Case Study #9a
A Case Study on Bone Tissue Structure and Repair
Alice Smith is a 39-year-old female who works for an airline manufacturing plant. While she was at work today a large box of metal rivets fell from a 20-ft.-high overhead shelf, striking her outstretched arm and knocking her to the ground. The ambulance personnel reported that she had lost quite a bit of blood at the accident scene and was “knocked out” with head injuries when they arrived. To minimize further hemorrhage, the paramedics applied a pressure bandage to her arm.
You meet the paramedics as they bring Alice into the emergency room and begin to assess her for injuries. She is awake and alert, but complaining of severe left arm and back pain, plus she has a “killer headache.” To fully examine her injuries you remove four blood-soaked bandages from her arm. You notice a large open wound on her arm with what appears to be bone tissue sticking out of the skin. She also has bruises covering her left shoulder, left wrist, and lower back. To determine the extent of her injuries Alice undergoes several x-rays, which reveal the following:
fracture of the left humerus at the proximal diaphysis,
depressed fracture of the occipital bone,
fracture of the 3rd lumbar vertebral body.
Discussion Questions: Case Study #9a: Pick 3 of the 5 Questions to answer.
One way bones are classified is by their shape. How would you classify the bones fractured of Alice?
The diaphysis of Alice’s humerus is fractured. What type of bone makes up the majority of the diaphysis of long bones like the humerus? Describe the layers of bone tissue found here.
Within days after a fracture, a “soft callus” of fibrocartilage forms. What fibers are found in this type of cartilage? Identify the cells required for fibrocartilaginous callus formation and list their functions.
As a fracture is repaired, new bone is added to the injury site. What term is used to describe the addition of new bone tissue? Identify which bone cell is responsible for this process and explain how it occurs.
In the final stage of bone repair, some of the osseous tissue must be broken down and removed. What term is used to define the breaking down of osseous tissue? Which bone cell would be best suited for this task?
Case Study #9b Muscle
Limb Girdle Muscular Dystrophy AGE:29 Gender:Male DIAGNOSIS: Limb Girdle Muscular Dystrophy (LGMD)
Patient History: 6 Years ago, developed progressive weakness in his limb muscles. The Neurologist diagnosed LGMD.
REASON FOR COMING FOR TREATMENT: The Patient had tried all available conventional treatments in the best of neurology hospitals in his country but with no improvement in his condition. The Patient was informed by the doctors that there is no treatment for this condition. He thought of trying new emerging treatments like stem cells, benefits of which he had heard about from other patients groups suffering from muscular dystrophies.
TREATMENT: Mesenchymal Stem Cells Derived from Wharton’s Jelly of Human Umbilical cord. He Received 5 injections of stem cells, 3 Through Intravenous Route in a dose of 1 Million cells/kg body weight and 2 Injections of adequate cells through intrathecal route.
BEFORE TREATMENT: There Was marked weakness in the muscles of all his limbs and in the power of shoulder, scapula and trunk muscles He Experienced difficulty in climbing stairs, walking and changing positions from sitting to standing position. He Fatigued easily and had diminished stamina for daily activities. Activities Such as combing hair, brushing teeth and eating with hands were difficult. However, He had no problem in writing.
AFTER TREATMENT: The Following improvements were noticed after 3 Months of follow-up:
There was improvement in the power of his shoulder muscles and now could raise his arms over the shoulder level.
Due To this improvement, he could perform activities such as combing hair and brushing teeth with less effort.
His Confidence and stamina were elevated now.
Disruption of dystrophin or the sarcoglycans within the dystrophin protein complex leads to muscular dystrophy. The dystrophin complex is enriched in myofibers and concentrated into costameres, rib-like structures in the plasma membrane. In the absence of dystrophin, the plasma membrane becomes fragile with reduced stiffness and increased leakiness, and exposing dystrophin-deficient muscle to hypoosmotic conditions produces membrane blebbing. These features are associated with an increase in intracellular calcium, reactive oxygen species (ROS), and activation of a protease cascade. The ensuing loss of myofibers, largely mediated by a necrotic cell death process, is associated with progressive replacement of the myofibers by fibrosis. Although membrane repair mechanisms may be activated, apparently repaired myofibers may exhibit defective function from the intracellular consequences of membrane disruption. Additionally, remodeling of the extracellular matrix for those surviving myofibers may also adversely affect muscle function. Thus, the causes of muscle weakness in muscular dystrophy are multifold and encompass the matrix, membrane and intracellular elements of muscle identifying multiple target pathways for therapeutic intervention.
Discussion Questions: Case Study #9b: Answer both Questions!
There are nine types of muscular dystrophy, with each type involving an eventual loss of strength, increasing disability, and possible deformity. Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), Myotonic muscular dystrophy, Congenital muscular dystrophy, Emery-Dreifuss muscular dystrophy, Facioscapulohumeral (FSHD) muscular dystrophy, Limb-girdle muscular dystrophy, Distal muscular dystrophy, and Oculopharyngeal muscular dystrophy. Pick one type and discuss it.
There is no known cure for muscular dystrophy and the causes are complex and multifold. Stem Cell treatment, however, as a cutting edge treatment is showing some initial hope for success. Please research and discuss.