Well this is my last entry as a participant in Skills Test 2008.
How indecisive are you? Can you decide in a minute if you want to go to college and return your long overdue library books(during you holidays!) or do you start worrying about the facts that:
it’s 6 km away
the day is very hot
buses are definitely hard to find
you don’t want to spend money on an auto
Do you absolutely detest writing your assignments? Wouldn’t you leap at the chance to go buy the latest Harry Potter book instead? Or the latest album by Robbie Williams? But then, you’re faced with the thought that you MUST be responsible… if you can identify with these sentiments, you’re not alone my friend.
What a relief! I never thought I’d be so thankful that they’re finally done.
As much as I hate exams, I’d be lying if I said that they haven’t taught me anything. Other than studies I mean.
Pharyngeal demulcents – they soothe the throat – directly as well as by promoting salivation – and reduce afferent impulses from the inflamed pharyngeal mucosa, thus provide symptomatic relief in dry cough arising from throat.
They are administered generally in the form of lozenges, troches, cough drops or linctuses.
They also serve as household remedy. Eg. Lemon oil, Eucalyptus oil, Tolu Balsam, and Liquorice.
They are the drugs which increases the production of demulcent respiratory fluid that covers and protects the irritated mucosa.
Mechanism of action – expectorants increase the bulk of the sputum by sensitizing the cells of the bronchial cavity and stimulates the bronchial reflux for the expulsion of the sputum.
It helps in softening of the sputum making it less tenacious and hard and acting like a mucolytic agent.
f. Directly acting
These bring about a stimulation of the secretory cells of the respiratory tract directly.
Drugs which are used in the symptomatic treatment of cough are called anti tussives.
Classification of anti tussives:
c. Pharyngeal Demulcents :
Eg. Syrups and Linctuses
i. Directly acting Eg. Sodium and Potassium Citrate or Acetate, Potassium Iodide, Balsam of Tolu
ii. Reflex acting Eg. Ammonium chloride or carbonate
iii. Mucolytics Eg. Bromhexine, Acetyl cysteine
e. Anti tussives (Central Cough suppressants):
i. Opioids Eg. Codeine, Morphine
ii. Non opioids Eg. Dextromethaphan, Noscapine
iii. Anti histamines Eg. Chlorpheniramine, Diphenhydramine, Promethazine
Anti tussives act in the CNS to rise the thresholds of cough centre or act peripherally in the respiratory tract to reduce tussal impulses or both these actions.
Because they aim to control rather than eliminate cough, anti tussives should be used only for dry unproductive cough or if cough is unduly tiring, disturbs sleep or is hazardous.
Cough is a protective reflex which helps to expel irritant matter from the respiratory tract. Mechanism of action is: irritation or stimulation of mucosal cells which sends afferent impulses to CNS which stimulates the cough centre leading to cough.
Types of Cough:
It is associated with a large amount of sputum. Impulse which reaches the cough centre induces coughing in the respiratory tract because of which fluid is secreted – “sputum”.
By the movement of cilia, sputum is taken up in the throat and spat out. When not spitted out in certain conditions, accumulation of sputum leads to bronchitis.
b. Non – productive and Dry
It is because of environmental irritants such as cigarette, dust, chemicals, pollen etc. Other causes include wax impacted in the ear, inflammation and eczema.
Dry cough is useless. It is aggravated during night. It should be suppressed.
Chronic persistent cough is caused by
Enlarged, infected tonsils
Gene knockout is a genetic technique in which an organism in engineered to carry genes that have been made inoperative.
Gene knockout is mainly carried out to analyse genes which have been “sequenced” but whose function is not known. Knocking out the activity of a gene provides information about what genes normally do.
Humans share many genes with mice. Consequently, observing the characteristics of knock out mice gives researchers information about working of genes in humans. In short, gene knockout technologies have become invaluable experimental tools for modelling genetic disorders, assigning functions of genes, evaluating drugs and toxins and helping to answer fundamental questions in basic and applied research. It finds application in various fields like studies related to hermoregulation, carcinogenesis and behavioural endocrinology.
Iontophoresis is an electrochemical method, which is used in transdermal drug delivery, by creating a potential gradient through skin with an applied electrical current.
It induces increased migration of the drugs into the skin by electrostatic repulsion. It is based on the phenomenon – “like charges repel, unlike charges attract”. The current is applied either in continuous or pulsatile manner. The device consists of a battery, a micro-processor, controller drug reservoir and electrodes. By varying current intensity, the delivery rates could be controlled.
The variables affecting iontophoresis include aspects of current, the physico-chemical properties of drugs, formulation factors, biological factors and electro-endoosmotic flow. Sometime, reverse iontophoresis is also used, to extract chemical or drugs from the body for testing.
There are various applications of iontophoresis all of which promote improved patient acceptance and improved quality of drug therapy.
Dendrimers are repeatedly branching molecules that are characterized by their structural perfection. The latter is based on both symmetry and polydispersity.
Dendron in Greek means tree. In the recent past, it has been found that the properties of highly branched macro-molecules, like this class, can be very different from conventional polymers. Their properties can be dominated by the functional group on the surface. They are inert, non-immunogenic and non-cytotoxic. They are highly branched 3 dimensional structures with all bonds emanating from a central core.
Dendrimer construction is fundamentally divided into divergent and convergent methods. Each subsequent branching unit is then referred to as a generation. When a critical branched state is reached, dendrimers cannot grow because of lack of space. This is called the starburst effect.
Because of their molecular architecture, they show improved physico-chemical properties compared to linear polymers.