HORMONES & VACCINES

HORMONES

A “hormone” (greek – ‘impetus’) is a class of signaling molecules produced by glandsin multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour.

HISTORY OF HORMONEOne hundred years ago Ernest Starling (1866–1927), almost surreptitiously, slipped the word ‘hormone’ into the English language. This review, beginning in the middle of the nineteenth century, attempts to trace the growth of ideas in endocrinology up to this important moment. There is no magic date from which to begin a survey of endocrinology ,

, for man has made use of endocrinological principles from time immemorial. Fuller Albright (1943) observed ‘The earliest beginnings of endocrinology had as their   such ends as the procurement of a form of man-power safe for the harem, the salvaging of a male soprano voice for the choir, and the increased palatability that a rooster attains when he turns into a capon.

HORMONES

Hormones are used to

communicate between

organs and tissues to regulate

physiological and

behavioral activities

EXAMPLES OF AMINE PEPT IDE PROTE IN AND STEROID HORMONE STURCTURE

STEROID HORMONES

Steroid hormones can be grouped into five groups by the receptors to which they bind: glucocorticoids, mineralocorticoids, androgens, estrogens and progestogens. Vitamin D derivatives are a sixth closely related hormone system with homologous receptors.

PROTEIN HORMONESPeptide hormones are proteins that have an effect on the endocrine system of animals. Like other proteins, peptide hormones are synthesized in cells from amino acids according to mRNA transcripts, which are synthesized from DNA templates inside the cell nucleus. Preprohormones, peptide hormone precursors, are then processed in several stages

HORMONE CLASS AND COMPONENTS

HORMONE CLASS COMPONENTSAMINE HORMONE Amino acids with

modified groups (norepinephrine’s carboxyl group is a replaced with a benzene ring)

PEPTIDE HORMONE

Short chains of linked amino acids

PROTEIN HORMONE

Long chains of linked amino acids

STEROID HORMONE

Derived from the lipid cholesterol

VACCINES

VACCINESA vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins.

The agent stimulates the

body's immune

system to recognize the

agent as foreign,

destroy it, and keep a record of it, so that the immune system can more easily recognize

Vaccines can be

prophylactic , (example : to

prevent or ameliorate

the effects of a future

infection by any natural

or ‘wild’ pathogen)

HISTORYHe used it in 1798 in the long title of his Inquiry into the...Variolae vaccinae...known...[as]...the Cow Pox, in which he described the protective effect of cowpox against smallpox.[1] In 1881, to honour Jenner, Louis Pasteur proposed that the terms should be extended to cover the new protective inoculations then being developed.[2]

Vaccines are made using

several different processes. The

first human vaccines

against viruses were based

using weaker or attenuated viruses to generate

immunity.

TYPES OF VACCINEVACCINE

TYPEVACCINES OF THIS TYPE ON

U.S.LIVE ,

ATTENUATEDMEASLES, MUMPS, RUBELLAVARICELLA (CHICKENPOX)INFLUENZA (NASAL SPRAY)ROTAVIRUS

INACTIVATED/KILLED POLIO

(IPV)HEPATITIS A

TYPES OF VACCINES

TOXOID (INACTIVATED

TOXIN)

Diphtheria, tetanus (part of DTaP combined immunazation)

SUBUNIT/CONJUGATE

HEPATITIS BINFLUENZA (INJECTION)HAEMOPHILUS INFLUENZA TYPE B (HIB)PERTUSSIS

TYPES OF VACCINES AND

THEIR MEANINGS

LIVE , ATTENUATED VACCINES

Attenuated vaccines can be made in several different ways. Some of the most common methods involve passing the disease-causing virus through a series of cell cultures or animal embryos ( typically chick embryos ). A virus targeted for use in a vaccine may be grown through --”passaged” through– upwards of 200 different embryos or cell cultures.

KILLED OR INACTIVATED VACCINESOne alternative to attenuated vaccines is killed or inactivated vaccine. Vaccines of this type are created by inactivating a pathogen, typically using heat or chemicals such as formaldehyde or formalin. This destroys the pathogen’s ability to replicate, but keeps it “intact” so that the immune system can still recognize.

TOXOIDSSome bacterial diseases are not directly caused by a bacterium itself, but by a toxin produced by the bacterium. One example is tetanus; its symptoms are not caused by the Clostridium tetani bacterium, but by a neurotoxin it produces (tetanospasmin). Immunizations created using inactivated toxins are called toxoids.

SUBUNIT AND CONJUGATE VACCINES

Both subunit and conjugate vaccines contain only pieces of the pathogens they protect against. Subunit vaccines use only part of a target to provoke a response from the immune system. This may be done by isolating a specific protein from a pathogen and presenting it as an antigen on its own. The acellular pertussis vaccine and influenze vaccine are examples of subunit vaccines.