Gas production by Paucilactobacillus wasatchensis WDCO4 is increased in Cheddar cheese containing sodium gluconate.

Paucilactobacillus wasatchensis can use gluconate (GLCN) as well as galactose as an energy source and because sodium GLCN can be added during salting of Cheddar cheese to reduce calcium lactate crystal formation, our primary objective was to determine if the presence of GLCN in cheese is another risk factor for unwanted gas production leading to slits in cheese. A secondary objective was to calculate the amount of CO2 produced during storage and to relate this to the amount of gas-forming substrate that was utilized. Ribose was added to promote growth of Pa. wasatchensis WDC04 (P.waWDC04) to high numbers during storage. Cheddar cheese was made with lactococcal starter culture with addition of P.waWDC04 on 3 separate occasions. After milling, the curd was divided into six 10-kg portions. To the curd was added (A) salt, or salt plus (B) 0.5% galactose + 0.5% ribose (similar to previous studies), (C) 1% sodium GLCN, (D) 1% sodium GLCN + 0.5% ribose, (E) 2% sodium GLCN, (F) 2% sodium GLCN + 0.5% ribose. A vat of cheese without added P.waWDC04 was made using the same milk and a block of cheese used as an additional control. Cheeses were cut into 900-g pieces, vacuum packaged and stored at 12°C for 16 wk. Each month the bags were examined for gas production and cheese sampled and tested for lactose, galactose and GLCN content, and microbial numbers. In the control cheese, P.waWDC04 remained undetected (i.e., <104 cfu/g), whereas in cheeses A, C, and E it increased to 107 cfu/g, and when ribose was included with salting (cheeses B, D, and F) increased to 108 cfu/g. The amount of gas (measured as headspace height or calculated as mmoles of CO2) during 16 wk storage was increased by adding P.waWDC04 into the milk, and by adding galactose or GLCN to the curd. Galactose levels in cheese B were depleted by 12 wk while no other cheeses had residual galactose. Except for cheese D, the other cheeses with GLCN added (C, E and F) showed little decline in GLCN levels until wk 12, even though gas was being produced starting at wk 4. Based on calculations of CO2 in headspace plus CO2 dissolved in cheese, galactose and GLCN added to cheese curd only accounted for about half of total gas production. It is proposed that CO2 was also produced by decarboxylation of amino acids. Although P.waWDC04 does not have all the genes for complete conversion and decarboxylation of the amino acids in cheese, this can be achieved in conjunction with starter culture lactococcal. Adding GLCN to curd can now be considered another confirmed risk factor for unwanted gas production during storage of Cheddar cheese that can lead to slits and cracks in cheese. Putative risk factors now include having a community of bacteria in cheese leading to decarboxylation of amino acids and release of CO2 as well autolysis of the starter culture that would provide a supply of ribose that can promote growth of Pa. wasatchensis.

Correction to: Intrinsic and inducible resistance to hydrogen peroxide in Bifidobacterium species.

In the published article, the co-author Abdelmoneim Abdalla's affiliation has been published incompletely. The additional affiliation is given below.

Applicability Domain Dependent Predictive Uncertainty in QSAR Regressions.

Predictive models used in decision making, such as QSARs in chemical regulation or drug discovery, call for evaluated approaches to quantitatively assess associated uncertainty in predictions. Uncertainty in less reliable predictions may be captured by locally varying predictive errors. In the current study, model-based bootstrapping was combined with analogy reasoning to generate predictive distributions varying in magnitude over a model's domain of applicability. A resampling experiment based on PLS regressions on four QSAR data sets demonstrated that predictive errors assessed by k nearest neighbour or weighted PRedicted Error Sum of Squares (PRESS) on samples of external test data or by internal cross-validation improved the performance of the uncertainty assessment. Analogy using similarity defined by Euclidean distances, or differences in standard deviation in perturbed predictions, resulted in better performances than similarity defined by distance to, or density of, the training data. Locally assessed predictive distributions had on average at least as good coverage as Gaussian distribution with variance assessed from the PRESS. An R-code is provided that evaluates performances of the suggested algorithms to assess predictive error based on log likelihood scores and empirical coverage graphs, and which applies these to derive confidence intervals or samples from the predictive distributions of query compounds.

Influence of polysorbate 80 and cyclopropane fatty acid synthase activity on lactic acid production by Lactobacillus casei ATCC 334 at low pH.

Lactic acid is an important industrial chemical commonly produced through microbial fermentation. The efficiency of acid extraction is increased at or below the acid's pKa (pH 3.86), so there is interest in factors that allow for a reduced fermentation pH. We explored the role of cyclopropane synthase (Cfa) and polysorbate (Tween) 80 on acid production and membrane lipid composition in Lactobacillus casei ATCC 334 at low pH. Cells from wild-type and an ATCC 334 cfa knockout mutant were incubated in APT broth medium containing 3 % glucose plus 0.02 or 0.2 % Tween 80. The cultures were allowed to acidify the medium until it reached a target pH (4.5, 4.0, or 3.8), and then the pH was maintained by automatic addition of NH4OH. Cells were collected at the midpoint of the fermentation for membrane lipid analysis, and media samples were analyzed for lactic and acetic acids when acid production had ceased. There were no significant differences in the quantity of lactic acid produced at different pH values by wild-type or mutant cells grown in APT, but the rate of acid production was reduced as pH declined. APT supplementation with 0.2 % Tween 80 significantly increased the amount of lactic acid produced by wild-type cells at pH 3.8, and the rate of acid production was modestly improved. This effect was not observed with the cfa mutant, which indicated Cfa activity and Tween 80 supplementation were each involved in the significant increase in lactic acid yield observed with wild-type L. casei at pH 3.8.

Validation of the Brazilian version in Portuguese of the Thoracic-Lumbar Control Scale for spinal cord injury.

STUDY DESIGN: Prospective clinical study. OBJECTIVES: This study aimed to translate, adapting to Brazilian version in Portuguese, validate and measure inter and intra-examinator reliability and internal consistency of the Thoracic-Lumbar Control Scale instrument. SETTING: State University of Campinas, São Paulo, Brazil. METHODS: This instrument was translated to Brazilian Portuguese by a bilingual translator, and it was retranslated to English for conflict correction and cultural adaptation. Two physiotherapists were previously trained to standardize the scale administration. In all, 22 patients were selected and initially assessed through FIM and American Spinal Injury Association (ASIA) instruments. Furthermore, they were evaluated through the Thoracic-Lumbar Control Scale by two examiners and revaluated 1 week after by only one examinator. RESULTS: The Brazilian Portuguese version of Thoracic-Lumbar Control Scale showed excellent intra and inter-examinator reliability (0.961 and 0.986), high value of internal consistence (0.934) and significant correlation with ASIA sensory score (r=0.83, P=0.001). CONCLUSIONS: The Brazilian Portuguese version of Thoracic-Lumbar Control Scale is a valid and efficient instrument to assess trunk control of after-spinal cord injury patients, which certifies its replicability by other neurology professionals.

Intrinsic and inducible resistance to hydrogen peroxide in Bifidobacterium species.

Interest in, and use of, bifidobacteria as a probiotic delivered in functional foods has increased dramatically in recent years. As a result of their anaerobic nature, oxidative stress can pose a major challenge to maintaining viability of bifidobacteria during functional food storage. To better understand the oxidative stress response in two industrially important bifidobacteria species, we examined the response of three strains of B. longum and three strains of B. animalis subsp. lactis to hydrogen peroxide (H2O2). Each strain was exposed to a range of H2O2 concentrations (0-10 mM) to evaluate and compare intrinsic resistance to H2O2. Next, strains were tested for the presence of an inducible oxidative stress response by exposure to a sublethal H2O2 concentration for 20 or 60 min followed by challenge at a lethal H2O2 concentration. Results showed B. longum subsp. infantis ATCC 15697 had the highest level of intrinsic H2O2 resistance of all strains tested and B. animalis subsp. lactis BL-04 had the highest resistance among B. lactis strains. Inducible H2O2 resistance was detected in four strains, B. longum NCC2705, B. longum D2957, B. lactis RH-1, and B. lactis BL-04. Other strains showed either no difference or increased sensitivity to H2O2 after induction treatments. These data indicate that intrinsic and inducible resistance to hydrogen peroxide is strain specific in B. longum and B. lactis and suggest that for some strains, sublethal H2O2 treatments might help increase cell resistance to oxidative damage during production and storage of probiotic-containing foods.

Catalytic effects by metal oxides on the formation and degradation of chlorinated aromatic compounds in fly ash.

Polychlorinated benzenes, dibenzo-p-dioxins (PCDD), and dibenzofurans (PCDF) may be formed below the combustion temperature in fly ash from municipal solid waste incinerators (MSWI). Copper catalyzes this formation, possibly by the Deacon reaction. Many other elements are also Deacon catalysts or promoters, and here we report results from a statistically designed experiment with 15 metal oxides added to fly ash and heated at 300 degrees C for 2h in an air atmosphere. A resolution IV fractional factorial design with four replicates was completed in 36 runs with the oxides of magnesium, yttrium, titanium, vanadium, niobium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, copper, zinc, and tin. All samples were analyzed for chlorinated benzenes and the results were evaluated by analysis of variance. The addition of copper significantly increased the amounts of the chlorinated benzenes, while cobalt, chromium and vanadium decreased the net formation. The oxides of zinc and iron seemed to have a slightly positive and negative effect respectively. The findings in this study seem to corroborate our previously reported results regarding the different catalytic effects of copper and chromium, and lack of a significant effect by nickel. Besides chromium, it also identifies cobalt and vanadium as potent catalysts for oxidative degradation of the chlorinated aromatic compounds found in MSWI fly ash.

A general structure-property relationship to predict the enthalpy of vaporisation at ambient temperatures.

The vapour pressure is the most important property of an anthropogenic organic compound in determining its partitioning between the atmosphere and the other environmental media. The enthalpy of vaporisation quantifies the temperature dependence of the vapour pressure and its value around 298 K is needed for environmental modelling. The enthalpy of vaporisation can be determined by different experimental methods, but estimation methods are needed to extend the current database and several approaches are available from the literature. However, these methods have limitations, such as a need for other experimental results as input data, a limited applicability domain, a lack of domain definition, and a lack of predictive validation. Here we have attempted to develop a quantitative structure-property relationship (QSPR) that has general applicability and is thoroughly validated. Enthalpies of vaporisation at 298 K were collected from the literature for 1835 pure compounds. The three-dimensional (3D) structures were optimised and each compound was described by a set of computationally derived descriptors. The compounds were randomly assigned into a calibration set and a prediction set. Partial least squares regression (PLSR) was used to estimate a low-dimensional QSPR model with 12 latent variables. The predictive performance of this model, within the domain of application, was estimated at n=560, q2Ext=0.968 and s=0.028 (log transformed values). The QSPR model was subsequently applied to a database of 100,000+ structures, after a similar 3D optimisation and descriptor generation. Reliable predictions can be reported for compounds within the previously defined applicability domain.

Metal catalyzed formation of chlorinated aromatic compounds: a study of the correlation pattern in incinerator fly ash.

Chlorinated aromatics are unintentionally formed and released from combustion and other thermal processes involving organic matter and chlorine. The catalytic activity of incinerator fly ash in the low-temperature formation of chlorinated aromatics has been demonstrated in both laboratory experiments and full-scale trials. Copper has been shown to be an effective catalyst, but several other transition metals possess a similar activity. Here results are reported from a series of full-scale combustion trials with different fractions of household and industrial wastes, with waste from forestry as a reference fuel. The composition of elements and chlorinated aromatics in the fly ash was evaluated with principal component analysis and partial least squares regression. The observed correlation pattern indicates that metals other than copper are of equal importance for the catalytic activity. Chromium and nickel are two of these metals, which may contribute to the de novo formation of chlorinated benzenes, phenols, PCDD and PCDF.

Serum C-reactive protein in elderly men and women: association with mortality, morbidity and various biochemical values.

OBJECTIVE: The primary aim of this study was to define the distribution and the prognostic value of serum C-reactive protein (s-CRP) measured by a high-sensitivity method in elderly subjects of both genders with special reference to the distribution below 10 mg/l. As a secondary aim, a possible gender difference of s-CRP was examined. MATERIAL AND METHODS: Baseline s-CRP was described in a population-based sample of opposite-sex, twin-pairs (197 F, 189 M available for blood-sampling) aged 71-80 years (mean age 74.5 years), considering mortality through the next 4 years, morbidity (myocardial infarction, angina pectoris, congestive heart failure, arterial hypertension, venous thromboembolism, stroke, diabetes, gout, psoriasis, rheumatoid arthritis) before and after blood sampling, biochemical values (serum levels of urate, urea, ApoA1, ApoB, folate, FSH, LH, oestradiol, progesterone, testosterone, cortisol) and anthropometric measurements (body mass index (BMI), circumference of waist, buttocks and hips). RESULTS: The level of s-CRP did not deviate substantially from what has been reported for younger subjects. Higher values indicated an increased risk of cardiovascular morbidity and diabetes in women but not in men. The s-CRP level was associated with serum levels of urate, progesterone, folate, ApoA1, ApoB and the quotient ApoB/ApoA1 as well as with BMI and waist circumference. CONCLUSIONS: For the 71-80 years age group, s-CRP below the 80th percentile (4.3 mg/l) seems to have prognostic capacity mainly in women. The highest association with mortality as well as with cardiovascular diseases, diabetes and rheumatoid arthritis is found for s-CRP above 10 mg/l, which is the arbitrary lower level for the earlier routine low-sensitivity s-CRP methods. The association of s-CRP with serum urate, folate and the ApoB/ApoA1 quotient should be considered.

From major amputation to prosthetic outcome: a prospective study of 190 patients in a defined population.

In this prospective study, the overall treatment and outcome of patients that underwent major lower limb amputation in a defined population is described. The study was performed over a five year period in the Health Care District of North-East Skåne, Sweden. Some 190 patients, permanent inhabitants of the Health Care District, underwent major lower limb amputation. Sixteen (16) of these patients had amputations before the study started and went through late second leg amputation during the period. One hundred and seventy four (174) patients had primary major amputation. Seventy nine (79) were men and 95 were women, with a median age of 81. The re-amputation rate was 17% although the primary knee preservation ratio was as high as 3.0:1. Rigid dressing was the standard method following trans-tibial amputation and was used for 5-7 days. ICEROSS silicone liner was used for compression therapy in 90% of all cases that resulted in delivery of a prosthesis. Prostheses were delivered to 43% of all patients with primary amputations. These patients spent a median of 13 days at the orthopaedic clinic. 55 days at the rehabilitation unit. Pressure casting was used as a standard method in the production of the prosthetic socket. ICEX carbon-fibre socket was used in 52%. New procedures, treatments and techniques were introduced, standardised and evaluated whilst the routines in the hospital were reorganised. In this way, a system has been implemented that better guarantees the outcome of the whole procedure and the service received by this category of patients.

Chlorinated aromatics from combustion: influence of chlorine, combustion conditions, and catalytic activity.

Research on the formation of chlorinated aromatics in combustion processes has mainly taken place in the laboratory. Previous attempts to correlate observation data from commercial plants have been inconclusive. This study reports on the outcome of an industrial experiment in a full-scale afterburner. The influence of chlorine input, combustion temperature, and catalytic activity was investigated in a factorial design with two blocks. Polychlorinated benzenes, dibenzo-p-dioxins, and dibenzofurans were formed both at combustion temperatures and below 400 degrees C. The results show that all three experimental factors have statistically significant impact on the formation and release of these toxic byproducts. The quantitative dependence between chlorine input and the occurrence of chlorinated aromatics is of particular interest due to previous controversy. The purpose with this study was to ensure that the installation of a boiler for energy recovery would not cause elevated emissions of chlorinated aromatics. The experiment demonstrated that this risk is probably low, since the presence of catalytic material or an increase in chlorine input is required for this to happen. A general conclusion was that industrial experimentation employing the principles of statistical design could improve the validity in recommendations regarding commercial plant operation.

Functional outcome after high tibial osteotomy: a study using individual goal achievement as the primary outcome variable.

Functional outcome after high tibial osteotomy (HTO) was evaluated with respect to both improvement and goal achievement. Fifty-seven subjects, 32 men and 25 women, with a mean age of 55 years were examined with the Functional Assessment System (FAS) 6 and 12 months after surgery. The FAS is an evaluation system, specifically designed to monitor lower extremity dysfunction. It shows a profile with preoperative status, individual goal, and postoperative status. Statistically significant improvement was seen in 6/20 variables after 6 months, and in 10/20 variables after 12 months. When goal achievement was examined, the results were not as impressive. The treatment goal was not reached on the group level for almost all variables. On the individual level, only 20\N40% of the patients achieved the goal as a result of surgery in most variables. Exceptions were pain and leisure time/hobbies, where there was a high degree of goal achievement. It is possible that postoperative training was inadequate. The authors recommend a new randomized study, where patients who receive specific individual training related to the individual goal and functional profile are compared with a control group.

Segmental movements of the spine during treadmill walking with normal speed.

OBJECTIVE: The aim of the present work is to investigate the segmental movement patterns of the spine during normal treadmill gait. DESIGN: The spine movement during treadmill gait of ten healthy subjects (five men and five women) has been investigated using an optoelectronic measuring system. METHODS: The spine was divided into seven segments, from C(7) to S(2). The subjects walked with their normal speed. All data were normalized to per cent of the gait cycle. The normal patterns of the spine segment movements were found in the sagittal and the frontal planes. RESULTS: The behaviour of the spine can be described as the motion of a stiff element with superimposed small, inter-segmental movements. These small inter-segmental movements were found both in the sagittal and the frontal planes. CONCLUSIONS: The small inter-segmental movements could play an important role in the reduction of the energy consumption during gait and in maintenance of the equilibrium. RELEVANCE: Any disability affecting the spine should result in changing spine movement pattern during gait, thus changing the overall gait pattern. Therefore, treatment and rehabilitation should not discard the influence of the spine malfunctioning, regardless of its nature.

Relaxed versus activated stump muscles during casting for trans-tibial prostheses.

In prosthetic practice, the question often arises as to whether the hand cast should be made from a contracted or from a non-contracted amputation stump. To elucidate this question, the authors have performed a study to quantify the volume difference between these 2 conditions, and to relate the differences to prosthetic fitting. Sixteen (16) trans-tibial amputees participated in the study. All of them were fitted with an ICEROSS silicone socket. Electromyographic studies, with electrodes attached to the anterior tibial and medial gastrocnemius muscles, were carried out to determine muscle contraction levels. Volume determinations were made with the CAPOD laser scanning system. Measurements were performed with and without the silicone liner on the stump. Without a silicone liner, the volume of the stump increased by 5.8% (SD=5.3) as the muscles contracted. This increase was statistically significant. With the liner donned the volume increased 3.5% (SD=3.3). This increase was also statistically significant. The volume of the prosthetic socket was also compared with the stump volume with a silicone liner on. For the relaxed stump, the difference was 1.8% (SD=10.1), and for the contracted stump -1.7% (SD=11.3). Neither difference was statistically significant. The importance of these volume changes and how they influence stiffness of the coupling between the stump and the socket are discussed. It is concluded, that the observed difference in volume between a contracted and a non-contracted stump are large enough to be considered by the prosthetist in his decision on how to make a hand cast.

Morphological changes during early trans-tibial prosthetic fitting.

Morphological changes in the amputation stump may have serious implications regarding the suspension and fit of the prosthetic socket. In an earlier study (Lilja and Oberg, 1997) the authors have shown that the volume of the trans-tibial amputation stump decreases according to a negative power function after amputation, and that the stump volume does not stabilise until four months after the operation. In the present study, Magnetic Resonance Imaging (MRI) technique was used to examine morphological changes in the amputation stump after trans-tibial amputation in a small number of cases. The authors expected to find a decrease in the cross-sectional area of the stump and of the separate muscles similar to the findings in earlier studies. However, two different patterns were found. The cross-sectional area of the entire stump as well as that of the medial muscle group changed according to the authors' hypothesis, i.e. an initial fast decrease, followed by a more moderate decrease of the area. In the lateral muscle group another pattern was found. After an initial rapid decrease the area increased, sometimes to a magnitude larger than the initial value. After the amputation the lateral muscle group may acquire a new function, contributing to the suspension of the socket. Despite the limited number of patients, this study presents findings which may be important in the clinical fitting of trans-tibial prostheses.

Accuracy and precision of volumetric determinations using two commercial CAD systems for prosthetics: a technical note.

The aim of this study was to evaluate the validity and reliability of volume determinations using the commercially available Seattle ShapeMaker CAD/CAM system for production of prosthetic sockets and to compare it with the commercially available CAPOD system. We used three types of reference objects for volumetric determinations: steel tubes, plaster of Paris casts, and residual limb models. Three different sizes were examined for each type of object. Volume measurements with the two CAD/CAM systems were compared with measurements obtained by water filling, water immersion, or mathematical calculation (tubes only). We found an inconsistent systematic error of less than 3.1% for ShapeMaker and no systematic error for CAPOD. Random errors, represented by the coefficient of variation, were below 1.3% for the ShapeMaker and, in most cases, below 0.4% for the CAPOD. Theoretical changes in volume of 2.6% and 0.8% are possible to detect with these CAD/CAM systems. In our opinion, both systems have sufficient precision for routine clinical use in prosthetics and orthotics. However, in our study, the ShapeMaker committed larger random and systematic errors than CAPOD. This means that, according to our study, CAPOD offers the best possibility to determine and detect small changes in residual limb volume as a function of time.

Worse functional status among old people when admitted for arthroplasty--an evaluation with a new assessment system.

The aim of this study was to investigate whether there is a difference in functional status between younger and elderly people referred to an orthopaedic clinic for total joint replacement. A total of 709 patients with osteoarthritis of the hip or knee (aged 27-91 years) and 42 healthy controls (aged 42-83 years) were examined with a new Functional Assessment System (FAS) for lower extremity dysfunction. Age effects were explored by one-way analysis of variance. Older people showed higher dysfunction scores in almost all variables, with the exception of pain, where there was an inverse relationship, i.e, old people had lower disability scores. This age-related increase in disability scores was not observed in the control group. Old people seem to be referred for joint replacement on different grounds from those of younger people, despite the fact that age was not included in the criteria for arthroplasty. The results may indicate a hidden, age-related criterion in the selection of patients for arthroplasty. Different interpretations are discussed.

Work load, fatigue, and pause patterns in clinical dental hygiene.

PURPOSE: Previous studies have suggested that high frequencies of shoulder and neck complaints in dental hygienists mainly were due to longstanding, low-level static load of the neck and shoulder muscles. The purpose of the present study was to make continuous recordings of myoelectric signals from the shoulder muscles of dental hygienists in order to assess static load. METHODS: Myoelectric signals were recorded from the right trapezius muscle of 10 Swedish dental hygienists during half of a normal working day. A portable system for collection and on-line processing of myoelectric signals was used. Signal parameters were obtained, indicating muscular load, fatigue, pause frequency, and pause duration, respectively. All measurements were referred to a resting value and a reference contraction value established with the hand loaded with a 0.5 kg weight at the beginning of the recording session. RESULTS: A static load of 50 to 100% of the reference contraction (0.5 kg hand load with raised arm) was found in the trapezius muscle. The median load for the whole group was 57% of the reference level. Group data analyses of frequency EMG seldom showed significant fatigue. At individual levels, however, it was possible to identify localized muscle fatigue and relate it to a specific work task. There were many short pauses with a duration of 1 to 2 seconds, but an almost total lack of pauses of a duration longer than five seconds. CONCLUSIONS: Individual dental hygienists exhibited significant muscle fatigue that might be related to development of work related myalgias of the shoulder muscles. Future study of muscle patterns and dental hygiene tasks may lead to improved work designs and patterns for dental hygienists.

Volumetric determinations with CAD/CAM in prosthetics and orthotics: errors of measurement.

During the next decade CAD/CAM technique will probably become routine in prosthetics and orthotics, not only as a complement to manual techniques, but also introducing new possibilities. However, even complex and sophisticated techniques have errors of measurement that must be considered. Such errors are of two principal kinds: systematic errors and random errors. In this study we have evaluated the Swedish CAPOD system with respect to volumetric determinations. We used two types of reference objects for volume determinations: cylinders and amputation residual limb models. Three different sizes were examined of each type of object. Volume measurements with CAPOD were compared with volumes obtained by water immersion or mathematical calculation (cylinders only). We found a constant, linear systematic error of +2.5%. Such an error can easily be corrected for. The random error, represented by the coefficient of variation, was 0.5%, which means that there is a theoretical possibility to detect volume changes exceeding 1%. We consider the precision sufficient for clinical practice in prosthetics and orthotics. Biological variations due to soft tissue deformation must be added on top of these errors. Such deformations were not evaluated in this study.