Cell Biology: Cell Division and Checkpoints

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Questions and Answers

What does the 'Regional' stage of cancer indicate?

Cancer has spread to nearby structures or regional lymph nodes. (correct)

Cancer has metastasized to distant organs.

Cancer is completely absent in the body.

Cancer is localized within the organ of origin.

Which of the following strategies is NOT a method of early detection for cancer?

Abdominal ultrasound for hepatocellular carcinoma

Bone scan for skin cancer (correct)

Low dose CT chest for lung cancer

Regular mammography for breast cancer

What is the primary intent of radical cancer therapy?

To relieve symptoms of advanced cancer

To completely cure cancer (correct)

To prolong life without addressing the disease

To manage side effects of treatment

Which of the following is an example of an adjuvant treatment?

Chemotherapy given after surgery for high-risk patients Signup and view all the answers

How can persistent symptoms aid in the early detection of cancer?

They may prompt further investigation for possible cancers. Signup and view all the answers

Which cancer detection method is specifically recommended for chronic heavy smokers?

Low dose CT chest Signup and view all the answers

In which scenario would adjuvant treatment be most likely considered?

After surgery in patients at high risk for recurrence Signup and view all the answers

What is the significance of detecting cancer at an early stage?

It allows for more promising prognosis and treatment options. Signup and view all the answers

What consequence can arise from a lack of human growth hormone (HGH)?

It can result in dwarfism. Signup and view all the answers

What is the primary purpose of the G1 checkpoint in the cell cycle?

To definitively commit the cell to division. Signup and view all the answers

Which factor does NOT initiate cell division?

Increased surface-to-volume ratio. Signup and view all the answers

What is one of the risks associated with mistakes during DNA replication in cell division?

Development of mutations. Signup and view all the answers

At what stage does the G2 checkpoint occur?

After the S phase. Signup and view all the answers

Which outcome can occur if a cell fails the G2 checkpoint?

The cell will repair any errors in DNA. Signup and view all the answers

What primarily influences the decision for a cell to enter the G phase during the G1 checkpoint?

Size and nutrient availability. Signup and view all the answers

What happens if the cell successfully passes all the checkpoints in the cell cycle?

It will inevitably enter the M phase. Signup and view all the answers

How do biomarker tests aid in the treatment of cancer?

They identify unique patterns of biomarkers for tailored therapies. Signup and view all the answers

What is a significant challenge of targeted therapies in cancer treatment?

Cancer cells can develop resistance to these therapies. Signup and view all the answers

Which mechanism do cancer cells use to evade the immune system?

They may alter surface proteins that inhibit immune activity. Signup and view all the answers

What role do immune checkpoint inhibitors play in cancer treatment?

They block signals that suppress immune responses against cancer. Signup and view all the answers

What is one way endocrine therapy can be utilized in cancer treatment?

By blocking or altering hormones that support cancer growth. Signup and view all the answers

Which of the following is NOT classified as an immunotherapy?

Chemotherapy agents that target dividing cells. Signup and view all the answers

What is a primary characteristic of immunotherapies?

They aim to activate and enhance the body's own immune response against cancer. Signup and view all the answers

What common feature do therapies such as EGFR inhibitors share?

They specifically target unique genetic changes in certain cancer types. Signup and view all the answers

Which of the following is not classified as a short-term adverse effect of cancer treatment?

Alopecia Signup and view all the answers

What can tumor lysis syndrome overwhelm in a patient's body?

The body's ability to excrete end products of cell death Signup and view all the answers

Which of the following is a medium to long-term adverse effect of cancer therapy?

Second malignancies Signup and view all the answers

How does cancer therapy primarily contribute to anemia in patients?

By causing cytokine production that affects erythropoietin synthesis Signup and view all the answers

Which of the following describes a common symptom of myelosuppression?

Decreased red blood cell count Signup and view all the answers

Which of these does not result from the destruction of rapidly dividing cancer cells?

Hypertension Signup and view all the answers

What type of toxicity can result from cancer treatments affecting the lungs?

Pulmonary toxicity Signup and view all the answers

Which cancer is most likely associated with the development of cytopenias?

Leukemias Signup and view all the answers

What granulocyte concentration significantly increases the risk of infection?

< 500/microL Signup and view all the answers

Which measure is NOT typically recommended for protecting patients with neutropenia from infection?

Regular vaccinations Signup and view all the answers

Which prophylactic antibiotic is sometimes given to patients with severe immunosuppression?

Trimethoprim/sulfamethoxazole Signup and view all the answers

What defines febrile neutropenia?

Fever > 38.5° C on two or more occasions Signup and view all the answers

Which medication is considered for antiviral prophylaxis in transplant patients positive for herpes simplex virus?

Acyclovir 800 mg orally twice a day Signup and view all the answers

Which additional evaluation should be performed in febrile neutropenia?

Immediate chest x-ray and blood cultures Signup and view all the answers

What type of antibiotics are generally NOT required for the majority of patients with neutropenia?

Prophylactic IV antibiotics Signup and view all the answers

What is a precaution suggested for febrile neutropenic patients regarding their environment?

They should avoid contact with sick individuals. Signup and view all the answers

Study Notes

Cell Division Factors

Events triggering cell division include cell death and release of growth hormones like Human Growth Hormone (HGH).
Insufficient HGH can lead to dwarfism; excessive HGH can result in gigantism.
Crowding of cells and inefficient size due to poor surface-to-volume ratios can inhibit cell division.

Internal Checkpoints in Cell Cycle

Internal control mechanisms ensure daughter cells are precise duplicates of parent cells.
Checkpoints exist at G1, G2/M transition, and during metaphase to halt progression until conditions are favorable.

G1 Checkpoint

Verifies cell size, DNA integrity, nutrient availability, and presence of growth factors.
If passed, the cell commits to replicating; if not, the cell seeks to fix issues or enters a resting phase (G phase).

G2 Checkpoint

Confirms complete and correct DNA replication post-S phase.
If errors are found, the cell attempts to correct them before entering M phase.

Cancer Staging

Local: cancer is confined to the organ of origin.
Regional: cancer spreads to nearby structures or lymph nodes.
Distant: cancer metastasizes to distant organs.

Importance of Early Cancer Detection

Early diagnosis significantly improves prognosis and cure rates.
Symptoms that are persistent and progressive may indicate cancer; for example, a lasting cough could suggest lung cancer.

Screening Strategies for Early Detection

Annual mammograms for breast cancer.
Pap smear and HPV testing for cervical cancer.
Abdominal ultrasound for hepatocellular carcinoma in cirrhotic patients.
Low-dose CT for early lung cancer detection in heavy smokers.
Colonoscopy and stool tests for colorectal cancer.
Digital rectal exam and PSA testing for prostate cancer.

Aims of Cancer Therapy

Radical Therapy: Primary strategy to cure cancer, often through surgery, radiation, or chemotherapy for hematological malignancies.
Adjuvant Therapy: Additional treatment post-surgery to lower recurrence risk.

Biomarker Testing

Identifies unique cancer patterns and assists in tailoring treatments.
Certain targeted therapies work only for cancers with specific biomarkers, e.g., EGFR inhibitors for genetic changes in that gene.
Resistance to targeted therapies can occur; combination with other treatments may enhance effectiveness.

Immunotherapy

Activates the immune system to combat cancer.
Cancer cells may evade the immune system via genetic alterations or surface proteins that inhibit immune responses.
Types include immune checkpoint inhibitors, cancer vaccines, and cytokine therapies.

Endocrine Therapy

Blocks or alters hormones that some cancers need to grow.
Also known as hormonal therapy.

Short-term Adverse Effects of Cancer Treatments

Gastrointestinal effects: mucositis, nausea, vomiting.
Hematopoietic effects: myelosuppression, leading to neutropenia, anemia, and thrombocytopenia.
Tumor lysis syndrome arises from rapid cell death due to treatment.

Medium to Long-term Adverse Effects

Alopecia, liver dysfunction, nephrotoxicity, cardiac toxicity.
Neurological toxicity may include peripheral neuropathy and pulmonary toxicity like fibrosis.
Potential for gonadal damage and second malignancies.

Cytopenias in Cancer Patients

Common due to cancer's impact on blood cells, particularly in blood and bone marrow cancers.

Anemia

A prevalent issue in gastrointestinal, liver, and several types of cancers.
Caused by cytokines affecting erythropoietin synthesis and iron utilization.

Neutropenia

Defined as low granulocyte count; less than 500/microL significantly increases infection risk.
Precautions include hand-washing, isolation, and sometimes prophylactic antibiotics or antivirals.

Management of Neutropenia

Close monitoring for fevers in afebrile neutropenic patients.
Severe febrile neutropenia requires immediate medical attention, evaluation for infection sources, and possible imaging and cultures for diagnosis.

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Description

Explore the crucial factors influencing cell division and the internal checkpoints that maintain genomic integrity. This quiz covers mechanisms like hormone influence, internal controls during the cell cycle, and checkpoints ensuring precise cell replication. Test your knowledge on key concepts essential for understanding cell biology and cancer staging.