Cyril D. Toma

Quantity of ethanol absorption after excessive hand disinfection using three commercially available hand rubs is minimal and below toxic levels for humans

BackgroundDespite the increasing promotion of alcohol-based hand rubs and the worldwide use of ethanol-based hand rubs in hospitals only few studies have specifically addressed the issue of ethanol absorption when repeatedly applied to human skin. The aim of this study was to assess if ethanol absorption occurs during hygienic and surgical hand disinfection using three different alcohol-based hand-rubs, and to quantify absorption levels in humans.MethodsTwelve volunteers applied three hand-rubs containing 95% (hand-rub A), 85% (hand-rub B) and 55% ethanol (hand-rub C; all w/w). For hygienic hand disinfection, 4 mL were applied 20 times for 30 s, with 1 minute break between applications. For surgical hand disinfection, 20 mL of each hand rub was applied to hands and arms up to the level of the elbow 10 times for 3 minutes, with a break of 5 minutes between applications. Blood concentrations of ethanol and acetaldehyde were determined immediately prior and up to 90 minutes after application using head space gas chromatography.ResultsThe median of absorbed ethanol after hygienic hand disinfection was 1365 mg (A), 630 mg (B), and 358 mg (C). The proportion of absorbed ethanol was 2.3% (A), 1.1% (B), and 0.9% (C). After surgical hand disinfection, the median of absorbed ethanol was 1067 mg (A), 1542 mg (B), and 477 mg (C). The proportion of absorbed ethanol was 0.7% (A), 1.1% (B), and 0.5% (C). The highest median acetaldehyde concentration after 20 hygienic hand disinfections was 0.57 mg/L (hand-rub C, after 30 min), after 10 surgical hand disinfections 3.99 mg/L (hand-rub A, after 20 minutes).ConclusionThe overall dermal and pulmonary absorption of ethanol was below toxic levels in humans and allows the conclusion that the use of the evaluated ethanol-based hand-rubs is safe.

Metatarsal reconstruction with use of free vascularized osteomyocutaneous fibular grafts following resection of malignant tumors of the midfoot. A series of six cases.

BACKGROUND Bone and soft-tissue sarcomas are uncommon, and their location in the foot is extremely rare. While limb salvage has become the standard of care in the treatment of sarcoma in an extremity, the unique anatomy of the foot presents challenges in reconstructing a viable and functional limb. METHODS Between 1998 and 2005, we used free microvascularized osteomyocutaneous fibular grafts to reconstruct the defects created after extensive midfoot resection in six consecutive patients with a primary malignant tumor. In all but one patient, the extent of the resection involved at least two metatarsals. The mean age (and standard deviation) at the time of the operation was 30+/-13 years. At the final follow-up examination, clinical and radiographic evaluations were performed on all patients, and functional outcome and quality of life were assessed with use of the Musculoskeletal Tumor Society score, the American Orthopaedic Foot and Ankle Society Score, and the Toronto Extremity Salvage Score. RESULTS The median duration of follow-up was 52.2 months. Limb salvage was achieved in five patients. In the remaining patient, amputation was necessary because of flap failure. Revision surgery was necessary in all patients because of complications (skin ulcerations in three patients; hematoma in two patients; and infection, necrosis of the second toe, and flap necrosis in one patient each). At the time of final follow-up, five patients had satisfactory function and reported good quality of life. The average Musculoskeletal Tumor Society, American Orthopaedic Foot and Ankle Society, and Toronto Extremity Salvage scores were 82%, 75 points, and 92%, respectively. At the time of the final follow-up, five patients had no evidence of disease and one patient had disease. CONCLUSIONS Following the resection of a malignant tumor in the midfoot, the use of microvascularized osteomyocutaneous fibular grafts has proven to be a successful surgical technique, offering an alternative to ablative surgery with functional restoration of the salvaged limb.

Reconstructing the extensor apparatus with a new polyester ligament

We analyzed the clinical outcome of patients who had reconstruction of the extensor apparatus with a new polyester ligament after extensive resection of malignant tumors around the knee. Twenty-two patients were included; 19 were evaluated after a mean followup of 44 months (range, 8-67 months) to assess active and passive knee range of motion, walking ability, need for revision, and TESS and Enneking scores. The patients were divided into two groups; patients in Group A had a weakened extensor mechanism and patients in Group B had a completely dissected extensor mechanism. Seven patients had excellent knee function with an extension lag less than 5°. Five patients had an extension deficit less than 20°, three patients had a deficit less than 40°, and four patients could not extend their limb against gravity. However, all patients were able to walk without walking aids. They had a mean Enneking score of 83 points and a mean TESS score of 82 points. Patients who had distal femur resections had worse results than patients who had proximal tibia resections. The LARS® ligament proved promising for augmentation and complete reconstruction of the extensor apparatus of the knee after extensive tumor resection, with excellent and good results in 59% of patients.Level of Evidence: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Microarray analysis identifies distinct gene expression profiles associated with histological subtype in human osteosarcoma

Osteosarcoma is the most common primary malignant bone tumour. Currently osteosarcoma classification is based on histological appearance. It was the aim of this study to use a more systematic approach to osteosarcoma classification based on gene expression analysis and to identify subtype specific differentially expressed genes. We analysed the global gene expression profiles of ten osteosarcoma samples using Affymetrix U133A arrays (five osteoblastic and five non-osteoblastic osteosarcoma patients). Differential gene expression analysis yielded 75 genes up-regulated and 97 genes down-regulated in osteoblastic versus non-osteoblastic osteosarcoma samples, respectively. These included genes involved in cell growth, chemotherapy resistance, angiogenesis, steroid- and neuropeptide hormone receptor activity, acute-phase response and serotonin receptor activity and members of the Wnt/ß-catenin pathway and many others. Furthermore, we validated the highly differential expression of six genes including angiopoietin 1, IGFBP3, ferredoxin 1, BMP, decorin, and fibulin 1 in osteoblastic osteosarcoma relative to non-osteoblastic osteosarcoma. Our results show the utility of gene expression analysis to study osteosarcoma subtypes, and we identified several genes that may play a role as potential therapeutic targets in the future.

Expression of the melatonin receptor (MT) 1 in benign and malignant human bone tumors

Abstract:  The beneficial effects of melatonin on bone homeostasis have been shown in various diseases. As this indoleamine causes dose‐dependent modulation of bone‐forming osteoblast and bone‐resorbing osteoclast activities by receptor‐independent and ‐dependent pathways, we investigated the expression of G‐protein‐coupled melatonin receptors (MTs) in malignant and non‐malignant human bone lesions. By TaqMan polymerase chain reaction (PCR), we analyzed 30 specimens from osteosarcoma and 11 from benign bone tumors for MT1‐mRNA expression. Furthermore, we determined mRNA expression levels of the osteoclast activity‐stimulating receptor activator of nuclear factor‐κ B ligand (RANKL) and its counterpart osteoprotegerin (OPG). Although mean MT1‐mRNA levels were similar (P = 0.596) in malignant (4.39 ± 4.98‐fold) and benign samples (4.64 ± 6.81‐fold), the highest MT1‐mRNA levels (up to 27‐fold) were observed in individual osteosarcomas, particularly, in two specimens of patients with local recurrence of the tumor. Moreover, mean RANKL‐ and OPG‐mRNA levels were similar in malignant and benign specimens (RANKL: 7.38 ± 9.61‐fold versus 3.57 ± 3.11‐fold, P = 0.207; OPG: 23.45 ± 32.76 versus 8.07 ± 7.23‐fold, P = 0.133). Again, highest RANKL‐ and OPG‐mRNA levels (up to 41‐ and 160‐fold, respectively) were observed in individual osteosarcomas. Expression of MT1‐mRNA was confirmed in two human osteosarcoma cell lines (HOS, MG63). High expression levels of MT1‐mRNA together with low OPG‐mRNA were found in both osteosarcoma cell lines, while in normal human osteoblasts and bone marrow stromal cells, high OPG‐mRNA levels were associated with low MT1‐mRNA levels. These data on the abundant expression of MT1‐mRNA in human bone tumors and osteosarcoma cells lines suggest an important role for MT1 in bone pathology.

Treatment and outcome of parosteal osteosarcoma: biological versus endoprosthetic reconstruction.

Due to its good prognosis despite local recurrence, more and less invasive methods for surgical treatment of parosteal osteosarcoma (POS) have been described. Aim of this retrospective single‐center study was to investigate differences in outcome after biological and prosthetic reconstruction.

Implications of staffing ratios and workload limitations on healthcare-associated infections and the quality of patient care.

843–846 4. Diebel L, Wilson RF, Heins J, et al: Enddiastolic volume versus pulmonary artery wedge pressure in evaluating cardiac preload in trauma patients. J Trauma 1994; 37:950–955 5. Hansen RM, Viquerat CE, Matthay MA, et al: Poor correlation between pulmonary arterial wedge pressure and left ventricular end diastolic volume after coronary artery bypass graft surgery. Anesthesiology 1986; 64: 764–770 6. Michard F, Teboul JL: Predicting fluid responsiveness in ICU patients. Chest 2002; 121:2000–2008 7. Kumar A, Anel R, Bunnell E, et al: Pulmonary artery occlusion pressure and central venous pressure fail to predict ventricular filling volume, cardiac performance, or the response to volume infusion in normal subjects. Crit Care Med 2004; 32:691–699 8. Michard F, Alaya S, Zarka V, et al: Global end-diastolic volume as an indicator of cardiac preload in patients with septic shock. Chest 2003; 124:1900–1908 9. The National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network; Wheeler AP, Bernard GR, Thompson BT, et al: Pulmonary-artery versus central venous catheter to guide treatment of acute lung injury. N Engl J Med 2006; 354:2213–2224 10. Osman D, Ridel C, Ray P, et al: Cardiac filling pressures are not appropriate to predict hemodynamic response to volume challenge. Crit Care Med 2007; 35:64–68 11. Ognibene FP, Parker MM, Natanson C, et al: Depressed left ventricular performance in response to volume infusion in patients with sepsis and septic shock. Chest 1988; 93: 903–910 12. The National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network; Wiedemann HP, Wheeler AP, Bernard GR, et al: Comparison of two fluid-management strategies in acute lung injury. N Engl J Med 2006; 354: 2564–2575

Splint Sterilization—A Potential Registration Hazard in Computer-Assisted Surgery

PURPOSE Registration of preoperative targeting information for the intraoperative situation is a crucial step in computer-assisted surgical interventions. Point-to-point registration using acrylic splints is among the most frequently used procedures. There are, however, no generally accepted recommendations for sterilization of the splint. An appropriate method for the thermolabile splint would be hydrogen peroxide-based plasma sterilization. This study evaluated the potential deformation of the splint undergoing such sterilization. Deformation was quantified using image-processing methods applied to computed tomographic (CT) volumes before and after sterilization. MATERIALS AND METHODS An acrylic navigation splint was used as the study object. Eight metallic markers placed in the splint were used for registration. Six steel spheres in the mouthpiece were used as targets. Two CT volumes of the splint were acquired before and after 5 sterilization cycles using a hydrogen peroxide sterilizer. Point-to-point registration was applied, and fiducial and target registration errors were computed. Surfaces were extracted from CT scans and Hausdorff distances were derived. Effectiveness of sterilization was determined using Geobacillus stearothermophilus. RESULTS Fiducial-based registration of CT scans before and after sterilization resulted in a mean fiducial registration error of 0.74 mm; the target registration error in the mouthpiece was 0.15 mm. The Hausdorff distance, describing the maximal deformation of the splint, was 2.51 mm. Ninety percent of point-surface distances were shorter than 0.61 mm, and 95% were shorter than 0.73 mm. No bacterial growth was found after the sterilization process. CONCLUSION Hydrogen peroxide-based low-temperature plasma sterilization does not deform the splint, which is the base for correct computer-navigated surgery.