An Osteochondral Allograft in a Patient with Ochronosis: A Case Report.

CASE: When a 31-year-old man with no prior medical history underwent diagnostic arthroscopy for posttraumatic knee pain, ochronotic arthropathy was identified. Subsequent blood tests led to the diagnosis of alkaptonuria. After a discussion regarding his future military career and prognosis, he elected to proceed with osteochondral allograft transplantation surgery (OATS). He was able to return to active-duty service with minimal knee pain. At the 32-month postoperative visit, he had functional, pain-free motion and an excellent Hospital for Special Surgery (HSS) knee score. CONCLUSION: Alkaptonuria is an uncommon metabolic disorder that causes arthropathy of peripheral joints. When there is a focal defect, an osteochondral allograft is a valid, joint-preserving option that allows return to activity.

Unusual Late Presentation of Hemophilia A in an Active Duty U.S. Marine Following Open Shoulder Surgery.

Hemophilia A is clotting disorder affecting 8:100,000 males in the United States. It is an X-linked recessive genetic disorder, although about one-third of cases occur spontaneously without known family history. Because of the risk of uncontrolled hemorrhage on the battlefield, hemophilia and other bleeding disorders exclude individuals from service in the U.S. military. We report a case of an active duty U.S. Marine whose underlying diagnosis of Hemophilia A was discovered and treated by a multidisciplinary team of orthopedic surgeons and hematologists following recurrent hematomas after open rotator cuff surgery. The patient gave informed consent for publication.

Effects of vitamin D analog on bladder function and sensory signaling in animal models of cystitis.

OBJECTIVE: To measure the effects of nonhypercalcemic vitamin D receptor agonist elocalcitol on bladder function in rats with cyclophosphamide-induced cystitis and on bladder function and sensory nerve activity in a mouse with acetic acid-evoked bladder irritation. MATERIALS AND METHODS: Female Wistar rats and male Balb/C mice were gavaged once daily with elocalcitol diluted in miglyol 812 (treatment group) or miglyol alone (control group). On experimental day 12, polyethylene tubing was implanted into the urinary bladder in all the animals. In the mice, a bipolar electrode was positioned under a single postganglionic bladder nerve. At 48 hours after surgery, bladder function was measured in awake, freely moving rats during bladder filling with 0.9% NaCl and both bladder function and sensory nerve activity was measured in awake, restrained mice during continuous intravesical infusion of 0.9% NaCl followed by 0.25% acetic acid. RESULTS: In rats, the treatment group showed a significant increase in bladder capacity and decrease in number of nonvoiding bladder contractions. In mice, the filling pressure during saline infusion was similar in both groups; however, during acetic acid infusion, the average filling pressure was significantly increased (47%) in the control group but not in the elocalcitol treatment group. The firing rate at filling pressure for the treatment group was 3.6-fold and 2.7-fold lower than that in the control group during the saline and acetic acid infusion, respectively. CONCLUSION: Oral treatment with elocalcitol suppressed signs of detrusor overactivity in both animal models and exerted strong suppressive effect on urinary bladder sensory signaling during filling in mice.

A non-anesthetized mouse model for recording sensory urinary bladder activity.

The goal of this study was to develop an in vivo awake mouse model for extracellular bladder sensory nerve recording. A bipolar 125-µm silver electrode was positioned under a single postganglionic bladder nerve. Efferent nerve signals were eliminated by tying off the postganglionic bladder nerve between the major pelvic ganglion and the recording electrode. Sensory nerve activity was measured in the conscious animals 48 h after surgery during continuous intravesical infusion of 0.9% saline/0.5% acetic acid followed by 0.5% acetic acid with capsazepine (10 µM) at a rate of 0.75 ml/h. Continuous infusion of 0.9% NaCl led to a gradual increase in the frequency of sensory nerve firing that peaked upon reaching threshold pressure. Non-micturition contractions were observed in some animals during filling and other animals exhibited only minimal pressure fluctuations; both types of events were associated with a rise in sensory nerve activity. Intravesical infusion of 0.5% acetic acid reduced the intermicturition interval. This was associated with a 2.1-fold increase in bladder pressure during filling and a two-fold increase at both threshold and micturition pressures. Concurrent with these changes, sensory activity increased 2.8-fold during filling and 2.4-fold at threshold pressure. Subsequent intravesical infusion of capsazepine in 0.5% acetic acid reduced filling and threshold pressures by 21 and 31.2%, respectively, and produced corresponding decreases of 36 and 23.4% in sensory nerve activity. The current study shows that multifiber sensory nerve recordings can be reproducibly obtained from conscious mice.

Insights into the Molecular Mechanisms Involved in Sea Urchin Fertilization Envelope Assembly: (fertilization membrane/dityrosine/hydrogen peroxide/extracellular matrix).

Sea urchin fertilization envelope assembly provides an ideal model system for investigating the production and modification of an extracellular matrix. The contents of secretory vesicles and the egg glycocalyx mix to initiate assembly. Limited proteolysis and covalent crosslinking by a transglutaminase act as early events to modify the nascent envelope. A subset of secreted proteins binds to this matrix through ionic interactions that require divalent cations. For example, one secreted protein, proteoliaisin, is responsible for attaching ovoperoxidase to the envelope. Ovoperoxidase hardens the envelope by using hydrogen peroxide, produced by the egg during the respiratory burst, to form dityrosine crosslinks between a subset of fertilization envelope proteins. Numerous spatial and temporal regulatory mechanisms exist to ensure that proper assembly occurs in an environment isolated from the normal cytosolic regulatory machinery.