Valor pronóstico de los parámetros metabólicos volumétricos del tumor primario y ganglios linfáticos en el PET/TC pretratamiento en el carcinoma nasofaríngeo / Prognostic value of primary tumor and lymph node volumetric metabolic parameters at pre-treatment F-18 FDG PET/CT in nasopharyngeal carcinoma

Objetivo El objetivo de este estudio fue evaluar el significado pronóstico de los parámetros metabólicos volumétricos de la PET/TC pretratamiento junto con las características clínicas en pacientes con carcinoma nasofaríngeo no metastásico. Material y métodos Setenta y nueve pacientes con carcinoma nasofaríngeo se sometieron a una PET/TC con [18F]FDG para evaluación previa al tratamiento y se incluyeron en este estudio. Se analizaron las características del paciente (edad, histopatología del tumor, estadio T/N, tamaño del tumor primario y ganglio cervical más grande) y parámetros PET: valores de captación estandarizados máximo, medio y pico (SUVmáx, SUVmean, SUVpico), volumen tumoral metabólico (MTV) y glucólisis de lesión total (TLG) para el tumor primario y el ganglio linfático cervical más grande. El análisis de supervivencia para la supervivencia libre de progresión (PFS) y la supervivencia global (OS) se realizó con el método de Kaplan-Meier utilizando los hallazgos de PET y las características clínicas. Resultados La mediana de duración del seguimiento fue de 29,7 meses (rango 3-125 meses). El MTV del tumor primario y el MTV de los ganglios linfáticos cervicales fueron factores pronósticos independientes para la PFS (p = 0,025 y p = 0,004, respectivamente). Los pacientes con MTV del tumor primario > 19,4 y los pacientes con MTV de los ganglios linfáticos > 3,4 tuvieron una PFS más corta. Para OS, la edad y el tamaño del ganglio linfático fueron factores pronósticos independientes (p = 0,031 y p = 0,029). Los pacientes mayores de 54 años y los pacientes con ganglios linfáticos > 1 cm se asociaron con una OS disminuida. Conclusión El MTV del tumor primario y el MTV de los ganglios linfáticos en la PET/TC previa al tratamiento son factores pronósticos significativos para la PFS a largo plazo en el carcinoma nasofaríngeo no metastásico (AU)

Background The aim of this study was to evaluate the prognostic significance of volumetric metabolic parameters of pre-treatment PET/CT along with clinical characteristics in patients with non-metastatic nasopharyngeal carcinoma. Material and methods Seventy-nine patients with nasopharyngeal carcinoma underwent F18-FDG PET/CT for pretreatment evaluation and included in this study. The patient features (patient age, tumor histopathology, T and N stage, size of primary tumor and the largest cervical lymph node) and PET parameters were analyzed: maximum, mean and peak standardized uptake values (SUVmax, SUVmean, SUVpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumor and largest cervical lymph node. After treatment, patients were evaluated for disease progression and mortality. Survival analysis for progression-free survival (PFS) and over-all survival (OS) was performed with Kaplan–Meier method using PET findings and clinical characteristics. Results The median follow-up duration was 29.7 months (range 3–125 months). Among clinical characteristics, no parameters had significance association for PFS. Primary tumor-MTV and cervical lymphnode-MTV were independent prognostic factors for PFS (p = 0.025 and p = 0.004, respectively). Patients with primary tumor-MTV > 19.4 and patients with lymph node-MTV > 3.4 had shorter PFS. For OS, age and the size of the lymph node were independent prognostic factor (p = 0.031 and p = 0.029). Patients with age over 54 years and patients with lymph node size > 1 cm were associated with decreased OS. Conclusion Primary tumor-MTV and lymph node-MTV on pre-treatment PET/CT are significant prognostic factors for long-term PFS in non-metastatic nasopharyngeal carcinoma (AU)

Methodological flaws introduce strong bias into molecular analysis of microbial populations.

AIMS: In this study, we report how different cell disruption methods, PCR primers and in silico analyses can seriously bias results from microbial population studies, with consequences for the credibility and reproducibility of the findings. Our results emphasize the pitfalls of commonly used experimental methods that can seriously weaken the interpretation of results. METHODS AND RESULTS: Four different cell lysis methods, three commonly used primer pairs and various computer-based analyses were applied to investigate the microbial diversity of a fermentation sample composed of chicken dung. The fault-prone, but still frequently used, amplified rRNA gene restriction analysis was chosen to identify common weaknesses. In contrast to other studies, we focused on the complete analytical process, from cell disruption to in silico analysis, and identified potential error rates. This identified a wide disagreement of results between applied experimental approaches leading to very different community structures depending on the chosen approach. CONCLUSIONS: The interpretation of microbial diversity data remains a challenge. In order to accurately investigate the taxonomic diversity and structure of prokaryotic communities, we suggest a multi-level approach combining DNA-based and DNA-independent techniques. SIGNIFICANCE AND IMPACT OF THE STUDY: The identified weaknesses of commonly used methods to study microbial diversity can be overcome by a multi-level approach, which produces more reliable data about the fate and behaviour of microbial communities of engineered habitats such as biogas plants, so that the best performance can be ensured.

Leaching of nano-ZnO in municipal solid waste.

Despite widespread use of engineered nanomaterials (ENMs) in commercial products and their potential disposal in landfills, the fate of ENMs in solid waste environments are still not well understood. In this study, the leaching behavior of nano ZnO -one of the most used ENMs- in fresh municipal solid waste (MSW) was investigated. Batch reactors containing municipal solid waste samples were spiked with three different types of nano ZnO having different surface stabilization. The leaching of ZnO was examined under acidic, basic and elevated ionic strength (IS) conditions. The results of the 3-day batch tests showed that the percent of the added nano-ZnO mass retained within the solid waste matrix ranged between 80% and 93% on average for the three types of nano-ZnO tested. The pH and IS conditions did not significantly influence the leaching behavior of ZnO. To further analyze the behavior of ZnO in the MSW matrix, a kinetic particle deposition/detachment model was developed. The model was able to reproduce the main trends of the batch experiments. Reaction rate constants for the batch tests ranged from 0.01 to 0.4 1/hr, reflecting the rapid deposition of nano-ZnO within the MSW matrix.

Leaching potential of nano-scale titanium dioxide in fresh municipal solid waste.

With the rapid development in nanotechnology in recent years, the number of commercially available products containing engineered nanomaterials (ENMs) has increased significantly. It is expected that large fractions of these ENMs will end up in landfills for final disposal. Despite the wide use of ENMs, little data is available on their fate within landfills. This study examined the leaching behavior of nanoscale titanium dioxide (nano-TiO2), one of the mostly used ENMs, in fresh municipal solid wastes (MSWs). Batch reactors containing municipal waste samples were spiked with a range of nano-TiO2 concentrations at different pH and ionic strength conditions. The Ti concentrations in leachate decreased rapidly and reached steady state after about 12-24 h. Results suggest that, for the environmental conditions considered, approximately 3-19% of the added nano-TiO2 remained in leachate. Batch tests conducted with individual synthetically-prepared solid waste components also showed low leaching potential (5.2% for organic waste, 3.3% for glass, 1.7% for both textile and paper and 0.6% for metal), indicating that all components of MSW contributed to the retention of the nano-TiO2 mass within the solid matrix.

Comparison of intermittent versus continuous vancomycin infusion for the treatment of late-onset sepsis in preterm infants.

BACKGROUND: Vancomycin a frequently used antimicrobial for the treatment of late-onset neonatal sepsis. It can be infused either intermittently or continuously, however, there is no consensus on the optimal dosing regimen. AIM: To evaluate microbiological outcomes, clinical response and adverse events of vancomycin when administered via continuos intravenous infusion. METHODS: The files of preterm infants (<34 weeks), who received either intermittent (group I, n = 41) or continuous (group II, n = 36) vancomycin infusion for the treatment of late-onset sepsis, were investigated retrospectively. Clinical and demographic features were recorded. RESULTS: Clinical improvement rates, Töllner scores and microbiological outcomes did not differ significantly between groups. At 48th hour of vancomycin infusion, 52.8% of infants achieved therapeutic concentrations of vancomycin in group II compared with 34.1% of patients in group I (p = 0.002). Thirty-nine percent of infants in group I had supratherapeutic concentrations of vancomycin at 48th hour compared with 5.6% in group II (p = 0.002). Dose adjustment rate in group I did not differ than group II (65.9% vs. 52.8% respectively, p = 0.3). However, when we subdivide group I into two according to dosing intervals, dose adjustment rates were more common in infants with a gestational age <29 weeks for whom intermittent infusion was performed in 18 hours intervals (92.9% vs 51.9% , p = 0.014). CONCLUSION: In preterm infants, continuous and intermittent infusions of vancomycin have similar clinical efficacies. Continuous infusion is well-tolerated and require less blood sampling compared to intermittent infusion especially in infants less than 29 weeks of gestational age.

Standardized uptake value and metabolic tumor volume measured by ¹8F FDG PET/CT are sensitive biomarkers for the presence of lymph node metastasis in patients with cervical carcinoma.

UNLABELLED: The aim of this study was to evaluate whether tumor standardized uptake value (SUVmax) and metabolic tumor volume (MTV) associate with the presence of PET-positive pelvic/para-aortic lymph nodes (LN) in cervical cancer patients. METHOD: Seventy-four patients with stage IB-IVB cervical cancer (squamous [n:66], nonsquamous [n:8]), who were referred to FDG-PET/CT department for initial staging, were enrolled in this study. RESULTS: Patients were staged according to International Federation of Gynecology and Obstetrics [FIGO] criteria as; stage I (n:5), stage II (n:25), stage III (n:15) and stage IV (n:29). PET/CT detected 53 patients with hypermetabolic LN (average SUVmax: 7.5 ± 4.1, range: 4.1-22.8, pelvic LN: 29 patients, para-aortic LN:5 patients, pelvic and para-aortic LN:19 patients). SUVmax and MTV were significantly higher in patients with PET-positive LN compared to others (18.4 and 88.8 cm(3) vs. 13.9 and 39.9 cm(3) respectively, p = 0.007 for SUVmax, p = 0.0001 for MTV). Cut-off values in association with PET-positive LN were 15.2 for SUVmax and 35 cm(3) for MTV on ROC curve analysis. There was no correlation between SUVmax and MTV (correlation coefficient (R(2)) = 0.07). MTV differed significantly with FIGO stages (41, 98 and 107 cm(3), in stage II, III and IV respectively, p = 0.015). CONCLUSION: Presence of PET-positive LN correlates with tumor SUVmax and MTV of cervical tumor. These findings support the use of PET/CT in the pretreatment evaluation of cervical cancer patients in order to identify cases with high risk of lymphatic involvement.

Respiratory epithelial adenomatoid hamartoma (REAH) of the nasopharynx with high 18F-FDG uptake on PET/CT.

Respiratory epithelial adenomatoid hamartoma (REAH) is a rare benign non-neoplastic sinonasal lesion that usually presents in the nasal cavity, paranasal sinuses, or olfactory cleft. We report a case of nasopharynx REAH mimicking a malignant tumour with incidental high 18-FDG uptake in a patient with colon cancer. Less than five similar cases have been reported to date, and this is the first case of REAH to show high uptake on PET/CT scans. Although hamartoma arising from the nasopharynx region is very rare, it should be considered in the differential diagnosis because it is a benign lesion and complete surgical resection is curative.

The contribution of each anterior cruciate ligament bundle to the Lachman test: a cadaver investigation.

The clinical diagnosis of a partial tear of the anterior cruciate ligament (ACL) is still subject to debate. Little is known about the contribution of each ACL bundle during the Lachman test. We investigated this using six fresh-frozen cadaveric lower limbs. Screws were placed in the femora and tibiae as fixed landmarks for digitisation of the bone positions. The femur was secured horizontally in a clamp. A metal hook was screwed to the tibial tubercle and used to apply a load of 150 N directed anteroposteriorly to the tibia to simulate the Lachman test. The knees then received constant axial compression and 3D knee kinematic data were collected by digitising the screw head positions in 30° flexion under each test condition. Measurements of tibial translation and rotation were made, first with the ACL intact, then after sequential cutting of the ACL bundles, and finally after complete division of the ACL. Two-way analysis of variance analysis was performed. During the Lachman test, in all knees and in all test conditions, lateral tibial translation exceeded that on the medial side. With an intact ACL, both anterior and lateral tibial landmarks translated significantly more than those on the medial side (p < 0.001). With sequential division of the ACL bundles, selective cutting of the posterolateral bundle (PLB) did not increase translation of any landmark compared with when the ACL remained intact. Cutting the anteromedial bundle (AMB) resulted in an increased anterior translation of all landmarks. Compared to the intact ACL, when the ACL was fully transected a significant increase in anterior translation of all landmarks occurred (p < 0.001). However, anterior tibial translation was almost identical after AMB or complete ACL division. We found that the AMB confers its most significant contribution to tibial translation during the Lachman test, whereas the PLB has a negligible effect on anterior translation. Section of the PLB had a greater effect on increasing the internal rotation of the tibia than the AMB. However, its contribution of a mean of 2.8° amplitude remains low. The clinical relevance of our investigation suggests that, based on anterior tibial translation only, one cannot distinguish between a full ACL and an isolated AMB tear. Isolated PLB tears cannot be detected solely by the Lachman test, as this bundle probably contributes more resistance to the pivot shift.

Does FK506 reduce the size of the watershed area after vascular injury of the sciatic nerve?

AIM: FK506 (also known Tacrolimus, Prograf) is an immunosuppressant drug which is used to prevent rejection after organ transplantation. Although there are several studies on neuroprotective effect of FK506 on brain ischemia, few reports on effects of FK506 after peripheral nerve ischemia have been reported. In the present study, we examined the size of watershed area after stripping of the epineurial vessels and studied the effect of FK506 on reduction of the size of watershed area. MATERIALS AND METHODS: Forty-eight adult female rats were used and randomly divided into four groups as control, sham, FK506-treated and vehicle-treated. In FK506-treated and vehicle-treated groups epineurial vessels around the sciatic nerve (vasa nervorum) were stripped. Additionally, FK506-treated group were received subcutaneous injection of 5 mg/kg FK506. Percent of watershed area (100 × total watershed areas / total nerve area) after stripping and FK506 treatment was calculated. RESULTS: We found no significant difference in comparison of the total size of watershed areas in FK506 and vehicle-treated groups or even the percent of the watershed area in both groups. CONCLUSIONS: We think that this study will be helpful to understand neuroprotective effect of FK506 and will give an insight into sparing of the nerve fibers from vascular injuries of the peripheral nerve.

Walking track analysis: an assessment method for functional recovery after sciatic nerve injury in the rat.

Walking track analysis was first described by de Medinaceli et al. This technique has been significantly modified to provide methods of indexing nerve function that are more valid. Moreover, it has been questioned by several authors. The aim of the present review is to offer a combined knowledge about walking track analysis for scientists who deal with neuroscience.

Application of a fuzzy logic control system for continuous anaerobic digestion of low buffered, acidic energy crops as mono-substrate.

A fuzzy logic control (FLC) system was developed at the Hamburg University of Applied Sciences (HAW Hamburg) for operation of biogas reactors running on energy crops. Three commercially available measuring parameters, namely pH, the methane (CH4) content, and the specific gas production rate (spec. GPR = m(3)/kg VS/day) were included. The objective was to avoid stabilization of pH with use of buffering supplements, like lime or manure. The developed FLC system can cover most of all applications, such as a careful start-up process and a gentle recovery strategy after a severe reactor failure, also enabling a process with a high organic loading rate (OLR) and a low hydraulic retention time (HRT), that is, a high throughput anaerobic digestion process with a stable pH and CH4 content. A precondition for a high load process was the concept of interval feeding, for example, with 8 h of interval. The FLC system was proved to be reliable during the long term fermentation studies over 3 years in one-stage, completely stirred tank reactors (CSTR) with acidic beet silage as mono-input (pH 3.3-3.4). During fermentation of the fodder beet silage (FBS), a stable HRT of 6.0 days with an OLR of up to 15 kg VS/m(3)/day and a volumetric GPR of 9 m(3)/m(3)/day could be reached. The FLC enabled an automatic recovery of the digester after two induced severe reactor failures. In another attempt to prove the feasibility of the FLC, substrate FBS was changed to sugar beet silage (SBS), which had a substantially lower buffering capacity than that of the FBS. With SBS, the FLC accomplished a stable fermentation at a pH level between 6.5 and 6.6, and a volatile fatty acid level (VFA) below 500 mg/L, but the FLC had to interact and to change the substrate dosage permanently. In a further experiment, the reactor temperature was increased from 41 to 50 degrees C. Concomitantly, the specific GPR, pH and CH4 dropped down. Finally, the FLC automatically enabled a complete recovery in 16 days.

The effects of change in volatile fatty acid (VFA) composition on methanogenic upflow filter reactor (UFAF) performance.

The effects of changes in composition of a volatile fatty acid mixture (namely acetic, propionic and butyric acids) fed to a methanogenic upflow filter reactor (UFAF) were investigated in terms of reactor chemical oxygen demand (COD) removal efficiency and biogas production level. A mixed substrate consisting of differing proportions of VFAs (on a COD basis) was fed to the reactor in semi-continuous mode under constant organic loading rate (OLR) and hydraulic retention time (HRT). At an OLR of 1.2 kg COD m(-3) x d and HRT of 4 days, increasing propionic acid concentrations of about 312 mg l(-1), 617 mg l(-1), 951 mg l(-1) and 1242 mg l(-1) fed to the reactor provided COD removal rates and biogas production levels of, 84.70%-1301 ml d(-1), 80.80%-1214 ml d(-1), 73.65%-1071 ml d(-1) and 65.53%-942 ml d(-1), respectively, indicating inhibitory effects of propionic acid on the methanogenic ecosystem. Subsequent introduction of butyric acid (247 mg l(-1)) in addition to propionic acid (891 mg l(-1)) increased the performance of the UFAF, yielding 76.10% COD removal and 1075 ml d(-1) of biogas production. The instability observed in the system towards the end of the study probably originated from operating the reactor at relatively high VFA concentrations for a long period of time. Change in VFA composition did not seem to have significant effects on the effluent MLVSS/MLSS ratio. The upflow anaerobic filter reactor adapted to variations in feed composition in a short period of time.