Validation of a method for “dose of the day” calculation in head-neck tomotherapy by using planning ct-to-MVCT deformable image registration

PurposeThe aim of this study was to test the feasibility and dosimetric accuracy of a method that employs planning CT-to-MVCT deformable image registration (DIR) for calculation of the daily dose for head and neck (HN) patients treated with Helical Tomotherapy (HT).MethodsFor each patient, the planning kVCT (CTplan) was deformably registered to the MVCT acquired at the 15th therapy session (MV15) with a B-Spline Free Form algorithm using Mattes mutual information (open-source software 3D Slicer), resulting in a deformed CT (CTdef). On the same day as MVCT15, a kVCT was acquired with the patient in the same treatment position (CT15). The original HT plans were recalculated both on CTdef and CT15, and the corresponding dose distributions were compared; local dose differences <2% of the prescribed dose (DD2%) and 2D/3D gamma-index values (2%-2 mm) were assessed respectively with Mapcheck SNC Patient software (Sun Nuclear) and with 3D-Slicer.ResultsOn average, 87.9% ± 1.2% of voxels were found for DD2% (on average 27 slices available for each patient) and 94.6% ± 0.8% of points passed the 2D gamma analysis test while the 3D gamma test was satisfied in 94.8% ± 0.8% of body’s voxels.ConclusionsThis study represents the first demonstration of the dosimetric accuracy of kVCT-to-MVCT DIR for dose of the day computations. The suggested method is sufficiently fast and reliable to be used for daily delivered dose evaluations in clinical strategies for adaptive Tomotherapy of HN cancer.     

Population health risk due to dietary intake of toxic heavy metals from Spinacia oleracea harvested from soils collected in and around Tshwane,South Africa

In order to assess the possible health risk associated with the consumption of vegetables harvested from waste dump sites, trace metal levels in Spinacia oleracea planted in soils collected from waste dump sites were investigated. Soil samples from different waste dump sites and mining areas were collected and placed in different pots. Seedlings of S. oleracea were introduced into the pots, harvested after 3 months and analysed for trace metal contents using ICP-MS. From the leaves of the plants, the concentration of Fe was found to be significantly higher than all other trace metals (p < 0.05). The trend in trace metal accumulation from the leaves was in the order Fe > Mn > Zn > Pb > Cu > Cr > Ni > Cd. A significantly different concentration of trace metals in the plant was noticed from different soils in different pots used (p < 0.05). Trace metal concentration from plant parts showed roots > leaves > stem. The risk to human health indicated as Hazard Quotient (HQ) was highest for Zn followed by Cu from all the plant parts. The HQ result showed that humans might be at risk if they consume spinach from these waste dump sites. From the study it was concluded that harvesting/consuming spinach from soil around a waste dump site may be extremely dangerous.     

Metabolic,hygric and ventilatory physiology of the red-tailed phascogale (Phascogale calura; Marsupialia,Dasyuridae): Adaptations to aridity or arboreality?

The red-tailed phascogale is a small arboreal dasyurid marsupial that inhabits semi-arid to arid regions of Western Australia's wheat belt. Its body mass (34.7 g) is only ～15% of that predicted based on its phylogenetic position among other dasyuromorphs; we interpret this as an adaptation to its scansorial and semi-arid/arid lifestyle. The standard physiology of this species at a thermoneutral ambient temperature of 30 °C conforms to that of other dasyurid marsupials; body temperature (34.7 ± 0.37 °C), basal metabolic rate (0.83 ± 0.076 mL O₂ g^?1 h^?1), evaporative water loss (1.68 ± 0.218 mg H₂O g^?1 h^?1) and wet thermal conductance (3.8 ± 0.26 J g^?1 h^?1 °C^?1) all fall within the 95% predication limits for the respective allometric relationships for other dasyurid species. Thermolability confers an energy savings at low T_a and water savings at high T_a. Torpor, observed at low T_a, was found to be more beneficial for energy savings than for water economy. The red-tailed phascogale therefore has a physiology suitable for the challenges of arid environments without any obvious requirement for adaptations to its scansorial lifestyle, other than its considerably lower-than-expected body mass.     

Correlation between serum trace elements and risk of preeclampsia: A case controlled study in Riyadh,Saudi Arabia

Preeclampsia is a serious medical complication during pregnancy. In response to an increasing number of preeclamptic cases and scarcity of data concerning the interrelation between trace element levels and preeclampsia, we carried out a hospital based case–control study in Riyadh, Saudi Arabia to study the correlation between levels of serum trace elements and risk of preeclampsia. One hundred and twenty pregnant women were enrolled in this study and divided into three groups of 40 each—Control group, HR group (women at high risk of preeclampsia) and PET group (Preeclampsia group). Serum trace element levels were estimated by inductively coupled plasma optical emission spectrophotometer. The analysis found that mean values of Ca, Mg and Zn were 90.08 ± 6.38, 19.33 ± 3.32 and 1.30 ± 0.83 mg/L respectively in normotensive control and 77.85 ± 4.47, 15.44 ± 1.43 and 0.98 ± 0.63 mg/L respectively in the HR group. The mean values of Ca, Mg and Zn in the preeclamptic group were 70.37 ± 4.66, 13.58 ± 1.98 and 0.67 ± 0.59 mg/L, respectively. Interelement analysis reflected a negative correlation between Ca and Mg and between Mg and Zn whereas positive correlation between Ca and Zn in preeclamptic women. However the correlation was not statistically significant. In conclusion, our study suggests that decreased levels of these trace elements in serum may act as predisposing factors in pathogenesis of Preeclampsia.     

Microwave-assisted drying of paclitaxel for removal of residual solvents

In this study, the residual solvent in final purified paclitaxel was effectively removed using microwave-assisted drying. When the sample final purified by silica-HPLC was concentrated using a rotary evaporator, the residual methanol easily met the ICH-specified value (3000 ppm), but methylene chloride did not meet the ICH-specified value (600 ppm). Thus, the efficiency of microwave-assisted drying according to microwave power (100, 200, and 300 W) and drying time was investigated using the sample (methylene chloride conc.: 26,000 ppm, methanol conc.: 50 ppm) concentrated by rotary evaporation. A higher microwave power was effective in removing methylene chloride, and the ICH requirements were met by drying at 300 W for 21 h. In addition, when the sample concentrated by rotary evaporation was vacuum dried (35 °C, 24 h), the concentration of methylene chloride could be reduced to 8500 ppm. When the vacuum-dried sample was subjected to microwave-assisted drying, the ICH requirements could be met by drying for 10 h at 200 W and 8 h at 300 W. The lower the initial concentration of the solvent and the higher the microwave power, the greater the improvement in the efficiency of microwave-assisted drying.     

A computational algorithm for classifying step and spin turns using pelvic center of mass trajectory and foot position

Transient changes in direction during ambulation are typically performed using a step (outside) or spin (inside) turning strategy, often identified through subjective and time-consuming visual rating. Here, we present a computational, marker-based classification method utilizing pelvic center of mass (pCOM) trajectory and time-distance parameters to quantitatively identify turning strategy. Relative to visual evaluation by three independent raters, sensitivity, specificity, and overall accuracy of the pCOM-based classification method were evaluated for 90-degree turns performed by 3 separate populations (5 uninjured controls, 5 persons with transtibial amputation, and 5 persons with transfemoral amputation); each completed turns using two distinct cueing paradigms (i.e., laser-guided “freeform” and verbally-guided “forced” turns). Secondarily, we compared the pCOM-based turn classification method to adapted versions of two existing computational turn classifiers which utilize trunk and shank angular velocities (AV). Among 366 (of 486 total) turns with unanimous intra- and inter-rater agreement, the pCOM-based classification algorithm was 94.5% accurate, with 96.6% sensitivity (accuracy of spin turn classification), and 93.5% specificity (accuracy of step turn classification). The pCOM-based algorithm (vs. both AV-based methods) was more accurate (94.5% vs. 81.1–80.6%; P < 0.001) overall, as well as specifically in freeform (92.9 vs. 80.4–76.8%; P < 0.003) and forced (96.0 vs. 83.8–81.8%; P < 0.001) cueing, and among individuals with (92.4 vs. 80.2–78.8%; P < 0.001) and without (99.1 vs. 86.2–80.8%; P < 0.001) amputation. The pCOM-based algorithm provides an efficient and objective method to accurately classify 90-degree turning strategies using optical motion capture in a laboratory setting, and may be extended to various cueing paradigms and/or populations with altered gait.     

Optimization of carotenoid production by Rhodotorula graminis DBVPG 7021 as a function of trace element concentration by means of response surface analysis

As the final step of a study aiming at the optimization of culture conditions for the production of carotenoids by red yeasts, a statistically-based experimental design has been applied to assess the influence of selected trace elements on carotenogenesis in Rhodotorula graminis DBVPG 7021. In particular, a central composite design scheme has been used to evaluate the influence of Fe³⁺, Co²⁺, Mn²⁺, Al²⁺ and Zn²⁺ (within the range 0–50 ppm) on various responses, namely biomass (B), total carotenoid production (TC) and percentage of specific carotenoids (β-CAR, β-carotene; γ-CAR, γ-carotene; TN, torulene; TD, torularhodin) on total carotenoids. Second-order polynomial models were calculated and reduced equations were designed by neglecting non-significant (P < 0.01) regression coefficients. Reduced equations were used to calculate the optimal concentration of trace elements in view of maximising the level of B, TC, β-CAR, γ-CAR, TN and TD. After optimization, average final values total carotenoids (TC = 803.2 μg/g DW) was about 370% of value observed as central point of the central composite design scheme. Under the same condition, average final values of other responses were: B = 5.40 g/L; β-CAR = 50.3%; γ-CAR = 15.4%; TN = 22.7%; TD = 11.6%. All above experimental data are in good agreement with calculated ones, thus confirming the reliability of the proposed empirical model in describing carotenoid production by R. graminis as a function of trace element concentrations.     

Limited versus total epithelial debridement ocular surface injury: Live fluorescence imaging of hemangiogenesis and lymphangiogenesis in Prox1-GFP/Flk1::Myr-mCherry mice

BackgroundImmunohistochemical staining experiments have shown that both hemangiogenesis and lymphangiogenesis occur following severe corneal and conjunctival injury and that the neovascularization of the cornea often has severe visual consequences. To better understand how hemangiogenesis and lymphangiogenesis are induced by different degrees of ocular injury, we investigated patterns of injury-induced corneal neovascularization in live Prox1-GFP/Flk1::myr-mCherry mice, in which blood and lymphatic vessels can be imaged simultaneously in vivo.MethodsThe eyes of Prox1-GFP/Flk1::myr-mCherry mice were injured according to four models based on epithelial debridement of the: A) central cornea (a 1.5-mm-diameter circle of tissue over the corneal apex), B) total cornea, C) bulbar conjunctiva, and D) cornea + bulbar conjunctiva. Corneal blood and lymphatic vessels were imaged on days 0, 3, 7, and 10 post-injury, and the percentages of the cornea containing blood and lymphatic vessels were calculated.ResultsNeither central corneal nor bulbar conjunctival debridement resulted in significant vessel growth in the mouse cornea, whereas total corneal and corneal + bulbar conjunctival debridement did. On day 10 in the central cornea, total cornea, bulbar conjunctiva, and corneal + bulbar conjunctival epithelial debridement models, the percentage of the corneal surface that was occupied by blood vessels (hemangiogenesis) was 1.9 ± 0.8%, 7.14 ± 2.4%, 2.29 ± 1%, and 15.05 ± 2.14%, respectively, and the percentage of the corneal surface that was occupied by lymphatic vessels (lymphangiogenesis) was 2.45 ± 1.51%, 4.85 ± 0.95%, 2.95 ± 1.27%, and 4.15 ± 3.85%, respectively.ConclusionsSubstantial corneal debridement was required to induce corneal neovascularization in the mouse cornea, and the corneal epithelium may therefore be partially responsible for maintaining corneal avascularity.General significanceOur study demonstrates that GFP/Flk1::myr-mCherry mice are a useful model for studying coordinated hemangiogenic and lymphangiogenic responses.     

Patients at risk for trace element deficiencies: Bariatric surgery

Obesity is a worldwide epidemic associated with diseases such as diabetes mellitus and cardiovascular disease. Current methods for weight loss are not very effective, particularly for those with morbid obesity. Surgical therapy may be recommended for those with a BMI ≥ 40 kg/m², or BMI ≥ 35 kg/m² with co-morbidities. This therapy can produce significant weight loss and improve/resolve co-morbidities including hypertension and hyperlipidemia. Yet successes may be tempered by adverse effects on trace element absorption and status. A PubMed literature search identified studies from January 1980 to February 2013 for inclusion in a meta-analysis. Publications that contained keywords ‘bariatric surgery or gastric bypass,’ ‘trace element or mineral or zinc or iron or copper or iodine or manganese’, and ‘absorption or status or rate or level’ were identified. Inclusion criteria were human markers that reflect changes in trace element status before and after bariatric surgery. The meta-analysis found a decrease in blood copper, zinc, hemoglobin, as well as an increase in iron, regardless of the type of surgery. The pooled effect sizes and 95% confidence intervals were 0.17 and −0.09 to 0.43 for plasma/serum iron (p = 0.20); −0.49 and −0.67 to −0.31 for blood hemoglobin (p = 0.00); −0.47 and −0.90 to −0.05 for plasma/serum copper (p = 0.03); −0.77 and −1.20 to −0.35 for plasma/serum zinc (p = 0.00). Differences in levels of these minerals pre- and post-surgery may have been influenced by the time period after surgery, a pre-existing deficiency, type and dose of vitamin–mineral supplements, and malabsorption due to elimination of parts of the gastrointestinal tract.     

An amperometric biosensor based on horseradish peroxidase immobilized onto maize tassel-multi-walled carbon nanotubes modified glassy carbon electrode for determination of heavy metal ions in aqueous solution

A biosensor for trace metal ions based on horseradish peroxidase (HRP) immobilized on maize tassel-multiwalled carbon nanotube (MT-MWCNT) through electrostatic interactions is described herein. The biosensor was characterized using Fourier transform infrared (FTIR), UV–vis spectrometry, voltammetric and amperometric methods. The FTIR and UV–vis results inferred that HRP was not denatured during its immobilization on MT-MWCNT composite. The biosensing principle was based on the determination of the cathodic responses of the immobilized HRP to H₂O₂, before and after incubation in trace metal standard solutions. Under optimum conditions, the inhibition rates of trace metals were proportional to their concentrations in the range of 0.092–0.55 mg L⁻¹, 0.068–2 mg L⁻¹ for Pb²⁺ and Cu²⁺ respectively. The limits of detection were 2.5 μg L⁻¹ for Pb²⁺ and 4.2 μg L⁻¹ for Cu²⁺. Representative Dixon and Cornish-Bowden plots were used to deduce the mode of inhibition induced by the trace metal ions. The inhibition was reversible and mixed for both metal ions. Furthermore, the biosensor showed good stability, selectivity, repeatability and reproducibility.     

Electromyography responses of pediatric and young adult volunteers in low-speed frontal impacts

No electromyography (EMG) responses data exist of children exposed to dynamic impacts similar to automotive crashes, thereby, limiting active musculature representation in computational occupant biomechanics models. This study measured the surface EMG responses of three neck, one torso and one lower extremity muscles during low-speed frontal impact sled tests (average maximum acceleration: 3.8 g; rise time: 58.2 ms) performed on seated, restrained pediatric (n = 11, 8–14 years) and young adult (n = 9, 18–30 years) male subjects. The timing and magnitude of the EMG responses were compared between the two age groups. Two normalization techniques were separately implemented and evaluated: maximum voluntary EMG (MVE) and neck cross-sectional area (CSA). The MVE-normalized EMG data indicated a positive correlation with age in the rectus femoris for EMG latency; there was no correlation with age for peak EMG amplitudes for the evaluated muscles. The cervical paraspinous exhibited shorter latencies compared with the other muscles (2–143 ms). Overall, the erector spinae and rectus femoris peak amplitudes were relatively small. Neck CSA-normalized peak EMG amplitudes negatively correlated with age for the cervical paraspinous and sternocleidomastoid. These data can be useful to incorporate active musculature in computational models, though it may not need to be age-specific in low-speed loading environments.     

Multimodal information improves the rapid detection of mental fatigue

One of the major challenge in the detection of mental states is improving the accuracy of brain activity-based detectors with additional information from extracranial signals. We assessed the suitability, for real-time mental fatigue detection, of EEG, EOG and ECG measurements, taken separately or together. Thirteen subjects performed six blocks of switching tasks. For each participant, the block with the lowest error rate from the first two blocks and the block with the highest error rate from the last three blocks were discriminated with a machine learning algorithm (support vector machine). The classification scores obtained with ECG or EOG were greater than would be expected by chance (>50%) for time windows of at least 8 s. EEG was the best single mode of detection, with classification scores ranging from 80 ± 3% with a 4 s time window to 94 ± 2% with a 30 s time window. The addition of ECG and EOG features to EEG features significantly increased classification scores for short time windows (e.g., to 86 ± 3% with a 4 s time window, p < 0.001). For short time windows (up to 12 s), ECG significantly increased the discriminatory power of EEG, whereas EOG did not. These results demonstrate that mental state detection on the basis of extracerebral measurements is feasible and that a combination of EEG and ECG is particularly appropriate for the rapid detection of mental fatigue.     

Effects of Yucca schidigera extract on fermentation and degradation of steroidal saponins in the rumen simulation technique (RUSITEC)

A rumen simulation technique (RUSITEC) apparatus with eight 940 ml fermentation vessels was used to study the effects of the steroidal saponins in Yucca schidigera extract (YE) on ruminal microbial activity and saponin degradation. The YE contained approximately 4.4% (w/w) saponin, as smilagenin equivalents, and was included at 0 (control) or 0.5 mg ml⁻¹ (n=4) in the McDougall's buffer infused continuously into the vessels (dilution rate=0.75 day⁻¹). Each vessel received 5 g chopped alfalfa hay and 5 g concentrate (as-fed basis) daily for 22 days. Ammonia concentrations were lower (P<0.05) in effluent from vessels receiving YE than from controls for the first half of the study, but did not differ thereafter. Total amounts of VFA in effluent were not affected (P>0.05) by YE, but molar proportions of iso-butyric and iso-valeric acids were lower (P<0.05) in the YE vessels than in the controls in the first half of the experiment. Yucca extract at 0.5 mg ml⁻¹ did not affect (P>0.05) dry matter disappearance (DMD) from hay or from concentrate, nor did it affect total gas or methane production, or bacterial numbers (total or cellulolytic populations) in homogenates prepared from fermenter vessel liquid and feed particles. Protozoal numbers in the homogenates were substantially reduced (P<0.01) by YE (at 0.5 mg ml⁻¹), protease activity was increased (P<0.05), deaminase activity and activity against Ala₂ were unaffected (P>0.05) and activity against Ala₅ was reduced by 25% (P>0.05). When the homogenates from control and YE-supplemented (0.5 mg ml⁻¹) vessels were used to inoculate roll tubes containing 0 or 5 mg ml⁻¹ of YE, fewer colonies developed (P<0.01) in roll tubes containing YE than in those without YE, irrespective of the source of inoculum. Homogenates were also assayed for saponin degradation and for protease, peptidase and deaminase activities. Inoculum from the vessels receiving YE degraded saponin slightly during a 2 h incubation. Yucca extract at 0.5 mg ml⁻¹ altered proteolytic activity and reduced protozoal numbers, but did not affect DMD or bacterial activity, and did not induce resistance to YE at a concentration of 5 mg ml⁻¹.     

Growth performances and carcass traits of Ovin Martinik lambs fed various ratios of tropical forage to concentrate under intensive conditions

Studies were conducted to determine the effects of supplementation upon intake, growth and carcass traits of Ovin Martinik hair sheep. Forty lambs weighing 20 ± 3.7 kg live weight (LW) were reared after weaning in individual pens during a 4-month experimental study. Four supplement levels were compared (10 lambs per treatment): the L0 group received the basal diet (tropical forage 0.75 UFL and 73 PDIN g kg⁻¹ DM, INRA system) without concentrate, the L150, L300 and L600 groups were offered in addition 150, 300 and 600 g day⁻¹ of concentrate (1.15 UFL and 151 PDIN g kg⁻¹ DM), respectively. Intake (5 days a week) and growth patterns (every fortnight) were measured on the 40 lambs, while digestibility measurements (five times throughout the experimental period) were determined on half of the animals fitted with faecal bags and which were slaughtered according to the standard procedure at 33–35 kg live weight for assessment of carcass traits and meat quality.The total dry matter intake (DMI) and digestibility increased (P < 0.01) with the inclusion ratio of the concentrate in the diet: 82 g DM kg W^−0.75 vs. 97 g DM kg W^−0.75 and 65% vs. 73% between the two extreme groups, whereas forage DMI decreased and the forage substitution ratio was calculated to be 0.65. Growth and feed/gain ratios significantly (P < 0.01) improved among the groups L0, L150 and L300, from an average of 134–188 g day⁻¹ and 7.0–5.7, respectively. The differences observed between L300 and L600 were not significant. Carcass weight and dressing out percentages significantly (P < 0.01) increased with the addition of concentrate to the ration: from 13.1 to 15.6 kg and from 39 to 46%, from L0 to L600, respectively. Consequently, the weights of the different cuts of the carcass varied. There was a significant effect of the supplementation level on the accumulation of internal fat tissues: the kidney fat weight increased from 107 to 237 g from the L0 to the L600 groups. No significant effect was observed on the carcass quality scores, the ultimate pH and the colour parameters of the meat.By increasing the nutritional density of the diet, it was possible to obtain well-conformed and heavier carcasses, with no apparent detrimental effect on the quality. The optimal supplement supply with good quality grass would be 300 g day⁻¹ in our conditions.     

Complete genome sequence,metabolic model construction and phenotypic characterization of Geobacillus LC300, an extremely thermophilic,fast growing,xylose-utilizing bacterium

We have isolated a new extremely thermophilic fast-growing Geobacillus strain that can efficiently utilize xylose, glucose, mannose and galactose for cell growth. When grown aerobically at 72 °C, Geobacillus LC300 has a growth rate of 2.15 h⁻¹ on glucose and 1.52 h⁻¹ on xylose (doubling time less than 30 min). The corresponding specific glucose and xylose utilization rates are 5.55 g/g/h and 5.24 g/g/h, respectively. As such, Geobacillus LC300 grows 3-times faster than E. coli on glucose and xylose, and has a specific xylose utilization rate that is 3-times higher than the best metabolically engineered organism to date. To gain more insight into the metabolism of Geobacillus LC300 its genome was sequenced using PacBio׳s RS II single-molecule real-time (SMRT) sequencing platform and annotated using the RAST server. Based on the genome annotation and the measured biomass composition a core metabolic network model was constructed. To further demonstrate the biotechnological potential of this organism, Geobacillus LC300 was grown to high cell-densities in a fed-batch culture, where cells maintained a high xylose utilization rate under low dissolved oxygen concentrations. All of these characteristics make Geobacillus LC300 an attractive host for future metabolic engineering and biotechnology applications.     

Effect of dl-malate on mixed ruminal microorganism fermentation using the rumen simulation technique (RUSITEC)

The objective of this study was to investigate the effects of dl-malate on the in vitro fermentation of a 50 : 50 forage : concentrate diet using the rumen simulation technique (RUSITEC) and to compare these effects with those induced by the addition of propionate. The RUSITEC system consisted of eight vessels: three of them received daily 5.62 mmol of dl-malate, three vessels received daily 5.62 mmol of propionate and two vessels received no additives (control). After an adaptation period of 11 days the main fermentation parameters were determined for five consecutive days. There were no significant differences between treatments either in pH or in the daily production of NH₃–N. Compared to control diet, the addition of dl-malate resulted in an increase (p < 0.05) of hemicellulose disappearance and a trend (p < 0.10) towards a greater disappearance of dry matter, organic matter and neutral detergent fibre. Differences between dl-malate and propionate in diet degradation were not significant. dl-malate treatment resulted in an increase (p < 0.01) of daily propionate production, and a decrease (p < 0.05) in the amount of both methane (mmol/g DM fermented) and l-lactate (mg/day). Compared to propionate, dl-malate produced an increase (p < 0.05) of acetate production and tended to produce a lower amount of propionate (p < 0.10). In conclusion, these results seem to indicate that dl-malate enhanced the in vitro fermentation by increasing production of propionate and digestibility of hemicellulose.     

Copper,zinc and iron levels in premature infants following red blood cell transfusion

This study aimed to investigate effect of erythrocyte suspension (ES) transfusion on Cu, Zn, and Fe levels. It was conducted on 53 premature infants who were admitted to Hacettepe Hospital and received EST for first time. Blood samples were drawn before and 96 h after ES transfusion to determine Cu, Zn, and Fe levels in plasma and/or erythrocytes. The mean plasma Cu levels were 99 ± 3 μg/dl and 113 ± 3 μg/dl; Zn levels were 105 ± 2 μg/dl and 115 ± 23 μg/dl; mean plasma Fe level was 58.1 ± 19.4 and 75.2 ± 25.4 μg/dl and mean erythrocyte Fe level was 4182 ± 2314 μg/ml and 7009 ± 5228 μg/ml, before and after ES transfusion. The differences between before and after ES transfusion in Cu, Zn and Fe levels were significant. Correlation between plasma and erythrocyte Fe levels was significant both before and after ES transfusion. Though Fe overload is a major cause of morbidity/mortality after ES transfusion, alterations in trace elements should also be considered when transfusing blood to infants and children.     

Cluster analysis and classification of heart sounds

Acoustic heart signals, generated by the mechanical processes of the cardiac cycle, carry significant information about the underlying functioning of the cardiovascular system. We describe a computational analysis framework for identifying distinct morphologies of heart sounds and classifying them into physiological states. The analysis framework is based on hierarchical clustering, compact data representation in the feature space of cluster distances and a classification algorithm. We applied the proposed framework on two heart sound datasets, acquired during controlled alternations of the physiological conditions, and analyzed the morphological changes induced to the first heart sound (S1), and the ability to predict physiological variables from the morphology of S1. On the first dataset of 12 subjects, acquired while modulating the respiratory pressure, the algorithm achieved an average accuracy of 82 ± 7% in classifying the level of breathing resistance, and was able to estimate the instantaneous breathing pressure with an average error of 19 ± 6%. A strong correlation of 0.92 was obtained between the estimated and the actual breathing efforts. On the second dataset of 11 subjects, acquired during pharmacological stress tests, the average accuracy in classifying the stress stage was 86 ± 7%. The effects of the chosen raw signal representation, distance metrics and classification algorithm on the performance were studied on both real and simulated data. The results suggest that quantitative heart sound analysis may provide a new non-invasive technique for continuous cardiac monitoring and improved detection of mechanical dysfunctions caused by cardiovascular and cardiopulmonary diseases.     

Influence of voxel S factors on three-dimensional internal dosimetry calculations

Internal dosimetry is a fundamental instrument for the personalization of nuclear medicine therapies, to maximize the therapeutic effect while minimizing the radiation burden to other organs. Three-dimensional (3D) dosimetry can quantify the impact of heterogeneous radiopharmaceutical distributions in organs, lesions and tissues.We analysed the influence of radionuclide voxel S factors in 3D dosimetry of ¹¹¹In, ¹⁷⁷Lu and ⁹⁰Y, the most used radionuclides in Peptide Receptor Radionuclide Therapy (PRRT). Calculations were carried out for kidneys on a workstation equipped with a software for 3D dosimetry (Imalytics STRATOS, Philips AG), adopting a computational anthropomorphic phantom and, retrospectively, the SPECT-CT image series of a clinical case of PRRT.Two sets of voxel S factors were adopted: the pre-loaded Philips kernels, calculated by direct Monte Carlo simulation, and the ones calculated through a previously proposed analytical approach. Philips ¹¹¹In kernel did not account for mono-energetic Auger or Conversion electrons.Results indicate a difference of about −32% in voxel S factors for ¹¹¹In in 4.42 mm voxel size and around −35% in 4.80 mm voxel size, particularly self-dose values; this lead to significant shift in dose histograms and average doses. For ¹⁷⁷Lu and ⁹⁰Y, differences are about 2% and 12% for 4.42 mm voxels and about −8% and 9% for 4.80 mm voxels, respectively, attributable to the different calculation methods of the voxel S factors; this does not lead to significant discrepancies between the two dose histograms. Consequently, voxel S factors must account accurately for all radiations emitted by the nuclide.     

A new bioprocess for the production of prebiotic lactosucrose by an immobilized β-galactosidase

A new bioprocess for the synthesis of lactosucrose was studied using a covalently immobilized β-galactosidase on macrospheres of chitosan. The effects of temperature and pH on the production of lactosucrose and other oligosaccharides were evaluated. At 30 °C and pH 7.0, the maximum concentration of lactosucrose reached to 79 g L⁻¹. The change of the reaction conditions allowed to modify the qualitative profile of the final products without quantitative change in the total of oligosaccharides produced. At pH 7 and 30 °C, products profile was 79 g L⁻¹ of lactosucrose, 37 g L⁻¹ of galactooligosaccharides and 250 g L⁻¹ of total oligosaccharides, while at pH 5 and 64 °C the concentrations for the same compounds were 40, 62 and 250 g L⁻¹, respectively. The immobilization increased the thermal stability up to 260-fold. Using 300 g L⁻¹ of sucrose and 300 g L⁻¹ of lactose, and 8.5 mg of chitosan mL⁻¹, 30 cycles of reuse were performed and the biocatalyst kept the maximal lactosucrose synthesis. These results fulfill some important aspects for the enzyme immobilization and oligosaccharides synthesis: the simplicity of the protocols, the high operational stability of the enzyme and the possibility of driving the final products.