Local induction of an insulin-like growth factor binding protein-3 degrading protease activity in the course of wound healing

Proteases that reduce insulin-like growth factor binding protein-3 affinity for insulin-like growth factor-I have been found in various biological fluids from human beings and rats. The aim of this study was to assess the local and systemic role of insulin-like growth factor binding protein-3 proteases in the course of wound healing. Six rats had polyvinyl alcohol sponges implanted subcutaneously. Wound fluid and serum were collected 3 days after wounding. Gel filtration experiments showed that insulin-like growth factor-I was present as a 150 kDa complex in both serum and wound fluid. However, insulin-like growth factor binding protein-3 measured by Western ligand blotting was virtually absent in wound fluid. Co-incubation of serum and wound fluid resulted in an ethylenediamine tetraacetic acid-inhibitable degradation of serum insulin-like growth factor binding protein-3, suggesting the presence of an insulin-like growth factor binding protein-3 degrading activity in wound fluid. Incubation of ((125)I)-labeled insulin-like growth factor binding protein-3 in wound fluid and serum showed a rapid and time-dependent proteolysis of insulin-like growth factor binding protein-3 in wound fluid with metabolites similar to those generated by human term pregnant serum. No sign of insulin-like growth factor binding protein-3 degrading activity was observed in rat-serum. In conclusion, there is an insulin-like growth factor binding protein-3 proteolytic activity in wound fluid, and it is hypothesized that this activity results in a localized increase in insulin-like growth factor-I bioactivity.     

Prospective Study of the Incidence of Transient Radicular Irritation in Patients Undergoing Spinal Anesthesia

Background: There is considerable controversy regarding the role of subarachnoid 5% hyperbaric lidocaine in the syndrome transient radicular irritation (TRI). This randomized, double-blinded, prospective study was designed to determine the incidence of TRI and identify factors possibly contributing to its development.

Methods: One hundred fifty-nine ASA physical status 1 or 2 patients undergoing outpatient knee arthroscopy or unilateral inguinal hernia repair were prospectively randomized to receive spinal anesthesia with 5% hyperbaric lidocaine with epinephrine (60 mg with 0.2 mg epinephrine for arthroscopy or 75 mg with 0.2 mg epinephrine for hernia repair), 2% isobaric lidocaine without epinephrine (60 mg for arthroscopy or 75 mg for hernia repair), or 0.75% hyperbaric bupivacaine without epinephrine (7.5 mg for arthroscopy or 9.0 mg for hernia repair) in a double-blinded fashion. On the 3rd postoperative day, patients were contacted by a blinded investigator and questioned regarding the incidence of postoperative complications including TRI, defined as back pain with radiation down one or both buttocks or legs occurring within 24 h after surgery. Postoperatively, time from injection to block resolution, ambulation, voiding, and ready for discharge were recorded by a postanesthesia care unit nurse blinded to the group assignment.

Results: The incidence of TRI was greater in patients receiving lidocaine than in those receiving bupivacaine (16% vs. 0%; P = 0.003). There was no difference in the incidence of TRI between the patients receiving 59% hyperbaric lidocaine with epinephrine and those receiving 2% isobaric lidocaine without epinephrine (16% vs. 16%; P = 0.98). The incidence of TRI was greater in patients undergoing arthroscopy than in those undergoing hernia repair (13% vs. 5%; P = 0.04). There was no difference in discharge times in patients receiving bupivacaine versus those receiving hyperbaric lidocaine with epinephrine (292 vs. 322 min; P = 0.61).     

Catastrophic failure of modular Zirconia—Ceramic femoral head components after total hip arthroplasty

Catastrophic failure of two zirconia—ceramic modular femoral heads occurred, despite the theoretical improved toughness of zirconia—ceramic relative to alumina—ceramic. This experience led the authors to return to cobalt—chromium as the metal of choice for articulation against polyethylene in total hip arthroplasty.     

Postural stability by computerized posturography in minor head trauma

Mild head injuries are very common among young children. Often, these injuries are followed by a variety of subjective complaints termed posttraumatic syndrome. Posturography (balance test) was performed immediately after the trauma in 21 children who had sustained mild head injury. Significant difference in performance was observed in head-injured children in all subparts of the test as compared with a control group. We conclude that posturography may serve as a simple cost-effective method in qualifying the posttraumatic imbalance.     

Development of subcutaneous wound oxygen measurement in humans: Contributions of Thomas K. Hunt, MD

When, in the early 1960s, Thomas K. Hunt, MD began investigating the role of oxygen in wound healing, he recognized that translation to humans would require the ability to measure oxygen tension in human wounds. This article will review his contributions to the development of subcutaneous tissue oxygen measurement and to the understanding of wound physiology and oxygen delivery, particularly through use of oxygen measurement. Hunt's major contributions to the field include the observations that all wounds show some degree of hypoxia, while many are severely hypoxic; the degree of hypoxia in wounds is sufficient to impair wound healing, and particularly bacterial killing by neutrophils, collagen deposition, angiogenesis, and epithelization; the sympathetic nervous system plays a central role in decreasing wound oxygen supply; and wound oxygen delivery and wound healing capacity can be increased by controlling the sympathetic nervous system. All these observations required tissue oxygen measurement, and, in particular, translation of basic scientific observations to clinical research required a method of measuring wound oxygen tension in humans.     

Outcome in Children With Significantly Abnormal Cerebral Blood Flow Detected by Doppler Ultrasonography: Focus on the Survivors

BACKGROUND AND PURPOSE: The Doppler waveform patterns of loss of diastolic flow, appearance of retrograde diastolic flow, or no detectable flow in the cerebral arteries suggest significantly abnormal cerebral blood flow (CBF). A retrospective study was performed to show that significantly abnormal CBF alone, without clinical criteria, is not necessarily specific to brain death in the young pediatric population. PATIENTS AND METHODS: Forty-seven pediatric patients, from newborn to 4 years of age, were found to have significantly abnormal CBF, including 7 patients with loss of diastolic flow, 28 with retrograde diastolic flow, and 23 with no detectable cerebral flow on serial Doppler sonographic examinations. Their clinical data and sonographic results were collected and analyzed. RESULTS: Forty-two patients died, a few of whom had only transient improvement of cerebral flow. All of the patients with no detectable cerebral flow expired. Five patients survived with or without sequelae. Their underlying conditions that caused increased intracranial pressure were treated by medical and/or surgical intervention, and diastolic reversal of CBF corrected within 1 day in all 5. CONCLUSIONS: Although no detectable flow is a lethal sign, pediatric patients with loss or reversal of diastolic flow may survive with prompt and effective treatment. Using Doppler ultrasound to diagnose cerebral circulatory arrest should be done with caution in pediatric patients.