry into the host. The most frequent portals of entry are the respiratory tract, the gastrointestinal tract and breaks in the superficial mucous membranes and skin. From the portal of entry the parasite may spread directly through the tissues or may proceed via lymphatic channels to the blood stream, which distributes it widely and permits it to reach tissues particularly suitable for its multiplication. Nevertheless, for the perpetuation of a parasitic species a satisfactory portal of exit of the parasite from the host and an effective mechanism for transmission to new hosts are also of paramount importance.
DEVELOPMENT OF DISEASE: Once the microorganism overcomes the defences of the host, development of infectious disease follows a sequence of events.
Period of Incubation: This is the time interval between the actual infection and the appearance of first clinical feature.
Prodromal Period: This relatively short period follows incubation period in some diseases. It is characterised by mild early symptoms such as general aches and malaise.
Period of Illness: This is the acute phase of illness characterised by typical clinical features of the infectious disease.
Period of Decline: During this period the signs and symptoms subside. The fever decreases and the feeling of malaise diminishes
Period of Convalescence: The person regains strength during this period and body returns to pre-diseased state.
LOCAL OR GENERALISED INFECTIONS: An infection may be restricted to the point of entry (local) or may spread throughout the body (generalized).
Generalised Infections: Bacteraemia, septicaemia and pyaemia are some of the generalised infections which spread through blood:
Bacteraemia: Bacteraemia is defined as the circulation of bacteria in the blood. It may be transient or of long duration depending upon the duration for which bacteria are present in the blood. Transient bacteraemia is a frequent event which occurs even in healthy individuals while chewing, brushing of teeth and straining while passing stools. Bacteraemia of long duration occurs with pathogenic organisms such as Salmonella typhi and Brucella and is essential for the initiation of disease process.
Septicaemia: This is a condition in which bacteria circulate and multiply in the blood, form toxic products and cause high swinging type of fever. This can be due to both endotoxin as well as exotoxin producing organisms.
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1. SEPTIC SHOCK
2. FEVERS
4. VIRULENCE OF MICROORGANISMS
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
PATHOGENESIS AND CLINICAL PICTURE: Human brucellosis infections result from direct contact with diseased animals or indirectly by way of contaminated foods, in particular unpasteurized milk and dairy products. The bacteria invade the body either through the mucosa of the upper intestinal and respiratory tracts or through lesions in the skin, then enter the subserosa or subcutis. From there they are transported by microphages or macrophages, in which they can survive, to the lymph nodes, where a lymphadenitis develops. The pathogens then disseminate from the affected lymph nodes, at first lymphogenously and then hematogenously, finally reaching the liver, spleen, bone marrow, and other tissues, in the cells of which they can survive and even multiply. The granulomas typical of intracellular bacteria develop. From these inflammatory foci, the brucellae can enter the bloodstream intermittently, each time causing one of the typical febrile episodes, which usually occur in the evening and are accompanied by chills. The incubation period is one to four weeks. B. melitensis infections are characterized by more severe clinical symptoms than the other brucelloses.
DIAGNOSIS: This is best achieved by isolating the pathogen from blood or biopsies in cultures, which must be incubated for up to four weeks. The laboratory must therefore be informed of the tentative diagnosis. Brucellae are identified based on various metabolic properties and the presence of surface antigens, which are detected using a polyvalent Brucella-antiserum in a slide agglutination reaction. Special laboratories are also equipped to differentiate the three Brucella species. Antibody detection is done using the agglutination reaction according to Gruber-Widal in a standardized method. In doubtful cases, the complement-binding reaction and direct Coombs test can be applied to obtain a serological diagnosis.
THERAPY: Doxycycline is administered in the acute phase, often in combination with gentamicin. A therapeutic alternative is cotrimoxazole. The antibiotic regimen must be continued for three to four weeks.
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4. FEVER
5. DIARRHEA
6. BACTERIOLOGY
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
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2. HEMMOLYTIC DISEASE OF THE NEW BORN
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
Isotonic: a solution with the same salt concentration
as in cells. The blood plasma is isotonic to red blood cells.
Hypotonic: a solution with a lower salt concentration
than in cells. Distilled water (0% salt) is hypotonic to human cells.
Hypertonic: a solution with a higher salt concentration
than in cells. Seawater (3% salt) is hypertonic to human cells.
When RBCs are in plasma, water moves into and out of them at equal rates, and the cells remain normal in size and water content.
If RBCs are placed in distilled water, more water will enter the cells than leave, and the cells will swell and eventually burst.
If RBCs are placed in seawater, more water will leave the cells than enter, and the cells will shrivel and die.
This knowledge of osmotic pressure is used when replacement fluids are needed for a patient who has become dehydrated. Isotonic solutions are usually used; normal saline and Ringer’s solution are examples. These will provide rehydration without causing osmotic damage to cells or extensive shifts of fluid between the blood and tissues.
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2. BLOOD PLASMA
3. WATER
4. IV FLUIDS
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
2) Water is a lubricant, which prevents friction where surfaces meet and move. In the digestive tract, swallowing depends upon the presence of saliva, and mucus is a slippery fluid that permits the smooth passage of food through the intestines. Synovial fluid within joint cavities prevents friction as bones move.
3) Water changes temperature slowly. Water has a high heat capacity, which means that it will absorb a great deal of heat before its temperature rises significantly, or it must lose a great deal of heat before its temperature drops significantly. This is one of the factors that helps the body maintain a constant temperature. Water also has a high heat of vaporization, which is important for the process of sweating. Excess body heat evaporates sweat on the skin surfaces, rather than overheating the body’s cells, and because of water’s high heat of vaporization, a great deal of heat can be given off with the loss of a relatively small amount of water.
INTRACELLULAR FLUID (ICF): This is the water within cells; about 65% of the total body water.
EXTRACELLULAR FLUID (ECF): All the rest of the water in the body; about 35% of the total. More specific compartments of extracellular fluid include:
Plasma; water found in blood vessels
Lymph; water found in lymphatic vessels
Tissue fluid or interstitial fluid; water found in the small spaces between cells.
Specialized fluids; synovial fluid, cerebrospinal fluid, aqueous humor in the eye, and others.
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1. PLASMA
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
Pharmacologic Class: Benzodiazepine; GABAA receptor agonist
ACTIONS AND USES: Diazepam binds to the GABA receptor–chloride channels throughout the CNS. It produces its effects by suppressing neuronal activity in the limbic system and subsequent impulses that might be transmitted to the reticular activating system. Effects of this drug are suppression of abnormal neuronal foci that may cause seizures, calming without strong sedation, and skeletal muscle relaxation. When used orally, maximum therapeutic effects may take from 1 to 2 weeks. Tolerance may develop after about 4 weeks. When given IV, effects occur in minutes, and its anticonvulsant effects last about 20 minutes.
ADMINISTRATION ALERTS: When administering IV, monitor respirations every 5 to 15 minutes. Have airway and resuscitative equipment accessible. The drug is pregnancy category D.
ADVERSE EFFECTS: Because of tolerance and dependency, use of diazepam is reserved for short term seizure control or for status epilepticus. When given IV, hypotension, muscular weakness, tachycardia, and respiratory depression are common.
Contraindications: When administered in injectable form, this medication should be avoided under the following conditions: shock, coma, depressed vital signs, obstetrical patients, and infants less than 30 days of age. In tablet form, the medication should not be administered to infants less than 6 months of age, to patients with acute narrow-angle glaucoma or untreated open-angle glaucoma, or within 14 days of monoamine oxidase inhibitor (MAOI) therapy.
INTERACTIONS: Drug–Drug: Diazepam should not be taken with alcohol or other CNS depressants because of combined sedation effects. Other drug interactions include cimetidine, oral contraceptives, valproic acid, and metoprolol, which potentiate diazepam’s action; and levodopa and barbiturates, which decrease diazepam’s action. Diazepam increases the levels of phenytoin in the bloodstream and may cause phenytoin toxicity.
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3. DEPRESSION
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
DEGREE OF ACIDITY AND ALKALINITY: The acidity or alkalinity (basicity) of a solution is measured on a scale of values called pH (parts hydrogen). The values on the pH scale range from 0 to 14, with 0 indicating the most acidic level and 14 the most alkaline. A solution with a pH of 7 is neutral because it contains the same number of H ions and OH ions. Pure water has a pH of 7. A solution with a higher concentration of H ions than OH ions is an acidic solution with a pH below 7. An alkaline solution, therefore, has a higher concentration of OH ions than H ions and has a pH above 7.
DYNAMICS OF pH IN THE BODY: A change of one pH unit is a 10-fold change in H ion concentration. This means that a solution with a Ph of 4 has 10 times as many H ions as a solution with a pH of 5, and 100 times as many H ions as a solution with a pH of 6. For example, gastric juice has a pH of 1 and coffee has a pH of 5. This means that gastric juice has 10,000 times as many H ions as does coffee. Although coffee is acidic, it is a weak acid and does not have the corrosive effect of gastric juice, a strong acid. The cells and internal fluids of the human body have a pH close to neutral. The pH of intracellular fluid is around 6.8, and the normal pH range of blood is 7.35 to 7.45. Fluids such as gastric juice and urine are technically external fluids, because they are in body tracts that open to the environment. The pH of these fluids may be more strongly acidic or alkaline without harm to the body. The pH of blood, however, must be maintained within its very narrow, slightly alkaline range. A decrease of only one pH unit, which is 10 times as many H ions, would disrupt the chemical reactions of the blood and cause the death of the individual.
Normal metabolism tends to make body fluids more acidic, and this tendency to acidosis must be continually corrected. Normal pH of internal fluids is maintained by the kidneys, respiratory system, and buffer systems.
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1. LACTIC ACID
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
ABNORMAL CELLULAR DIVISION: Malignant (cancer) cells, however, are characterized by uncontrolled cell division. Our cells are genetically programmed to have particular life spans and to divide or die. One gene is known to act as a brake on cell division; another gene enables cells to live indefinitely, beyond their normal life span, and to keep dividing. Any imbalance in the activity of these genes may lead to abnormal cell division. Such cells are not inhibited by contact with other cells, keep dividing, and tend to spread.
MALIGNANCY: A malignant tumor begins in a primary site such as the colon, then may spread or metastasize. Often the malignant cells are carried by the lymph or blood to other organs such as the liver, where secondary tumors develop. Metastasis is characteristic only of malignant cells; benign tumors do not metastasize but remain localized in their primary site. A malignant cell is created by a mutation, a genetic change that brings about abnormal cell functions or responses and often leads to a series of mutations.
CAUSES OF CANCER: Environmental substances that cause mutations are called carcinogens. One example is the tar found in cigarette smoke, which is definitely a cause of lung cancer. Ultraviolet light may also cause mutations, especially in skin that is overexposed to sunlight. For a few specific kinds of cancer, the trigger is believed to be infection with certain viruses that cause cellular mutations. Carriers of hepatitis B virus, for example, are more likely to develop primary liver cancer than are people who have never been exposed to this virus. Research has discovered two genes, one on chromosome 2 and the other on chromosome 3, that contribute to a certain form of colon cancer. Both of these genes are the codes for proteins that correct the “mistakes” that may occur when the new DNA is synthesized. When these repair proteins do not function properly, the mistakes (mutations) in the DNA lead to the synthesis of yet other faulty proteins that impair the functioning of the cell and predispose it to becoming malignant.
PROGRESSION OF CANCER: Once cells have become malignant, their functioning cannot return to normal, and though the immune system will often destroy such cells, sometimes it does not, especially as we get older. Therefore, the treatments for cancer are directed at removing or destroying the abnormal cells. Surgery to remove tumors, radiation to destroy cells, and chemotherapy to stop cell division or interfere with other aspects of cell metabolism are all aspects of cancer treatment. New chemotherapy drugs are becoming more specific, with very precise targets. For example, the cells of several types of solid-tumor cancers have been found to have mutations in the gene for the cell membrane receptor for a natural growth factor (epidermal growth factor receptor, or EGFR). These altered receptors, when triggered by their usual growth factor, then cause the cell to divide uncontrollably, an abnormal response. Medications that target only these altered receptors have already been developed for some forms of lung cancer and breast cancer. Not only do they show promise in treating the cancer, they do not have the side effects of other forms of chemotherapy.
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1. APOPTOSIS
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
Pharmacologic Class: Tricyclic antidepressant
ACTIONS AND USES: Imipramine blocks the re-uptake of serotonin and norepinephrine into nerve terminals. It is used mainly for major depression, although it is occasionally used for the treatment of nocturnal enuresis (bed wetting) in children. It may also be prescribed for a number of unlabeled uses, including intractable pain, anxiety disorders, and withdrawal syndromes from alcohol and cocaine. Therapeutic effectiveness may not occur for 2 or more weeks.
ADMINISTRATION ALERTS: Paradoxical diaphoresis can be a side effect of TCAs; therefore, diaphoresis may not be a reliable indicator of other disease states such as hypoglycemia.
Imipramine causes anticholinergic effects and may potentiate effects of anticholinergic drugs administered during surgery. Do not discontinue abruptly because rebound dysphoria, irritability, or sleeplessness may occur. Pregnancy category C.
ADVERSE EFFECTS: Side effects include sedation, drowsiness, blurred vision, dry mouth, and cardiovascular symptoms such as dysrhythmias, heart block, and extreme hypertension. Agents that mimic the action of norepinephrine or serotonin should be avoided because imipramine inhibits their metabolism and may produce toxicity. Some patients may experience photosensitivity and hypersensitivity to tricyclic drugs.
Warning: Antidepressants increase the risk of suicidal thinking and behavior, especially in children, adolescents, and young adults with major depressive disorder and other psychiatric disorders. This drug is not approved for use in pediatric patients.
Contraindications: This drug should not be used in cases of acute recovery after MI, defects in bundle-branch conduction, narrow-angle glaucoma, and severe renal or hepatic impairment. Patients should not use this drug within 14 days of discontinuing MAOIs.
INTERACTIONS: Drug–Drug: Concurrent use of other CNS depressants, including alcohol, may cause sedation. Cimetidine may inhibit the metabolism of imipramine, leading to increased serum levels and possible toxicity. Imipramine may reverse the antihypertensive effects of clonidine and potentiate CNS depression. Use of oral contraceptives may increase or decrease imipramine levels. Disulfiram may lead to delirium and tachycardia. Antithyroid agents may produce agranulocytosis. Phenothiazines cause increased anticholinergic and sedative effects. Sympathomimetics may result in cardiac toxicity. Methylphenidate or cimetidine may increase the effects of imipramine and cause toxicity. Phenytoin is less effective when taken with imipramine. MAOIs may result in neuroleptic malignant syndrome.
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1. DEPRESSION
Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
Pharmacologic Class: Opioid receptor agonist
ACTIONS AND USES: Morphine binds with both mu and kappa receptor sites to produce profound analgesia. It causes euphoria, constriction of the pupils, and stimulation of cardiac muscle. It is used for symptomatic relief of serious acute and chronic pain after non-narcotic analgesics have failed, as pre-anesthetic medication, to relieve shortness of breath associated with heart failure and pulmonary edema, and for acute chest pain connected with MI.
ADMINISTRATION ALERTS: The oral solution may be given sublingually. The oral solution comes in multiple strengths; carefully observe drug orders and labels before administering. Morphine causes peripheral vasodilation, which results in orthostatic hypotension. Pregnancy category B (D in long-term use or with high doses).
ADVERSE EFFECTS: Morphine may cause dysphoria (restlessness, depression, and anxiety), hallucinations, nausea, constipation, dizziness, and an itching sensation. Overdose may result in severe respiratory depression or cardiac arrest. Tolerance develops to the sedative, nausea-producing, and euphoric effects of the drug. Cross-tolerance also develops between morphine and other opioids such as heroin, methadone, and meperidine.
Physical and psychological dependence develops when high doses are taken for prolonged periods.
Warning: When morphine is administered as an epidural drug, due to the risk of adverse effects, patients must be observed in a fully equipped and staffed environment for at least 24 hours. Morphine administered as extended-release tablets has an abuse liability similar to other opioid analgesics. Morphine is a Schedule II controlled substance and should be taken properly according to dispensing instructions (i.e., tablets/capsules should be taken whole and not broken, chewed, dissolved, or crushed). Alcohol should be avoided with morphine products. Failure to follow these warnings could result in fatal respiratory depression.
Contraindications: Morphine may intensify or mask the pain of gallbladder disease, due to biliary tract spasms. Morphine should also be avoided in cases of acute or severe asthma, GI obstruction, and severe hepatic or renal impairment.
INTERACTIONS: Drug–Drug: Morphine interacts with several drugs. For example, concurrent use of CNS depressants, such as alcohol, other opioids, general anesthetics, sedatives, and antidepressants such as monoamine oxidase (MAO) inhibitors and tricyclics, potentiate the action of opiates, increasing the risk of severe respiratory depression and death.
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Godfrey Kateregga as the author and administrator of this page, is a Ugandan youth male Graduate from Mbarara University of Science and Technology, Faculty of Medicine, Western Uganda. He is a medical scientist with over half a decade in instructing medical students and, interested in sharing medical information and medical informatics plus ICT, widely experienced in training Adults with special needs.
