Dubious Botulinum Neurotoxin: A Brief Introduction 刘英琪生物科学

Transcription

1 Dubious Botulinum Neurotoxin: A Brief Introduction 刘英琪生物科学

2 Botulinum OUTLINE 1. Origin of Batulinum Neurotoxins 2. Characteristics of Batulinum Neurotoxins 3. Brief Working Mechanism 4. Potential Health Hazards and Cosmetics Market Health Hazards Symptoms of Infections Harms of Infections Composition of Infections Possible Treatment Possible Prevention Methods Cosmetics Use

3 Botulinum Origin Batulinum neurotoxins (BoNTs) are produced by various toxigenic strains of sporeforming anaerobic Clostridium botulinum. FACTS OF Clostridium botulinum Gram-positive, rod-shaped bacterium Obligate anaerobic but can endure low concentration of oxygen with the presence of SOD Form endospores when environment turns unfavourable 7 types of neurotoxins secreted by the species have been isolated and identified

4 Botulinum Characteristics Highly potent with the function to paralyze interneuron signal transmission Persistent but reversible inhibition potency Causative of many deadly diseases, i.e. extreme toxicity Easiness of production in events of warfares Relative slow recovery

5 Botulinum Working Mechanisms Mechanisms 1. BoNTs destroy crucial protein components of the neuroexocytosis apparatus 2. Interneuron signal transmission is inhibited since acetylcholine is not to be released 3. Without acetylycholine, muscles cannot contract and are paralyzed, resulting in flaccid muscle paralysis

6 Botulinum Health Hazards : Symptoms & Harms Symptoms occur normally 18 to 36 hours after exposure but they may appear as early as 6 hours and late as 10 days. Symptoms may include: double vision or blurred vision drooping eyelids slurred speech difficulty swallowing dry mouth muscle weakness More seriously if left untreated the infected may endure muscle paralysis! May end up with muscle problems such as paralysis, and the infections can be FATAL!!

7 Botulinum Composition of Infections In the United Sates, 110 cases are reported on average each year. 25 percent are foodborne botulism. 72 percent are infant botulism. 3 percent are wound botulism.

8 Botulinum Possible Treatment Treatment may include: antitoxin treatment for foodborne and wound botulism (when diagnosed early) removal of contaminated food in the gut through induced vomiting or enemas surgical treatment for infected wounds (to remove the source of the toxin) respiratory assistance (ventilator) for patients who experience respiratory failure and paralysis intensive medical and supportive care Recovery from botulism may take many weeks. Treatment for severe botulism may take several months. Fatigue and shortness of breath may persist for years.

9 Botulinum Possible Prevention Methods 1. To reduce contamination, home-canning should be done following strict hygienic procedures 2. Botulism spores are killed by high temperatures. It is advisable to boil home-canned foods for 10 minutes before consumption. 3. Other preventive measures should include the following: Garlic and other herbs in oils should be refrigerated. Potatoes baked in aluminum foil should be kept hot until served or refrigerated. Children under the age of 12 months should not be fed honey, because it can contain botulism spores. Seek prompt medical care for infected wounds. Do not use injectable street drugs.

10 Botulinum Cosmetics Use Injection of modest concentration can be safe. But it is meantime individual-specific and consultations with physicians are advised.am

11 References otoxz.jpg ulinum