Bio-
precipitation processes can result in organic deposits, such as plaques, fats, and other undesirable amorphous-substance buildup in the body.
Another instance of unfavorable biocrystallization or bioprecipitation concerns physiologically low-
solubility pharmaceuticals or pharmaceuticals that complex with tissue or other bodily substances.
Here they cause inflamation with pain and swelling and limitation of motion of the involved joint.
Acute attacks of pseudogout often occur in the knees and are incapacitating for days or weeks.
Unfortunately, no treatment is available to dissolve the
crystal deposits.
An extremely destructive
arthritis may occur at the shoulder, "Milwaukee shoulder," or at hips and knees in
elderly people.
However, in most cases the cause of
soft tissue apatide deposition is not known.
The acute
arthritis or periarthritis can be treated with VSAIDS or
colchicine but no agent capable of preventing this potentially destructive type of
phase transition is known.
The presence of
uric acid crystals in the kidneys can cause renal failure.
It is a major cause of morbidity in the United States and elsewhere.
As the table below shows, the treatment for many types of renal stones is imperfect and the occurrence of renal calculi continues to cause significant morbidity and high cost to the health care
system associated with emergency room visits, etc.
The regulation of
bone formation and removal is complex and involves both systemic and local regulation.
In addition, many drugs can cause bone loss, such as
heparin,
ethanol, glucocorticoids and some anti-convulsants.
However, all forms of
bone density loss are ultimately the result of the loss of mineralization of bone.
In addition there is a predilection for
precipitation into certain tissues.
The lesions of calcinosis are small or medium sized hard nodules that can cause
muscle atrophy, and contractions, and may produce significant disability.
Dental calculus is a distinct oral detriment because it is especially difficult to remove with
dental floss and serves as a localized physical irritant to the
gingival tissue.
However, no generally effective means to control the formation of dental calculus is known.
However, if the bile is supersaturated, vesicles fail to dissolve completely and instead fuse to form large,
cholesterol-rich multilamellar liquid crystals from which excess
cholesterol may precipitate as plate-like
cholesterol monohydrate crystals.
This may account for the two-fold increase risk of cholesterol
gallstones in women during their childbearing years.
In addition some hypocholesterolemic drugs such as the fibric acid derivatives clofibrate and gemfibrizol directly stimulate
secretion of cholesterol into bile and are associated with
increased risk of cholesterol
gallstones.
Thus the formation of
gallstones is a major medical problem associated with significant morbidity and mortality and expense.
This rigid deformation of the red blood cells, in turn, causes
occlusion of the microvasculature.
However, when the
mutant gene is inherited from both parents then sickle
cell disease results and this is associated with chronic
anemia and recurrent pain and the periodic occurrence of, possibly life threatening "sickle
cell crisis".
In addition, a common and extremely serious condition called osteonecrosis may occur because of the reduction of
blood flow to the bones, resulting in painful bone infarctions.
This deformation causes vaso-
occlusion and the resulting decrease in
blood supply causes the diverse symptoms of the disease.
However, the
delay times usually exceed capillary transit times and so cells do not accumulate significant amounts of
polymer until they are in a large
vein where they cannot elicit vasoocclusion.
Unfortunately local vascular perturbations may cause unusual
delay in the
transit time and allow sickling to take place in the capillary, causing a potentially disastrous decrease in
blood supply to the organ.
However this is primarily an
emergency procedure and has many disadvantages, such as transmission of infectious agents and high cost.
They are the leading cause of
blindness in the world and the leading cause of visual loss in Americans older than age 40.
The
normal protein matrix of the lens may
cross link and precipitate over the course of time causing loss of transparency to visual light.
Although
cataracts may be treated surgically by removal of the opacified lens, no agent capable of preventing the
phase transition responsible for this tissue change is known.
No clinical classification of the
amyloid diseases is entirely satisfactory.
But given the enormous variety of disorders due to physical-state changes in animals, it has been extremely tedious to perform the huge number of experiments to determine the conditions, compounds, or compositions that will prevent, inhibit, or reverse these undesirable physical-state changes or promote or induce desirable physical-state changes.
And because many factors influence
crystallization, precipitation, deposition, and other physical-state changes of inorganic and organic substances, testing to find conditions, compounds, or compositions that can inhibit or reverse such processes or induce desirable physical state changes is an extremely tedious process.
At present, industry does not have the time or resources to test hundreds of thousands of combinations to find the right conditions, compounds, or compositions adverse to undesired physical-state changes.