Tag: AIIMS PG

Habit shown in the the photograph below has shown some protective effect against ?

A. Breast Carcinoma.

B. Liver cancer.

C. Ulcerative colitis.

D. Crohn’s disease.

Correct Answer » C Explanation

Ans:C. Ulcerative Colitis

Benficial effects of Tobacco Smoking on following diseases:

• Uterine fibroids and endometriosis,

• hypertensive disorders and vomiting of pregnancy ,

• decreasing the risk of endometrial cancer,

• recurrent aphthous ulcers,

• ulcerative colitis,

• control of body weight ,

• Parkinson’s disease,

• Alzheimer’s dementia.

A variety of mechanisms for potentially beneficial effects of smoking have been proposed, but three predominate: the ‘anti-estrogenic effect’ of smoking; alterations in prostaglandin production; and stimulation of nicotinic cholinergic receptors in the central nervous system.

A. Less prevalent in developing countries.

B. Toxicogenic strains usually causes ulcers.

C. Urea breath test is positive.

D. Gram negative organism.

Correct Answer » A Explanation

Organism shown in the picture above represents Helicobacter pylori.

H. pylori infection are inane prevalent in developing countries.

The prevalence of H. pylori is approx. 30% in U.S. and other developed countries as against > 80% in most developing countries.

H. Pylori is a gram negative, spiral, flagellated bacillus – Harrison

Strains producing toxins (strains possessing cag pathogenicity DNA island) are more likely to give rise to severe gastritis, peptic ulceration and gastric cancer than strains without it.

DNA island or cag pathogenicity island is a large region of DNA which has genes that control production of toxins.

Urea breath test is a simple, inexpensive and consistently accurate test for H.pylori detection

A. Wilson’s disease

B. Autoimmune Hepatitis

C. Hemangioma

D. Chronic Hepatitis B & C

Correct Answer » C Explanation

Ans is C Hemangioma

Procedure is Liver biopsy

A liver biopsy is a procedure in which a small needle is inserted into the liver to collect a tissue sample. This is performed as an office or outpatient procedure or during surgery. The tissue is then analyzed in a laboratory to help doctors diagnose a variety of disorders and diseases in the liver.

Concentration of compound shown in the photograph below is mostly?

A. 1%.

B. 2%.

C. 5%.

D. 10%.

Correct Answer » D Explanation

Ans:D. 10%.

Concentration of compound povidone iodine is mostly 10%.

Povidone Iodine

• Povidone-iodine is an antiseptic used for skin disinfection before and after surgery.
• It may be used both to disinfect the skin of the patient and the hands of the healthcare providers.

• It may also be used for minor wounds. It may be applied to the skin as a liquid or a powder.

• It contains from 9% to 12% available iodine.

• It works by releasing iodine which results in the death of a range of microorganisms.

• It is contraindicated in patients with hyperthyroidism (overactive thyroid gland) and other diseases of the thyroid, after treatment with radioiodine, and in patients with dermatitis herpetiformis.

True about the infectious agent shown in the photograph below are all except?

A. Associated with Cruetzfeldt-Jacob disease.

B. Heat labile.

C. Sensitive to proteases.

D. Infectious proteinaceous particles.

Correct Answer » B Explanation

Ans:B. Heat Labile.

The infectious agent shown in the photograph above is prions.

Prions.

• Prions are unconventional virus like agent.

• Prions are transmissible particles that are devoid of nucleic acid and seem to be composed exclusively of a modified protein.

• They are resistant to heat (90 degree C for 3 minutes), UV rays and nucleases and sensitive to proteases.

• Prion diseases may present as genetic, infectious, or sporadic disorders, all of which involve modification of the prion protein (PrP).

• Bovine spongiform encephalopathy (BSE), scrapie of sheep, and Creutzfeldt-Jakob disease (CJD) of humans are among the most notable prion diseases.

Moist heat during the process shown in the picture below kills all of the following microorganisms, EXCEPT?

A. Coxiella burnetii.

B. Brucella.

C. Salmonella.

D. Mycobacterium.

Correct Answer » A Explanation

Ans:A. Coxiella burnetii

The process shown in the picture above represents Pasteurization.

Pasteurization

• It is a process that kills microbes (mainly bacteria) in food and drink.

• It is used widely in the dairy industry and other food processing industries to achieve food preservation and food safety.

• Unlike sterilization, pasteurization is not intended to kill all microorganisms in the food.

• Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease.Spores are not affected by pasteurization. Commercial-scale sterilization of food is not common because it adversely affects the taste and quality of the product.

• This is considered adequate for destroying almost all yeasts, molds, and common spoilage bacteria and also to ensure adequate destruction of common pathogenic, all non-sporing pathogens such as mycobacteria, brucellae and salmonellae but not Coxiella burnetii, which causes Q fever.

• Coxiella burnetii is relatively heat resistant and may survive the holder method.

• The temperature employed is either 630C for 30 minutes (the holder method) 720C for 15-20 seconds (the flash process) followed by cooling quickly to 130C or lower.

• The dairy industry routinely uses to test to determine whether products have been pasteurized: the phosphatase test (phosphatase is an enzyme naturally present in milk). If the product has been pasteurized, phosphatase will have been inactivated.

The infectious agent shown in the picture below are best killed by?

A. Autoclaving at 121°C.

B. 5% formaline.

C. Sodium hydroxide.

D. Sodium hypochloride.

Correct Answer » C Explanation

The infectious agent shown in the picture above are prions.

Prions

• A prion is an infectious agent composed entirely of protein material, called PrP (short for prion protein).

• They are suspected to be the cause of transmissible spongiform encephalopathies.

• The infectious agent responsible for the transmission of prion diseases is a misfolded conformer of the prion protein, PrPSc, a pathogenic isoform of the host-encoded, cellular prion protein,PrPC.

• Prions are best killed by Sodium hydroxide.

• Incineration is apparently the only way of disinfecting prion-contaminated materials or tissues.

• Boiling or irradiation have no effect and even routine autoclaving (at 121°C) is not reliable. Therefore, where there is a risk of exposure, surgeons use disposable instruments.

• To sterilize reusable instruments, WHO currently recommends combined use of a strong solution of sodium hydroxide and extended autoclaving at 134°C.

“Autoclaving at 134°C for 5 hrs or treatment with 2 N NaOH for several hours is recommended for sterilization of prions”.

A. Steam under pressure.

B. Dry heat

C. Convection current in water molecules.

D. Tyndallisation.

Correct Answer » B Explanation

Ans:B. Dry heat.

The instrument shown in the picture above represents hot air oven.

Hot air ovens .

Sterilization

• It is the process of killing all microorganisms (bacterial, viral, and fungal) with the use of either physical or chemical agents.

1. Sterilization by heat:

Sterilization by Moist Heat

• Moist heat acts by denaturation and coagulation of protein, breakage of DNA strands, and loss of functional integrity of cell membrane.

• Sterilization at 100°C:Boiling/Steaming.

• Single exposure/Tydallization(Fractional Sterilization).

• Sterilization above 100°C: Autoclaving.

Sterilization by Dry Heat

• Mechanisms. (1) Protein denaturation, (2) Oxidative damage, (3) Toxic effect of elevated electrolyte (in absence of water).

• Dry heat at 160°C (holding temperature for one hour is required to kill the most resistant spores). The articles remain dry.

• Red heat,/Flaming/Sterilization by Hot Air

• Hot Air Oven (Sterilizer). It Is one of the most common method used for sterilization.

• Glass wares, swab sticks, all-glass syringes, powder and oily substances are sterilized in hot air oven. For sterilization, a temperature of 160°C is maintained (holding) for one hour. Spores are killed at this temperature. It leads to sterilization.

2. Chemical Sterilization:Ethylene Oxide,Nitrogen

• Dioxide,Ozone,Glutaraldehyde,Formaldehyde,Hydrogen peroxide,Peracetic acid.

3. Radiation Sterilization:Ionizing and non-ionising Radiation

The infectious agent shown in the picture below consist of ?

A. DNA and RNA.

B. DNA, RNA and Protein.

C. RNA and protein.

D. Only proteins.

Correct Answer » D Explanation

Ans:D. Only proteins.

The infectious agent shown in the picture above represents prions.

Prions consists of only proteins.

Prions

• A prion is an infectious agent composed entirely of protein material, called PrP .

• They are suspected to be the cause of transmissible spongiform encephalopathies.

• The infectious agent responsible for the transmission of prion diseases is a misfolded conformer of the prion protein, PrPSc, a pathogenic isoform of the host-encoded, cellular prion protein,PrPC.

Which type of Bacillus is used to test efficacy of sterilisation by an instrument shown below?

A. Bacillus anthracis.

B. Bacillus pumilis.

C. Bacillus stearothermophilus.

D. Coxiella burnetti.

Correct Answer » C Explanation

Ans:C. Bacillus stearothermophilus.

The instrument shown in the picture above is an autoclave.

Sterilization

• It is a process designed to kill all microbes.

• Autoclave uses moist heat for sterilization.

• Because we can’t actually test whether all microbes are killed during the sterilization process, the next best thing is to determine whether the process kills the most resistant microbe.

• Bacterial spores have been selected as the most resistant type of microbe, and provide the foundation for the process of sterilization.

• For various methods of sterilization following biological indicators are used :-

• For moist heat sterilization process, spores of suitable strains Bacillus stearothermophilus are commercially available as biological indicators and frequently employed.

• Other heat-resistant spore-forming microorganisms such as Clostridium sporogenes,Bacillus subtilis and Bacillus coagulans have also been used in the validation of moist heat sterilization processes.