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Immediately after the body is injured, it starts the processes of stopping blood loss, restoring function, and preventing infection from pathogens on the skin or objects that may have caused the damage. The microenvironment of the injured area is in constant flux with the host cells continuously responding to the fluids, bacteria, and the dead and dying cells at the wound site.

One of the first phases of the healing process is for circulating platelets to attach to a fibrous scaffold, a matrix, to stop blood flow. Platelets, recently defined as immune cells, release cytokines, immune messengers, which permit cells to communicate with one another.

 Once the flow of blood ceases, specialized immune cells enter the area setting up an inflammatory response that “cleans” the wound site and removes bacteria, damaged tissues, and foreign matter. In order to achieve the appropriate levels of inflammation, many complex cell-to-cell interactions occur in specific order.

Accumulation of fluids, exudates, results from inflammation, along with swelling at the wound site. Exudates are essential for the healing process and contain debris, inflammatory cells, bacteria, and a large variety of immune proteins. Depending on their concentrations, factors may enhance healing or interfere with the process. Proteins found in exudates have a variety of functions including regulation of inflammatory responses, triggering growth of new blood vessels, and stimulating growth of new cells.

A delicate balance of inflammatory and anti-inflammatory messengers is crucial and it determines the pace, and outcome of healing. Homeostatic, balanced, inflammatory responses are essential. Too little, too great, or too lengthy of an inflammatory response damages healthy tissue and delays healing.

The remodeling phase is one where tissues regenerate and close the wound. Closure occurs as cells cross-link and organize themselves attaching to a scaffold, a matrix that will draw edges of the skin closed and cover the area.

Poorly Healing Wounds

The presence of bacteria, foreign bodies, a lack of oxygen in the tissues, and/or fragments of necrotic, dead, tissue can stimulate inflammatory cells continuously, resulting in uncontrolled inflammation and wounds that heal poorly.

Infection of a wound site also interferes with proper healing. Communities of bacteria tend to organize themselves into a biofilm, a thin sheet of bacteria. Biofilms increase survival of bacteria colonies, reducing chances that inflammatory immune responses, or antibiotics, can control them.

Exudates in poor healing wounds contain an over abundance of inflammatory cells and immune mediators that increase inflammation. Sufficient anti-inflammatory factors to control the damaging effects of excessive inflammation may not be available.

Proteolysis is another one of the steps required for healthy healing. This is an event during which the body degrades necrotic tissue, and dead and dying pathogens. [Think of proteolysis as an acid/enzyme reaction that breaks down tissues.] When immune cells release too many proteolytic proteins over a longer period, they become destructive of healthy tissue, and the body’s ability to heal the wound is overwhelmed.

Individuals with non-healing skin ulcers, such as those found in diabetics, not only struggle with excessive inflammatory responses, but their proteolytic enzyme levels are significantly elevated giving rise to further imbalances in inflammatory responses and interference with the body’s repair mechanisms.

Summary

The sensitive balance between stimulating and inhibitory mediators during diverse repair of wound is crucial to achieving tissue homeostasis following injury. Once unbalanced and excessive inflammation is controlled, will healing begin.

 
There is no fee for speaking with Dr. Hellen. She may be contacted by using this form or at: 302.265.3870 (ET).


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The brain, being the “control center” of the body is cushioned by fluid, and is protected by bone and layers of membranes that support blood vessels that feed the brain.

Concussions
Direct or indirect mechanical impact to the brain may result from sports activities or workplace accidents. These may result in trauma to the brain. Rapid acceleration or deceleration, e.g., motor vehicle accidents or intense changes in pressure, e.g., blast exposures can also lead to brain damage.

The term “concussion” is commonly used to refer to a brain injury resulting from the head being hit with a great deal of force. Shaking the upper body and head violently can also cause brain damage.

Concussions alter the way the brain functions. The effects are usually short-lived, but may include being dazed, headaches, and problems with concentration, memory, balance, and coordination.

Brain injuries may result in loss of consciousness, but since the majority of cases do not end in “blackouts”, concussions often occur without the individual realizing they have had damage. The impact may seem relatively mild, and the individual may appear only to be dazed and with time and rest they may heal properly.

Serious untreated concussions can result in long-term brain damage and may even end in death.
Repetitive head injuries are a major issue especially when an individual sustains additional head injuries before the damage from the prior injury has been completely resolved.

The effects are cumulative. Cumulative sports concussions increase the likelihood of permanent neurologic disability. Complete recovery from an initial trauma can take from 6-18 months, and multiple concussions over time may result in long-term problems, including neurological deterioration, dementia-like symptoms, memory disturbances, behavioral, and personality changes, Parkinsonism, and speech and gait abnormalities.

In a minority of cases, additional trauma to the brain, even occurring from days to weeks following a prior event, can lead to collapse and death within minutes.

How quickly and completely one heals, depends on a number of factors including one’s genetic makeup. (This would be expected since genes determine a cell’s ability to withstand mechanical stress, regenerate, and heal.)

Inflammation and Concussions
For years it was thought that the membranes around the brain acted as a blood-brain barrier which stopped the brain from responding with inflammatory responses when it was confronted by infection. However, it has now been shown that concussions and other brain injuries, or infection or disease, will trigger inflammatory responses.

The types of immune cells found throughout the body are also found in the brain, but additionally, the brain has unique immune cells. When activated, brain-specific microglia and astrocytes, produce inflammatory cytokines that remain localized in the brain.

In response to brain injury, the immune system releases a tidal wave of pro- and anti-inflammatory cytokines, molecules that trigger and/or stop an inflammatory response depending on what is needed.

In small amounts, these cytokines help protect the brain and heal it. However, prolonged exposure to inflammatory cytokines, or too high a level of these proteins, will result in damage that accumulates after injury. High levels of inflammatory cytokines are localized at the injury site, and may be found on the opposite side of the head from the side that was hit.

There is increasing evidence suggesting that much of the neurological damage that occurs after the brain is injured is the result of a delayed inflammatory response that lasts hours, days, or even for months after the injury. This chronic inflammatory response may cause more damage to the brain tissue than the mechanical impact itself.

Immune Homeostasis, Immune Balance is the Key
Unfortunately, pharmaceutical treatments known to reduce inflammation appear to interfere with the brain’s natural repair mechanisms. Therefore it is necessary for the body to control its inflammatory responses. It has to produce enough of a response to help brain tissue heal, but not an overly exaggerated inflammatory response which may cause more damage after injury.

In order for the brain to heal after trauma, the immune system must generate the proper balance, and types, of pro-inflammatory and inflammatory cytokines. For those with brain injuries, maintaining immune homeostasis, immune balance, may be the best way to minimize damage.

 

Dr. Hellen is available at 302.265.3870 for discussion on the role of inflammation and immune homeostasis in our health.  She may be contacted at: drhellen@drhellengreenblatt.info, or use the contact form.  Thank you.

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