Biostatistics and Medical Concepts Quiz

Regression Analysis

• Statistical method analyzing the influence of independent (qualitative or quantitative) on a dependent (quantitative) variable.

Odds Ratio & Relative Risk

• Measure the strength of association between two categorical variables.

Fungal Infections

• Aspergillus fumigatus: Thin septate hyphae with acute V-shaped branching.
• Rhizopus and Mucor: Broad ribbon-shaped nonseptate hyphae that branch at right or wide angles.

Carbohydrates

• Maltose: Glucose + Glucose
• Sucrose: Glucose + Fructose
• Lactose: Galactose + Glucose

Physiologic Gynecomastia

• Benign condition in adolescent boys due to hormonal imbalance during mid-puberty.
• Presents as unilateral or bilateral tender breast enlargement.
• Resolves within a year.

Ventilation

• Minute ventilation: Tidal volume x breaths per minute
• Alveolar ventilation: (Tidal volume - dead space volume) x breaths/min

Uniparental Disomy

• Both copies of a chromosome inherited from one parent.
• Example: Prader-Willi syndrome.

Kidney Development

• Horseshoe kidney: Fusion of kidneys at lower poles prevents ascent from the pelvis.
• Inferior mesenteric artery: Prevents kidney ascent.

A-a Gradient

• Normal: 4-15 mmHg (High altitude, CNS depression, obesity)
• Increased: Diffusion limitation (Emphysema) and V/Q mismatch (Pulmonary embolism, pneumonia)

Benzodiazepine Overdose

• CNS depression and hypoventilation.
• CO2 retention, respiratory acidosis.
• Decreased PaO2, leading to hypoxemia.
• Normal alveolar-arterial O2 gradient.

Tracheoesophageal Fistula with Esophageal Atresia

• Failure of the primitive foregut to divide into trachea and esophagus.
• Infants present with cyanosis and choking during feeding.

MHC Class II Molecules

• Encoded by HLA-DP, HLA-DQ, and HLA-DR genes.
• Expressed on antigen-presenting cells (B cells and macrophages).
• Loaded with extracellular antigen in an acidified lysosome.
• Associated with:
  • Rheumatoid arthritis
  • Type I diabetes mellitus
  • Celiac disease

MHC Class I Molecules

• Encoded by HLA-A, HLA-B, and HLA-C genes.
• Expressed on nucleated cells.
• Loaded with cytoplasmic antigen in the endoplasmic reticulum.
• Associated with:
  • Seronegative spondyloarthropathies (ankylosing spondylitis, reactive arthritis, arthritis associated with IBD) related to HLA B27 expression.

Pyruvate Dehydrogenase Deficiency

• Presents with lactic acidosis and neurological defects.
• Deficiency in pyruvate dehydrogenase, which converts pyruvate to acetyl-CoA.
• Build-up of pyruvate leads to lactic acidosis.
• Treated with a ketogenic diet and lysine/leucine supplementation.

Baseball Injury

• Damage to the lateral antebrachial cutaneous nerve.
• Sensory loss on the lateral forearm and loss of biceps reflex.

Primary Amebic Encephalitis

• Caused by Naegleria fowleri.
• Penetrates the olfactory mucosa.
• Migrates through the olfactory nerve to the brain.
• Usually occurs after exposure to warm, fresh water.

Bone Pain and Elevated Alkaline Phosphatase

• Osteoblast metastases: Bone pain and elevated alkaline phosphatase in elderly patients.
• Paget disease of the bone: Biopsy reveals a mosaic pattern of lamellar bone. Initial phase characterized by osteoclastic activity.

Genetic Heterogeneity

• Locus heterogeneity: Similar phenotype caused by mutations in different genetic loci (different chromosomes). Example: Albinism.
• Allelic heterogeneity: Same chromosome.

Androgen Insensitivity Syndrome

• Dysfunction of androgen receptors.
• Individuals with XY chromosomes and testes, but no external or internal male genitalia.
• Female external genitalia develop due to lack of androgen effect.
• Anti-Müllerian hormone leads to absence of internal female genital ducts.

Tension Pneumothorax

• Increasing intrapleural pressure.
• Contralateral mediastinal shifting and vena cava collapse.
• Hypotension, tachycardia, and obstructive shock due to decreased venous return.

Guyon Canal Syndrome

• Compression of the ulnar nerve in Guyon's canal.
• Often occurs after a fall on an outstretched hand or fracture of the hook of the hamate.

Scaphoid Fracture

• Tenderness in the snuffbox after a fall on an outstretched hand.
• Can disrupt retrograde blood supply to the proximal scaphoid, increasing risk of avascular necrosis.

Phenotypic Mixing

• Co-infection of a host cell with two viral strains.
• Results in progeny virions with nucleocapsid proteins from one strain and unchanged parental genome of the other.
• No genetic exchange, progeny revert to original phenotypes in the next generation.

Point Prevalence

• Number of existing cases in a population divided by the total number of people in the population.

Regulatory T Cells

• FOXP3 is a transcriptional regulator required for their development.

Heme Oxygenase

• Converts heme to biliverdin, causing the greenish color in bruises.

Congenital Hypothyroidism

• Usually asymptomatic at birth.
• Symptoms develop after maternal T4 wanes:
  • Constipation
  • Lethargy
  • Hypotonia
  • Macroglossia
  • Umbilical hernia
  • Large anterior fontanelle

West Nile Virus

• Harbored in birds and transmitted to humans by mosquitos.
• Most patients are asymptomatic.
• Can cause:
  • Influenza-like illness
  • Neuroinvasive disease (meningitis, encephalitis, flaccid paralysis)

Deformation

• Mechanical forces altering the shape or position of a developing structure.
• Example: Clubfoot.

Regression Analysis

• Statistical technique used to describe the effect of independent variables on a dependent variable.
• Independent variables can be quantitative or qualitative.
• Dependent variable is quantitative.

Odds Ratio and Relative Risk

• Measure the strength of association between two categorical variables.

Fungal Infections

• Aspergillus fumigatus: Produces thin, septate hyphae with acute V-shaped branching.
• Rhizopus and Mucor: Form broad, ribbon-shaped, non-septate hyphae that branch at right or wide angles.

Carbohydrate Disaccharides

• Maltose: Glucose + Glucose
• Sucrose: Glucose + Fructose
• Lactose: Galactose + Glucose

Physiologic Gynecomastia

• Benign condition caused by transient proestrogenic hormonal imbalance during mid-puberty.
• Presents in adolescent boys with unilateral or bilateral tender breast enlargement.
• Resolves within a year.

Ventilation

• Minute Ventilation: Tidal volume x breaths per minute
• Alveolar Ventilation: (Tidal volume - dead space volume) x breaths per minute

Uniparental Disomy

• Both copies of a chromosome are inherited from one parent.
• Example: Prader-Willi syndrome.

Horseshoe Kidney

• Fusion of kidneys at their lower poles during embryological development.
• Prevents kidney ascent from the pelvis.
• Inferior mesenteric artery may also prevent ascent.

A-a Gradient

• Normal: 4-15 mmHg
• High altitude, CNS depression, and obesity all have a normal A-a gradient.
• Increased A-a gradient: Diffusion limitation (emphysema) and V/Q mismatch (pulmonary embolism and pneumonia).

Benzodiazepine Overdose

• CNS depression and hypoventilation.
• CO2 retention, respiratory acidosis, decreased PaO2 leading to hypoxemia.
• Normal alveolar-arterial oxygen gradient.

Tracheoesophageal Fistula with Esophageal Atresia

• Failure of the primitive foregut to divide into trachea and esophagus.
• Infants present with cyanosis and choking during feeding shortly after birth.

HLA Genes

• Class II: HLA-DP, HLA-DQ, HLA-DR
  • Expressed on antigen-presenting cells (B cells and macrophages).
  • Loaded with extracellular antigens in acidified lysosomes.
  • Examples: Rheumatoid arthritis, type I diabetes mellitus, and celiac disease.
• Class I: HLA-A, HLA-B, HLA-C
  • Expressed on nucleated cells.
  • Loaded with cytosolic antigens in the endoplasmic reticulum.
  • Seronegative spondyloarthropathies (ankylosing spondylitis, reactive arthritis, and arthritis associated with IBD) are related to HLA-B27 (class I) expression.

Pyruvate Dehydrogenase Deficiency

• Presents with lactic acidosis and neurologic defects.
• Pyruvate dehydrogenase converts pyruvate to acetyl-CoA.
• Deficiency leads to pyruvate buildup and lactic acidosis.
• Ketogenic diet is implemented.
• Lysine and leucine are ketogenic and cannot metabolize to pyruvate.

Lateral Antebrachial Cutaneous Nerve Injury

• Occurs in baseball injuries.
• Causes sensory loss on the lateral forearm and loss of biceps reflex.

Primary Amebic Encephalitis

• Due to Naegleria fowleri.
• Penetrates the olfactory mucosa and migrates to the brain via the olfactory nerve.
• Usually happens due to exposure to warm, fresh water during recreational activities.

Bone Pain and Elevated Alkaline Phosphatase

• Osteoblast metastases and Paget disease of the bone in elderly patients.
• Biopsy shows a mosaic pattern of lamellar bone.
• Initial phase characterized by osteoclastic activity.

Locus Heterogeneity

• Similar phenotype produced by mutations in different genetic loci on different chromosomes.
• Example: Albinism.

Allelic Heterogeneity vs. Locus Heterogeneity

• Allelic heterogeneity: Mutations in the same chromosome.
• Locus heterogeneity: Mutations in different chromosomes.

Androgen Insensitivity Syndrome

• Caused by dysfunction of androgen receptors.
• Individuals are XY with testes but no external or internal male genitalia.
• Female external genitalia develop.
• Anti-Mullerian hormone results in the absence of internal female genital ducts.

Tension Pneumothorax

• Progressive increase in intrapleural pressure.
• Contralateral mediastinal shifting and vena cava collapse.
• Hypotension, tachycardia, and obstructive shock develop due to decreased venous return to the heart.

Guyon Canal Syndrome

• Compression of the ulnar nerve within Guyon canal.
• Can develop following a fall on an outstretched hand.
• Typically occurs due to fracture of the hook of the hamate.

Scaphoid Fracture

• Due to fall on an outstretched hand.
• Tenderness in the snuff box.
• Can disrupt retrograde blood supply to the proximal scaphoid, increasing risk of avascular necrosis.

Phenotypic Mixing

• Co-infection of a host cell with two viral strains.
• Progeny virions have nucleocapsid proteins from one strain and the unchanged parental genome of the other strain.
• No genetic exchange occurs.
• Next generation of virions revert to their original unmixed phenotypes.

Point Prevalence

• Existing cases in a population / total number of people in the population.

FOXP3

• Transcriptional regulator protein required for the development of regulatory T cells.

Heme Oxygenase

• Converts heme to biliverdin.
• Biliverdin causes the greenish color of bruises.

Congenital Hypothyroidism

• Usually asymptomatic at birth.
• After maternal T4 wanes, infants develop constipation, lethargy, hypotonia, macroglossia, umbilical hernia, and large anterior fontanelle.

West Nile Virus

• Harbored in birds and transmitted to humans by mosquitoes.
• Most patients are asymptomatic.
• Can cause influenza-like illness or neuroinvasive disease (meningitis, encephalitis, flaccid paralysis).

Deformation

• Mechanical forces alter the shape or position of a normally developing structure.
• Example: Clubfoot.

Test your knowledge on regression analysis, odds ratios, fungal infections, carbohydrates, and physiological gynecomastia. This quiz covers essential biostatistics and medical terms, providing a comprehensive assessment of your understanding of these topics.