Biomedical subjects

Paul McCormick

Publications and source records attributed to Paul McCormick.

3 recordsLinked to original sources

PubMed2007

Human skin penetration of sunscreen nanoparticles: in-vitro assessment of a novel micronized zinc oxide formulation.

The extent to which topically applied solid nanoparticles can penetrate the stratum corneum and access the underlying viable epidermis and the rest of the body is a great potential safety concern. Therefore, human epidermal penetration of a novel, transparent, nanoparticulate zinc oxide sunscreen formulation was determined using Franz-type diffusion cells, 24-hour exposure and an electron microscopy to verify the location of nanoparticles in exposed membranes. Less than 0.03% of the applied zinc content penetrated the epidermis (not significantly more than the zinc detected in receptor phase following application of a placebo formulation). No particles could be detected in the lower stratum corneum or viable epidermis by electron microscopy, suggesting that minimal nanoparticle penetration occurs through the human epidermis.

Administration, Cutaneous↗

PubMedDate not supplied

Management of postprocedural discitis.

BACKGROUND CONTEXT: Fortunately, the incidence of postprocedural discitis is relatively uncommon. The paucity of physical examination findings behooves the spine care practitioner to have a high index of suspicion in any patient presenting with increasing back pain after an invasive spinal procedure. The diagnosis can often be established in a timely fashion based on the history, physical examination, laboratory studies (erythrocyte sedimentation rate, C-reactive protein and blood cultures) and imaging studies (plain radiographs, magnetic resonance imaging, computed tomography and radionuclide scanning). PURPOSE: To review the English literature on the subject of postprocedural discitis. The incidence, pathophysiology, laboratory markers and imaging findings are discussed. Recommendations on treatment strategies are presented along with long-term clinical outcomes of this postprocedure complication. METHODS: A contemporary English literature search of MEDLINE and PubMed on the topic of postoperative discitis was performed. RESULTS: The incidence of postprocedural discitis is approximately 0.2%. The most common etiologic agent is Staphylococcus aureus. The C-reactive protein is the most sensitive clinical laboratory marker to assess the presence of infection and effectiveness of treatment response. Magnetic resonance imaging is the imaging modality of choice in the diagnosis of spinal infection. The majority of patients are managed adequately with organism-specific antibiotics and spinal immobilization with good long-term outcomes. Operative intervention (open biopsy followed by antibiotic treatment and spinal immobilization or debridement and reconstruction) in patients who fail to respond to nonoperative treatment or in the presence of neurologic worsening has been demonstrated. CONCLUSION: Postprocedural discitis is a rare complication after any invasive spinal procedure. It is imperative for the treating surgeon to maintain a high index of suspicion. Appropriate laboratory and imaging studies are invaluable in establishing a timely diagnosis. In the majority of patients, antibiotic treatment along with spinal immobilization has been shown to produce good long-term outcomes. Operative intervention is rarely necessary in patients failing conservative treatment.

Anti-Bacterial Agents↗

PubMedDate not supplied

Propofol use in pediatric patients with severe cancer pain at the end of life.

This article describes the use and effectiveness of adjuvant propofol for pain control for pediatric oncology patients at the end of life. All patients experienced severe pain and agitation, not well controlled by continuous infusion opioids and benzodiazepines. Upon starting propofol, most patients had a temporary stabilization in the dose of opioids with subjective improvement in pain control, increased alertness, and improved ability to interact. Propofol infusions were continued until death in most patients. Two patients received propofol infusions at home. Subsequent increases in opioids in 6 patients and propofol in all patients were required for optimal pain control. Adverse effects included agitation in 5 patients and hallucinations in 2, which were controllable with benzodiazepines. One patient developed severe tetany, requiring propofol interruption; propofol was successfully restarted at a lower dose with an adjuvant benzodiazepine. The authors conclude that propofol is a useful and tolerable adjuvant agent for pain management in pediatric oncology patients at the end of life. It is a useful adjuvant if pain is unresponsive to continuous infusion opioids or if rapidly escalating doses of opioids are required.

Child↗