Ch 9 Flashcards
From 1990 to 2010, which of the following decreased and which ones increased:
A. mortality due to HIV/AIDS
B. Mortality from infection, maternal, neonatal, and nutritional disorder
C. Noncommunicable diseases like cancer, CV disease, and diabetes
A and C increased.
B decreased.
What is the single leading global cause of health loss (defined as morbidity and premature death)
Undernutrition
What are the leading cause of death in developed countries?
Ischemic heart disease and cerebrovascular disease
In postnatal period, about 50% of all deaths in children younger than 5 are attributed to only what three conditions?
- pneumonia
- diarrheal disease
- malaria
Change in global climate is expected to have a serious negative impact on human health which includes:
- Cardiovascular, cerebrovascular, respiratory disease (made worse by heat waves and air pollution)
- Gastroenteritis, cholera, and other food borne and water borne infectious disease due to contamination and disruption of clean water
- Vector-borne infectious disease - related to increased temperature, crop failure, and more extreme weather variation
- Malnutrition - change in local climate
In what two ways is xenobiotics metabolized?
- Phase I: reaction, chemicals undergo hydrolysis, oxidation or reduction which produces the Primary metabolite. Products of phase I reactions are often metabolized into water soluble compounds through phase II.
- Phase II: reactions which include glucoronidation, sulfation, methylation, conjugation and glutathione
What is the most important catalyst of phase I reaction of metabolism of xenobiotics/drugs?
cytochrome p-450 enzyme system (CYP)
P-450 system catalyzes reactions that either 1 xenobiotics, or less commonly, convert xenobiotics into 2
- detoxify
2. convert into active compounds that cause cellular injury
What are some inducers of P450?
Environmental chemicals, drugs, smoking, alcohol, hormones
What fasting or starvation decrease or increase CYP activity?
decrease
Inducers of CYP do so by binding to nuclear receptor which then heterodimerize with 1 receptor to form a transcriptional activation complex that associates with promoter located in the _ 2_region of CYP gene.
- Retinoic X receptor (RXR)
2. 5’ flanking region
Which 6 pollutants does the US Environmental Protection Agency monitors and sets allowable upper limits?
- Sulfur dioxide
- Carbon monoxide
- ozone
- nitrogen dioxide
- lead
- particulate matter
Collectively these make up smog in air.
How is ozone created? and what role does it play in protecting the earth?
Ozone is produced by interaction of UV radiation and oxygen in the stratosphere and naturally accumulates int he zone layer 10 to 30 miles above earth’s surface. This layer protects early by absorbing the most dangerous UV radiation emitted by the sun.
In the past 35 years, the stratospheric zone layer decreased in both thickness and extend to due to the widespread use of what gases as found in air conditioners and refrigerators and as aerosol propellents?
Chlorofluorocarbon gases
In contrast to the “good” ozone in the stratosphere, what produces the ozone that accumulates in the lower atmosphere (ground level ozone)? How does it cause harm to human?
Gas formed by the reaction of nitrogen oxides and volatile organic compounds in presence of light, like industrial emissions and motor vehicle exhaust. Ozone toxicity is in large part mediated by production of free radicals, which injure epithelial cells along the respiratory tract and type I alveolar cells, and cause the release of inflammatory mediators.
What sized particulate matter (aka soot) is the most harmful for human?
Ultrafine particles less than 10um in diameter cuz it can pass through the filters in the nose and get into the lungs uninterrupted and cause inflammation in the alveoli
What kind of environment might one encounter carbon monoxide? What are signs and symptoms of carbon monoxide poisoning.
Chronic poisoning may occur in people who work in tunnels, underground garage, in highway toll booths with high exposures to automobile fumes.
Acute exposure, small closed garage, gasoline-powered generators
Acute poisoning: induce CNS depression. Hemoglobin saturation decreases drastically causing hypoxia. Can lead to unconsciousness and death when saturation drops to 60-70%.
In light skinned people, cherry-red color of the skin and mucous membrane (due to high levels of carboxyhemolgobin)
The slowly developing hypoxia as seen with CO poisoning evoke widespread ischemic changes in the CNS but particularly marked in what part of the brain?
Basal ganglia and lenticular nuclei.
Checking blood levels of what compound is a way to diagnose carbon monoxide poisoning?
carboxyhemoglobin level
What are some examples of indoor air pollutants that can cause diseases?
- cigarette smokes
- bioaerosols (microbiologic agents that can cause disease like Legionnaires disease viral pneumonia)
- Radon present in soil and in homes that can cause lung cancer
- polycyclic hydrocarbons (from cooking oil)
- formaldehyde
What is the mechanism via which lead poisoning cause disease?
Lead is readily absorbed metal that binds to sulfhydryl groups in proteins and interferes with calcium metabolism, effects that leads to hematologic, skeletal, neurologic, GI, and renal toxicities.
what are some environmental sources of lead exposure risks?
- Mining
- foundries,
- batteries
- old lead containing peeling paint
- spray paint
beyond what level does the CDC recomment to limit lead exposure?
5ug/dL
At what level of blood lead content is treatment mandated?
45ug/dL
What are some signs of low-level lead poisoning in youngsters?
subtle deficits in intellectual capacity, behavioral problems like hyperactivity, poor organizational skills.
With lead poisoning what disturbances are seen in kids vs adults?
In kids you’ll see CND disturbances.
In adults: peripheral neuropathies predominate
Where are lead lines found? epiphyses in chidlren
Lead interfere with normal remodeling of cartilage and primary bone trabeculae in epiphyses in children. this causes bone density detected as radio dense lead lines.
Also seen in gum due to hypermigmentation
what effect does lead exposure have on bones?
inhibits healing of fractures by increasing chondrogenesis and delay cartilage mineralization. It also interferes with normal remodeling of cartilage and primary bone trabculae in epiphyses in kids
what effect does lead have on heme biosynthesis?
lead inhibits the activity of two enzymes involved in heme synthesis, delta-aminolevulinic acid dehydratase and ferrochelatase.
which type of anemia is associated with lead poisoning?
microcytic hypochromic anemia stemming from suppression of hemoglobin synthesis.
how is lead poisoning diagnosed?
- suspected on the basis of neurologic and behavior changes in kids and detection of elevated blood levels of lead and free red cell protoprophyrin
what major anatomic targets does lead poisoning involve?
- bone marrow and blood
- nervous system
- GI
- kidneys
At around what blood level of lead are you likely to see decreased hemoglobin synthesis?
about 40um/mL
At around what blood levels of lead are you likely to see decreased nerve conduction velocity, increased level of erythrocyte protoporphyrin, altered vitamin D metabolism and calcium homeostasis?
Aroudn 10-20 um/mL
What the biochemistry of how mercury poisoning causes damage?
Like lead, mercury binds to sulfhydryl groups in certain proteins with affinity, leading to damage in CNS and kidney.
What are some sources of mercury?
contaminated fish (methyl mercury) and mercury vapors released from metallic mercury in dental amalgam, a possible occupational hazard for dental worker
What are some signs and symptoms of mercury poisoning?
- tremor, gingivitis, bizarre behavior like Mad Hatter in Alice in wonderland.
- Developing brain is extremely sensitive to mercury. it causes disturbing neuromotor cognitive, and behavioral functions.
What intracellular antioxidant acts as the main protective mechanism against mercury-induced CNS and kidney damage? How?
Glutathione by acting as sulfhydryl donor
What clinical signs are associated with Minamata disease?
cerebral palsy, deafness, blindness, mental retardation, and other major CNS defects in children exposed to methyl mercury in utero.
What is the main mode of how arsenic exposure cause disease?
Arsenic salt interfere with several aspect of cellular metabolism, leading to toxicities that are most prominent in the GI tract, nervous system, skin, and heart.
Most of the diseases associated with arsenic exposure is due to which form of arsenic?
Trivalent compounds, arsenic trioxide, sodium arsenite, arsenic trichloride
If large quantities of arsenic was ingested, what toxicities are you likely to see and what is the underlying cause of those toxicities?
- Acute GI toxicities
-CV toxicities
-CNS toxicities
These toxicities are partly due to interference of mitochondria oxidative phosphorylation since trivalent arsenic can replace the phosphates in ATP.
which metal is used as a frontline treatment for acute promylocytic leukemia?
arsenic trioxide
What neurological symptoms are associated with arsenic exposure and how soon are these signs apparent?
occurs within 2-8 weeks after exposure, consist of sensorimotor neuropathy that causes paresthesias, numbness and pain.
what skin abnormalities are associated with arsenic exposure?
Chronic exposure to arsenic causes skin changes consisting of hyperpigmentation and hyperkeratosis
What is one single greatest risk of arsenic exposure?
Increased risk for developing cancer particularly of lungs, bladder and skin. Arsenic induced skin tumors are different from sun exposed in that arsenic induced tumors appear on palms and soles
What organs are mainly affected by cadmium toxicity and what is the underlying mechanism?
Kidneys (renal tubular damage) and lungs (obstructive lung disease) through involvement of increased production of reactive oxygen species.
What is the most important source of cadmium exposure for the general public?
Food contaminated with cadmium.
Which metal uses the same transporter as zinc for uptake into cells.
cadmium. ZIP8 is the transporter
what effect does cadmium exposure have on skeletal system?
Calcium loss. –> osteomalacia and osteoprosis associated with renal disease. Itai-Itai (Japanese for ouch ouch)
Acute exposure to organic solvents like chloroform, carbon tetrachloride as seen in dry cleaning agents and paint removers, are associated with what acute symptoms?
- dizziness
- confusion
- leads to CNS depression and even coma
- Toxic to liver and kidney
Occupational exposure of rubber works to benzene and 1,3 butadiene increases the risk of what cancer?
Leukemia
Polycyclic hydrocarbons is among the most potent carcinogens and industrial exposures have been implicated in the development of what cancers?
- Lung and bladder cancers. (think
Dioxins and PCB causes skin disorders characterized by _
folliculitis and dermatisos known as chloracne that is characterized by acne, cyst formation, hyperpigmentation, hyperkeratosis, generally around face and behind ears.
Inhalation of coat dust, silica, asbestos and beryllium have all been implicated for what chronic condition?
nonneoplastic lung disease known as pneumoconioses
Exposure to what substance is known to increase risk of cancer for the person exposed and extends to the family members of those exposed?
asbestos
a person who works at factory that makes plastic products like pipes, wires, and cable coatings are at risk of exposure to what chemical and what cancer is it associated with?
Exposure to vinyl chloride used int he synthesis of polyvinyl resins. Leads to development of angiosarcoma of liver.
Bisphenol A (BPA) used in the synthesis of polycarbonate food and water containers and of epoxy resins that line almost all food bottles and cans, is known to cause what?
- BPA is a potential endocrine disruptor.
- studies also shows elevated levels linked to heart disease in adult population