Immune Function, Acid-Base Balance, Cancer, and HIV/AIDS Review

Flashcard practice set covering innate and acquired immunity, systemic inflammation, acid-base imbalances, cancer biology and therapies, and HIV/AIDS management based on lecture notes.

What is the definition of immunity?

The body's ability to resist infection and disease.

What components constitute the first line of defense in innate immunity?

Skin, mucous membranes, and secretions of skin and mucous membranes.

What components make up the second line of defense in innate immunity?

The inflammatory response, interferons, phagocytosis, and complement.

What are the primary lymphoid organs of the lymphatic system?

The thymus and bone marrow.

What percentage of white blood cells are neutrophils, and what is their primary role?

Neutrophils make up $55\% \text{--} 70\%$ of WBCs; they act as a first line of defense by phagocytizing and destroying bacteria.

Which leukocytes respond in allergic reactions, and what percentage of WBCs do they represent?

Eosinophils and basophils, which make up $1\% \text{--} 2\%$ of total WBCs.

What are the four sequential steps of the inflammatory response?

1. Damaged tissues release histamines, increasing blood flow to the area. 2. Histamines cause capillaries to leak, releasing phagocytes and clotting factors into the wound. 3. Phagocytes engulf bacteria, dead cells, and cellular debris. 4. Platelets move out of the capillary to seal the wounded area.

What are the five cardinal signs of inflammation?

Erythema, heat, edema, pain, and drainage.

What diagnostic criteria define Systemic Inflammatory Response Syndrome (SIRS)?

Temperature $< 96.8^\circ\text{F}$ or $> 100.4^\circ\text{F}$, heart rate $> 90\,\text{beats per minute}$, respiratory rate $> 20\,\text{breaths per minute}$ or $PaCO_2 < 32\,\text{mm Hg}$, and WBC $< 4000/\mu\text{L}$, $> 12{,}000/\mu\text{L}$, or $> 10\%$ bands.

How do active and passive acquired immunity differ in their natural and artificial forms?

Naturally acquired active immunity results from infection or pathogen contact, while naturally acquired passive immunity occurs via maternal antibody transfer through the placenta or milk. Artificially acquired active immunity occurs via vaccines with dead or attenuated pathogens, while artificially acquired passive immunity occurs via injection of immune serum (gamma globulin).

What are the three compensatory mechanisms for acid-base balance and their response times?

The Buffer System (primary regulator, acts in seconds), the Respiratory System (second line of defense, $10 \text{--} 30\,\text{second}$ response), and the Renal System (takes hours to respond).

What are the standard reference values for arterial blood gas (ABG) parameters?

$pH$: $7.35 \text{--} 7.45$, $PaO_2$: $80 \text{--} 100\,\text{mm Hg}$, $PaCO_2$: $35 \text{--} 45\,\text{mm Hg}$, and $HCO_3$: $22 \text{--} 26\,\text{mEq/L}$.

How does the ROME mnemonic apply to acid-base interpretations?

Respiratory Opposite: in respiratory issues, $pH$ and $PaCO_2$ move in opposite directions ($pH \uparrow PCO_2 \downarrow$ in alkalosis; $pH \downarrow PCO_2 \uparrow$ in acidosis). Metabolic Equal: in metabolic issues, $pH$ and $HCO_3$ move in the same direction ($pH \uparrow HCO_3 \uparrow$ in alkalosis; $pH \downarrow HCO_3 \downarrow$ in acidosis).

What is the most common cause of respiratory acidosis?

Chronic Obstructive Pulmonary Disease (COPD).

What are the primary clinical manifestations of respiratory acidosis?

Hypoventilation, decreased $pH$, increased $PaCO_2$, drowsiness/unconsciousness, disorientation, dyspnea, headache, hyperkalemia, dysrhythmias, and muscle weakness with hyperreflexia.

What management strategies are indicated for respiratory alkalosis?

Promote $CO_2$ retention by calming the patient, reducing fear/anxiety/panic, having the patient breathe more slowly, or rebreathing into a paper bag. Sedatives may be given for severe anxiety.

What specific respiratory pattern serves as a compensatory mechanism in metabolic acidosis?

Kussmaul respirations, which are deep, rapid respirations that perform compensatory hyperventilation.

What is the most common cause of metabolic alkalosis?

Vomiting or gastric suction.

What activities and durations characterize the $G_1$, $S$, and $G_2$ phases of the cell cycle?

$G_1$ ($8\text{ or more hours}$): postmitotic growth phase with increased RNA and protein synthesis. $S$ ($6 \text{--} 8\,\text{hours}$): nucleic acid synthesis and chromosome replication. $G_2$ ($2 \text{--} 5\,\text{hours}$): ongoing RNA and protein synthesis prior to mitosis.

How do benign and malignant neoplasms differ in growth, tissue interaction, and recurrence?

Benign tumors are local, cohesive, encapsulated, slow-growing, easily removed, and do not recur. Malignant tumors are invasive, non-cohesive, rapid-growing, invade surrounding tissues, metastasize to distant sites, and can recur.

What are the most common sites of metastasis for cancer cells?

Liver, lung, bones, lymph nodes, and brain.

What are the specific eligibility requirements for annual lung cancer screening with low-dose CT (LDCT)?

Individuals aged $55 \text{--} 74\,\text{years}$ in fairly good health who currently smoke or have quit within the past $15\,\text{years}$ and have at least a $30\,\text{pack-year}$ smoking history.

What warning sign corresponds to each letter in the CAUTION mnemonic for cancer?

C - Change in bowel or bladder habits; A - A sore that does not heal; U - Unusual bleeding or discharge; T - Thickening or lump in breast or elsewhere; I - Indigestion or difficulty swallowing; O - Obvious change in a wart or mole; N - Nagging cough or hoarseness.

How are cancer stages defined from Stage I through Stage IV?

Stage I: localized and contained. Stage II: invasion of deeper tissues or lymph node involvement. Stage III: large or locally invasive tumors. Stage IV: distant metastasis (all hematological cancers are Stage IV at diagnosis).

How are primary tumor size, lymph node involvement, and distant metastasis categorized under the TNM system?

T1 is $< 3\,\text{cm}$, T2 is $> 3\,\text{cm}$, T3 is near airway/chest wall/diaphragm, T4 invades airway/heart/esophagus. N0 has no node involvement, N1/N2 affect same-side nodes, N3 affects opposite chest/collarbone/neck nodes. M0 has no metastases; M1 has distant metastases.

What safety distinction exists between unsealed and sealed radiation sources in brachytherapy?

For unsealed isotopes (oral, IV, or instilled), both the patient and their body waste products are radioactive. For sealed/solid isotopes (seeds, implants, needles), the patient emits radiation, but their body wastes are not radioactive.

What is meant by the term 'nadir' during chemotherapy?

The point at which blood counts reach their lowest level, typically $7 \text{--} 10\,\text{days}$ after chemotherapy administration.

What selected side effects are documented for Filgrastim?

Bone pain, malaise, fever, fatigue, headache, and skin rash.

Which immune cells are primarily targeted and depleted by HIV?

$CD4^+$ cells (helper T cells).

What transmission category accounts for the majority of new HIV infections in the United States according to 2014 data?

Male-to-male sexual contact, accounting for $70\%$ ($26{,}200$) of new infections.

Which racial or ethnic group was most affected by new HIV diagnoses in 2015?

African Americans, representing $45\%$ of new HIV diagnoses.

What lab threshold or clinical condition marks Stage III HIV (AIDS)?

A $CD4$ cell count dropping below $200\,\text{cells/mm}^3$ or the development of an opportunistic illness.

What combination defines Highly Active Antiretroviral Therapy (HAART)?

A minimum of $3$ antiretroviral drugs prescribed from at least $2$ different drug classes.

What is the mechanism of action and primary adverse effect of Nucleoside Reverse Transcriptase Inhibitors (NRTIs)?

NRTIs prevent viral RNA from becoming viral DNA by inhibiting the enzyme reverse transcriptase; their main documented adverse effect is lactic acidosis.

What steps must a health care worker immediately take following occupational exposure to a bloodborne pathogen via a needle stick?

Wash needle sticks and cuts with soap and water, report the incident to a supervisor, and immediately seek medical treatment.