223 Questions
What is the most common route of transmission for viruses?
Respiratory route
What is the least common route of transmission for viruses?
Genital route
What is a potential source of infection from blood transfusions?
Hepatitis B
What is vertical transmission?
From mother to child
What is the potential risk associated with organ transplants?
Cytomegalovirus
What is the most common route of dissemination for viruses?
Blood
Which type of infections are restricted to certain areas but can have generalized effects on the body?
Localized infections
What kind of individuals are at risk for transmission through medical or surgical instruments, blood transfusions and blood products, and organ transplantation?
Professionals, politransfused, drug addicts
Which cells are key for the establishment of infection after successful entry of the virus?
Permissive cells
Which viruses are capable of replication in cells residing in the superficial layers of the dermis?
Viruses entering through the skin
Which of the following best describes the pathogenesis of a viral infection?
The process by which a viral infection causes a disease.
What is the relationship between viral pathogenesis and host permissiveness?
Host permissiveness plays a role in viral pathogenesis.
What are the important events in viral pathogenesis?
Viral entry into the host and overcoming of local defenses.
How can virulence for each type of virus be determined?
By small mutations in the virus genome
What is the balance in viral pathogenesis?
A double result of the spread of the virus and host survival
What is the role of oncogenic viruses and chemical carcinogens in tumor formation?
They initiate and promote tumor formation
What percentage of human cancers has a viral etiology?
15%
Which two cancers have been associated with viral etiology?
Female cervical cancer and cancer of the liver
What is the role of oncogenes and tumor suppressor genes in normal cell proliferation?
Oncogenes are positive regulators and tumor suppressor genes are negative regulators
What is the role of oncogenes in cellular homeostasis?
They are necessary for cellular homeostasis
What is the causative agent of Burkitt lymphoma?
Epstein-Barr virus (EBV)
What virus is associated with Kaposi's sarcoma and primary effusion lymphoma?
Human herpesvirus 8 (HHV8)
Which virus is associated with adult T-cell leukemia (ATL)?
Retrovirus as HTLV-1
What is the virus associated with cervical cancer?
Papillomavirus (HPV)
What is the role of HBV in hepatocarcinogenesis?
Indirectly promotes genome instability
What is the incubation period?
The interval between the acquisition of infection and the onset of disease
Which of the following is a modality of viral elimination?
Airway
What is a latent infection?
The virus remains in the form of integrated nucleic acid into the host cell genome or present in the cell nucleus in the episomic form
Which of the following viruses can diffuse through the nervous route?
Rhabdoviruses
What characterizes chronic infections?
The virus is characterized by the continuous presence of the virus, that continues to be produced even after the acute phase but usually at much lower levels and for a long time
What is the main cause of chronic hepatopathy and its outcomes in liver cirrhosis and hepatocellular carcinoma?
Rising plasma levels of liver enzymes
What is the role of E6 and E7 proteins in HPV-related cancer?
They alter the activity of proteins p53 and Rb, respectively
What is the association between EBV and nasopharyngeal carcinoma?
EBV is associated with nasopharyngeal carcinoma
What is the significance of the translocation of c-myc from chromosome 8 to 14?
It is observed in 90% of cases
What are some examples of slow infections?
Hepatitis B and C, HIV and HTLV, and Papovavirus
What is a cytopathic effect (CPE)?
The rounding of the cells with subsequent lysis
What is apoptosis?
Programmed cell death
What are prions?
Non-conventional agents that cause slow infections
What are some examples of cytopathic effects?
All of the above
What is apoptosis?
A form of cell suicide encoded by specific genes.
What is transformation?
A process by which a cell loses control of its proliferation and becomes cancerous.
What is the difference between immortalization and unordered stacked growth in transformation?
Immortalization is the formation of lines or clones, while unordered stacked growth is the indefinite multiplication of cells.
What is the major role of apoptosis in fighting viral infections?
To eliminate virus-infected cells and prevent the spread of the virus within the host organism.
What are some mechanisms developed by viruses to overcome host processes specifically activated to fight viral infections?
Interference with the action of specific cytokines, complement activation, and antigen presentation.
What is the virion?
The inert form of the virus
What is the process by which a viral infection causes a disease?
Pathogenesis
What determines the virulence of each type of virus?
Small mutations in the genome
What is the most important event in viral pathogenesis?
Viral entry into the host
What is the double result of the spread of the virus and host survival?
Balance
What is the most common route of transmission for viruses?
Transmission by respiratory route
Which route of transmission is influenced by social and economic conditions, such as contaminated food and poor environmental remediation?
Transmission through the gastrointestinal tract
Which of the following is a potential source of infection for viruses, such as hepatitis B, hepatitis C, and HIV?
Blood transfusion
Which type of transmission is influenced by the degree of sexual promiscuity and only interests adults?
Transmission by genital route
Which type of transmission may be subject to environmental and seasonal influences?
Transmission through skin lesions caused by insects and animals
What virus is associated with primary hepatocellular carcinoma (HCC)?
HCV
What is the causative agent of Burkitt lymphoma?
Epstein-Barr virus (EBV)
What virus is associated with adult T-cell leukemia (ATL)?
HTLV-1
Which virus is associated with cervical cancer?
Papillomavirus (HPV)
What virus is associated with Kaposi's sarcoma and primary effusion lymphoma?
Human herpesvirus 8 (HHV8)
What is the role of a promoter in tumor formation?
It results in the formation of the tumor
What is the function of oncogenes in cellular homeostasis?
They are necessary for normal cell proliferation
Which viruses are associated with widespread tumors in humans?
HPV and HBV
What is the function of tumor suppressor genes in cellular homeostasis?
They negatively control cell growth
What is the possible reason for neoplastic transformation due to oncogenes?
Gene amplification
What is the interval between acquisition of infection and transmission of infection to another individual called?
Generation time
What is the phenomenon called when the virus remains in the form of integrated nucleic acid into the host cell genome or present in the cell nucleus in the episomic form?
Latent infection
Which of the following viruses are suspected to have some forms of latency?
Measles virus
What is the characteristic of chronic infections?
Continuous presence of the virus
What are the main modalities of viral elimination?
Airway, digestive tract, and urogenital tract
What is the most common route of dissemination for viruses?
Systemic blood
Which type of infections are restricted to certain areas but can have generalized effects on the body?
Localized infections
What is the potential risk associated with organ transplantation?
Risk of viral transmission
Which viruses are capable of replication in cells residing in the superficial layers of the dermis?
Rhinoviruses
What is the route of dissemination that presupposes the lymphatic drainage of the virions and their release into the circulation?
Lymphatic drainage
What are slow infections characterized by?
A long incubation period followed by a progressive disease
What is the cytopathic effect (CPE)?
All of the above
What is apoptosis?
A virus-induced programmed cell death
What is the potential outcome of a virus-induced transformation?
All of the above
Which of the following is an example of a slow infection?
HIV
What is the less common, but frequent route of transmission for viruses?
Genital route
Which route of transmission for viruses is poorly influenced by social and economic conditions, but can suffer environmental and seasonal influences?
Respiratory route
What is the potential source of infection through blood transfusion?
Hepatitis B
What is the modality of transmission for viruses that is influenced by social and economic conditions, as in case of contaminated food and poor environmental remediation?
Gastrointestinal route
Which modality of transmission for viruses may be subject to environmental and seasonal influences, caused by skin lesions from insects and animals?
Skin lesions caused by medical instruments
What is the role of oncogenes in normal cell proliferation?
They are necessary for cellular homeostasis
What is the difference between initiators and promoters in tumor formation?
Initiators induce heritable changes in some cells, promoters result in the formation of the tumor
What percentage of human cancers has a viral etiology?
15%
What is the function of tumor suppressor genes?
They negatively control cell growth
Which virus is associated with female cervical cancer?
HPV
What is apoptosis?
A form of cell suicide encoded by specific genes
Which viruses are capable of inhibiting the expression of proteins directly involved in apoptosis and their related targets?
Adenovirus p53, CMV p53, EBV p53, HBV p53, HPV p53, Adenovirus bcl-2, EBV bcl-2, Poxvirus caspases, Adenovirus TNF receptor
What is the process by which a cell loses control of its proliferation and becomes cancerous?
Transformation
What is the most common route of dissemination for viruses?
Systemic blood (viremia)
What is the result of several cumulative effects that change the control of cell proliferation?
Transformation
Which individuals are at risk for transmission through medical or surgical instruments, blood transfusions and blood products, and organ transplantation?
Professionals, politransfused, drug addicts
What is the role of apoptosis in the release of naked viruses?
It facilitates the release of the virus
What are localized infections?
Infections that remain confined to the tissues of the site of entry or to those adjacent to it
What is distant spread?
Spread in all systemic infections
Which viruses are capable of replication in cells residing in the superficial layers of the dermis?
Rhinoviruses
What virus is associated with primary hepatocellular carcinoma (HCC)?
Hepatitis C virus (HCV)
What virus is associated with Burkitt lymphoma?
Epstein-Barr virus (EBV)
What virus is associated with Kaposi's sarcoma and primary effusion lymphoma?
Human herpesvirus 8 (HHV8)
What virus is associated with adult T-cell leukemia (ATL)?
Retrovirus as HTLV-1
What virus is associated with cervical cancer?
Herpes simplex virus type 2 (HSV-2)
What is the role of rising plasma levels of liver enzymes in chronic hepatopathy and its outcomes in liver cirrhosis and hepatocellular carcinoma?
They are evidence of damage produced by the cytolytic action of CTL and subsequent fibrotic repair.
What is the main cause of HBV hepatocarcinogenesis?
Integration of HBV genome in cell genome.
What is the association between E6 and E7 proteins and HPV-related cancer?
They result in loss of oncosuppressor genes such as p53 and prb.
Which virus is associated with Burkitt's lymphoma in children in central Africa and New Guinea?
EBV/HHV4
What is the difference in viral genome location between benign neoplasia and cervix carcinoma caused by HPV?
In benign neoplasia, viral genome is in episomial form. In cervix carcinoma, viral genome is integrated in DNA of infected cell.
What is the definition of pathogenesis in the context of viral infections?
The process by which a viral infection causes a disease
What is the role of the virion in viral infections?
It represents the inert form of the virus
What determines the virulence of a virus?
Small mutations in the genome
What are the important events in viral pathogenesis?
Viral entry into the host, viral replication, overcoming of local defenses, diffusion from the place of implant, dissemination to target organs
What is the link between viral pathogenesis and host permissiveness?
The viral pathogenesis is generally linked to the permissiveness of the host and its organs
What are slow infections characterized by?
A long incubation period followed by an acute stage
What is the cytopathic effect (CPE)?
Morphological alterations that occur both in the host and in cell cultures in vitro
What is apoptosis?
Programmed cell death
What are some examples of slow infections?
Infections caused by prions
What is the difference between cytocide infections and transformation?
Cytocide infections lead to cell death while transformation changes the cell's behavior
What is the incubation period?
The interval between the acquisition of infection and the onset of disease.
What is the difference between the incubation period and the generation time?
The incubation period is the interval between the onset of disease and the acquisition of infection, while the generation time is the interval between the acquisition of infection and the onset of disease.
What is the main modality of viral elimination?
Airway
What is a chronic infection?
An infection that is detectable during the acute phase of replication but no longer detectable as infectious virus if not in successive reactivation.
What is a latent infection?
An infection that is only present during the latency phase.
What is apoptosis?
A form of cell suicide encoded by specific genes
What is transformation?
The induction of morphological, biochemical and biological changes at a genetic level
What are the major animal viruses capable of inhibiting the expression of proteins directly involved in apoptosis and their related targets?
Adenovirus p53, CMV p53, EBV p53, HBV p53, HPV p53, Adenovirus bcl-2, EBV bcl-2, Poxvirus caspases, Adenovirus TNF receptor
What is a tumor?
The result of several cumulative effects that change the control of cell proliferation
What is the process by which a virus enters a host cell and replicates inside it called?
Infection
What is the most common route of dissemination for viruses?
Systemic blood
Which type of infections are restricted to certain areas but can have generalized effects on the body?
Localized infections
What are the main ways viruses can be transmitted through?
Medical or surgical instruments, blood transfusions and blood products, organ transplantation
What is the mechanism by which viruses can migrate to find cells permissive for viral replication?
Body fluids
Which type of infections are superficial and affect the skin, conjunctiva, and mucous membranes?
Superficial infections
What is the process by which a viral infection causes a disease called?
Pathogenesis
What represents the inert form of a virus?
The virion
What are the important events in viral pathogenesis?
Viral entry into the host, viral replication, and overcoming of local defenses
What determines the virulence of each type of virus?
The number of viral mutations in the genome
What is the double result of the spread of the virus and host survival called?
Balance
What is the most common route of transmission for viruses?
Respiratory route
Which of the following is a potential source of infection from blood products?
HIV
Which of the following is a virus that can be transmitted through breast-feeding?
HIV
Which of the following is a virus that can be transmitted through the genital route?
HIV
Which of the following routes of transmission is influenced by social and economic conditions?
Gastrointestinal route
What is a slow infection characterized by?
A long incubation period and a progressive disease
What is the cytopathic effect (CPE)?
Morphological alterations that occur in the host
What is apoptosis?
Programmed cell death
What is the potential outcome of a virus-induced transformation?
Oncogenesis
What is a prion?
A non-conventional agent
What is the role of the E2 gene in HPV-related cancer?
It controls the production of E6 and E7 proteins
What is the virus associated with nasopharyngeal carcinoma?
EBV/HHV4
What is the causative agent of Burkitt's lymphoma?
EBV/HHV4
What is the main mechanism responsible for chronic hepatopathy and its outcomes?
Rising plasma levels of liver enzymes (transaminases) due to cytolytic action of CTL
What is the role of E6 and E7 proteins in HPV-related cancer?
They alter the activity of proteins p53 and Rb
What percentage of translocation of c-myc from chromosome 8 to 14 is observed in cases of Burkitt's lymphoma?
90%
What virus is associated with adult T-cell leukemia (ATL)?
Retrovirus as HTLV-1
Which virus is associated with primary effusion lymphoma (BCLB)?
Human herpesvirus 8 (HHV8)
What virus is associated with cervical cancer?
Papillomavirus (HPV)
Which virus is associated with Burkitt lymphoma?
Epstein-Barr virus (EBV)
Which virus is associated with Kaposi's sarcoma?
Human herpesvirus 8 (HHV8)
What is the incubation period?
The time between acquisition of infection and the onset of disease
What is the generation time?
The time between acquisition of infection and transmission to another individual
Which viruses can cause latent infections?
Retroviruses (HIV), measles virus and some enteroviruses
What is the main modality of viral elimination through the body?
Airway
What is a chronic infection?
They are characterized by the continuous presence of the virus, that continues to be produced even after the acute phase but usually at much lower levels and for a long time, compatible with the survival of the host.
What is responsible for chronic hepatopathy and its outcomes in liver cirrhosis and hepatocellular carcinoma?
The cytolytic action of CTL and subsequent fibrotic repair
What is the role of E6 and E7 proteins in HPV-related cancer?
They alter the activity of proteins p53 and Rb, respectively
Which virus is associated with nasopharyngeal carcinoma?
Epstein-Barr virus (EBV/HHV4)
What is the causative agent of Burkitt's lymphoma?
Epstein-Barr virus (EBV/HHV4)
What is the percentage of cases of translocation of c-myc from chromosome 8 to 14?
10%
What is apoptosis?
A form of cell suicide encoded by specific genes
What are some mechanisms used by viruses to overcome host processes activated to fight viral infections?
Inhibition of antigen presentation and specific cytokine action, complement activation, and apoptosis
What is transformation?
The process by which a cell loses control of its proliferation and becomes cancerous
What is a tumor?
The result of several cumulative effects that change the control of cell proliferation
What is the difference between immortalization and unordered stacked growth in the process of transformation?
Immortalization is the indefinite multiplication of cells with the formation of lines or clones, while unordered stacked growth is characterized by loss of contact inhibition that can cause the formation of a tumor when inoculated into an appropriate host
What is the role of oncogenic viruses and chemical carcinogens in tumor formation?
They both act as initiators in tumor formation
What are oncogenes and tumor suppressor genes?
Oncogenes are positive regulatory genes that promote cell growth, while tumor suppressor genes are negative regulatory genes that inhibit cell growth
What is the difference between v-onc and c-onc genes?
v-onc genes are found in retroviruses, while c-onc genes are found in normal cells
What is the function of the proteins encoded by oncogenes?
Growth factors, membrane receptors for growth factors, tyrosine proteinchinases, GTP-binding proteins, and nuclear proteins
What is the difference between complete carcinogens and other agents?
Complete carcinogens are capable of both initiation and promotion, while other agents are only capable of one
What is the process by which a viral infection causes a disease called?
Pathogenesis
What is the inert form of the virus called?
Virion
What creates a new entity called the infected cell?
Penetration
What is the double result of the spread of the virus and host survival called?
Balance
What are the important events in viral pathogenesis?
All of the above
What is the most common route of transmission for viruses?
Respiratory route
Which route of transmission for viruses is influenced by social and economic conditions?
Gastrointestinal route
What is the potential risk associated with organ transplants?
Risk of developing cytomegalovirus and Epstein-Barr virus
What is the term used to describe the transmission of a virus from mother to child?
Vertical transmission
Which virus can be transmitted through breast-feeding?
HIV
What is the most common route of dissemination for viruses?
Systemic blood (viremia)
What are some examples of localized infections?
Rhinoviruses
What is the main factor for the establishment of infection after a virus enters the body?
Availability of sensitive and permissive cells
What is the mechanism by which some viruses can spread to the central nervous system?
Nervous route
What is the difference between localized and systemic infections?
Localized infections remain confined to the site of entry or adjacent tissues, while systemic infections spread throughout the body
What is apoptosis?
A process facilitating the release of virus from infected cells
What is transformation?
The process by which a cell loses control of its proliferation and becomes cancerous
What is the role of tumor antigens (T) in some cases of tumor formation?
They are expressed at the surface of tumor cells
What is the difference between oncogenes and tumor suppressor genes?
Oncogenes are necessary for cellular homeostasis, while tumor suppressor genes negatively control cell growth.
What is the potential outcome of neoplastic transformation caused by oncogenes?
Tumor formation
Which type of viruses are able to induce transformation and/or tumor in vitro and in vivo?
DNA viruses or RNA viruses that synthesize DNA during replication
What percentage of human cancers has a viral etiology?
Approximately 15%
What is the function of tumor suppressor genes in cellular homeostasis?
Negatively control cell growth
What is the role of CTL in liver cirrhosis and hepatocellular carcinoma?
CTL causes damage to liver enzymes.
What is the role of HBV genome integration in cell genome?
It leads to genome instability involving genes encoding Cyclin E1 and Tert, loss of oncosuppressor genes such as p53 and prb, and up-regulation of oncogenes such as Cyclin E1 and Tert.
What is the role of E6 and E7 proteins in HPV-related cancer?
E6 and E7 proteins alter the activity of proteins p53 and Rb, respectively.
Which virus is associated with nasopharyngeal carcinoma?
EBV/HHV4
What is the association of EBV with B lymphocytes?
The presence of EBV genome in B lymphocytes immortalizes these cells.
What is the incubation period of a viral infection?
The interval between the acquisition of infection and the onset of disease.
What is the difference between the incubation period and the generation time?
The incubation period is the interval between the onset of disease and the acquisition of infection, while the generation time is the interval between the acquisition of infection and the onset of disease.
Which of the following is a modality of viral elimination?
Urogenital tract
What is a latent infection?
An infection that is detectable during the acute phase of replication but is no longer detectable as infectious virus if not in successive reactivation.
What characterizes chronic infections?
The continuous presence of the virus, that continues to be produced even after the acute phase but usually at much lower levels and for a long time.
What is a characteristic of slow infections?
They have a long incubation period followed by a progressive disease
What is the cytopathic effect (CPE) caused by viruses?
The formation of clusters of viral constituents and/or altered cellular structures in the nucleus or cytoplasm of the cell
What is apoptosis?
Programmed cell death
What is the difference between cytocide infections and transformation caused by viral infection?
Cytocide infections lead to cell death while transformation changes the genetic and regulatory state of the cell
What is an example of a virus that causes slow infections?
Prions
What virus is associated with adult T-cell leukemia (ATL)?
Retrovirus as HTLV-1
What virus is associated with primary hepatocellular carcinoma (HCC)?
Hepatitis B virus (HBV)
Which virus is associated with Burkitt lymphoma?
Epstein-Barr virus (EBV)
What virus is associated with Kaposi's sarcoma?
Human herpesvirus 8 (HHV8)
What virus is associated with cervical cancer?
Papillomavirus (HPV)
"Test Your Knowledge on Viral Transmission: From Medical Instruments to Skin Entry" - This quiz will challenge your understanding of viral transmission through various means such as medical instruments, blood transfusions, and skin entry. Learn about the risks and individuals at risk, and enhance your knowledge on important preventive measures.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
