Harvard School of Public Health (HSPH)
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Hepatitis A
An acute viral disease of the liver caused by the Hepatitis A virus (HAV), transmitted through contaminated food or water.
Hematology
The branch of medicine concerned with the study of the cause, prognosis, treatment, and prevention of diseases related to blood.
Hybridoma
A culture of hybrid cells that results from the fusion of B cells and myeloma cells.
Hepatitis B
A viral liver disease caused by the Hepatitis B virus (HBV), transmitted by infected blood or blood products, or through unprotected sex with someone who is infected.
Hepatitis C
A viral liver disease caused by the Hepatitis C virus (HCV), which is found in the blood of persons who have the disease. HCV is spread by contact with the blood and body fluids of an infected person.
Hydrodynamic diameter
A commonly used parameter to characterise a nanomaterial sample in solution. It is the diameter of a hypothetical hard sphere that diffuses with the same speed as the particle being measured.
Herpes Zoster
A disease characterized by painful skin lesions that occur mainly on the trunk (back and stomach) of the body but can also develop on the face and in the mouth. Complications include headache, vomiting, fever, and meningitis. Recovery can take up to 5 weeks. Herpes Zoster is caused by the same virus responsible for chickenpox. Most people are exposed to this virus during childhood. After the primary infection (chickenpox), the virus becomes dormant, or inactivated. In some people the virus reactivates years, or even decades, later and causes herpes zoster. Also known as the shingles.
Hepatitis D
A viral liver diseases caused by Hepatitis D virus (HDV) that needs the hepatitis B virus to exist. Hepatitis D virus (HDV) is found in the blood of persons infected with the virus.
Hygroscopicity
A material’s ability to absorb moisture from the environment.
Heterogeneity
Phenomenon where observed intervention effects being more different from each other than one would expect due to random error (chance) alone.
Hepatitis E
A viral liver disease caused by the Hepatitis E virus (HEV), transmitted in much the same way as hepatitis A virus. Generally, it is more severe for pregnant women.
Hyperimmune sera
Serum with a high titre of specific polyclonal antibodies, usually from animals that have recently been exposed to the antigen.
Haemophilus influenzae type b (Hib)
A Gram-negative coccobacillus that commonly infects the upper respiratory tract of children through the transfer of nasal secretions. Whereas non-encapsulated strains of the bacillus are relatively benign, strains with a polysaccharide capsule or coat cause a more serious disease. The polysaccharide, is the primary factor associated with virulence.
Herbal Medicine
The art or practice of using herbs and herbal preparations to maintain health and to prevent, alleviate, or cure disease.
Hyperlipidemia
High levels of blood lipids (fats and waxes such as cholesterol).
Half maximal effective concentration (EC50)
The concentration of a drug that induces a response halfway between the baseline and maximum.
High Throughput Screening (HTS)
The use of automated equipment to rapidly test thousands to millions of samples for biological activity at the model organism, cellular, pathway, or molecular level.
Hypersensitivity
A condition in which the body has an exaggerated response to a substance such as a food or drug. Also known as allergy.
Half Maximal Inhibitory Concentration (IC50)
A measure of the concentration of a drug or compound required to inhibit a particular biological or biochemical process by 50%.
High-Efficiency Particulate Air Filter (HEPA Filter)
A type of air filter that captures and remove at least 99.95 to 99.97% of pollen, dirt, dust, moisture, bacteria (0.2–2.0 μm), virus (0.02–0.3 μm), and submicron liquid aerosol (0.02–0.5 μm).
Hyperthermia
An abnormally high body temperature caused by a failure of the heat-regulating mechanisms of the body to deal with the heat coming from the environment.
Harvesting
The procedure by which the cells, inclusion bodies or crude supernatants containing the unpurified active ingredient are recovered.
High-Performance Liquid Chromatography (HPLC)
A technique in analytical chemistry used to separate the components in a mixture, and to identify and quantify each component. It relies on high pressure pumps, which deliver mixtures of various solvents, called the mobile phase, which flows through the system, collecting the sample mixture on the way, delivering it into a cylinder, called the column, filled with solid particles, made of adsorbent material, called the stationary phase. Each component in the sample interacts differently with the adsorbent material, causing different migration rates for each component. These different rates lead to separation as the species flow out of the column into a specific detector such as UV detectors.
Hyposensitivity
A condition in which the body has a weakened or delayed reaction to a substance.
Hazard
Chemical, microbiological, and physical elements and states that may remain in food, pharmaceuticals, etc., and could potentially pose harmful effects on human health.
Histology
The branch of biology that studies the microscopic anatomy of biological tissues.
Hypothermia
A serious medical condition in which a person’s body temperature falls below the usual level as a result of being in severe cold for a long time.
Head to Head Comparison Trial
Study design which investigational medicine is directly compared to an existing standard of care, not placebo.
Hives
The eruption of red marks on the skin that are usually accompanied by itching. This condition can be caused by an allergy (e.g., to a food or drug), stress, infection, or physical agents such as heat or cold. Also known as urticaria.
Head to Head Randomized Trial
Clinical trial where researchers are not comparing an intervention against a placebo or sham control but instead are comparing two different interventions that have each previously been shown effective.
Homogeneity
In meta-analysis, measured differences or similarities between the several studies.
Health economics
A branch of economics concerned with issues related to efficiency, effectiveness, value and behavior in the production and consumption of health and healthcare.
Hormone
Chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions.
Heat Transfer
A discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems.
Hospitalization
To place in a hospital as a patient.
Heavy Metal Analysis
The content of heavy metals included in active pharmaceutical ingredients according to the specified test method. Typically controlled to be below 20 ppm.
Host
A larger organism that harbours a smaller organism.
Helminth
A parasitic worm (such as a tapeworm, liver fluke, ascarid, or leech).
Hot Air Drying
The process of removing moisture from surfaces and coatings by using dry, hot air.
Hemagglutination
A reaction where red blood cells suspended in a liquid collect into clumps usually as a response to a specific antibody.
Humanized mouse
Mice expressing human genes via transgenesis (e.g., HLA or human immunoglobulin transgenic mice).