Superiority of manual disinfection using pre-soaked wipes over automatic UV-C radiation without prior cleaning.

BACKGROUND: The efficacy of ultraviolet C (UV-C) radiation against a broad spectrum of micro-organisms has been demonstrated in several studies, but differences in the specific doses and the extent of microbial reduction were found. Furthermore, the conditions of laboratory tests differ greatly from reality, such that efficacy achieved in tests may not necessarily be assumed in reality. Consequently, it is important to investigate the effectiveness of UV-C in representative field trials. The aim was therefore to develop and establish a field test to evaluate automatic UV-C in comparison to manual disinfection. METHODS: Before and after disinfection, samples were repeatedly collected from naturally highly contaminated surfaces using the swab technique to obtain representative data sets for disinfected and non-disinfected surfaces. Subsequently, the log reduction values (LRV) and the disinfection success were evaluated for UV-C radiation and full compliant manual disinfection using alcohol-based wipes. RESULTS: Surfaces that are naturally contaminated with bacteria on a regular and nearly uniform basis have been identified as particularly suitable for field testing. Mean contamination was reduced from 23.3 to 1.98 cfu/cm2 (LRV 0.9) and 29.7 to 0.26 cfu/cm2 (LRV 1.2) for UV-C and manual disinfection, respectively. UV-C disinfection achieved 75.5% successful disinfected surfaces, whereas manual disinfection showed 98.1%. CONCLUSIONS: Full compliant manual disinfection showed slightly higher LRVs and disinfection success than automatic UV-C disinfection. Successful, operator-independent UV-C disinfection still has the potential to improve disinfection performance in addition to manual disinfection.

Tolerance of clinical vancomycin-resistant Enterococcus faecium isolates against UV-C light from a mobile source.

BACKGROUND: Admission to a room previously occupied by patients carrying environmentally robust pathogens implies an increased risk of acquiring those pathogens. Therefore, 'No-touch' automated room disinfection systems, including devices based on UV-C irradiation, are discussed to improve terminal cleaning. It is still unclear if clinical isolates of relevant pathogens behave differently under UV-C irradiation compared to laboratory strains used in the approval process of disinfection procedures. In this study we analysed the susceptibility of well characterized clonally divergent vancomycin-resistant enterococci (VRE) strains, including a linezolid-resistant isolate, against UV-C radiation. METHODS: Susceptibility against UV-C of ten clonally divergent clinical isolates of VRE was determined in comparison to the commonly used test organism Enterococcus hirae ATCC 10541. Ceramic tiles contaminated with 105 to 106 colony forming units/25 cm² of the different enterococci were positioned at a distance of 1.0 and 1.5 m and irradiated for 20 s, resulting in a UV-C dose of 50 and 22 mJ/cm², respectively. Reduction factors were calculated after quantitative culture of the bacteria recovered from treated and untreated surfaces. RESULTS: Susceptibility to UV-C varied considerably among the strains studied, with the mean value of the most robust strain being up to a power of ten lower compared to the most sensitive strain at both UV-C doses. The two most tolerant strains belonged to MLST sequence types ST80 and ST1283. The susceptibility of the laboratory strain E. hirae ATCC 10541 ranged between the most sensitive and most tolerant isolates for both irradiation doses. However, for UV-C dose of 22 mJ/cm², the reduction of the most tolerant isolate of ST1283 was statistically significantly lower compared to E. hirae ATCC 10541. The most susceptible strains belonged to the MLST sequence types ST117 and ST203. CONCLUSIONS: These results indicate that UV-C doses reported in the literature are sufficient for the reduction of commonly used reference strains of enterococci but could be insufficient for the reduction of tolerant patient VRE-isolates in a hospital setting. Therefore, for future studies, the most tolerant clinical isolates should be used to validate automated UV-C devices or longer exposure times should be expected to ensure efficacy in the real world.

Remote Individual Addressing of Quantum Emitters with Chirped Pulses.

We propose to use chirped pulses propagating near a band gap to remotely address quantum emitters. We introduce a particular family of chirped pulses that dynamically self-compress to subwavelength spot sizes during their evolution in a medium with a quadratic dispersion relation. We analytically describe how the compression distance and width of the pulse can be tuned through its initial parameters. We show that the interaction of such pulses with a quantum emitter is highly sensitive to its position due to effective Landau-Zener processes induced by the pulse chirping. Our results propose pulse engineering as a powerful control and probing tool in the field of quantum emitters coupled to structured reservoirs.

Circumventing Magnetostatic Reciprocity: A Diode for Magnetic Fields.

Lorentz reciprocity establishes a stringent relation between electromagnetic fields and their sources. For static magnetic fields, a relation between magnetic sources and fields can be drawn in analogy to the Green's reciprocity principle for electrostatics. So far, the magnetostatic reciprocity principle remains unchallenged and the magnetostatic interaction is assumed to be symmetric (reciprocal). Here, we theoretically and experimentally show that a linear and isotropic electrically conductive material moving with constant velocity is able to circumvent the magnetostatic reciprocity principle and realize a diode for magnetic fields. This result is demonstrated by measuring an extremely asymmetric magnetic coupling between two coils that are located near a moving conductor. The possibility to generate controlled unidirectional magnetic couplings implies that the mutual inductances between magnetic elements or circuits can be made extremely asymmetric. We anticipate that this result will provide novel possibilities for applications and technologies based on magnetically coupled elements and might open fundamentally new avenues in artificial magnetic spin systems.

Critical Thermalization of a Disordered Dipolar Spin System in Diamond.

Statistical mechanics underlies our understanding of macroscopic quantum systems. It is based on the assumption that out-of-equilibrium systems rapidly approach their equilibrium states, forgetting any information about their microscopic initial conditions. This fundamental paradigm is challenged by disordered systems, in which a slowdown or even absence of thermalization is expected. We report the observation of critical thermalization in a three dimensional ensemble of ∼10^{6} electronic spins coupled via dipolar interactions. By controlling the spin states of nitrogen vacancy color centers in diamond, we observe slow, subexponential relaxation dynamics and identify a regime of power-law decay with disorder-dependent exponents; this behavior is modified at late times owing to many-body interactions. These observations are quantitatively explained by a resonance counting theory that incorporates the effects of both disorder and interactions.

Ultrafocused Electromagnetic Field Pulses with a Hollow Cylindrical Waveguide.

We theoretically show that a dipole externally driven by a pulse with a lower-bounded temporal width, and placed inside a cylindrical hollow waveguide, can generate a train of arbitrarily short and focused electromagnetic pulses. The waveguide encloses vacuum with perfect electric conducting walls. A dipole driven by a single short pulse, which is properly engineered to exploit the linear spectral filtering of the cylindrical hollow waveguide, excites longitudinal waveguide modes that are coherently refocused at some particular instances of time, thereby producing arbitrarily short and focused electromagnetic pulses. We numerically show that such ultrafocused pulses persist outside the cylindrical waveguide at distances comparable to its radius.

Assessment of liposome bupivacaine infiltration versus continuous femoral nerve block for postsurgical analgesia following total knee arthroplasty: a retrospective cohort study.

OBJECTIVE: Perioperative pain management is an important aspect of recovery from total knee arthroplasty (TKA) because severe pain can delay ambulation and hospital discharge. The objective of this retrospective sequential cohort study was to determine the impact of local infiltration analgesia using liposome bupivacaine (Exparel 1 ) when compared with a continuous femoral nerve block (FNB) following TKA. METHODS: This retrospective cohort study included consecutive patients who underwent TKA between April 2011 and April 2014, and received one of three interventions. Study Group A received adductor canal infiltration with bupivacaine HCl and knee infiltration with liposome bupivacaine. Study Group B received adductor canal infiltration with liposome bupivacaine and knee infiltration with liposome bupivacaine. The control group received a continuous FNB with ropivacaine HCl delivered via an elastomeric pump. Numeric pain rating scores (NPRS), distance walked, length of stay (LOS), and dose of narcotic medication were the key efficacy variables of interest. RESULTS: A total of 237 patients were included in this study: 98 in Group A, 34 in Group B, and 105 controls. On postoperative day (POD) 0, mean (standard deviation [SD]) NPRSs were similar between Group A (1.8 [1.7]), Group B (2.7 [1.8]), and the control group (2.3 [2.4]). Significantly (p < 0.05) more patients in Group A (58%) and Group B (44%) walked on POD0 than in the control group (0%); almost all patients walked on POD1. The mean (SD) distance walked was also significantly greater (p < 0.05) on POD1 in Group A (193 [203] feet) and Group B (211 [144] feet) than in the control group (46 [73] feet). Mean (SD) LOS was significantly (p < 0.05) shorter in Group B (2.2 [1.2] days), than in the control group (3.2 [0.7] days) and Group A (3.0 [1.7] days). CONCLUSIONS: Local infiltration analgesia using liposome bupivacaine was associated with improved ambulation and shorter LOS following TKA when compared with continuous FNB in this retrospective cohort study.

[Usability testing of the canal expander - a new implant for canaloplasty]. / Gebrauchstauglichkeitstest des Kanal-Expander - ein neues Implantat für die Kanaloplastik.

BACKGROUND: Canaloplasty is a bleb-independent glaucoma surgery in which Schlemm's canal is dilated with a microcatheter and viscoelastic material, and stretched by a tensioning suture. The suture stent has numerous drawbacks such as the technical challenging implantation, deficient knowledge of proper suture tension, late loosening of the suture, or suture extrusion into the anterior chamber. The Stegmann Canal Expander (SCE) was developed to replace the suture stent and to make canaloplasty easier and more reproducible. The aim of this test was evaluate the usability regarding effectiveness, efficacy, and satisfaction of the implanting ophthalmologist (test person). METHODS: In an experimental setting, the test persons were asked to implant the SCE in human autopsy eyes with a surgically prepared Schlemm's canal by means of surgical instruments and an operating microscope. The standardised test was performed in terms of participant observation with a subsequent opinion survey based on checklist and photographic documentation. Data for a successful handling of the task and qualitative data from the experience of the test person with the product were anonymised, collected and registered in an assessment sheet. The evaluation comprised the aspects of instructions for use, packaging, identification, handling, and implantation of the SCE. RESULTS: The implantation took 2 to 5 min (mean: 3 min). All questions in the assessment sheet regarding effectiveness, efficacy, and satisfaction (n=35) were answered by all test persons (6/6) with the best category ("completely true"; or "no, no problem"). CONCLUSIONS: The usability of the SCE under standardised and experimental conditions regarding effectiveness, efficacy, and satisfaction has been rated as very positive, especially allowing for the fact that some of the ophthalmologists did not have experience in glaucoma surgery or only little experience in ophthalmic surgery.

Factors associated with therapeutic success in HIV-positive individuals in southern Brazil.

WHAT IS KNOWN AND OBJECTIVE: Therapeutic success is characterized by undetectable viral load, immune reconstitution confirmed by CD4+ T-cell count and no clinical manifestations of disease. High treatment adherence is a major determinant of therapeutic success that needs prevention of viral replication, allowing immune reconstitution. Adherence to treatment <95% has been associated with both immune and viral failure. The objective of this study was to evaluate factors associated with therapeutic success in adult patients on highly active antiretroviral therapy (HAART) in a specialized centre for HIV-AIDS in southern Brazil, being defined therapeutic success as achieving and maintaining undetectable viral load, stable immune status (CD4+ T lymphocyte count ≥200 cells/mm(3) ) and adherence to HAART ≥ 95%. METHODS: We conducted a historical cohort study nested in the PC-HIV randomized clinical trial of PC-HIV. We included adults who were on HAART at Pelotas HIV/AIDS Assistance Service between June 2006 and July 2007 and for whom information on treatment adherence, viral load and CD4+ cell count was available. Pregnant women were excluded. We obtained clinical data from medical records and socio-demographic information in an interview. Therapeutic success was defined as achieving and maintaining undetectable viral load, stable immune status (CD4+ T lymphocyte count ≥200 cells/mm(3) ) and adherence to HAART ≥95%. RESULTS AND DISCUSSION: We included 136 patients (60% male) in the cohort study. Mean age was 40 ± 10 years, and median treatment duration was 59 months (IQR 25-93). Family income varied from 0 to 8 times the minimum wage (IQR 1·0-2·3). Therapeutic success was achieved by 90% (122 patients), and it was associated with previously undetectable viral load (PR = 1·30; 95% CI = 1·13-1·49) and treatment adherence prior to study entry (PR = 1·34; 95% CI = 1·07-1·69), independently of sex, age and previous immune status. WHAT IS NOW AND CONCLUSION: When undetectable viral load, CD4+ cell count ≥200 cells/mm(3) and treatment adherence above 95% are included in the definition of therapeutic success, the rate was elevated (90%) and the factors associated were previous history of adherence to HAART and previous undetectable viral load.

Practitioner experience with sonic osteotomy compared to bur and ultrasonic saw: a pilot in vitro study.

The aim of the present study was to compare subjective experiences using bur, ultrasonic, and sonic osteotomy systems. Ten novice (N) and 10 expert (E) practitioners performed osteotomies on bovine ribs with each system. They scored ease of handling and sense of accuracy on visual analogue scales. The duration of the osteotomy procedure and the amount of noise were recorded objectively. Learning experience was evaluated in a second run. The Mann-Whitney U-test, Wilcoxon signed rank tests, and Spearman's rank correlation coefficient were used for the statistical analyses. The sonic system was significantly slower, with the worst noise impact (92.9dB; standard deviation (SD) 7.1). However, both user groups improved significantly in the second run (N 7.9, E 7.6). There were no significant differences in handling. The sense of accuracy was evaluated to be significantly best for the sonic system (N 8.4, E 8.4), compared to the ultrasonic system (N 7.1, E 7.1; both P=0.043) and bur system (N 5.5, P=0.002; E 6.0, P=0.006). The practitioners had a promising experience with the application of the ultrasonic system and particularly with the sonic system.

Nanometre-scale thermometry in a living cell.

Sensitive probing of temperature variations on nanometre scales is an outstanding challenge in many areas of modern science and technology. In particular, a thermometer capable of subdegree temperature resolution over a large range of temperatures as well as integration within a living system could provide a powerful new tool in many areas of biological, physical and chemical research. Possibilities range from the temperature-induced control of gene expression and tumour metabolism to the cell-selective treatment of disease and the study of heat dissipation in integrated circuits. By combining local light-induced heat sources with sensitive nanoscale thermometry, it may also be possible to engineer biological processes at the subcellular level. Here we demonstrate a new approach to nanoscale thermometry that uses coherent manipulation of the electronic spin associated with nitrogen-vacancy colour centres in diamond. Our technique makes it possible to detect temperature variations as small as 1.8 mK (a sensitivity of 9 mK Hz(-1/2)) in an ultrapure bulk diamond sample. Using nitrogen-vacancy centres in diamond nanocrystals (nanodiamonds), we directly measure the local thermal environment on length scales as short as 200 nanometres. Finally, by introducing both nanodiamonds and gold nanoparticles into a single human embryonic fibroblast, we demonstrate temperature-gradient control and mapping at the subcellular level, enabling unique potential applications in life sciences.

Orbital haemorrhage associated with orbital fractures in geriatric patients on antiplatelet or anticoagulant therapy.

Retrobulbar haemorrhage is a sight-threatening condition that can occur after orbital trauma. The aim of this study was to evaluate the frequency and outcome of orbital haemorrhages following orbital fractures in geriatric patients receiving anticoagulants. All patients aged 65 years or more suffering from orbital fractures between 2008 and 2009 were included in this study. The mechanism of trauma, underlying diseases, and medication were recorded. In case of a retrobulbar haemorrhage, surgical exploration, the elapsed time between the onset of haemorrhage symptoms and surgical treatment, and the outcome regarding visual acuity were documented. Sixty-eight orbital fractures occurred (31 males, 37 females, age 65-95 years) resulting in six (3%) orbital haemorrhages. Four cases were associated with initial orbital bleeding, two other patients developed orbital haemorrhage as a complication after surgical reconstruction. Anticoagulant therapy, but not aspirin, was associated with a significantly increased risk of retrobulbar haematoma (p=0.02). Two patients permanently lost vision, two partial recoveries and two total recoveries were observed. Patients receiving anticoagulants have a higher risk of orbital haemorrhage after orbital fracture and should be monitored closely. Any evidence of visual impairment should lead to further investigation and prompt treatment.

[Painful and rapidly growing exophytic lesion of the vestibular upper lip]. / Schmerzhafte und rapid exophytisch wachsende Raumforderung der vestibulären Oberlippe.

A 49-year-old healthy woman presented with a painful exophytic-growing mucous lesion on her upper lip that had been primarily noted for 2 weeks. The biopsy showed histological changes of a dense infiltration of lymphoid cell elements. The immunohistological examination presented the diagnosis of primary cutaneous CD30-positive large cell T-cell lymphoma. In the diagnosis of oral lesions cutaneous CD30-positive large cell T-cell lymphoma constitutes a rare but important differential diagnosis.

Room-temperature quantum bit memory exceeding one second.

Stable quantum bits, capable both of storing quantum information for macroscopic time scales and of integration inside small portable devices, are an essential building block for an array of potential applications. We demonstrate high-fidelity control of a solid-state qubit, which preserves its polarization for several minutes and features coherence lifetimes exceeding 1 second at room temperature. The qubit consists of a single (13)C nuclear spin in the vicinity of a nitrogen-vacancy color center within an isotopically purified diamond crystal. The long qubit memory time was achieved via a technique involving dissipative decoupling of the single nuclear spin from its local environment. The versatility, robustness, and potential scalability of this system may allow for new applications in quantum information science.

Intra-arterial infusion of autologous bone marrow mononuclear cells in patients with moderate to severe middle cerebral artery acute ischemic stroke.

Transplantation of autologous bone marrow mononuclear cells (BMMCs) has been proven safe in animal and human studies. However, there are very few studies in stroke patients. In this study, intra-arterial autologous BMMCs were infused in patients with moderate to severe acute middle cerebral artery infarcts. The subjects of this study included 20 patients with early or late spontaneous recanalization but with persistent deficits, in whom treatment could be initiated between 3 and 7 days after stroke onset. Mononuclear cells were isolated from bone marrow aspirates and infused at the proximal middle cerebral artery of the affected hemisphere. Safety analysis (primary endpoint) during the 6-month follow-up assessed death, any serious clinical events, neurological worsening with ≥ 4-point increase in National Institutes of Health Stroke Scale (NIHSS) scores, seizures, epileptogenic activity on electroencephalogram, and neuroimaging complications including new ischemic, hemorrhagic, or neoplastic lesions. Satisfactory clinical improvement (secondary endpoint) at 90 days was defined according to the pretreatment NIHSS scores as follows: modified Rankin Scale score of 0 in patients with NIHSS <8, modified Rankin Scale scores of 0-1 in patients with NIHSS 8-14, or modified Rankin Scale scores 0-2 in patients with NIHSS >14. Good clinical outcome was defined as mRS ≤2 at 90 days. Serial clinical, laboratory, electroencephalogram, and imaging evaluations showed no procedure-related adverse events. Satisfactory clinical improvement occurred in 6/20 (30%) patients at 90 days. Eight patients (40%) showed a good clinical outcome. Infusion of intra-arterial autologous BMMCs appears to be safe in patients with moderate to severe acute middle cerebral artery strokes. No cases of intrahospital mortality were seen in this pilot trial. Larger prospective randomized trials are warranted to assess the efficacy of this treatment approach.

Scalable architecture for a room temperature solid-state quantum information processor.

The realization of a scalable quantum information processor has emerged over the past decade as one of the central challenges at the interface of fundamental science and engineering. Here we propose and analyse an architecture for a scalable, solid-state quantum information processor capable of operating at room temperature. Our approach is based on recent experimental advances involving nitrogen-vacancy colour centres in diamond. In particular, we demonstrate that the multiple challenges associated with operation at ambient temperature, individual addressing at the nanoscale, strong qubit coupling, robustness against disorder and low decoherence rates can be simultaneously achieved under realistic, experimentally relevant conditions. The architecture uses a novel approach to quantum information transfer and includes a hierarchy of control at successive length scales. Moreover, it alleviates the stringent constraints currently limiting the realization of scalable quantum processors and will provide fundamental insights into the physics of non-equilibrium many-body quantum systems.

Cell surface proteins in S. pneumoniae, S. mitis and S. oralis.

BACKGROUND AND OBJECTIVES: Streptococcus pneumoniae, a major human pathogen, is closely related to the commensal species S. mitis and S. oralis. S. pneumoniae surface proteins are implicated in virulence and host interaction of this species, but many of them have recently been detected in S. mitis B6 in silico. We tested for the presence of such genes usinga set of eight S. mitis and eleven S. oralis strains from different geographic locations. MATERIALS AND METHODS: An oligonucleotide microarray was designed based on the genomes of S. pneumoniae R6 and TIGR4 as well as S. mitis B6 to include 63 cell surface proteins. The S. pneumoniae genes encoding neuraminidases, hyaluronidase and pneumolysin were also included. In addition to comparative genomic hybridization experiments, homologues were identified in silico in the genome of S. oralis Uo5. RESULTS AND CONCLUSIONS: The results document that many S. pneumoniae related surface proteins are ubiquitously present among the Mitis group of streptococci. All 19 samples hybridized with the pavA probe representing a gene important for adherence and invasion of S. pneumoniae. Only eight genes were not recognized in any strain, including the S. pneumoniae PcpC gene as the only virulence gene of the S. pneumoniae core genome.The fact that only 12 out of 26 genes present in the S. oralis Uo5 genome could be detected by microarray analysis confirms the sequence variation of surface components.

Bisphosphonate-related osteonecrosis of the maxilla and sinusitis maxillaris.

Bisphosphonates (BPs) are widely used as bone-stabilizers, but side effects of BP therapy include bisphosphonate-related osteonecrosis of the jaw (BRONJ), which is resistant to therapy. The aim of this study was to evaluate the outcome of maxillary BRONJ involving sinusitis maxillaris. 21 patients presenting with maxillary BRONJ, from 2005 to 2008, were included in the study. In 18 cases BP had been administered for carcinoma and in 3 cases for osteoporosis, with an average exposure time of 47.4 months. 12 patients spontaneously developed BRONJ. The 10 patients diagnosed with stage III BRONJ presented with concomitant sinusitis maxillaris. Despite treatment, there were six recurrences of BRONJ, four of them with additional sinusitis maxillaris. Whether BRONJ occurred spontaneously or after extraction there was no difference in the outcome. Patients with advanced maxillary BRONJ often suffer from sinusitis maxillaris, both of which are frequently resistant to therapy.

Predictors of short-term outcome in brain-injured patients with disorders of consciousness.

OBJECTIVES: To investigate predictors of recovery from the vegetative state (VS) and minimally conscious state (MCS) after brain injury as measured by the widely used Disability Rating Scale (DRS) and to explore differences in rate of recovery and predictors of recovery during inpatient rehabilitation in patients with non-traumatic (NTBI) and traumatic brain injury (TBI). DESIGN: Longitudinal observational cohort design and retrospective comparison study, in which an initial DRS score was collected at the time of study enrollment. Weekly DRS scores were recorded until discharge from the rehabilitation center for both NTBI and TBI patients. SETTING: Seven acute inpatient rehabilitation facilities in the United States and Europe with specialized programs for VS and MCS patients (the Consciousness Consortium). PARTICIPANTS: One hundred sixty-nine patients with a non-traumatic (N=50) and a traumatic (N=119) brain injury who were in the VS or MCS states. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: DRS score at 13 weeks after injury; change in DRS score over 6 weeks post-admission; and time until commands were first followed (for patients who did not show command-following at or within 2 weeks of admission). RESULTS: Both time between injury and enrollment and DRS score at enrollment were significant predictors of DRS score at week 13 post-injury but the main effect of etiology only approached significance. Etiology was however a significant predictor of the amount of recovery observed over the 6 weeks following enrollment. Time between injury and enrollment was also a good predictor of this outcome, but not DRS score at enrollment. For the time until commands were first followed, patients with better DRS scores at enrollment, and those with faster early rates of change recovered command following sooner than those with worse DRS scores or slower initial rates of change. The etiology was not a significant predictor for this last outcome. None of these predictive models explained sufficient variance to allow their use in individual clinical decision making. CONCLUSIONS: Time post-injury and DRS score at enrollment are predictors of early recovery among patients with disorders of consciousness, depending on the outcome measure chosen. Etiology was also a significant predictor in some analyses, with traumatically injured patients recovering more than those with non-traumatic injuries. However, the hypothesized interaction between etiology and time post-injury did not reach significance in any of the analyses suggesting that, within the time frame studied, the decline in prognosis with the passage of time was similar in the two groups.

[Giant ameloblastoma of the jaw]. / Monströses Ameloblastom des Unterkiefers.

Ameloblastomas represent benign, epithelial alveolar tumors, which originate from epithelial enamel cells (ameloblasts). Due to their locally aggressive character, they may develop pathological significance. Radical surgery remains the therapy of choice. As demonstrated by the case of a 71-year-old patient with giant ameloblastoma of the upper jaw, early resection is recommended. The high propensity for recurrence demands long-term post-operative follow-up, since late recidive tumours may also occur.