See: AGEING.
Alkylating agents are important because they interfere with the growth and reproduction of cells, disrupting their replication. This CYTOTOXIC property is used to retard the division and growth of cancer cells, and alkylating drugs are widely used in the chemotherapy of malignant tumours – often in conjunction with surgery and sometimes with radiotherapy. Unfortunately, troublesome side-effects occur, such as: damage to veins when the drug is given intravenously, with resultant leakage into adjacent tissues; impaired kidney function due to the formation of URIC ACID crystals; nausea and vomiting; ALOPECIA (hair loss); suppression of BONE MARROW activity (production of blood cells); and adverse effects on reproductive function, including TERATOGENESIS. Indeed, cytotoxic drugs must not be given in pregnancy, especially during the ?rst three months. Prolonged use of alkylating drugs, especially when accompanying radiotherapy, is also associated with a sign?cant rise in the incidence of acute non-lymphocytic LEUKAEMIA. Among the dozen or so alkylating drugs in use are CYCLOPHOSPHAMIDE, CHLORAMBUCIL, MELPHALAN, BUSULFAN and THIOTEPA. (See also CHEMOTHERAPY.)... alkylating agents
The effects of ageing include: cessation of MENSTRUATION in females; wrinkling of the skin due to a loss of elastic tissue; failing memory (especially short term) and a reduced ability to learn new skills, along with slowed responses
– changes caused by the loss of or less e?cient working of nerve cells; the senses become less acute; the lungs become less e?cient, as does heart muscle, both causing a fall in exercise tolerance; arteries harden, resulting in a rise in blood pressure and poor blood circulation; joints are less mobile, bones beome more brittle (OSTEOPOROSIS) and muscle bulk and strength are reduced; the lens of the EYE becomes less elastic, resulting in poorer sight, and it may also become opaque (CATARACT).
In developed countries people are living longer, in part because infant and child mortality rates have dropped dramatically over the past 100 years or so. Improved standards of living and more e?ective health care have also contributed to greater longevity: the proportion of people over 65 years of age has greatly increased, and that of the over-75s is still rising. The 2001 census found 336,000 people in the UK aged over 90 and there are 36,000 centenarians in the US. This extreme longevity is attributed to a particular gene (see GENES) slowing the ageing process. Interestingly, those living to 100 often retain the mental faculties of people in their 60s, and examination of centenarians’ brains show that these are similar to those of 60-year-olds. (See MEDICINE OF AGEING; CLIMACTERIC.)
Help and advice can be obtained from Age
Concern and Help the Aged. See www.helpthaged.org.uk www.ageconcern.org.uk... ageing
Habitat: Throughout India, up to an altitude of 1,800 m.
English: Goat Weed, White Weed.Ayurvedic: Dochunty, Uchunti, Sahadevi (related sp.).Action: Anti-inflammatory, antibacterial, antifungal, styptic.
The leaf is reported to contain stig- masterol (59.9%) and beta-sitosterol (26.7%) as major component of sterol faction. The dried flowering plant contains the pyrrolizidine alkaloids, lycop- samine and echinatine.An aqueous extract of leaves is reported to show haemostatic activity. The plant extract exhibited muscle relaxant activity experimentally. The ethanolic extract (95%) of roots possesses anti-inflammatory and analgesic properties.The aqueous extract of leaves exhibits antifungal and crude plant extract antibacterial properties.... ageratum conyzoides
Maintaining an up-to-date evidence base of ‘what works’ in public health and health improvements.
Providing useful information to health practitioners.
Commissioning research to remedy the gaps in the evidence base for medical practice.
Improving health promotion and advising on the standards for (and implementation of) public-health activities.
(See APPENDIX 7: STATUTORY ORGANISATIONS.)... health development agency (hda)
This substance may be contaminated in manufacture with the highly toxic , commonly known as dioxin (see defoliant poisoning).... agent orange
Sulphonylureas The main group of hypoglycaemic agents, these act on the beta cells to stimulate insulin release; consequently they are e?ective only when there is some residual pancreatic beta-cell activity (see INSULIN). They also act on peripheral tissues to increase sensitivity, although this is less important. All sulphonylureas may lead to HYPOGLYCAEMIA four hours or more after food, but this is relatively uncommon, and usually an indication of overdose.
There are several di?erent sulphonylureas; apart from some di?erences in their duration or action (and hence in their suitability for individual patients) there is little di?erence in their e?ectiveness. Only chlorpropamide has appreciably more side-effects – mainly because of its prolonged duration of action and consequent risk of hypoglycaemia. There is also the common and unpleasant chlorpropamide/ alcohol-?ush phenomenon when the patient takes alcohol. Selection of an individual sulphonylurea depends on the patient’s age and renal function, and often just on personal preference. Elderly patients are particularly prone to the risks of hypoglycaemia when long-acting drugs are used. In these patients chlorpropamide, and preferably glibenclamide, should be avoided and replaced by others such as gliclazide or tolbutamide.
These drugs may cause weight gain and are indicated only if poor control persists despite adequate attempts at dieting. They should not be used during breast feeding, and caution is necessary in the elderly and in those with renal or hepatic insu?ciency. They should also be avoided in porphyria (see PORPHYRIAS). During surgery and intercurrent illness (such as myocardial infarction, COMA, infection and trauma), insulin therapy should be temporarily substituted. Insulin is generally used during pregnancy and should be used in the presence of ketoacidosis.
Side-effects Chie?y gastrointestinal disturbances and headache; these are generally mild and infrequent. After drinking alcohol, chlorpropamide may cause facial ?ushing. It also may enhance the action of antidiuretic hormone (see VASOPRESSIN), very rarely causing HYPONATRAEMIA.
Sensitivity reactions are very rare, usually occurring in the ?rst six to eight weeks of therapy. They include transient rashes which rarely progress to erythema multiforme (see under ERYTHEMA) and exfoliate DERMATITIS, fever and jaundice; chlorpropamide may also occasionally result in photosensitivity. Rare blood disorders include THROMBOCYTOPENIA, AGRANULOCYTOSIS and aplastic ANAEMIA.
Biguanides Metformin, the only available member of this group, acts by reducing GLUCONEOGENESIS and by increasing peripheral utilisation of glucose. It can act only if there is some residual insulin activity, hence it is only of value in the treatment of non-insulin dependent (type 2) diabetics. It may be used alone or with a sulphonylurea, and is indicated when strict dieting and sulphonylurea treatment have failed to control the diabetes. It is particularly valuable in overweight patients, in whom it may be used ?rst. Metformin has several advantages: hypoglycaemia is not usually a problem; weight gain is uncommon; and plasma insulin levels are lowered. Gastrointestinal side-effects are initially common and persistent in some patients, especially when high doses are being taken. Lactic acidosis is a rarely seen hazard occurring in patients with renal impairment, in whom metformin should not be used.
Other antidiabetics Acarbose is an inhibitor of intestinal alpha glucosidases (enzymes that process GLUCOSIDES), delaying the digestion of starch and sucrose, and hence the increase in blood glucose concentrations after a meal containing carbohydrate. It has been introduced for the treatment of type 2 patients inadequately controlled by diet or diet with oral hypoglycaemics.
Guar gum, if taken in adequate doses, acts by delaying carbohydrate absorption, and therefore reducing the postprandial blood glucose levels. It is also used to relieve symptoms of the DUMPING SYNDROME.... hypoglycaemic agents
Lifestyle While this may change as people grow older – for instance, physical activity is commonly reduced – some lifestyle factors are unchanged: for example, cigarette smoking, commonly started in adolescence, may be continued as an adult, resulting in smoker’s cough and eventually chronic BRONCHITIS and EMPHYSEMA; widespread ATHEROSCLEROSIS causing heart attacks and STROKE; osteoporosis (see BONE, DISORDERS OF) producing bony fractures; and cancer affecting the lungs and bladder.
Genetic factors can cause sickle cell disease (see ANAEMIA), HUNTINGTON’S CHOREA and polycystic disease of the kidney.
Ageing process This is associated with the MENOPAUSE in women and, in both sexes, with a reduction in the body’s tissue elasticity and often a deterioration in mental and physical capabilities. When compared with illnesses described in much younger people, similar illnesses in old age present in an atypical manner
– for example, confusion and changed behaviour due to otherwise asymptomatic heart failure, causing a reduced supply of oxygen to the brain. Social adversity in old age may result from the combined effects of reduced body reserve, atypical presentation of illness, multiple disorders and POLYPHARMACY.
Age-related change in the presentation of illnesses This was ?rst recognised by the specialty of geriatric medicine (also called the medicine of ageing) which is concerned with the medical and social management of advanced age. The aim is to assess, treat and rehabilitate such patients. The number of institutional beds has been steadily cut, while availability of day-treatment centres and respite facilities has been boosted – although still inadequate to cope with the growing number of people over 65.
These developments, along with day social centres, provide relatives and carers with a break from the often demanding task of looking after the frail or ill elderly. As the proportion of elderly people in the population rises, along with the cost of hospital inpatient care, close cooperation between hospitals, COMMUNITY CARE services and primary care trusts (see under GENERAL PRACTITIONER (GP)) becomes increasingly important if senior citizens are not to suffer from the consequences of the tight operating budgets of the various medical and social agencies with responsibilities for the care of the elderly. Private or voluntary nursing and residential homes have expanded in the past 15 years and now care for many elderly people who previously would have been occupying NHS facilities. This trend has been accelerated by a tightening of the bene?t rules for funding such care. Local authorities are now responsible for assessing the needs of elderly people in the community and deciding whether they are eligible for ?nancial support (in full or in part) for nursing-home care.
With a substantial proportion of hospital inpatients in the United Kingdom being over 60, it is sometimes argued that all health professionals should be skilled in the care of the elderly; thus the need for doctors and nurses trained in the specialty of geriatrics is diminishing. Even so, as more people are reaching their 80s, there seems to be a reasonable case for training sta? in the type of care these individuals need and to facilitate research into illness at this stage of life.... medicine of ageing
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