Unlimited Confusion & Desolation

proudly presents:

The Inofficial Homepage of DGPT

 


Basic Principles of Toxicology

Multiple Choice questions and short answer questions)

Klausur 2022

Please describe the difference between HAZARD and RISK:

What is Pharmacodynamics (PD) …

        investigates the action of a substance and the cellular or biological response to stimuli

        the biological pharmacodynamical effects are always evident and the same, independent of the concentration of a substance or intensity of a stimulus

        PD focusses on mechanisms, while pharmacokinetic (PK) investigates substance levels (that cause the effect observed in PD) over time

        The therapeutic window is the amount of a medication between the amount that gives an effect (effective dose) and the amount that gives the maximum desired effect

        Pharmacodynamics places particular emphasis on dose–response relationships

Define “Volume of Distribution “

The half-life (t1/2)

        is the time it takes for concentration to be reduced to half its initial value

        is dependent on the concentration in plasma

        can range from seconds to months or even years

        is only relevant in pharmacology but not in toxicology

        biological effects may still be present although the concentration has dropped below the minimal effective concentration

In postmortem toxicology which one of the following is the matrix of choice for the quantitative analysis of most drugs to derive their acute effect at the time of death:

        Larvae that are feeding on the corpse

        Cardiac blood from the right ventricle

        Whole blood from the femoral vein

        Filtered stomach contents

        Vitreous humour

What does the abbreviation NPS stand for?

Name three classes of drugs that are classified as NPS.

Name an antidote for bradycardia induced by cardiac glycosides. Where is it working?

Which of the following information on cocaine and its derivates is wrong?

        Cocaine derivates like procaine and lidocaine are used as local anesthetics

        Lidocaine is also used as antiarrhythmic drug

        Amide derivates of cocaine are metabolized to para-aminobenzoic acid, which can induce allergic reactions.

        Cocaine inhibits Na+/K+ channels and the reuptake of (nor)epinephrine.

        Cocaine addiction results in cardiomyopathy and a reduced blood ejection.

Which of the following drugs or toxins blocks acetylcholine release?

        Atropine

        Toxin from Clostridium botulinus

        α-Latratoxin

        Aconitine

        Tetrodotoxin

Why is the metabolite of acetylsalicylic acid (ASA) salicylic acid secreted more efficiently in a basic urine?

Which skin layer typically determines the resorption speed of a toxicant through the skin (one answer is correct)?

        basal membrane

        dermis

        stratum corneum

        stratum spinosum

        stratum basale

        stratum granulosum

Which of the following adverse reactions is a typical reaction for eye toxicity (one answer is correct)?

        contact urticaria

        allergic alveolitis

        pancytopenia

        immunosupression

        corneal deposits

Which statements about methemoglobinemia are correct (two answers are correct)?

        In methemoglobinemia, all iron ions bound to heme are in the ferrous (Fe2+) state

        Methemoglobin cannot bind O2, but results in increased O2 affinity in the remaining heme sites.

        The heme-bound iron must be in the Fe3+ state to bind oxygen.

        Nitrobenzenes can lead to methemoglobinemia

        There is no autooxidation of iron under physiological conditions

Name the three major compartments of the respiratory tract. For each compartment, delineate one possible clearance route

Name two agents that cause different types of lung injury and/or disease. Describe the major

hallmarks of the resulting disease and name what is currently known about the underlying molecular mechanisms

Please mark the right word to complete the sentence: The _____________________ the LD50 measurement, the more toxic the substance.

        higher

        lower

The LD50 for Vitamin A is 200.000 mg/kg. How many chewable vitamin tablets would a 10 kg child have to consume to reach the LD50 if each tablet contains 1 mg Vitamin A?

        2.000 tablets

        20.000 tablets

        tablets

        10.000 tablets

What was Thalidomide prescribed for?

Which major side effects have been observed after Thalidomide treatment?

What is true about developmental toxicology? (Indicate all that apply).

        Mutation can be a mechanism underlying teratogenesis.

        Decreased nutrient supply can be a mechanism underlying teratogenesis.

        The majority of the birth defects are caused by exposure to radiation, drugs, chemicals or maternal metabolic imbalances.

        Teratogenic agents can have an effect on the placenta only.

Humans are exposed to 4-aminobiphenyl which is metabolized and reacts with biomolecules such as DNA and blood proteins (hemoglobin, albumin). Which biomarker can still be found 3 months after a single exposure (one answer is correct)?

        urinary metabolites of 4-aminobiphenyl

        hemoglobin adducts of 4-aminobiphenyl

        DNA adducts of 4-aminobiphenyl

        exhaled 4-aminobiphenyl

Some environmental and occupational pollutants form covalent adducts with blood proteins. What are the advantages to measure such adducts instead of measuring only the concentration of the chemicals in the environment?

Complexes of Cyclins and Cyclin-dependent kinases drive and control the cell cycle. How can their activities be regulated? Mark the correct answers (more than one answer can be correct)

        Expression of the correct Cyclin in the respective cell cycle phase

        Inactivation by cyclin kinase inhibitors

        Activating phosphorylation on Cdk

        Inhibiting phosphorylation on Cdk

Apoptotic cells can be distinguished from necrotic and healthy cells by FACS. Which statements are correct?

        Healthy cells are perfectly stained by propidium iodide (PI).

        Annexin V FITC conjugate stains external phosphatidylserine on apoptotic cell membranes.

        Necrotic cells are stained by both Annexin V AND PI.

        Necrotic cells are not stained by Annexin V and PI.

Typically, one can distinguish two modes of mitochondria initiated/executed cell death. One is called MAC, the other MPT. What do these abbreviations mean? How do they lead to cell death?

Explain the general differences between the concepts of „General Unknown Screening, GUS“ and “Targeted Compound Analysis, TCA” when analyzing any sample for the presence of any poison.

Electrospray ionization (ESI) is a common and highly robust and beneficial technique for ionization of analytes often coupled to chromatographic separation. Which statements are correct?

        ESI induces fragmentation of analytes by bombardment with electrons submitted from an emitter electrode.

        ESI applied in positive mode typically transfers protons to the analytes thus producing positively charged ions suitable for mass spectrometric detection.

        ESI is a technique best suited for online coupling to UV- and fluorescence detection of drugs of abuse.

        ESI belongs to the techniques for soft ionization of analytes to convert them into ions thereby typically not inducing fragmentation.

        ESI belongs to the techniques for soft ionization of analytes to convert them into ions thereby typically not inducing fragmentation.

(Blood) plasma, urine and hair are typical specimens for toxicological and forensic analysis. Which statements are correct?

        Hair analysis is best suited to document the acute phase of poisoning and clearly indicates toxicants that were incorporated a few hours before.

        Urine analysis is best suited for post-exposure evidence of all polar poisons that were incorporated more than 3 months before sample drawing.

        Plasma is the ideal specimen to provide data on acute exposure to any poison documenting the actual concentrations influencing the organism.

        For urine analysis phase II conjugates of analytes (e.g. drugs and drugs of abuse) are typically subjected to enzymatic degradation using e.g. glucuronidases prior to instrumental analysis thus enhancing analyte concentrations.

        Chronic poisoning and continuous drug consumption might be documented by the analysis of hair cut into small segments thus allowing the estimation of past periods of drug or poison incorporation.

Which cancers can be caused by the occupational exposure to the following toxicants: Aflatoxins, Aromatic amines, Asbestos, Ultraviolet irradiation, Benzene Write the right toxicant behind the corresponding cancer type.

Cancer:

        Leukaemia

        Mesothelioma

        Hepatocellular carcinoma

        Skin Cancer

        Bladder Cancer à

DALYs (Disability Adjusted Life Years) are sometimes used to estimate the quantitative role of occupational toxicology in preventing diseases due to occupational toxicants. What do they consist of (multiple answers possible)?

        Years After the Diagnosis (YAD) of a disability related to the occupational exposure to a toxicant

        Occupational Exposure Years (OEY) based on the time of a known exposure to a toxicant

        Years of Life Lost due to premature death (YLL) based on the number of deceased persons and the life expectancy at birth

        Years between Disability Onset and first Exposure (YDOE) to an occupational toxicant

        Years Lived with Disability (YLD) based on the prevalence and a disability weight

Regulatory Toxicology

        is a subdiscipline of environmental toxicology.

        aims to protect human beings (and nature) from toxic effects.

        enacts laws.

        does not include biocides and drugs.

Which statement about human exposure assessment is true?

        External and internal exposure are related by a simple calculation factor.

        Internal exposure to a substance can be estimated on the basis of external exposure data.

        Internal exposure to a substance can exclusively be determined by measurement (human biomonitoring).

        Measurement of internal exposure to a substance (e.g. in blood) generally causes higher costs than measurement of external exposure (e.g. in ambient air).

Which statement about ADI (acceptable daily intake) values is true ?

        ADI values can in principle be derived for all kinds of potentially toxic substances.

        Exposure to a potentially toxic substance exceeding the ADI value always implies high acute risk of health damage.

        ADI values are usually derived from toxicological findings in humans.

        ADI values are defined for lifetime exposure and are valid for all groups of humans (including e.g. children, pregnant women).

How would you define a Maximum Residue Level (MRL)?

In EU chemical legislation, REACH stands for … (Only one answer is correct)

        Risk and Exposure Assessment of Chemicals

        Regulation, Assessment and Control of Chemicals

        Registration, Evaluation and Authorisation of Chemicals

        Regulation on Environmental Analysis and Control of Hazards

The European Food Safety Authority (EFSA) … (Only one answer is correct)

        authorises both active ingredients and plant protection products.

        accepts only animal studies for toxicity testing.

        identifies endocrine disruptors using a different methodology from that used by the European Chemicals Agency (ECHA).

        assesses risks to both human health and the environment.

How many DNA molecules are in a healthy diploid human cell nucleus (genome size 6,2x109 base pairs)?

What is the predominant DNA damage mechanism during ionizing radiation exposure? (Only one answer is correct)

        direct ionization

        single strand break formation

        radical attack

        lipid oxidation

Which of the following 2 pathways repair DNA double strand breaks? (Two correct answers)

        TC-NER

        HR

        SSBR

        NHEJ

Please name three cellular consequences of DNA damage.

Which of the following statements are true?

        Base excision repair is responsible for the repair of “small” DNA lesions introduced by reactive oxygen species or methylating/ethylating agents.

        DNA glycosylases are responsible for the sealing of DNA single strand gaps after excision of the DNA lesion and resynthesis of the missing bases.

        Non-homologous end joining (NHEJ) is the main repair pathway responsible for the repair of DNA SINGLE strand breaks?

        Nucleotide excision repair is responsible for the repair of big bulky DNA adducts.

        Pharmacological targeting of DNA repair factors can be employed in cancer therapy.

        DNA polymerases that are responsible for DNA translation synthesis have a very HIGH catalytic efficiency, fidelity and processivity.

What are the most permanent changes environmental carcinogens inflict? (Only one answer is correct)

        Protein changes

        RNA changes

        Epigenetic changes

        DNA changes

        All of the above

What are the molecular hallmarks of smoking-induced cancers? (Only one answer is correct)

        KRAS mutations

        TP53 mutations

        C > A transversions

        High mutation burdens

        All of the above

What are the potential environmental causes of lung cancer in addition to smoking? (Only one answer is correct)

        Human papillomavirus infection

        Helicobacter pylori infection

        Frequent gestations (pregnancies)

        Frequent multi-partner sexual intercourse

        Irradiation

Please list the main essential metals.

What are the most relevant (highly toxic) heavy metals for human?

Please, select the correct list of essential trace metals.

        Lead, arsenic, cobalt and manganese.

        Zinc, iron, cobalt, copper, cobalt and manganese.

        Calcium, magnesium, zinc and iron.

        Cadmium, mercury, lead and arsenic.

Please describe briefly the molecular mode of action of botulinum toxin within the cytoplasm of an axon ending.

Please mark correct statements:

        Any incidence of intoxication with biological toxins almost certainly indicates a terrorist attack.

        Reliable diagnosis of biological toxins often requires a combination of immunological, mass spectroscopic and functional biological detection methods.

        Standard therapy of intoxication by many biological toxins is often only symptomatic, since specific antitoxins are not always available.

        All biological toxins show markedly specific organ tropism.

        Cyanotoxin poisoning occurs exclusively after consumption of fish or shellfish.

Please mark correct statements regarding Botulinum toxin and Ricin:

        Botulinum toxin belongs to the group of AB toxins.

        After surviving a botulinum intoxication, patients develop lifelong immune protection through antibody formation.

        Inhalation of botulinum toxin is a typical mechanism of exposure.

        Ricin causes a breakdown of DNA synthesis in cells.

        Past exposure to ricin can be detected by immunological tests.

What does NOAEL stand for?

What stands ADA for? In case ADA is developed what are the expected effects in toxicity studies

        ADA stands for anti-drug antibodies. The antibodies show effects by neutralization of the test item. This results in higher direct test item related toxicity - but lower test item related pharmacological efficacy.

        ADA stands for anti-drug antibodies. The antibodies show effects by neutralization of the test item. This results in lower direct test item related toxicity and in addition in in putative ADA related immunotoxic effects.

        ADA stands for Adalimumab which is an antibody used in therapy of Rheumatoid Arthritis. ADA increases the risk of cancer in patients which might be wrongly addressed to the test substance in toxicity studies.

        ADA stands for anti-drug antibodies. An immunotoxic effect related to ADA could develop. However, the exposure with the test item is not changed and no effect on the data obtained on toxicity is expected.

 

Neue Fragen? Dann maile sie sofort an herbsjo1@gmx.de

E-Mail bitte deutlich schreiben. Ich bin Brillenträger!


Last Update: 30. Dezember 2022