Habitat: Throughout India, from Himachal Pradesh to Assam and Mizoram, and all over southern India.
English: Creat.Ayurvedic: Kaalmegha, Bhuunimba, Bhuuminimbaka, Vishwambharaa, Yavtikta, Kalpanaatha, Kiraata-tikta (var.).Unani: Kiryaat.Siddha/Tamil: Nilavembu.Action: Hepatoprotective, cholin- ergic, antispasmodic, stomachic, anthelmintic, alterative, blood purifier, febrifuge. It acts well on the liver, promoting secretion of bile. Used in jaundice and torpid liver, flatulence and diarrhoea of children, colic, strangulation of intestines and splenomegaly; also for cold and upper respiratory tract infections.
Key application: As bitter tonic, febrifuge and hepatoprotective. (Indian Herbal Pharmacopoeia.)Kaalmegha, officinal in IP, consists of dried leaves and tender shoots, which yield not less than 1% andro- grapholide on dry-weight basis.Several active constituents have been identified from the leaf and rhizome, including andrographolide, deoxyan- drographolide and other diterpenes.Andrographolide exhibited strong choleretic action when administered i.p. to rats. It induces increase in bile flow together with change in physical properties of bile secretion. It was found to be more potent than sily- marin.Andrographolide was found to be almost devoid of antihepatitis-B virus surface antigen-like activity (when compared with picroliv.)The leaf and stem extracts of Kaal- megha/andrographolide given s.c. or orally did not change blood sugar level of normal or diabetic rats.Alcoholic extract of the plant exhibited antidiarrhoeal activity against E. coli enterotoxins in animal models.Clinical evidence of effectiveness of andrographis in humans is limited to the common cold. Preliminary evidence suggests that it might increase antibody activity and phagocytosis by macrophages, and might have mast cell-stabilizing and antiallergy activity. (Natural Medicines Comprehensive Database, 2007.)The herb is contraindicated inbleed- ing disorders, hypotension, as well as male and female sterility (exhibited infertility in laboratory animals).Dosage: Whole plant—5-10 ml juice; 50-100 ml decotion; 1-3 g powder. (CCRAS.)... andrographis panicultataHabitat: Native to the Moluccas Islands; grown in the Nilgiris, Kerala, Karnataka and West Bengal.
English: Nutmeg, Mace.Ayurvedic: Jaatiphala, Jaatishasya, Maalatiphala (seed kernel).Jaatipatri, Jaatipatra, Jaatipatraka, Jaatikosha (mace).Unani: Jauzbuwaa (seed), Bisbaasaa (mace).Siddha/Tamil: Jaathikkai, Saadikai (nutmeg); Saadippatthiri, Jaadip- patiri (mace).Action: Nutmeg—carminative, spasmolytic, antiemetic, orexi- genic; topically anti-inflammatory. Mace—stimulant carminative. Narcotic in high doses.
Nutmeg is used in flatulency, diarrhoea, nausea and vomiting. Mace is used in rheumatism, chronic bowel complaints and asthma. When roasted, both nutmeg and mace are used for diarrhoea, colic, flatulence and dyspepsia.Key application: Dried seed and aril—included among unapproved herbs by German Commission E. Following actions have been considered: antispasmodic, MAO inhibition, inhibition of prostaglandin synthesis.The Ayurvedic Pharmacopoeia of India recommends the kernel of the fruit in spermatorrhoea.An aqueous extract of nutmeg is reported to show anti-secretory activity against E. coli heat-labile enterotoxin; the hexane soluble fraction of the alcoholic extract inhibited the heat-labile and heat-stable-enterotoxin-induced secretory response in animal studies.The hexane extract contains myris- ticin, an anti-inflammatory principle, and licarin-B and dehydro di- isoeugenol which exhibited CNS depressant properties. The extracts of nutmeg decreased kidney prostaglan- din levels in rats. They also inhibited platelet aggregation (due to eugenol and isoeugenol). The anti-inflammatory activity observed in carrage- enan-induced oedema in rats and enhanced vascular permeability in mice, are attributed to myristicin present in mace.Mace also activates hepatic detoxification process. Monomeric and dimer- ic phenyl propanoids (myristicin, de- hydro diisoeugenol) from mace, on p.o. administration in mice, produced suppression of lipid peroxidation in liver.Seeds contain about 0.24% myris- ticin, whereas volatile oil about 3.12%.The resorcinols, malabaricones B and C, isolated from the seed coat (mace) exhibited strong antibacterial and antifungal activities. Neoplasm inhibitors, phenylpropyl derivatives, have been isolated from pulverized mace.Dosage: Endosperm of dried seed (kernel of fruit)—0.5-1.0 g powder. (API, Vol. I.)... myristica fragransStaphylococcal food poisoning occurs after food such as meat products, cold meats, milk, custard and egg products becomes contaminated before or after cooking, usually through incorrect handling by humans who carry S. aureus. The bacteria produce an ENTEROTOXIN which causes the symptoms of food poisoning 1–8 hours after ingestion. The toxin can withstand heat; thus, subsequent cooking of contaminated food will not prevent illness.
Heat-resistant strains of Cl. perfringens cause food poisoning associated with meat dishes, soups or gravy when dishes cooked in bulk are left unrefrigerated for long periods before consumption. The bacteria are anaerobes (see ANAEROBE) and form spores; the anaerobic conditions in these cooked foods allow the germinated spores to multiply rapidly during cooling, resulting in heavy contamination. Once ingested the bacteria produce enterotoxin in the intestine, causing symptoms within 8–24 hours.
Many di?erent types of Salmonella (about 2,000) cause food poisoning or ENTERITIS, from eight hours to three days after ingestion of food in which they have multiplied. S. brendeny, S. enteritidis, S. heidelberg, S. newport and S. thompson are among those commonly causing enteritis. Salmonella infections are common in domesticated animals such as cows, pigs and poultry whose meat and milk may be infected, although the animals may show no symptoms. Duck eggs may harbour Salmonella (usually S. typhimurium), arising from surface contamination with the bird’s faeces, and foods containing uncooked or lightly cooked hen’s eggs, such as mayonnaise, have been associated with enteritis. The incidence of human S. enteritidis infection has been increasing, by more than 15-fold in England and Wales annually, from around 1,100 a year in the early 1980s to more than 32,000 at the end of the 1990s, but has since fallen to about 10,000. A serious source of infection seems to be poultry meat and hen’s eggs.
Although Salmonella are mostly killed by heating at 60 °C for 15 minutes, contaminated food requires considerably longer cooking and, if frozen, must be completely thawed beforehand, to allow even cooking at a su?cient temperature.
Enteritis caused by Campylobacter jejuni is usually self-limiting, lasting 1–3 days. Since reporting of the disease began in 1977, in England and Wales its incidence has increased from around 1,400 cases initially to nearly 13,000 in 1982 and to over 42,000 in 2004. Outbreaks have been associated with unpasteurised milk: the main source seems to be infected poultry.
ESCHERICHIA COLI O157 was ?rst identi?ed as a cause of food poisoning in the early 1980s, but its incidence has increased sharply since, with more than 1,000 cases annually in the United Kingdom in the late 1990s. The illness can be severe, with bloody diarrhoea and life-threatening renal complications. The reservoir for this pathogen is thought to be cattle, and transmission results from consumption of raw or undercooked meat products and raw dairy products. Cross-infection of cooked meat by raw meat is a common cause of outbreaks of Escherichia coli O157 food poisoning. Water and other foods can be contaminated by manure from cattle, and person-to-person spread can occur, especially in children.
Food poisoning associated with fried or boiled rice is caused by Bacillus cereus, whose heat-resistant spores survive cooking. An enterotoxin is responsible for the symptoms, which occur 2–8 hours after ingestion and resolve after 8–24 hours.
Viruses are emerging as an increasing cause of some outbreaks of food poisoning from shell?sh (cockles, mussels and oysters).
The incidence of food poisoning in the UK rose from under 60,000 cases in 1991 to nearly 79,000 in 2004. Public health measures to control this rise include agricultural aspects of food production, implementing standards of hygiene in abattoirs, and regulating the environment and process of industrial food production, handling, transportation and storage.... food poisoning
(See also poison; poisoning; toxaemia.)... toxic shock syndrome
Among the smallest and simplest microorganisms are the viruses. First described as ?lterable agents, and ranging in size from 20–30 nm to 300 nm, they may be directly visualised only by electron microscopy. They consist of a core of deoxyribonucleic or ribonucleic acid (DNA or RNA) within a protective protein coat, or capsid, whose subunits confer a geometric symmetry. Thus viruses are usually cubical (icosahedral) or helical; the larger viruses (pox-, herpes-, myxo-viruses) may also have an outer envelope. Their minimal structure dictates that viruses are all obligate parasites, relying on living cells to provide essential components for their replication. Apart from animal and plant cells, viruses may infect and replicate in bacteria (bacteriophages) or fungi (mycophages), which are damaged in the process.
Bacteria are larger (0·01–5,000 µm) and more complex. They have a subcellular organisation which generally includes DNA and RNA, a cell membrane, organelles such as ribosomes, and a complex and chemically variable cell envelope – but, unlike EUKARYOTES, no nucleus. Rickettsiae, chlamydia, and mycoplasmas, once thought of as viruses because of their small size and absence of a cell wall (mycoplasma) or major wall component (chlamydia), are now acknowledged as bacteria; rickettsiae and chlamydia are intracellular parasites of medical importance. Bacteria may also possess additional surface structures, such as capsules and organs of locomotion (?agella) and attachment (?mbriae and stalks). Individual bacterial cells may be spheres (cocci); straight (bacilli), curved (vibrio), or ?exuous (spirilla) rods; or oval cells (coccobacilli). On examination by light microscopy, bacteria may be visible in characteristic con?gurations (as pairs of cocci [diplococci], or chains [streptococci], or clusters); actinomycete bacteria grow as ?laments with externally produced spores. Bacteria grow essentially by increasing in cell size and dividing by ?ssion, a process which in ideal laboratory conditions some bacteria may achieve about once every 20 minutes. Under natural conditions, growth is usually much slower.
Eukaryotic micro-organisms comprise fungi, algae, and protozoa. These organisms are larger, and they have in common a well-developed internal compartmentation into subcellular organelles; they also have a nucleus. Algae additionally have chloroplasts, which contain photosynthetic pigments; fungi lack chloroplasts; and protozoa lack both a cell wall and chloroplasts but may have a contractile vacuole to regulate water uptake and, in some, structures for capturing and ingesting food. Fungi grow either as discrete cells (yeasts), multiplying by budding, ?ssion, or conjugation, or as thin ?laments (hyphae) which bear spores, although some may show both morphological forms during their life-cycle. Algae and protozoa generally grow as individual cells or colonies of individuals and multiply by ?ssion.
Micro-organisms of medical importance include representatives of the ?ve major microbial groups that obtain their essential nutrients at the expense of their hosts. Many bacteria and most fungi, however, are saprophytes (see SAPROPHYTE), being major contributors to the natural cycling of carbon in the environment and to biodeterioration; others are of ecological and economic importance because of the diseases they cause in agricultural or horticultural crops or because of their bene?cial relationships with higher organisms. Additionally, they may be of industrial or biotechnological importance. Fungal diseases of humans tend to be most important in tropical environments and in immuno-compromised subjects.
Pathogenic (that is, disease-causing) microorganisms have special characteristics, or virulence factors, that enable them to colonise their hosts and overcome or evade physical, biochemical, and immunological host defences. For example, the presence of capsules, as in the bacteria that cause anthrax (Bacillus anthracis), one form of pneumonia (Streptococcus pneumoniae), scarlet fever (S. pyogenes), bacterial meningitis (Neisseria meningitidis, Haemophilus in?uenzae) is directly related to the ability to cause disease because of their antiphagocytic properties. Fimbriae are related to virulence, enabling tissue attachment – for example, in gonorrhoea (N. gonorrhoeae) and cholera (Vibrio cholerae). Many bacteria excrete extracellular virulence factors; these include enzymes and other agents that impair the host’s physiological and immunological functions. Some bacteria produce powerful toxins (excreted exotoxins or endogenous endotoxins), which may cause local tissue destruction and allow colonisation by the pathogen or whose speci?c action may explain the disease mechanism. In Staphylococcus aureus, exfoliative toxin produces the staphylococcal scalded-skin syndrome, TSS toxin-1 toxic-shock syndrome, and enterotoxin food poisoning. The pertussis exotoxin of Bordetella pertussis, the cause of whooping cough, blocks immunological defences and mediates attachment to tracheal cells, and the exotoxin produced by Corynebacterium diphtheriae causes local damage resulting in a pronounced exudate in the trachea.
Viruses cause disease by cellular destruction arising from their intracellular parasitic existence. Attachment to particular cells is often mediated by speci?c viral surface proteins; mechanisms for evading immunological defences include latency, change in viral antigenic structure, or incapacitation of the immune system – for example, destruction of CD 4 lymphocytes by the human immunode?ciency virus.... microbiology
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