Staphylococcus aureus alpha toxin suppresses effective innate and adaptive immune responses in a murine dermonecrosis model

An optimal host response against Staphylococcus aureus skin and soft tissue infections (SSTI) is dependent on IL-1β and IL-17 mediated abscess formation. Alpha toxin (AT), an essential virulence factor for SSTI, has been reported to damage tissue integrity; however its effect on the immune response has not been investigated. Here, we demonstrate that infection with USA300 AT isogenic mutant (Δhla), or passive immunization with an AT neutralizing mAb, 2A3, 24 h prior to infection with wild type USA300 (WT), resulted in dermonecrotic lesion size reduction, and robust neutrophil infiltration. Infiltration correlates with increase in proinflammatory cytokines and chemokines, as well as enhanced bacterial clearance relative to immunization with a negative control mAb. In addition, infection with Δhla, or with WT +2A3, resulted in an early influx of innate IL-17⁺γδT cells and a more rapid induction of an adaptive immune response as measured by Th1 and Th17 cell recruitment at the site of infection. These results are the first direct evidence of a role for AT in subverting the innate and adaptive immune responses during a S. aureus SSTI. Further, these effects of AT can be overcome with a high affinity anti-AT mAb resulting in a reduction in disease severity.

Alternate serotype adenovector provides long-term therapeutic gene expression in the eye

PURPOSE

To determine whether the duration of transgene expression from an alternate adenovector serotype, Ad35, can provide advantages over an Ad5 serotype vector following a single intravitreal (IVT) administration.

METHODS

To assess the transgene expression profile, mice received one IVT injection of Ad5- or Ad35-based vectors expressing green fluorescent protein (GFP), luciferase or pigment epithelium-derived factor (PEDF). At specified time points following vector administration, eyes were monitored for GFP expression, or eyes were harvested and assayed for adenovector genomes, luciferase activity or PEDF levels. Ad35-based vector in vivo biologic activity was investigated using a mouse model of laser-induced choroidal neovascularization (CNV). On Day 0, mice received one IVT injection of Ad5.PEDF or Ad35.PEDF (HI-RGD) followed by laser-induced CNV on Day 28. Fourteen days later, animals were perfused with fluorescein-labeled dextran and CNV lesion size quantitated in choroidal flat mounts.

RESULTS

These studies demonstrate that following a single IVT adenovector administration: 1) gene expression is prolonged following administration of an Ad35 compared to an Ad5-based vector; 2) the amount of vector genomes in the eye remain constant out to 60 days post injection of both Ad5 and Ad35-based vectors; and 3) an Ad35.PEDF (HI-RGD) vector inhibits CNV in a mouse model at 42 days post injection.

CONCLUSIONS

These studies show that transgene and genome levels are prolonged in the eye following 1 IVT injection of an Ad35-based vector. Moreover, therapeutic gene levels from 1 IVT administration of Ad35.PEDF (HI-RGD) vector block abnormal blood vessel growth in a laser-induced CNV mouse model.

Repeated administration of adenovector in the eye results in efficient gene delivery

PURPOSE

To determine whether repeat administration of an adenovector (Ad) into the eye results in efficient gene delivery and to test whether transgenes can be expressed from an adenovector expression system in the presence of preexisting, neutralizing anti-Ad antibodies.

METHODS

To assess the efficiency of repeated gene delivery of an adenovector expression system, C57Bl/6 mice received one, two, or three injections (intravitreal [IVT] or periocular [PO]) of AdNull.11D (empty cassette) at 2-week intervals, followed by a single AdLuciferase (AdL.11D) IVT or PO injection. Mice were killed approximately 24 hours after AdL.11D injection and the eyes were enucleated and stored until assayed. Serum samples were also analyzed to determine whether repeated IVT or PO injections lead to induction of neutralizing antibodies directed against an adenovector delivery system. To determine whether preexisting neutralizing anti-Ad antibodies would block transgene expression, mice were preimmunized with one, two, or three intramuscular (IM) injection(s) of AdNull.11D (1 x 10(9) particle units [pu]). Fourteen days later, when systemic anti-Ad antibody titers were expected to exist, mice were given a single AdL.11D injection (IVT or PO) and killed, and the eyes and serum collected.

RESULTS

These studies show that multiple injections at 2-week intervals with adenovectors (IM, IVT, or PO) did not prevent transgene expression in the eye. Moreover, measurement of neutralizing anti-Ad antibody titers revealed that measurable anti-Ad antibody titers in mice did not ablate transgene expression.

CONCLUSIONS

These studies suggest that transgene expression after repeated adenovector administration into the eye is feasible and repeated injections, whether given IVT or PO, do not lead to an immediate increase in neutralizing anti-Ad antibody titers. Moreover, preimmunization of mice by systemic exposure to adenovector, does not block transgene expression in the eye. These studies indicate that repeat administration of adenovectors (IVT and PO) into the eye can be considered in designing future clinical trials and that the pre-existence of neutralizing anti-Ad antibodies probably does not mitigate activity.

Laser hair removal update

Laser hair removal has made possible the permanent reduction of unwanted hair. However, this technology remains far from perfect. Many advances have occurred in the past several years to improve laser hair removal, including lengthening pulse widths and adding mechanisms to cool the skin during treatment. These advances have improved results and broadened the scope of patients who are candidates for this procedure. This article reviews the latest advances as well as the various laser hair removal systems currently available.

A successful 15-year experience in double-dome tip surgery via endonasal approach: nuances and pitfalls

BACKGROUND

Endonasal double-dome techniques provide a reliable method to approach the nasal tip.

OBJECTIVES

To review one surgeon's 15-year experience using a graduated method of endonasal double-dome tip surgery including patient selection, intraoperative techniques, and postoperative complications and to emphasize the nuances to achieve symmetry and consistent results.

PATIENTS AND METHODS

Three hundred eighty-six patients who had adequate follow-up after undergoing endonasal double-dome tip rhinoplasty.

RESULTS

Results at 1 year showed high rates of supratip (94%), dome (96%), and nostril (88%) symmetry. There was a high rate of patient satisfaction with a low rate of revision (7%).

CONCLUSION

Endonasal double-dome tip surgery provides the surgeon the ability to achieve consistent results with high patient satisfaction and a low rate of revision.

Optimal sample preparation conditions for the determination of uranium in biological samples by kinetic phosphorescence analysis (KPA)

Kinetic phosphorescence analysis (KPA) is a proven technique for rapid, precise, and accurate determination of uranium in aqueous solutions. Uranium analysis of biological samples require dry-ashing in a muffle furnace between 400 and 600 degrees C followed by wet-ashing with concentrated nitric acid and hydrogen peroxide to digest the organic component in the sample that interferes with uranium determination by KPA. The optimal dry-ashing temperature was determined to be 450 degrees C. At dry-ashing temperatures greater than 450 degrees C, uranium loss was attributed to vaporization. High temperatures also caused increased background values that were attributed to uranium leaching from the glass vials. Dry-ashing temperatures less than 450 degrees C result in the samples needing additional wet-ashing steps. The recovery of uranium in urine samples was 99.2+/-4.02% between spiked concentrations of 1.98-1980 ng (0.198-198 microg l(-1)) uranium, whereas the recovery in whole blood was 89.9+/-7.33% between the same spiked concentrations. The limit of quantification in which uranium in urine and blood could be accurately measured above the background was determined to be 0.05 and 0.6 microg l(-1), respectively.

Determination of the isotopic composition of uranium in urine by inductively coupled plasma mass spectrometry

A simple method based on inductively coupled plasma mass spectrometry (ICP-MS) was developed to identify exposure to depleted uranium by measuring the isotopic composition of uranium in urine. Exposure to depleted uranium results in a decreased percentage of 235U in urine samples causing measurements to vary between natural uranium's 0.72% and depleted uranium's 0.2%. Urine samples from a non-depleted uranium exposed group and a suspected depleted uranium exposed group were processed and analyzed by ICP-MS to determine whether depleted uranium was present in the urine. Sample preparation involved dry-ashing the urine at 450 degrees C followed by wet-ashing with a series of additions of concentrated nitric acid and 30% hydrogen peroxide. The ash from the urine was dissolved in 1 M nitric acid, and the intensity of 235U and 238U ions were measured by ICP-MS. After the samples were ashed, the ICP-MS measurements required less than 5 min. The 235U percentage in individuals from the depleted uranium exposed group with urine uranium concentrations greater than 150 ng L(-1) was between 0.20%-0.33%, correctly identifying depleted uranium exposure. Samples from the non-depleted uranium exposed individuals had urine uranium concentration less than 50 ng L(-1) and 235U percentages consistent with natural uranium (0.7%-1.0%). A minimum concentration of 14 ng L(-1) uranium was required to obtain sufficient 235U to allow calculating a valid isotopic ratio. Therefore, the percent 235U in urine samples measured by this method can be used to identify low-level exposure to depleted uranium.

Mersilene mesh chin augmentation. A 14-year experience

During the past 20 years, a variety of alloplastic materials have been introduced for chin augmentation. Mersilene mesh (Ethicon, Sommerville, NJ), introduced in 1950, demonstrates many qualities that make it an ideal implant. This article reviews the senior author's (S.W.P.) successful 14-year experience using Mersilene mesh chin implants. Between 1983 and 1997, 264 patients underwent chin implantation procedures. The results show a low rate of infection (0.8%) and displacement (1.5%). There were 14 temporary paresthesias and no cases of permanent anesthesia. There were no incidences of absorption, rejection, or extrusion. Mersilene provides a soft, natural appearance to the chin, and it continues to be our choice for chin implantation.

Transformation of human osteoblast cells to the tumorigenic phenotype by depleted uranium-uranyl chloride

Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Although the health effects of occupational uranium exposure are well known, limited data exist regarding the long-term health effects of internalized DU in humans. We established an in vitro cellular model to study DU exposure. Microdosimetric assessment, determined using a Monte Carlo computer simulation based on measured intracellular and extracellular uranium levels, showed that few (0.0014%) cell nuclei were hit by alpha particles. We report the ability of DU-uranyl chloride to transform immortalized human osteoblastic cells (HOS) to the tumorigenic phenotype. DU-uranyl chloride-transformants are characterized by anchorage-independent growth, tumor formation in nude mice, expression of high levels of the k-ras oncogene, reduced production of the Rb tumor-suppressor protein, and elevated levels of sister chromatid exchanges per cell. DU-uranyl chloride treatment resulted in a 9.6 (+/- 2.8)-fold increase in transformation frequency compared to untreated cells. In comparison, nickel sulfate resulted in a 7.1 (+/- 2.1)-fold increase in transformation frequency. This is the first report showing that a DU compound caused human cell transformation to the neoplastic phenotype. Although additional studies are needed to determine if protracted DU exposure produces tumors in vivo, the implication from these in vitro results is that the risk of cancer induction from internalized DU exposure may be comparable to other biologically reactive and carcinogenic heavy-metal compounds (e.g., nickel).

Endoscopic excision of a forehead mass

Endoscopic applications in facial plastic surgery have recently increased with the advent of new instrumentation and as surgeons have become more accustomed to their use. We report the first case (to our knowledge) of an endoscopic removal of a forehead soft tissue mass. The endoscopic approach allows the surgeon access to the forehead area with placement of a skin incision in the hair-bearing scalp. This type of approach is especially of value in patients with a predisposition to unusual scar formation or in those with smooth skin in which a direct incision would yield a noticeable scar.

Concepts in lip reconstruction

Reconstruction of defects of the lip presents a significant challenge to the facial plastic surgeon. Both functional and aesthetic considerations exist. Each defect should be evaluated in terms of its location, size, and depth. Using these three factors, the appropriate reconstructive options can be chosen in a systematic fashion.

A comparison of ibuprofen versus acetaminophen with codeine in the young tonsillectomy patient

OBJECTIVE: To compare the use of ibuprofen with the use of acetaminophen with codeine for posttonsillectomy management.

BACKGROUND: We were not satisfied with our traditional pain-management practice for tonsillectomy patients. We hoped to find a new approach for improved patient comfort and avoid scheduled, abusable drugs such as codeine.

DESIGN: Intervention, prospective, randomized control trial. Follow-up was 1 month.

SETTING: University referral center; institutional pediatric practice, ambulatory.

PATIENTS: 110 children undergoing tonsillectomy with or without other procedures. Consecutive patients were offered participation. Enrollees were randomly assigned to one of two classes and analyzed with the initial assignment. No patients withdrew for adverse effects, although 12 in group 2 used codeine and 5 of those used acetaminophen, whereas 2 in group 1 received ibuprofen.

INTERVENTIONS: Patients received either acetaminophen with codeine (group 1) or ibuprofen (group 2) for postoperative pain control.

MAIN OUTCOME MEASURES: The main outcomes, determined before initiation of the study, were assessment of (1) postoperative bleeding, (2) pain, (3) efficacy of relief of pain by drug, (4) nausea, (5) emesis, (6) readmission to hospital, (7) average temperature, and (8) highest temperature after surgery.

RESULTS: The only statistically significant difference is less nausea in patients receiving ibuprofen ( p = 0.0049). Of note, no difference existed in postoperative bleeding, pain, or temperature control.

CONCLUSIONS: Ibuprofen is at least as effective as acetaminophen with codeine for postoperative pain control in children after tonsillectomy. (Otolaryngol Head Neck Surg 1997;117:76–82.)

A comparison of ibuprofen versus acetaminophen with codeine in the young tonsillectomy patient

OBJECTIVE

To compare the use of ibuprofen with the use of acetaminophen with codeine for posttonsillectomy management.

BACKGROUND

We were not satisfied with our traditional pain-management practice for tonsillectomy patients. We hoped to find a new approach for improved patient comfort and avoid scheduled, abusable drugs such as codeine.

DESIGN

Intervention, prospective, randomized control trial. Follow-up was 1 month.

SETTING

University referral center; institutional pediatric practice, ambulatory.

PATIENTS

110 children undergoing tonsillectomy with or without other procedures. Consecutive patients were offered participation. Enrollees were randomly assigned to one of two classes and analyzed with the initial assignment. No patients withdrew for adverse effects, although 12 in group 2 used codeine and 5 of those used acetaminophen, whereas 2 in group 1 received ibuprofen.

INTERVENTIONS

Patients received either acetaminophen with codeine (group 1) or ibuprofen (group 2) for postoperative pain control.

MAIN OUTCOME MEASURES

The main outcomes, determined before initiation of the study, were assessment of (1) postoperative bleeding, (2) pain, (3) efficacy of relief of pain by drug, (4) nausea, (5) emesis, (6) readmission to hospital, (7) average temperature, and (8) highest temperature after surgery.

RESULTS

The only statistically significant difference is less nausea in patients receiving ibuprofen (p = 0.0049). Of note, no difference existed in postoperative bleeding, pain, or temperature control.

CONCLUSIONS

Ibuprofen is at least as effective as acetaminophen with codeine for postoperative pain control in children after tonsillectomy.