Starting with A for "ACE inhibitor" and continuing through to Y for "Yolk Sac Tumour", we give you succinct explanations for scientific and medical terms in clear and simple words.
- Paget's diseasesee osteodystrophia deformans
- pallora lack of colour in the skin
- Palmar ErythemaName for permanent reddening of the inner surface of the hands, particularly on the thumb and ball of the little finger. Palmar erythema occurs as a so-called liver skin sign, e.g. in chronic liver inflammation and liver cirrhosis.
- palpitationsa sensation of pounding or racing of the heart, resulting from an increase in the force of contraction of the heart
- PancreasGland which is 15-20 cm long and which weighs ca. 70-80 g. The main efferent duct (Ductus pancreaticus) and the bile duct (Ductus choledochus) both exit in the small intestine. The pancreas consists of an exocrine portion which produces enzymes and an endocrine portion which produces hormones. The endocrine portion is made up of all the islets of Langerhans , the so-called islet system.
1. Exocrine (secretory) function: production of digestive juice which contains enzymes. The 24 h production is ca. 1-1.5 l and secretion is controlled by nerves (vagus, sympathetic system) and hormones. The most important enzymes are a) Protein-splitting enzymes (proteases), particularly trypsin and chymotrypsin and peptide-splitting enzymes (peptidases); b) Lipid-splitting enzymes (esterases), particularly pancreatic lipase, lecithinases A and B, phosphatase and cholinesterase; c) Carbohydrate-splitting enzymes such as amylases and maltase; d) Nucleic acid-splitting enzymes (nucleases); 2. endocrine function: see islets of Langerhans. Cf. type 2 diabetes
- Pancreatic CarcinomaMalignant tumour of the pancreatic gland and third most frequent tumour of the digestive tract. The peak frequency is between 50 and 60 years of age. Men are somewhat more often affected than women.
Causes: The exact causes are unknown. Risk factors include smoking, alcohol abuse, chronic inflammation of the pancreas (pancreatitis) and cases of pancreatic carcinoma in the family (possible genetic cause). Pancreatic carcinoma rapidly forms metastases.
Symptoms: There is almost no typical early symptom. Later there is pain in the upper abdomen which extends into the back, loss of weight, loss of appetite, anaemia, jaundice (see icterus), enlargement of the gallbladder and more rarely to digestive problems because of deficiencies in digestive enzymes.
Diagnosis: Laboratory investigation of substances which are produced by cancer cells, the so-called tumour markers (e.g. CA 19-9, CA 50), examination of the bile and pancreatic ducts with a small tube with camera (the so-called ERCP = endoscopic retrograde cholangiopancreaticography), nuclear spin tomography, ultrasound investigation.
Therapy: An operation is possible in only 20% of cases. Often only operations are possible which improve the patients quality of life, by reducing pain or restoring the ability to digest. Cure is only rarely possible.
Prognosis: The 5-year survival is only 5%.
- Pancreatic TumoursBenign and malignant tumours of the pancreas. For malignant tumours, see Pancreatic Carcinoma. The benign tumours are usually derived from the gland cells of the pancreas gland and also produce the corresponding hormones: glucagon (raises blood sugar concentration), insulin (reduces blood sugar concentration, see Islet Cell Carcinoma), gastrin (stimulates digestion). In rarer cases the benign tumours originate from connective tissue or lymph duct cells.
Diagnosis: Ultrasound investigation, computer tomography, nuclear spin tomography, extraction of samples from the tumour and examination of the cells, possibly hormone investigation
- pancytopeniaa reduction in the number of all types of blood cells
- PandemicSpreading of an infectious disease over countries and continents, e.g. influenza pandemic. Cf. endemic disease, epidemic.
- Papilloma of the LarynxBenign cabbage-shaped pale red tumour in the area of the larynx. Several tumours may occur at the same time (so-called laryngeal papillomatosis) and this particularly occurs in children. Malignancy may develop, especially in adults.
Symptoms: Laryngeal papilloma causes hoarseness and breathing difficulties, although the individual symptoms depend on how large the papilloma is and where it is situated.
Diagnosis: The diagnosis is made on the basis of (microscopic) laryngoscopy and the examination of tissue samples.
Therapy: Therapy consists of the removal of the papilloma by laser surgery or microsurgery. This should be as complete as at all possible. Spontaneous regression during puberty may occur. Cf. Precancerosis, Larnygeal.
- Parainfluenza VirusGroup of RNA viruses for which 15 serotypes are distinguished in man, cows, sheep, monkeys, dogs and mice. Four serotypes which cause disease are known in man. The distribution is throughout the world. Sporadic disease and small epidemics of different severity, particularly in winter, may occur. Inflammation in the throat, rhinitis, acute bronchitis and pneumonia may develop. Children and older people are mainly affected. The course of the disease may be severe on first infection and in babies. Subsequent infections either cause only mild symptoms or none at all.
- Paralysis of the Trochlear NerveParalysis of the muscle (Musculus obliquus superior) which is responsible for the movements of the ball of the eye and which is served by the Nervus trochlearis (fourth cranial nerve).
1.Unilateral paralysis of the trochlear: Upward deviation of the affected eye when looking inwards, outward cycloversion, vertical double images. The head is leant towards the other side to balance these effects. 2. Bilateral paralysis of the trochlear: Alternating upward deviation of one eye, depending on the horizontal field of view, marked outward cycloversion. Patients tend to look upwards with the head forwards.
The main causes of trochlear nerve paralysis as a single symptom are injury, nerve disease from poor perfusion (particularly in type 2 diabetes or type 1 diabetes and high blood pressure). Trochlear nerve paralysis in combination with paralysis of other cranial nerves develops in disease of the base of the skull or brain stem.
- Paranasal Sinusitissee sinusitis
- ParathormoneAbbreviation PTH; also known as parathyrin
Parathormone is a hormone of calcium metabolism which is formed in the adrenal gland; its secretion depends on the calcium concentration in blood serum. A low calcium concentration raises and a high concentration reduces its production and release.
Points of action and metabolic effects
1. Skeleton: Increases bone breakdown; the osteoclasts break down bone and are stimulated by parathormone. As a result of the activity of the osteoclasts, calcium is released from bone, leading to an increase in serum calcium concentration; 2. Kidneys: Increases the secretion of phosphate, inhibits the re-uptake of phosphate, increases the re-uptake of calcium; 3. Parathormone favours the conversion of 25-hydroxycholecalciferol in the kidney to the hormone calcitriol. Result: Increase in the concentration of calcium and decrease in the concentration of phosphate in blood. Increase in the activity of alkaline phosphatase. The hormone calcitonin opposes the action of parathormone.
- parathyroid glandssmall glands located in the neck that produce parathyroid hormone
- PCRsee Polymerase Chain Reaction
- pericardial effusioncollection of fluid or blood in the sac (pericardium) that surrounds the heart
- peripheral vascular diseasedisease of blood vessels outside the heart and brain; often a narrowing of vessels that carry blood to leg and arm muscles
- peritoneal dialysisa procedure performed in the peritoneal cavity in which the peritoneum acts as the semipermeable membrane
- permeableallowing fluids and certain other substances to pass through a membrane
- pernicious anemiaPernicious anemia (pernicious = malevolent) is a form of anemia (bloodlessness) based on vitamin B12 deficiency. Vitamin B12 plays a significant role in blood formation. This anemia due to vitamin B12 deficiency must be treated by administering vitamin B12. It is commoner in women than in men, mainly affecting elderly patients. Vitamin B12 is found only in foods of animal origin, especially in liver. The daily requirement is 23 micrograms. The vitamin is absorbed from food in the intestine with the aid of a special protein molecule (intrinsic factor) secreted in the stomach, which binds the vitamin and in this way protects it from destruction
- Personalised HealthcarePHC in general describes an approach to healthcare that specifically takes into account emerging knowledge about the molecular pathology of diseases and of patients individual characteristics.
- pHunit used to describe the acidity of a solution
- PhagocytesPhagocytes are specialised white blood cells, which are capable of taking up, destroying and breaking down solid particles, such as tissue residues, foreign bodies and microorganisms. A distinction is made between largely locally fixed phagocytes (macrophages) from those which circulate in the body (monocytes and granulocytes).
- phagocytosiscell eating
- Pharyngeal CarcinomaMalignant tumour of the mucous membrane of the throat.
- PhosphatasesEnzymes which hydrolyse organic monoesters of phosphoric acid. Frequently of low specificity. They act in antagonism to enzymes which transfer phosphate groups.
The phosphatases are classified on the basis of the compounds from which they remove phosphate (e.g. glucose-6-phosphatase, fructose-1, 6-bisphosphatase, nucleotidases) and the acidity at which they act best (pH optimum).
Abbreviation AP (pH optimum at 5). This mostly occurs in the prostate, red blood cells and blood platelets, kidneys, liver, pancreas and spleen. Raised concentration in blood serum are particularly found in prostatic cancer, bone metastases of cancer and various bone diseases.
Abbreviation ALP (pH optimum at 7-8). This mostly occurs in the liver, bone, mucous membrane of the small intestine and in the epithelium of the bile duct. Raised concentrations are particularly found in bone diseases which are accompanied by increased osteoblast activity, such as early rickets, in metastatic cancer in the bone and in diseases of the liver and bile ducts.
- PhosphatesSalts derived from orthophosphoric acid. A distinction is made between primary, secondary and tertiary phosphates, depending on whether one, two or three atoms of hydrogen are replaced by metals.
- Pickwick syndromealso known as the cardiopulmonary syndrome
Syndrome associated with heavily overweight individuals and named after the figure Little Joe in Dickens' "The Pickwick Papers". Disease associated with the sleep apnoea syndrome, extreme overweight, oxygen deficiency in arterial blood (hypoxaemia), with raised blood carbon dioxide (hypercapnia), excessive cardiac stress and respiratory acidosis. These symptoms are caused by restrictions to breathing caused by excessive deposits of fat in the neighbourhood of the lungs. The production is increased of red blood cells (which bind oxygen). This increases blood viscosity and thus decreases the perfusion of small blood vessels. Sleepiness and attacks of sudden sleep (carbon dioxide "autonarcosis") occur as a result of the hypercapnia.
- Pituitaryalso known as Glandula pituitaria or pituitary gland
The pituitary is an organ which lies at the base of the skull. It forms hormones and is the size of a cherry. It is directly connected to the hypothalamus through the pituitary stalk and together with this forms a functional unit. The pituitary consists of different sections: 1. Anterior pituitary lobe (abbreviated as APL): so-called adenopituitary; this is a hormone-producing gland which is connected with the midbrain (diencephalon) through a special vascular system. Six hormones have been shown to be formed in the APL: FSH, LH, TSH, ACTH, prolactin and STH. With the exception of the latter (which acts directly), these are all hormones which regulate the function of other subsidiary organs which also produce hormones. The hormone release by the pituitary is regulated by the so-called releasing hormones. 2. Intermediate pituitary lobe (abbreviated as IPL), which in man is only present in an atrophied or rudimentary form. The hormone MSH is formed here. 3. Posterior pituitary lobe (abbreviated as PPL), the so-called neuropituitary. This is connected with the hypothalamus by nerve fibres. The hormones oxytocin and vasopressin (ADH) are stored in the PPL and then released.
- Plasma CellsPlasma cells are a type of white blood cell. They are formed from B-cells and have the job of forming antibodies when the human body is confronted with foreign substances, such as infective agents.
- plasma proteinsproteins dissolved in blood plasma
- PlasmacytesSee Plasma cells.
- Pleural MesotheliomaRare malignant tumour of the pulmonary pleura (lung covering), which can grow as an isolated tumour or as several scattered foci in the area of the ribs, diaphragm and the inside of the abdominal cavity. It is frequently caused by asbestos and then occurs 20 to 40 years after exposure (see Occupational Cancer).
Symptoms: Pain in the chest, breathing problems, accumulation of fluid between the folds of the pulmonary pleura (pleural effusion), cough, loss of weight, fever.
Diagnosis: X-ray investigation of the chest, computer tomography, removal of fluid from the space between the folds of the pulmonary pleura (pleural punctation), investigation of the inside of the chest with the help of a camera which is introduced into the chest through a small tube (thorascopy).
Therapy: Operation, radiotherapy and chemotherapy. The prognosis for pleural mesathelioma is very poor.
- pluripotentnot fixed as regards developmental potential; capable of differentiating into one of many cell types
- Pneumocystis carinii PneumoniaPneumocysis carinii pneumonia is a form of inflammation of the lung which is caused by the infective agent Pneumocystis carinii. The disease mostly occurs in patients with weakened immune systems, particularly with HIV disease. The detection leads to the diagnosis of AIDS. The disease either increases gradually in severity and the symptoms, such as cough or difficulties in breathing are present for a protracted period. Alternatively, particularly in patients with a weakened immune system, the disease may be sudden and intense and then frequently leads to death. What is typical is the lack of correlation between the severity of the clinical picture and the X-ray findings, which are often normal. This can lead to mistakes in the evaluation of the condition.
- PneumoniaPneumonia is the technical medical expression for inflammation of the lung. Severe pneumonia involves chills, a rapid increase in temperature, rapid breathing, marked tendency to cough and bloody sputum. Since the introduction of antibiotic therapy this is only rarely observed. There is usually an irregular and slow increase in body temperature with slimy and pussy sputum. The disease is mostly detected in the X-rays. Changes in blood count also occur. The infectious agent can be detected in body fluids. Depending on the symptoms, the treatment includes general measures such as reduced physical activity, moistening of the air breathed, increase in amount of fluid drunk, etc..
- PollenPollen is the dust from flowers. Pollen causes allergies in an increasing number of people. These allergies are seen as hay fever, occasionally together with inflammation of the conjunctiva of the eyes. In some cases asthma or rash may develop.
- polycystic kidney diseasean inherited progressive disease characterised by formation of multiple cysts of varying size scattered diffusely throughout both kidneys and resulting in destruction of the kidney tissue, hypertension, bloody urine and uremia
- polycythemiaa condition in which the number of red blood cells in the circulation is elevated above normal, resulting in increased viscosity or thickness of the blood
- PolygeniaDependence of a hereditary characteristic on several genes. Most physical properties which occur to a variable degree are polygenic, i.e. determined by several genes. The genes involved are also called polygenic. There is additive polygenia when different degrees of the occurrence of a characteristic are caused by the different numbers of activated genes (e.g. physical size, hair colour).
- Polymerase Chain ReactionThe polymerase chain reaction is a technique in molecular biology which is used in genetic engineering and diagnosis. Special techniques are used to identify genes or gene sections (e.g. of viruses or on the chromosomes of cancer cells).These are amplified with the help of an enzyme (polymerase), so that they can be measured or used for other purposes in genetic engineering.
Applications: Diagnosis of hereditary diseases, even before birth. Diagnosis of certain infectious diseases and types of cancer.
The polymerise chain reaction makes it possible to prepare thousands of millions of copies of genetic material within a few hours. This permits the detection of DNA and RNA even before antibodies are formed. The polymerase chain reaction allows not only the diagnosis of a disease at a very early stage, but makes it possible to follow the development of the disease and its response to therapy in a highly precise manner.
- PolymerisationChemical or biochemical reaction by means of which many identical or related molecules (monomers) are connected to form a so-called macromolecule (polymer); e.g. glucose can give glycogen or starch.
- PolyneuropathyDisease of peripheral nerves which is unrelated to injury. Peripheral nerves are nerves which are not in the brain or spinal chord.
Depending on the cause, e.g.: 1. hereditary polyneuropathy; 2. polyneuropathy due to metabolic diseases, e.g. in Type 2 Diabetes, blood poisoning with substances which are usually excreted in the urine (uraemia), e.g. in kidney failure; 3. polyneuropathy in pathologically disturbed digestion or false or deficient nutrition; 4. polyneuropathy in infectious diseases; 5. polyneuropathy in diseases of the hormonal systems; 6. polyneuropathy caused by externally administered poisons (e.g. alcohol, drugs).
Stocking-shaped areas in which there is either loss of feeling or irritation. This may be manifested as abnormal feelings, such as itching or dull pain or in a loss in sensitivity. Usually starts in the lower limbs. After this there may develop flabby paralysis, loss of reflexes, muscular atrophy and disturbances in the vegetative nervous system (cardiovascular system, bladder, rectum, sexual function, skin). The symptoms are typically symmetrically distributed on both sides of the body. The symptoms are however usually asymmetric in types 1 and 2 diabetes.
Treatment of the underlying disease or removal of the cause of the condition; physiotherapy.
- polypeptidea chain of amino acids (the building blocks of proteins)
- PolysaccharidesMultiple sugar
Polysaccharides are high molecular weight carbohydrates, which arise by the connection of more than 20 monosaccharides (simple sugars).
Depending on their function, they are classified as 1. Structural polysaccharides (e.g. cellulose, chitin); 2. Water binding polysaccharides; 3. Reserve polysaccharides (e.g. inulin, starch, glycogen).
- PolyuriaPathologically increased urine volume (more than 1.5 ml/min or 2 l/24 hours). Polyuria occurs for example in type 2 diabetes, type 1 diabetes, diabetes insipidus and kidney disease.
- Porosis1. Decrease in bone substance (see osteoporosis); 2. Formation of cavities in organs (e.g. porencephaly, the formation of cavities in the brain).
- porphyriaa group of genetic disorders in which substances called porphyrins build up in the blood, often causing rashes brought on by exposure to sunlight and reactions to certain drugs
- Portal VeinLarge vein which collects all the blood from the abdominal cavity and transports it to the liver. Blood from the stomach, intestine, the spleen and the pancreas flows into the portal vein. Specific metabolic processes are performed by the liver cells on the components of this blood (see Liver Functions).
- Post-exposure ProtectionProtection against an infection after the patient has come into contact with the infective agent. Post-exposure protection (or prophylaxis) is recommended for HIV, for example, after injury with an infected needle in a hospital. Studies are now being carried out to establish whether protection of this sort is useful after, for example, sexual contact.
- PrecancerosisChanges in the body which can possibly develop to a carcinoma. Both symptoms and tissue changes are used in an attempt to evaluate the statistical probability with which precancerosis will develop into a malignant tumour. A distinction is made between facultative precancerosis, which only rarely becomes malignant, and obligative precancerosis, which has a high risk of becoming malignant within a relatively short period.
- Precancerosis, LaryngealChanges in the mucous membrane of the larynx which are directly recognisable by eye and which are the basis for the development of the development of laryngeal carcinoma. They may be accompanied by hoarseness, the urge to clear the throat and the feeling of a foreign body. The probable causes are external damage, such as consumption of tobacco and alcohol or radiation damage. Three different grades of laryngeal precancerosis are distinguished, on the basis of the different degrees of the changes to the cells: simple, intermediate and severe
Diagnosis: The diagnosis is made on the basis of (microscopic) laryngoscopy and the examination of tissue samples.
Therapy: Therapy consists in avoiding the toxic substances and the surgical removal of the altered tissue. Regular controls of the findings are advisable, as malignant changes are possible. Cf. Papilloma of the Larynx.
- PrediabetesState between normal glucose metabolism and diabetes mellitus. Cf. type 2 diabetes
- Pregnancy diabetessee gestational diabetes
- PreloadMechanical preload of the heart with respect to stretching and length of the muscle fibres in the left chamber (ventricle), immediately before the start of ventricular contraction (systole). The preload is directly connected to the en-diastolic pressure (the so-called filling pressure), which can be determined by heart catheterisation. The end diastolic volume is determined by the preload. The degree of shortening of the muscle fibres in the subsequent systole is determined by the preload and afterload of the ventricle.
- prevalencethe number of cases of a specific condition or disease existing in a given population at a specific time
- Primary TumourThe tumour which is formed first; cf. Metastasis.
- Probes of Liver FunctionInvestigations to evaluate the metabolic capacity of the liver and to establish the severity of liver diseases. The different tests can measure different abnormalities in the liver:
1. Cell damage from the determination of certain enzymes
2. Abnormalities in the synthesis of metabolic products by determination, for example, of proteins or clotting factors.
3. Abnormalities in the secretion of bile, e.g. by determination of bilirubin
4. Abnormalities in storage function and utilisation, by determination of, for example, iron and copper in serum.
- Probucolsee lipid sinkers
- Procedure, imagingTerm for apparative investigative procedures, with the help of which structures in the human organism can be depicted. These procedures are of particular value in the diagnosis of morphological changes caused by disease. For example ultrasound diagnosis, X-ray diagnosis, scintigraphy, positron emission tomography, nuclear spin tomography, computer tomography.
- progenitoran originator of a line of descent
- Progesteronealso known as luteohormone, corpus luteum hormone or yellow body hormone
Progesterone is the main natural gestagen and is mostly formed in the yellow body, the placenta and in the adrenal cortex (even in the male). It is an important precursor of many steroid hormones, including oestrogens, glucocorticoids, calciferols and others.
Progesterone acts as an antagonist to oestrogens, for example in the breakdown of proteins. With oestrogens it participates in almost all functions related to female reproduction. Together with oestrogens, progesterone regulates the female period (menstrual cycle). Progesterone increases body temperature, by about 0.6 °C, from one day after ovulation extending to the next period bleeding. It increases the cyclical growth of the mucous membrane of the womb and the implantation and further development of the fertilised egg cell. During pregnancy, it inhibits the maturation of further egg cells and stimulates the development of the milk glands. Deficient formation of progesterone during pregnancy leads to miscarriage. In the male, progesterone increases the motility of the sperms and their ability to penetrate into the egg cell.
- Progressive Multifocal LeukoencephalopathyPathological change in the nerve fibres in the brain, which usually occur in patients with disturbances in the immune system, such as HIV disease, malignant tumours or treatment with drugs which suppress the immune system.
Cause: Virus infection (polyoma viruses)
Symptoms: There are usually changes in personality, abnormal movements or visual problems (loss of visual fields). Incontinence or problems in coordination occur more rarely. The disease leads to death within an average of 3 to 6 months after its start.
- prospectiverefers to a study that is designed in advance, in which study participants are selected, assigned to groups and examined according to a specific study plan (protocol)
- Prostate carcinomaMalignant tumour of the prostate. Prostate carcinoma is the most frequent malignant tumour in man and mostly occurs between 50 and 70 years of age. It initially spreads within the prostate and then grows into the seminal vesicles, the connective tissue of the pelvis and (more rarely) into the bladder, the colon and the urethra. Metastases arise when the tumour cells are spread through the lymph ducts and blood into the pelvic area, skeleton, liver or lungs. Some cases of prostate carcinoma are so-called latent prostate carcinoma, which never cause symptoms and which do not primarily cause death. The patients usually die of other causes and the carcinoma is only found by chance during the autopsy.
Symptoms: Problems in emptying the bladder, pain when passing urine, blood in the urine and back pains (like sciatica) only develop when the disease is advanced.
Diagnosis: Rectal investigation and palpation of the prostate through the intestine (part of the cancer screening tests). If the findings on palpation are abnormal, prostate cells can be extracted through the intestine with a thin needle and then examined under the microscope. Ultrasound investigations and clinical chemistry tests are also performed. To look for metastases, X-rays of the skeleton, computer tomography and nuclear spin tomography can be performed, possibly also including taking a sample of lymph nodes from the pelvis.
Therapy: Depending on the type of the tumour, operative removal of the prostate together with the neighbouring lymph nodes, radiotherapy and reduction of the male sex hormone which can further tumour growth, by removing the testicles of administering blocking drugs. Therapy can be dispensed with if the patient is very old or the tumour of low malignancy.
Prognosis: 90% of cases are cured if the therapy is started at an early stage.
- Protease InhibitorsDrugs which inhibit virus multiplication by inhibiting a certain enzyme (protease). As a result of this, the virus cannot form all proteins which are necessary for forming its structure. The first protease inhibitors were introduced in 1995 and this produced great changes in the treatment of HIV disease. In particular, the combination of protease inhibitors and reverse transcriptase inhibitors has increased the rate of survival and reduced the number of opportunistic infections.
- Protective InoculationProtective inoculation is performed to make the body insusceptible to an infection to microorganisms, in other words, to make the organisms immune to the pathogens. A distinction is made between active and passive immunisation.
Active immunisation can be administered in several ways.
1. By artificial production of an attenuated disease, by administering attenuated pathogens or inoculation germs ( Vaccination), so that the body develops defence to these.
2. By injecting the organism with foreign substances (antigens), so that the organism develops defence (antibodies) to these.
3. By administering inoculating germs or antigens through the mouth, nose or skin or by inhalation, so that local protection against infection can be developed in the mucous membranes.
Examples of protective active immunisation: protective inoculation against hepatitis A, hepatitis B, German measles, tetanus
In passive immunisation, the organism is injected with specific antibodies (preparations of immunoglobulins) against the disease for which treatment or prophylaxis is intended.
Cf. Hepatitis A Vaccine, Hepatitis B Vaccine.
- Protective VaccinationProduction of immunity to prevent infectious diseases.
1. Active immunisation: The antigen is administered and the body is intended to produce the corresponding antibodies. One example is the artificial production of a weakened or low-level disease. The viruses or bacteria which are administered to the subject can reproduce, but can cause only very mild disease. The aim is stable immunity to the disease; 2. Passive immunisation: Injection of specific antibodies or serum from actively immunised humans or animals. Non-infectious or non-poisonous antibodies are used for the prevention or direct treatment of infectious diseases. The antibodies must not be first formed by the body; 3. Simultaneous vaccination is a combination of active and passive immunisation, i.e. antigen and antibody are administered at the same time. This is meant to bridge the unprotected gap between infection and antibody production. Examples of this are the vaccinations to tetanus, rabies and hepatitis B. Cf. vaccine, polyvalent; combination vaccine; vaccination complication.
- Protective Vaccination to InfluenzaProtective vaccination to influenza is a protective vaccination with active immunisation, i.e. the body must produce the antibodies to the influenza virus itself. The vaccine consists of inactivated influenza viruses, mostly combined A and B, or components of the virus (neuraminidases, haemagglutinins). The strains used in the vaccination must be as almost identical or closely related to the current pathogens, so that appropriate formation of antibodies takes place. The antigenic drift of the influenza virus makes it necessary to modify the vaccine continually. Vaccination should take place before the start of the flu season. Revaccination should be carried out every year, as vaccination only protects for a maximum of one year.Cf. vaccination calendar.
- protein-energy malnutritionmalnutrition due to inadequate intake of calories or protein or both
- ProteinsProteins consist of at least 100 aminoacid residues bound to each other by ester linkages. They are formed by biosynthetic reactions and have characteristic aminoacid sequences and spatial structure. They can forfeit this structure and thus their properties through the action of heat, organic solvents, salt and extreme pH values. The loss of activity can be either reversible or irreversible. Like peptides, simple proteins consist simply of aminoacid residues connected to each other. Complex proteins also have a non-protein component (e.g. glycoproteins: proteins with a bound carbohydrate portion and lipoproteins
The main roles of protein in the organism are as 1. enzymes; 2. hormones; 3. cell membrane proteins; 4. supportive or structural proteins (e.g. collagen, keratin); 5. proteins in muscles with the ability to contract (e.g. actin, myosin); 6. plasma proteins (e.g. albumins); 7. transport proteins (e.g. haemoglobin); 8. antibodies; 9. blood coagulation factors; 10. alloantigens (e.g. blood group antigens); 11. so-called reserve substances for energy supply during hunger. Cf. digestion of proteins
- proteinuriathe presence of protein in the urine
- ProteomicsStudy of the proteins resulting from the information contained in a set of genes. Unlike the genome, which is a finite, essentially static entity, proteomes are dynamic, responding to shifts in temperature and nutrient environment, for example, or to the effects of stress and medication.
A proteome thus comprises the total complement of proteins expressed by the genes of a cell or organism during a particular growth phase and under a particular set of environmental conditions. These proteins can be separated and then related to their corresponding genes by mass spectrometry.
Roche scientists have already constructed a number of proteome maps, and to date, thousands of the proteins they contain have been matched to the genes coding for them. Such analyses could conceivably be used to investigate the effects of pharmaceuticals, toxins or biological agents on an organism or to observe how, or how effectively, a drug acts during a specific stage of a disease.
- Protozoal InfectionsProtozoa are one-celled forms of life, of which many can infect the human body. A distinction is made between flagellates (such as trichomonads), rhizopoda (such as amoebae), spore formers (such as toxoplasma) and ciliophora.
- Psychogenic eating disordersPsychogenic eating disorders are disturbances in eating or in body weight without organic cause. There are different clinical presentations, which may change with time.
1. Extreme thinness as a result of anorexic fasting; 2. anorexia with vomiting and abuse of laxatives and diuretics (anorexia with bulimia); 3. bulimia; 4. latent pathological overweight; 5. pathological overweight with increased food intake; 6. BED.
- PTCAAbbreviation for precutaneous transluminal coronary angioplasty
Procedure for expanding the coronary arteries. During arterial heart catheterisation and coronary angiography coronary arteries are expanded, particularly when they are only narrowed for a short stretch at the start. Balloon catheters, lasers and ultramills are used, sometimes in combination with a stent, which is a prosthetic device like a scissor grid, which widens spontaneously when inserted in the vessel and which holds the vessel open. Cf. coronary heart disease.
- PTHsee parathormone
- pure red cell aplasia (PRCA)anemia associated with a low reticulocyte count, an absence of erythroblasts in the bone marrow, resistance to epoetin therapy and neutralising antibodies against erythropoietin
- pyelonephritisinflammation of the renal pelvis
Glossary entries: Roche and Walter de Gruyter, Berlin