Pathology Techniques And Disease Monitoring Biology Essay

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Pathology techniques and procedures are used in pathology departments to help diagnose and monitor diseases. Findings and results obtained using these techniques aid the treatment and control of diseases. Currently, there are four pathology disciplines and they all have specific techniques and procedures used to diagnose and monitor different diseases. This essay aims to explain either a technique/test/procedure from each of the pathology disciplines; Haematology, Chemistry, Histology, Microbiology, the principle of the test, how it is used to help in the diagnosis and monitoring of disease and any possible investigation(s) that needs to be carried out as a consequence of the initial results obtained.

Haematology discipline uses full blood count technique amongst other techniques in the diagnosis and monitoring of diseases. Full blood count is very useful in the diagnosis of diseases because blood is the main transport medium in the body and it accesses every body organ. In addition to this, blood samples are taken from patients using non-invasive methods. Full blood count can be carried out manually or by using automated analysers. Manual methods are more accurate because it does not exclude any blood cell unlike the automated analysers but it is slow and time consuming due to the large amount of samples sent to the departments. Automated analysers measure haemoglobin concentration, white blood cells (to five part differential) numbers, platelets numbers and red blood cells numbers in the blood. The analyser checks the barcode of every sample before splitting in two parts; one part of the sample is used to measure the red cells and the other part has its red blood cells lysed to be able to measure other blood contents based on size, granularity and population. The results are shown on a computer to which the analyser is attached. Abnormal results are highlighted while normal results are sent out to the appropriate department. Further investigation is carried out on abnormal results. Blood films are made from the samples with abnormal result. These films are stained and observed under the microscope. Comments about the abnormal results are sent out to Gps, doctors, clinics, wards or the appropriate department. Full blood count has helped in the diagnosis of diseases with similar symptoms. For example, high white blood cell count could indicate either glandular fever or tonsillitis. Using full blood count test, results with normal neutrophils count but high lymphocytes count identifies the disease been investigated to be Glandular fever while high neutrophils count and normal lymphocytes count indicates tonsillitis. Full blood count is used to investigate other diseases such as malaria, anaemia, diseases of the liver, cancer of the blood also known as leukaemia and haemoglobin disorders.

Glucose test is a major test carried out daily in the department of biochemistry. Glucose is biochemical substance of high importance to the human body with a normal concentration range of 3.5-5.5 mM. Excess increase or decrease of blood glucose in the body may lead to diseased and life threatening conditions such as hypoglycaemia, hyperglycaemia, kidney problems and in extreme cases organ failures. (Ahmed et al, 2007) Gps and doctors may request for a glucose test when a patient exhibits symptoms of low blood glucose, high blood glucose, slow healing process, weight loss and other diabetic symptoms. Sometimes glucose tests are ordered as part of routine physical examination or when the patient has a family history of diabetes. Blood glucose can measured using fasting blood sample or non-fasting blood sample. Fasting blood samples are taking from patients that have been restricted from food consumption for about eight hours prior to the sample collection. (Eckman, 2010) Glucose tests are performed on venous blood samples sent to the laboratory in tubes containing fluoride oxalate. The fluoride oxalate present in the tube prevents metabolism of the glucose present in the blood sample. After these samples are measured for their glucose content concentration, the glucose concentrations readings are sent back to Gps and doctors that ordered them. The test result helps the Gp/doctor to access the state of the patient. If the glucose level is low, the condition is called is called Hypoglycaemia an indicator of Type 1 diabetes while a high level of glucose is known as Hyperglycaemia an indicator of Type 2 diabetes. Further investigations can be carried out to understand the severity of the diseased conditions in patients. Microalbuminuria, Blood Urea Nitrogen and Serum Creatinine tests may be ordered detect kidney damage in patients. Also, urine protein electrophoresis can be carried out and in an extreme case; kidney biopsy may be required to observe the disease at the cellular level.

Biopsy and preparation of samples for staining is a very important technique in the department of histology because it helps in the diagnosis of diseases at the cellular level. Biopsy entails the taking of tissue samples from patients by competent professionals to be examined under a microscope. Samples are collected using various methods from any part of the body depending on the disease or condition that is been investigated. The samples are received, examined and dissected by histopathologists as soon as they arrive in the department. Next, the required parts of the dissected samples are put into colour labelled cassettes ready for the tissue processing stage. The tissue processing stage is carried out using a machine called a Tissue Processor. This stage involves the use of fluids in fixing samples. Alcohol is used to remove water and formalin contents from the sample and this is followed by removal of the alcohol contents from the sample using xylene. It is essential that the tissues are fixed properly so that the characteristics of the tissues are not disturbed which may affect observations under the microscope. Embedding process is the next process after this stage. Here, molten paraffin wax is used to enclose each sample in a mould and then allowed to solidify into blocks in a cooling area. The embedding process helps the tissue sample to be resistant to breakage during cutting in the microtomy section. (Bancroft, 2008) Afterwards the samples are passed to the microtomy section of the department. Here a machine called microtome is used to cut the embedded tissue into wafer thin slices. The slices are put in hot water bath with a temperature of about forty-fifty degree Celsius for thirty seconds so as to flatten out the creases. (Bancroft, 2008) The slices are picked up from the hot water bath using slides and they are ready to be stained. This technique is used to investigate problems and diseases such liver diseases, lung infections and disorders, cancer, and cancer malignancy. Further investigations can be carried out such biochemistry and microbiology tests to rule out any discrepancies in microscopic observation.

Identification of the disease causative agent is an important part of the treatment process of a disease. Swabs are used in the discipline of microbiology to identify causative organisms of different diseases. This procedure is usually requested by GP’s and doctors whose patients have wounds, ulcerations, secretions or are not symptom specific. Kinds of swabs include wound swabs, throat swabs, eye swabs, ear swabs and vaginal swabs. Wound swabs go through the diagnostic cycle in the laboratory that begins with sample reception where the name and other details on the form are matched with the details on the sample. Next, the wound type is assessed followed by narrowing of the spectrum for possible site diseases. This step is followed by the recovery process. This process involves using a growth media as a broth to grow the organisms present in the sample. This allows for observation of characteristics exhibited by organisms in the sample also called identification process. Afterwards, susceptibility and antibiogram tests are carried out on the samples and finally presence and sensitivity of the causative organism is reported to the appropriate place. All other swabs go through the diagnostic cycle. Ear swab tests are mainly used to identify pseudomonas species and infections caused by staphylococcus aureus. Throat swabs are used to identify causative agents of various infections and diseases including diphtheria, pharyngitis and Methicillin resistant Staphylococcus Aureus. Eye swabs are used to detect infections and diseases such chlamydia, conjunctivitis and blepharitis. Vaginal swabs are used to detect infections such Trichomonas Vaginalis, genital warts, thrush, Group A, C and G Neisseria and chylamydia. Swabs may not be able to identify the causative organisms in some cases sometimes due to different reasons such as inappropriate way of sample collection therefore other investigations may be carried out. Biopsies may be required depending on the condition and cases like genital warts can be further investigated in the cytology unit of histology department.

Conclusively, this essay has explained a procedure/test from each of the pathology disciplines. Also, this essay helped to emphasise the important role pathology plays in the diagnosis and monitor of diseases, the interdependence between pathology departments and the interaction between medical personnel (such as Gps, Nurses, mortuary managers and doctors) and biomedical scientists. In addition, this essay helps to understand that the future of medicine, biomedical science, disease treatment and control greatly depends on the discovery of more and efficient biomedical procedures and tests.