eChapters

Objectives

Immobilization of fracture of mandible.

Requirements

‘U’ Plate 4 Pins Electric drill Orthopaedic hammer Pin cutter

Procedure

Under local infiltration of an anesthetic & parenteral sedatives the 4 pins are drilled 2 on either side of the fracture site from one side mandible to other side mandible. During drilling the pin, the holes, importance should be given for the passage of the pin through prefix of the drill hole in metal frame

The fracture end should come accurate apposition during pinning procedure & the symmetry of the fractured mandible should be as norma! as possible.

Sterilised antiseptic gauge bandages are covered, the pin between frame and the body. The pins are retained in position either with nut-bolt or by passing a plastic tube after which the hole of the plastic tube is filled with resin.

To know the method of immobilization of the limb after repair of the transected gastrocnemius tendon (tendo achiles).

Procedure

The immobilization procedure of limb after gastrocnemius tendon repair is done in 2 stages.

1^ST Stage

Immobilization of limb for avoiding movement at tendon suture site.

It is done by placing the sutured area within a pre- fabricated metal frame so as to keep the limb undisturbed at the suture site.

The frame is given in Figure 1.

The purpose of addition of the metal frame is to immobilize the limb keeping the fetlock and foot away from in a flexed manner to avoid weight bearing during healing period.

The limb is immobilized with netted bamboo splint (Fig. 2).

The immobilized limb is placed within the metal frame keeping the fetlock and foot in a flexed manner

Aim: To know the method of immobilization of the limb after repair of the flexor tendon.

Procedure

The immobilization procedure of limb after flexor tendon repair is done in 2 stages.

Definition: Mandible forms the skeleton of lower jaw and comprises of a body and two rami. The two halves of this bone fuse incompletely at the mandibular symphysis, situated at the midline within the body.

Indication: Immobilization of fractured mandible, minimally or non displaced fractures with an intact opposite hemimandible, vertical ramus fracture.

Anasthesia: Local anaesthesia for large animals. A20 gauze 2.5 cm needle is used to deposit 5-1 Omi of lidocaine at the exit site and into the canal.

Infectious diseases are the result of a complex interaction between the host and the microbes. Evasions of protective immunity by the parasites critically determine the survival and pathogenicity of the microbes. The invasion of the body by harmful microorganisms is called infection.

Infection refers to the invasion of harmful microorganisms into the body and causing disease. The most important function of the immune system is to protect the body of the host against various viruses, bacteria, fungi and parasites. The grounds of immune surveillance stand on the basis of innate and specific immunity that build up against the evasive mechanisms of the disease causing organisms. Infectious disease is result of a complex interaction between  the host and the microbes. Evasions of protective immunity by the parasites critically determine the survival and pathogenicity of the microbes. The invasion of the body by harmful microorganisms is called infection. Infections are dangerous in any part of the body. Microorganisms spread vary easily into the blood stream and cause blood poisoning which is called septicemia.

A. Answer the following.

Q.1.     How lysozyme kills Gram + and Gram – bacteria ?
Ans.     Lysozyme kills Gram + bacteria by splitting cell wall proteoglycans and Gram – bacteria in conjunction with complement.

Q.2.     Describe the different forms of leprosy ?
Ans.     Leprosy occurs in two different forms (1) tuberculoid (2) lepromatous. Tuberculoid leprosy occurs in 80% cases. Tuberculoid leprosy patients mount a strong CMI response. These patients have few organisms in their tissues and therefore few lesions. The lesions are infiltrated with macrophages and patients show a positive delayed type hypersensitivity reaction to I/D

The study of the immune system, in its various aspects, is called immunology. Immunology is the branch of bioscience which deals with the defense mechanisms including all physical, chemical and biological properties of the organism that help it to combat its susceptibility to foreign agents and microorganisms. Immunology includes the development and functions of various components of immune system by which the body responds, destroys or neutralizes foreign agents or pathogens. It includes the study at cellular as well as molecular level. Immunology is an interdisciplinary subject which incorporates and requires the knowledge of many branches of biology like microbiology, biochemistry, molecular biology and clinical medicine.

Immunity

Immunity is the resistance of body against extraneous etiological factors of disease, which is afforded by the interaction of chemical, humoral and cellular reactions in body. This is an integral part of the body without, which one cannot think of life. During the process of evolution, nature has provided this defense mechanism in the bodies of all living creatures particularly of higher animals and man, that protects them from physical, chemical and biological threats. It can be classified as natural or paraspecific and acquired or specific immunity.

Natural/paraspecific immunity

There are some species which are resistant to particular diseases due to presence of natural resistance against them e.g. horse, pig, cat are resistant to canine distemper virus; dogs are resistant to feline panleucopenia virus, chickens are resistant to anthrax. Even within species, there is natural resistance that protects some individuals while others are susceptible e.g. Indian deshi cattle Zebu (Bos indicus) is quite resistant to piroplasmosis in comparison to Bos taurus. Besides, there are the mechanisms or barriers in body provided by nature.

Introduction

Anatomy of the immune system in birds differs from that in mammals. Immune cells are present in primary lymphoid organs (PLO) and secondary lymphoid organs (SLO). In birds, thymus and bursa of Fabricius (cloacal bursa) are primary lymphoid organs. Secondary lymphoid organs include the spleen, bone marrow, Harderian gland, aggregates of lymphoid tissue in various organs; i.e. in the gut called gut-associated lymphoid tissue (GALT); in bronchi called bronchial- associated lymphoid tissue (BALT). SLO contains aggregates of lymphocytes and antigen presenting cells. Birds do not have lymph nodes.

In PLO, the lymphoid cells are processed for differentiation and maturation. T lymphocytes differentiate and mature in the thymus, whereas B lymphocytes mature in bursa of Fabricius. Functional lymphocytes move from PLO to SLO. Like mammals, birds defend the body against pathogens through innate immunity (non-adaptive immunity) and adaptive or acquired immunity. Under innate immunity system, physical barriers present in birds play their important role preventing the entry of pathogens into the body. Physical barriers are feathers, skin, aggregates of lymphoid cells in various organs and ciliary defence in the respiratory system. Phagocytosis is first defence for pathogens entering the body, evading the physical barriers. Phagocytic cells include mainly heterophils and macrophages. Natural killer cells (NK cells), thrombocytes and complement also help in innate immunity.

Adaptive immunity is a particular defence which develops when the innate immunity is inadequate to impart protection. Adaptive immunity is antigen specific. T cell, B cell and macrophages play a major role in adaptive immunity. Adaptive immunity is brought about by antibodies (humoral immunity) or also by cells (cell-mediated).

In animals with a long gestation period, such as domestic animals, the acquired immune system is fully developed at birth, but cannot function at full adult levels for several weeks. The complete development of the acquired immunity depends on antigenic stimulation. The proper development of B cells and B cell antigen receptor (BCR) diversity requires clonal selection and antigen driven cell multiplication. Thus, the newborn animals are vulnerable to infection for the first few weeks of life. Hence, the temporary assistance in defending themselves at this time is provided by the mother in the form of antibodies and possibly T cells.
 
Development of the Immune System

The thymus is first lymphoid organ to develop, followed closely by the secondary lymphoid organs. B cells appear soon after the development of spleen and  lymph nodes, but antibodies are not usually found until late in foetal life, if at all. The ability of fetus to respond to antigens develops very rapidly after the lymphoid organs appear, but all antigens are not equally capable of stimulating fetal lymphoid tissue. The immune system in a series of steps, each step permitting the foetus to respond to more antigens. These steps are driven by a gradual increase in the use of gene conversion or somatic mutation to antibody diversity. The ability to mount cell mediated immune (CMI) responses develops at the time as antibody production. Data from humans suggest that T cell receptor diversity is limited in the fetus and neonate and that cytokine production may be low. This may simply be due to their lack of to foreign antigens.

Depressed immune responses have been observed frequently in cancer patients. Cancer and other stress are known to affect different components of the immune system. Cancer treatment is relying mainly on surgery, anti-cancer chemotherapy and radiation therapy. Most chemotherapeutic agents are responsible to myeloid toxicity, which leads to leukemia and immunosuppression affecting both humoral and cell-mediated immunity. This is a very serious disadvantage of chemotherapy besides they are cytotoxic drugs.

Diagnosis of parasitic infections is routinely done with conventional parasitological techniques as described earlier. However, when the parasitaemia is too low to be detected by the conventional methods as in subclinical infections and/or carrier animals advanced diagnostic tools are used for the early, sensitive as well as specific diagnosis. Serological techniques Diagnostic techniques used mostly in laboratories needs various reagents and equipments to perform the test. However, a diagnostic kit is the extrapolation of the same method by packing it in a user friendly format, accompanied by all or most of the reagents required to perform the test and can also be done outside the lab or under field conditions. Various immunodiagnostic kits are available which are based on different diagnostic methods like Enzyme-linked immuno sorbent assay (ELISA). Complement fixation test (CFT), Agar gel immunodiffusion test (AGID), Immunofluorescent tests (IFT), Latex agglutination tests (LAT) etc. ELISA is the most commonly used test system and numerous kits based on ELISA are available commercially.

Diagnosis of parasitic infections is routinely done with conventional parasitological techniques as described earlier. However, when the parasitaemia is too low to be detected by the conventional methods as in subclinical infections and/or carrier animals advanced diagnostic tools are used for the early, sensitive as well as specific diagnosis.

Serological techniques

Diagnostic techniques used mostly in laboratories need various reagents and equipments to perform the test. However, a diagnostic kit is the extrapolation of the same method by packing it in a user friendly format, accompanied by all or most of the reagents required to perform the test and can also be done outside the laboratory or under field conditions.

Immunoblotting or Western blotting is a technique employed to observe proteins separated through gel electrophoresis. After the proteins migrate from the gel to a nitrocellulose or PVDF membrane due to an electrical current, the membrane is exposed to antibodies tailored for the desired target. Subsequently, secondary antibodies and detection reagents are utilized to visualize the proteins of interest on the membrane.

1. Preparation of tissue homogenate

The initial phase of sample preparation involves extracting proteins from their origin. Typically, proteins are extracted from cells or tissues through a process called lysis. This procedure disrupts the cell membrane to separate proteins from the insoluble components of the cell. Different lysis buffers are available for sample preparation in Western blotting and they differ in the potency of their detergents used to liberate soluble proteins.

Introduction

Immunology deals with the body defence system consisting of various cells and biomolecules that prevents entry of foreign infectious and toxic agents by different mechanisms. The mammalian immune system operates in two ways like innate or non specific immunity and adaptive or acquired or specific immunity. Innate part constitutes the physical (skin, hair, tears and mucous secretions) containing enzymes that prevents primarily entry of pathogen. It is the first line of defence action, very fast but not adequate. Adaptive form constitutes defensive cells and secreted immunoglobulins. It takes time to develop effectively, especially when the body sees the organism for the first time. Immunoglobulins (Ig) or antibodies are a group of proteins produced from B lymphocytes and plasma cells in response to the presence of any foreign substances. They are 5 basic types like M, A, G, E and D each with specific function. The system can produce antibody molecules, directed to about 1 million different kinds of antigens. All immunoglobulins have a similar basic structure.

The wellbeing of a person depends on his immune system. Any deficiency in any component of the immune system is called immunodeficiency and it may impair the normal functioning of his body and makes the person more susceptible to infections.

The well-being of a person depends on his immune system. Any deficiency in any component of immune system may lead to defects in the normal functioning of his body and makes him more susceptible to diseases. The immunodeficiency may be either in specific components (B cells or T cells) or nonspecific component (phagocytes and complement) of the immune system.

A. Answer the following.

Q.1.    Which protein is coded by gag gene in HIV ?
Ans.     It codes for protein that form the core (p24 and p17).

Q.2.     Which protein is coded by pol gene in HIV ?
Ans.    It codes for a protein that cleaved into 4 enzymes. 

Q.3.     Which protein is coded by env gene in HIV ?
Ans.    It codes for protein that is cleaved into two proteins (gp120 and gp41).