Prevalence of exclusive lower extremity metastases at 18F-NaF PET/CT

AbstractObjective:To evaluate the prevalence of exclusive lower extremity metastases, specifically in the femur and below the knee, observed at 18F-NaF PET/CT.Materials and Methods:One thousand consecutive PET/CT studies were retrospectively evaluated for the presence of exclusive uptake in lower extremities suggesting metastatic involvement. The presumptive diagnoses based on such uptakes were subsequently obtained by evaluation of other imaging studies.Results:No exclusive uptake suggestive of metastasis below the femur was observed in the present series. Exclusive uptake was observed in the proximal femur with a presumptive diagnosis of metastasis in two patients.Conclusion:The prevalence of exclusive metastasis below the femur is low and scanning from head to knees is appropriate in most cases.

Rotational assessment of distal femur and its relevance in total knee arthroplasty: analysis by magnetic resonance imaging

AbstractObjective:To define the distal femur rotation pattern in a Brazilian population, correlating such pattern with the one suggested by the arthroplasty instruments, and analyzing the variability of each anatomic parameter.Materials and Methods:A series of 101 magnetic resonance imaging studies were evaluated in the period between April and June 2012. The epidemiological data collection was performed with the aid of the institution's computed imaging system, and the sample included 52 male and 49 female patients. The measurements were made in the axial plane, with subsequent correlation and triangulation with the other plans. The posterior condylar line was used as a reference for angle measurements. Subsequently, the anatomical and surgical transepicondylar axes and the anteroposterior trochlear line were specified. The angles between the reference line and the studied lines were calculated with the aid of the institution's software.Results:The mean angle between the anatomical transepicondylar axis and the posterior condylar line was found to be 6.89°, ranging from 0.25° to 12°. For the surgical transepicondylar axis, the mean value was 2.89°, ranging from –2.23° (internal rotation) to 7.86°, and for the axis perpendicular to the anteroposterior trochlear line, the mean value was 4.77°, ranging from –2.09° to 12.2°.Conclusion:The anatomical transepicondylar angle showed mean values corresponding to the measurement observed in the Caucasian population. The utilized instruments are appropriate, but no anatomical parameter proved to be steady enough to be used in isolation.

Low-level laser therapy for the prevention of low salivary flow rate after radiotherapy and chemotherapy in patients with head and neck cancer

Abstract Objective: To determine whether low-level laser therapy can prevent salivary hypofunction after radiotherapy and chemotherapy in head and neck cancer patients. Materials and Methods: We evaluated 23 head and neck cancer patients, of whom 13 received laser therapy and 10 received clinical care only. An InGaAlP laser was used intra-orally (at 660 nm and 40 mW) at a mean dose of 10.0 J/cm2 and extra-orally (at 780 nm and 15 mW) at a mean dose of 3.7 J/cm2, three times per week, on alternate days. Stimulated and unstimulated sialometry tests were performed before the first radiotherapy and chemotherapy sessions (N0) and at 30 days after the end of treatment (N30). Results: At N30, the mean salivary flow rates were significantly higher among the laser therapy patients than among the patients who received clinical care only, in the stimulated and unstimulated sialometry tests (p = 0.0131 and p = 0.0143, respectively). Conclusion: Low-level laser therapy, administered concomitantly with radiotherapy and chemotherapy, appears to mitigate treatment-induced salivary hypofunction in patients with head and neck cancer.

Using computational fluid dynamics to predict head losses in the auxiliary elements of a microirrigation sand filter

It is often assumed that total head losses in a sand filter are solely due to the filtration media and that there are analytical solutions, such as the Ergun equation, to compute them. However, total head losses are also due to auxiliary elements (inlet and outlet pipes and filter nozzles), which produce undesirable head losses because they increase energy requirements without contributing to the filtration process. In this study, ANSYS Fluent version 6.3, a commercial computational fluid dynamics (CFD) software program, was used to compute head losses in different parts of a sand filter. Six different numerical filter models of varying complexities were used to understand the hydraulic behavior of the several filter elements and their importance in total head losses. The simulation results show that 84.6% of these were caused by the sand bed and 15.4% were due to auxiliary elements (4.4% in the outlet and inlet pipes, and 11.0% in the perforated plate and nozzles). Simulation results with different models show the important role of the nozzles in the hydraulic behavior of the sand filter. The relationship between the passing area through the nozzles and the passing area through the perforated plate is an important design parameter for the reduction of total head losses. A reduced relationship caused by nozzle clogging would disproportionately increase the total head losses in the sand filter

HPV & head and neck cancer: a descriptive update

The incidence of head and neck squamous cell carcinoma (HNSCC) has been gradually increasing over the last three decades. Recent data have now attributed a viral aetiology to a subset of head and neck cancers. Several studies indicate that oral human papillomavirus (HPV) infection is likely to be sexually acquired. The dominance of HPV 16 in HPV+ HNSCC is even greater than that seen in cervical carcinoma of total worldwide cases. Strong evidence suggests that HPV+ status is an important prognostic factor associated with a favourable outcome in head and neck cancers. Approximately 30 to 40% of HNSCC patients with present with early stage I/II disease. These patients are treated with curative intent using single modality treatments either radiation or surgery alone. A non-operative approach is favored for patients in which surgery followed by either radiation alone or radiochemotherapy may lead to severe functional impairment. Cetuximab, a humanized mouse anti-EGFR IgG1 monoclonal antibody, improved locoregional control and overall survival in combination with radiotherapy in locally advanced tumours but at the cost of some increased cardiac morbidity and mortality. Finally, the improved prognosis and treatment responses to chemotherapy and radiotherapy by HPV+ tumours may suggest that HPV status detection is required to better plan and individualize patient treatment regimes.

Tacrolimus vs. Azathioprine in myasthenia gravis treatment: a multicenter, prospective, randomized, double blind, head to head clinical trial

Current evidences show that tacrolimus could be a good therapeutic option in patients non-responsive to first-line treatments and even it could become one of the first-line drugs for treating MG. Our study will try to determine the effectivity and safety of tacrolimus in 190 myasthenia gravis patients with suboptimal response to azathioprine: after 12 months of treatment they will be randomized to continue with azathioprine or they will be switched to tacrolimus. Patients will follow the allocated treatment during 14 months and the response will be assessed as well as adverse effectsPURPOSE: To compare azathioprine vs. tacrolimus effectivity and safety in MG patients with suboptimal response to azathioprine at 12 monthsDESIGN: A 14 months multicenter, prospective, randomized, double blind, head to head clinical trial

Structural development of the harvester head saw unit

The main goal of the thesis was to further develop harvester head saw device to the Finnish forest machine manufacturer. The work was done from the basis of the manufacturer´s current production model and the earlier study from this same subject called: “Development of chain saw for harvester” Tero Kaatrasalo, 2004. The work was focused to improving the serviceability and reliability of the saw device, but design also included adding few beforehand determined new features into the saw unit. This was done to give some added value for the end customer. The work includes analysis of the earlier saw devices and ideations of the improvements for the structure.

Free Flap Monitoring. Using Tissue Oxygen Measurement and Positron Emission Tomography

Aims:This study was carried out to evaluate the feasibility of two different methods to determine free flap perfusion in cancer patients undergoing major reconstructive surgery. The hypotheses was that low perfusion in the flap is associated with flap complications. Patients and methods: Between August 2002 and June 2008 at the Department of Otorhinolaryngology – Head and Neck Surgery, Department of Surgery, and at the PET Centre, Turku, 30 consecutive patients with 32 free flaps were included in this study. The perfusion of the free microvascular flaps was assessed with positron emission tomography (PET) and radioactive water ([¹⁵O] H₂O) in 40 radiowater injections in 33 PET studies. Furthermore, 24 free flaps were monitored with a continuous tissue oxygen measurement using flexible polarographic catheters for an average of three postoperative days. Results: Of the 17 patients operated on for head and neck (HN) cancer and reconstructed with 18 free flaps, three re-operations were carried out due to poor tissue oxygenation as indicated by p_tiO₂ monitoring results and three other patients were reoperated on for postoperative hematomas in the operated area. Blood perfusion assessed with PET (BF_PET) was above 2.0 mL / min / 100 g in all flaps and a low flap-to-muscle BFPET ratio appeared to correlate with poor survival of the flap. Survival in this group of HN cancer patients was 9.0 months (median, range 2.4-34.2) after a median follow-up of 11.9 months (range 1.0-61.0 months). Seven HN patients of this group are alive without any sign of recurrence and one patient has died of other causes. All of the 13 breast reconstruction patients included in the study are alive and free of disease at a median follow-up time of 27.4 months (range 13.9-35.7 months). Re-explorations were carried out in three patients due data provided by p_tiO₂ monitoring and one re-exploration was avoided on the basis of adequate blood perfusion assessed with PET. Two patients had donorsite morbidity and 3 patients had partial flap necrosis or fat necrosis. There were no total flap losses. Conclusions: P_tiO₂ monitoring is a feasible method of free flap monitoring when flap temperature is monitored and maintained close to the core temperature. When other monitoring methods give controversial results or are unavailable, [₁₅O] H₂O PET technique is feasible in the evaluation of the perfusion of the newly reconstructed free flaps.

Detection and partial characterization of a carlavirus causing stem necrosis of soybean in Brazil

Stunting and stem necrosis were noticed in soybeans (Glycine max) grown in 2000/2001 in West Central Brazil the same condition was also observed in the following year in plantations as far as 2,000 km from the initial area. Based on transmission (mechanical, graft, insect vector), purification and serology, electron microscopy and molecular studies the causal agent was determined to be a whitefly-borne carlavirus which is possibly related to Cowpea mild mottle virus (CpMMV).

A risk infection simulation model for fusarium head blight of wheat

Fusarium Head Blight (FHB) is a disease of great concern in wheat (Triticum aestivum). Due to its relatively narrow susceptible phase and environmental dependence, the pathosystem is suitable for modeling. In the present work, a mechanistic model for estimating an infection index of FHB was developed. The model is process-based driven by rates, rules and coefficients for estimating the dynamics of flowering, airborne inoculum density and infection frequency. The latter is a function of temperature during an infection event (IE), which is defined based on a combination of daily records of precipitation and mean relative humidity. The daily infection index is the product of the daily proportion of susceptible tissue available, infection frequency and spore cloud density. The model was evaluated with an independent dataset of epidemics recorded in experimental plots (five years and three planting dates) at Passo Fundo, Brazil. Four models that use different factors were tested, and results showed all were able to explain variation for disease incidence and severity. A model that uses a correction factor for extending host susceptibility and daily spore cloud density to account for post-flowering infections was the most accurate explaining 93% of the variation in disease severity and 69% of disease incidence according to regression analysis.

Targeting Adenoviral Gene Therapy Vectors to Head and Neck Squamous Cell Carcinoma and Heart

Gene therapy aims to treat diseases by introducing genetic material to the diseased tissue. For cancer treatment it is important to destroy cancerous cells; this can be achieved by introducing a gene, which induces cell death or by allowing viral vectors to replicate, which also results in destruction of cancerous cells. For cardiac diseases the approach is more like the former, except the gene produces beneficial effects, like angiogenesis. Adenoviruses have many beneficial qualities, which make the virus an interesting gene therapy vector; it can be produced relatively easily, its manipulation is quite easy and it has naturally broad tropism. By removing or replacing certain genes in the adenoviral genome, it can be made non-replicative. In this study, adenoviral receptor expression patterns were characterized in both head and neck squamous cell carcinoma and the human heart. Adenovirus serotype 5 receptor expression in head and neck cancer cell lines was found to be highly variable between cell lines and overall at lower levels, while Ad35 receptor expression was more uniform and at higher levels in all analyzed cell lines. It was also shown that a hybrid virus Ad5/35 is able to infect cells refractory to Ad5, which correlates with receptor expression in these cells. Furthermore, this difference in infection properties extends to cell killing efficiency in case of conditionally replicative viruses. Expression levels of adenoviral receptors CAR, CD46, CD86 and αv-integrins were found to be high both in normal and dilated cardiomyopathy heart tissue. The receptor levels also correlate with transduction efficiency after intracardiac injection. Ad5 showed superior transduction ability compared with Ad5/35, but evoked also a more profound immune reaction when administered this way. Adenoviral gene therapy vectors are the most used delivery vehicles in clinical trials to date. These vectors have proven to be well tolerated and positive results have been obtained when combined with traditional treatments, although poor transduction efficiency has often been reported due to low-level expression of viral receptors on target cells. In spite of this, the results are encouraging and merit for further research.