Precision Medicine for More Oxygen (P4O2)-Study Design and First Results of the Long COVID-19 Extension

Introduction: The coronavirus disease 2019 (COVID-19) pandemic has led to the death of almost 7 million people, however, with a cumulative incidence of 0.76 billion, most people survive COVID-19. Several studies indicate that the acute phase of COVID-19 may be followed by persistent symptoms including fatigue, dyspnea, headache, musculoskeletal symptoms, and pulmonary functional-and radiological abnormalities. However, the impact of COVID-19 on long-term health outcomes remains to be elucidated. Aims: The Precision Medicine for more Oxygen (P4O2) consortium COVID-19 extension aims to identify long COVID patients that are at risk for developing chronic lung disease and furthermore, to identify treatable traits and innovative personalized therapeutic strategies for prevention and treatment. This study aims to describe the study design and first results of the P4O2 COVID-19 cohort. Methods: The P4O2 COVID-19 study is a prospective multicenter cohort study that includes nested personalized counseling intervention trial. Patients, aged 40-65 years, were recruited from outpatient post-COVID clinics from five hospitals in The Netherlands. During study visits at 3-6 and 12-18 months post-COVID-19, data from medical records, pulmonary function tests, chest computed tomography scans and biological samples were collected and questionnaires were administered. Furthermore, exposome data was collected at the patient's home and state-of-the-art imaging techniques as well as multi-omics analyses will be performed on collected data. Results: 95 long COVID patients were enrolled between May 2021 and September 2022. The current study showed persistence of clinical symptoms and signs of pulmonary function test/radiological abnormalities in post-COVID patients at 3-6 months post-COVID. The most commonly reported symptoms included respiratory symptoms (78.9%), neurological symptoms (68.4%) and fatigue (67.4%). Female sex and infection with the Delta, compared with the Beta, SARS-CoV-2 variant were significantly associated with more persisting symptom categories. Conclusions: The P4O2 COVID-19 study contributes to our understanding of the long-term health impacts of COVID-19. Furthermore, P4O2 COVID-19 can lead to the identification of different phenotypes of long COVID patients, for example those that are at risk for developing chronic lung disease. Understanding the mechanisms behind the different phenotypes and identifying these patients at an early stage can help to develop and optimize prevention and treatment strategies.

Microalgae as biological treatment for municipal wastewater - effects on the sludge handling in a treatment plant

A mix of microalgae and bacteria was cultivated on pre-sedimented municipal wastewater in a continuous operated microalgae-activated sludge process. The excess material from the process was co-digested with primary sludge in mesophilic and thermophilic conditions in semi-continuous mode (5 L digesters). Two reference digesters (5 L digesters) fed with waste-activated sludge (WAS) and primary sludge were operated in parallel. The methane yield was slightly reduced (≈10%) when the microalgal-bacterial substrate was used in place of the WAS in thermophilic conditions, but remained approximately similar in mesophilic conditions. The uptake of heavy metals was higher with the microalgal-bacterial substrate in comparison to the WAS, which resulted in higher levels of heavy metals in the digestates. The addition of microalgal-bacterial substrate enhanced the dewaterability in thermophilic conditions. Finally, excess heat can be recovered in both mesophilic and thermophilic conditions.

Anaerobic co-digestion of sludge and microalgae grown in municipal wastewater - a feasibility study

In this study a natural mix of microalgae grown in wastewater of municipal character was co-digested with sewage sludge in mesophilic conditions, in both batch and semi-continuous modes. The semi-continuous experiment was divided into two periods with OLR₁ (organic loading rate) of 2.4 kg volatile solids (VS) m^-3 d^-1 and HRT₁ (hydraulic retention time) of 15 days, and OLR₂ of 3.5 kg VS m^-3 d^-1 and HRT₂ of 10 days, respectively. Results showed stable conditions during both periods. The methane yield was reduced when adding microalgae (from 200 ± 25 NmL CH₄ g VS_in^-1, to 168 ± 22 NmL CH₄ g VS_in^-1) but VS reduction was also decreased by 51%. This low digestibility was confirmed in the anaerobic batch test. However, adding microalgae improved the dewaterability of the digested sludge. The high heavy metals content in the microalgae resulted in a high heavy metals content in the digestate, making it more difficult to reuse the digestate as fertilizer on arable land. The heavy metals are thought to originate from the flue gas used as a CO₂ source during the microalgae cultivation. Therefore the implementation of CO₂ mitigation via algal cultivation requires careful consideration regarding the source of the CO₂-rich gas.

Life cycle assessment of sludge management with phosphorus utilisation and improved hygienisation in Sweden

To provide input to sewage sludge management strategies that address expected new regulations in terms of hygienisation and phosphorus recovery in Sweden, an environmental life cycle assessment (LCA) was made. The LCA identified environmental hot spots for methods that may permit sludge or phosphorus from sludge to be applied on agricultural land. In particular, thermophilic digestion, pasteurisation, thermal hydrolysis, urea treatment and mono-incineration with phosphorus recovery were compared. In addition, a sludge management system involving drying of sludge before use in forestry was investigated. The results showed that some major impacts are related to large uncertainties, such as those related to emissions from sludge storage. It also showed that large gains can be achieved when products from the systems replace other products, in particular when biogas is used to replace natural gas in vehicles, but also when sludge is used in agriculture and forestry. In general, there are small differences between the sludge management methods. Retaining the sludge matrix to allow for its utilisation in agriculture may conflict with keeping emissions to air and water from the sludge matrix low. It is recommended that any sludge management option minimises emissions from sludge to air and water and that resources are recovered and used, in line with the principles of a circular economy.

Low doses of eicosapentaenoic acid and docosahexaenoic acid from fish oil dose-dependently decrease serum triglyceride concentrations in the presence of plant sterols in hypercholesterolemic men and women

Plant sterols (PSs) lower LDL cholesterol (LDL-C) concentrations, whereas the n-3 (ω-3) fish fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) lower triglyceride (TG) concentrations. Incorporating both PSs and EPA+DHA from fish oil (FO) in a single food format was expected to beneficially affect 2 blood lipid risk factors. The aim of this study was to investigate the dose-response relation between low doses (<2 g/d) of EPA+DHA from FO, incorporated in a low-fat PS-enriched spread, and TG concentrations. In addition, effects on LDL-C were investigated. The study was designed as a randomized, double-blind, placebo-controlled parallel study. After a 4-wk run-in period, subjects were randomly assigned to consume either a control (C) spread (no PSs, no FO) or 1 of 4 intervention spreads containing a fixed amount of PSs (2.5 g/d) and varying amounts of FO (0.0, 0.9, 1.3, and 1.8 g/d of EPA+DHA) for 4 wk. Before and after the intervention, fasting blood samples were drawn for measuring serum lipids and EPA and DHA in erythrocyte membranes. In total, 85 hypercholesterolemic men and 247 women with a mean age of 57.9 y (range: 25-74 y) were included. Eighteen subjects dropped out during the study. At baseline, mean TG and LDL-C concentrations were 1.09 and 4.00 mmol/L, respectively. After the intervention, a significant dose-response relation for the TG-lowering effect of EPA+DHA [βln (TG) = -0.07 mmol/L per gram of EPA+DHA; P < 0.01] was found. Compared with the C group, TG concentrations were 9.3-16.2% lower in the different FO groups (P < 0.05 for all groups). LDL-C concentrations were 11.5-14.7% lower in the different PS groups than in the C group (P < 0.01 for all groups). EPA and DHA in erythrocyte membranes were dose-dependently higher after FO intake than after the C spread, indicating good compliance. Consumption of a low-fat spread enriched with PSs and different low doses of n-3 fatty acids from FO decreased TG concentrations in a dose-dependent manner and decreased LDL-C concentrations. This trial was registered at clinicaltrials.gov as NCT01313988.

Impacts of climate change on rainfall extremes and urban drainage systems: a review

A review is made of current methods for assessing future changes in urban rainfall extremes and their effects on urban drainage systems, due to anthropogenic-induced climate change. The review concludes that in spite of significant advances there are still many limitations in our understanding of how to describe precipitation patterns in a changing climate in order to design and operate urban drainage infrastructure. Climate change may well be the driver that ensures that changes in urban drainage paradigms are identified and suitable solutions implemented. Design and optimization of urban drainage infrastructure considering climate change impacts and co-optimizing these with other objectives will become ever more important to keep our cities habitable into the future.

A longitudinal study of physical function in patients with early-onset dementia

Background

The aim of this study was to explore changes in mobility in terms of ambulation and transfer over 1 year in patients with early-onset Alzheimer's disease (EOAD), and to compare mobility in EOAD with patients with other types of early-onset dementia (EOOD).

Method

Forty-two patients with EOAD and 30 patients with EOOD were included. All patients were home-dwelling and had mild or moderate degree of dementia. Mobility was assessed using the Timed Up and Go Test (TUG), a modified version of the Clinical Outcome Variables Scale, timed stair walking, and timed rise from the floor.

Results

The EOAD group performed significantly better than the EOOD group on all mobility tests. After 1 year, 25 persons with EOAD were tested again. The performance on TUG (p = 0.028) and stair walking (p = 0.02) had deteriorated at the 1-year follow-up in the EOAD group.

Conclusion

Patients with EOAD performed better on mobility tasks than patients with EOOD, but their performance deteriorated at 1-year follow-up.

Whole grain rye breakfast - sustained satiety during three weeks of regular consumption

Whole grain rye products have previously been shown to increase feelings of satiety for up to 8h after intake under standardized conditions. This study was set out to investigate the sustainability of the satiating effect after regular consumption of breakfast meals with whole grain rye porridge or refined wheat bread. The study was randomized, cross-over and double-blind. Healthy subjects (n=24) were randomly assigned to daily consumption of iso-caloric standardized breakfast meals with whole grain rye porridge or refined wheat bread for two 3-wk phases, separated by a wash out of 3-4weeks. Each intervention phase had 3 scheduled visit days (days 1, 8 and 22) when appetite ratings (hunger, satiety and desire to eat) were registered for 24h at standardized conditions. Orocecal transit time (salicylazosulfapyridine/sulfapyridine method) and breath hydrogen as an indicator of colonic fermentation were measured at day 8 of each 3-wk phase in a subgroup (n=16). To investigate effects of breakfast on free-living food intake, 3-day weighed food diaries were self-registered during both intervention phases. Whole grain rye porridge breakfast resulted in higher ratings of satiety and lower hunger and desire to eat during 4h post consumption compared to refined wheat bread breakfast (p<0.001). This effect was sustained throughout the 3-wk study phases. Unlike previous studies, the effects did not persist into the afternoon (4-8h). The orocecal transit times after consumption of both breakfasts were similar and in the range of 5-6h. The rye porridge resulted in high levels of breath hydrogen 4-8h after intake, showing extensive colonic fermentation. This was however not related to any changes in appetite during this time-period. There were no significant differences in self-reported macronutrient- and energy intake between diets. This study shows that the satiating effect of rye persists after repeated daily consumption for up to three weeks. Clinicaltrials.gov Identifier: NCT01117363.

Paediatric drug use with focus on off-label prescriptions in Swedish outpatient care--a nationwide study

AIM

To determine drug prescription and proportion of off-label dispensing in the Swedish paediatric outpatient population.

METHODS

All dispensed outpatient prescriptions to children aged 0 < 18 years as well as the proportion of off-label drug use during 2007 were analysed using data from the Swedish Prescribed Drug Register.

RESULTS

In total, 2.19 million drug prescriptions of 898 different drug substances were dispensed to paediatric patients, and of those substances, 64% had been dispensed off-label at least once. The overall off-label rate of all prescriptions was 13.5%, among which topical drugs as well as sex hormones were the most commonly prescribed off-label drugs. More than half of all children in Sweden had received at least one prescribed drug in 2007.

CONCLUSIONS

There is a high prescribing of medicines to children in outpatient care in Sweden with a considerable amount of off-label prescriptions. Topically administered drugs, sex hormones, antidepressants, hypnotics, cardiovascular drugs and nonsteroidal anti-inflammatory drugs were commonly prescribed off-label.

Genetic population structure of perch Perca fluviatilis along the Swedish coast of the Baltic Sea

In this study, the genetic variation of perch Perca fluviatilis from 18 different sites along the Swedish coast of the Baltic Sea was assessed. There was a relative strong support for isolation by distance and the results suggest an overall departure from panmixia. The level of genetic divergence was moderate (global F(ST) = 0·04) and indications of differences in the population genetic structure between the two major basins (central Baltic Sea and Gulf of Bothnia) in the Baltic Sea were found. There was a higher level of differentiation in the central Baltic Sea compared to the Gulf of Bothnia, and the results suggest that stretches of deep water might act as barriers to gene flow in the species. On the basis of the estimation of genetic patch size, the results corroborate previous mark--recapture studies and suggest that this is a species suitable for local management. In all, the findings of this study emphasize the importance of considering regional differences even when strong isolation by distance characterize the genetic population structure of species.

Effects of probiotic fermented milk on symptoms and intestinal flora in patients with irritable bowel syndrome: a randomized, placebo-controlled trial

OBJECTIVE

The effect of probiotics on IBS symptoms has been mixed, but remains an intriguing treatment option with appeal to the patient.

MATERIAL AND METHODS

Patients fulfilling the Rome II criteria were randomized double-blind to a daily intake of 500 ml of fermented milk containing at least 5 × 10(7) CFU/ml of Lactobacillus paracasei ssp paracasei F19, Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 or an equal volume of acidified milk for 8 weeks. Symptoms were assessed at baseline and weekly using a disease-specific validated symptom rating scale (IBS-SSI). The predefined primary outcome measure was patient reported adequate symptom relief. Adherence to study protocol were assessed by performing stool samples at the of the treatment period.

RESULTS

Eight-one patients were screened. Sixty-four patients were randomized; 18 patients did not complete the study due to protocol violations or withdrew due to lack of effect. Fifty-two patients (13 males) completed the study as per protocol; mean age was 51.3 years (range 29-67). The proportion of patients reporting adequate symptom relief increased in both patient groups, but there was not any statistical difference between the groups. IBS-SSI scores did not differ statistically between the groups at the end of the treatment period, but improved during the study period in both groups.

CONCLUSIONS

During this 8-week trial gastrointestinal symptoms improved. However, there was no difference between treatment with fermented milk containing probiotics or acidified milk. The effect of probiotics on IBS symptoms remains uncertain and further studies are warranted.

Effects of probiotic fermented milk on symptoms and intestinal flora in patients with irritable bowel syndrome: a randomized, placebo-controlled trial

OBJECTIVE

The effect of probiotics on IBS symptoms has been mixed, but remains an intriguing treatment option with appeal to the patient.

MATERIAL AND METHODS

Patients fulfilling the Rome II criteria were randomized double-blind to a daily intake of 500 ml of fermented milk containing at least 5 × 10(7) CFU/ml of Lactobacillus paracasei ssp paracasei F19, Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 or an equal volume of acidified milk for 8 weeks. Symptoms were assessed at baseline and weekly using a disease-specific validated symptom rating scale (IBS-SSI). The predefined primary outcome measure was patient reported adequate symptom relief. Adherence to study protocol were assessed by performing stool samples at the of the treatment period.

RESULTS

Eight-one patients were screened. Sixty-four patients were randomized; 18 patients did not complete the study due to protocol violations or withdrew due to lack of effect. Fifty-two patients (13 males) completed the study as per protocol; mean age was 51.3 years (range 29-67). The proportion of patients reporting adequate symptom relief increased in both patient groups, but there was not any statistical difference between the groups. IBS-SSI scores did not differ statistically between the groups at the end of the treatment period, but improved during the study period in both groups.

CONCLUSIONS

During this 8-week trial gastrointestinal symptoms improved. However, there was no difference between treatment with fermented milk containing probiotics or acidified milk. The effect of probiotics on IBS symptoms remains uncertain and further studies are warranted.

Preferred sound levels of portable music players and listening habits among adults: a field study

The main purpose of this descriptive field study was to explore music listening habits and preferred listening levels with portable music players (PMPs). We were also interested in seeing whether any exposure differences could be observed between the sexes. Data were collected during 12 hours at Stockholm Central Station, where people passing by were invited to measure their preferred PMP listening level by using a KEMAR manikin. People were also asked to answer a questionnaire about their listening habits. In all, 60 persons (41 men and 19 women) took part in the questionnaire study and 61 preferred PMP levels to be measured. Forty-one of these sound level measurements were valid to be reported after consideration was taken to acceptable measuring conditions. The women (31 years) and the men (33 years) started to use PMPs on a regular basis in their early 20s. Ear canal headphones/ear buds were the preferred headphone types. Fifty-seven percent of the whole study population used their PMP on a daily basis. The measured LAeq60 sec levels corrected for free field ranged between 73 and 102 dB, with a mean value of 83 dB. Sound levels for different types of headphones are also presented. The results of this study indicate that there are two groups of listeners: people who listen less frequently and at lower, safer sound levels, and people with excessive listening habits that may indeed damage their hearing sensory organ in time.

Rye kernel breakfast increases satiety in the afternoon - an effect of food structure

Background

The structure of whole grain cereals is maintained to varying degrees during processing and preparation of foods. Food structure can influence metabolism, including perceived hunger and satiety. A diet that enhances satiety per calorie may help to prevent excessive calorie intake. The objective of this work was to compare subjective appetite ratings after consumption of intact and milled rye kernels.

Methods

Two studies were performed using a randomized, cross-over design. Ratings for appetite (hunger, satiety and desire to eat) were registered during an 8-h period after consumption of whole and milled rye kernels prepared as breads (study 1, n = 24) and porridges (study 2, n = 20). Sifted wheat bread was used as reference in both study parts and the products were eaten in iso-caloric portions with standardized additional breakfast foods. Breads and porridges were analyzed to determine whether structure (whole vs. milled kernels) effected dietary fibre content and composition after preparation of the products. Statistical evaluation of the appetite ratings after intake of the different breakfasts was done by paired t-tests for morning and afternoon ratings separately, with subjects as random effect and type of breakfast and time points as fixed effects.

Results

All rye breakfasts resulted in higher satiety ratings in the morning and afternoon compared with the iso-caloric reference breakfast with sifted wheat bread. Rye bread with milled or whole kernels affected appetite equally, so no effect of structure was observed. In contrast, after consumption of the rye kernel breakfast, satiety was increased and hunger suppressed in the afternoon compared with the milled rye kernel porridge breakfast. This effect could be related to structural differences alone, because the products were equal in nutritional content including dietary fibre content and composition.

Conclusions

The study demonstrates that small changes in diet composition such as cereal grain structure have the potential to effect feelings of hunger and satiety.

Trial registration

This trial was registered at clinicaltrials.gov as NCT01042418.

Characterization and reduction of noise in dynamic PET data using masked volumewise principal component analysis

Masked volumewise principal component (PC) analysis (PCA) is used in PET to distinguish structures that display different kinetic behaviors after administration of a tracer. When masked volumewise PCA was introduced, one article proposed noise prenormalization because of temporal and spatial variations of the noise between slices. However, the noise prenormalization proposed in that article was applicable only to datasets reconstructed using filtered backprojection (FBP). The study presented in this article aimed at developing a new noise prenormalization that is applicable to datasets regardless of whether they were reconstructed with FBP or an iterative reconstruction algorithm, such as ordered-subset expectation maximization (OSEM).

METHODS

A phantom study was performed to investigate differences in the expectation values and SDs of datasets reconstructed with FBP and OSEM. A novel method, higher-order PC noise prenormalization, was suggested and evaluated against other prenormalization methods on clinical datasets.

RESULTS

Masked volumewise PCA of data reconstructed with FBP was much more dependent on an appropriate prenormalization than was analysis of data reconstructed with OSEM. Higher-order PC noise prenormalization showed an overall good performance with both FBP and OSEM reconstructions, whereas the other prenormalization methods performed well with only 1 of the 2 methods.

CONCLUSION

Higher-order PC noise prenormalization has potential for improving the results from masked volumewise PCA on dynamic PET datasets independent of the type of reconstruction algorithm.

Effect of a vegetable-oil emulsion on body composition; a 12-week study in overweight women on a meal replacement therapy after an initial weight loss: a randomized controlled trial

Purpose

The maintenance of an obtained lower weight level is often found to be difficult. The aim of this study was to determine weight maintenance after an initial weight loss by consumption of a meal replacement with a vegetable-oil emulsion associated with prolonged satiety.

Methods

After a 6-week weight loss period with very low calorie diet (VLCD), subjects with >5% body weight (BW) loss were randomized to a 12-week weight maintenance follow-up period, comparing a partial meal replacement diet containing a vegetable-oil emulsion (test) or dairy fat (control). Anthropometric data and safety variables were collected at baseline and after 4, 8 and 12 weeks.

Results

A significant weight loss was observed during the 12-week weight maintenance diet in the test and control group, respectively; 1.0 ± 2.1 kg (p < 0.05) versus 1.3 ± 2.1 kg (p < 0.05) with no significant difference between the groups. Body fat mass (BFM) decreased significantly (p < 0.05) in the test group (−1.7%) compared to the control group (−0.8%).

Conclusions

Addition of a vegetable-oil emulsion to a meal replacement weight maintenance program after an initial weight loss using VLCD was associated with decreased BFM by 0.9% without any change in BW between the two groups.

Signal extraction and separation in in vivo animal PET studies with masked volumewise principal-component analysis

The standardized uptake value is commonly used as a tool to supplement visual interpretation and to quantify the images acquired from static in vivo animal PET. The preferred approach for analyzing PET data is either to sum the images and calculate the standardized uptake value or to use kinetic modeling. The aim of this study was to investigate the performance of masked volumewise principal-component analysis (MVW-PCA) used in dynamic in vivo animal PET studies to extract and separate signals with different kinetic behaviors.

METHODS

PET data were acquired with a small-animal PET scanner and a fluorine tracer in a study of rats and mice. After acquisition, the data were reconstructed by use of 4 time protocols with different frame lengths. Data were analyzed by use of MVW-PCA with applied noise prenormalization and a new masking technique developed in this study.

RESULTS

The resulting principal-component images showed a clear separation of the activity in the spine into the first MVW-PCA component and the activity in the kidneys into the second MVW-PCA component. In addition, the different time protocols were shown to have little or no impact on the results obtained with MVW-PCA.

CONCLUSION

MVW-PCA can efficiently separate different kinetic behaviors into different principal-component images. Moreover, MVW-PCA is a stable technique in the sense that the time protocol chosen has only a small impact on the resulting principal-component images.

Effect of fat emulsion (Fabuless) on orocecal transit time in healthy men

BACKGROUND

Given the growing prevalence of overweight and related health consequences, there is increased interest in the search for novel dietary strategies for weight control. A food ingredient, an emulsion based on palm and oat oil (Fabuless, previously known as Olibra), has been associated with short-term reductions of food intake, induction of satiety, alternation in the satiety hormones, as well as long-term effects on weight control. The mechanism by which it can exert these effects is so far unclear, though it has been suggested that the "ileal break" may play a role in increasing gastrointestinal transit time. The aim of this study was to investigate the effects of this stable fat emulsion on orocecal transit time in healthy men.

MATERIAL AND METHODS

In a controlled, double-blind, cross-over-designed study, 15 healthy men (aged 20-59 years, body mass index (BMI) 22-28), randomly allocated to two treatments, consumed the stable fat emulsion or a milk fat in yoghurt during two days of investigation, with an interval of 1 week. Orocecal transit time was determined by following blood sulfapyridine levels, which is a metabolite of salazopyrine in the colon.

RESULTS

A statistically significant delay in the appearance of sulfapyridine in serum was obtained after active treatment versus control treatment, corresponding to a 45-min longer orocecal transit time due to fat emulsion consumption.

CONCLUSIONS

This study provides the first evidence to suggest that this stable fat emulsion may affect the ileal brake mechanism by slowing down the gastrointestinal transit time, which might explain the weight control and appetite suppression previously observed in association with this emulsion.

Clinical trial: the effects of a fermented milk containing three probiotic bacteria in patients with irritable bowel syndrome - a randomized, double-blind, controlled study

BACKGROUND

The effects of probiotic bacteria in IBS remain controversial.

AIM

To study the effects of a probiotic product on IBS symptoms.

METHODS

We randomized 74 IBS patients to receive 8 weeks of daily treatment with 400 mL milk fermented with the yoghurt bacteria and containing Lactobacillus paracasei, ssp. paracasei F19, Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 (Cultura; active) or acidified milk without these bacteria (control). The primary endpoint was the proportion of subjects reporting adequate relief of their IBS symptoms at least 50% of the weeks. IBS symptom severity, psychological symptoms and quality of life were assessed.

RESULTS

The proportion of responders was 38% (14/37 patients) in the active group and 27% (10/37 patients) in the control group (P = 0.3). IBS symptom severity improved significantly in both groups during the treatment period. This change was greater in the active group during the first 2 weeks, but thereafter, no significant group differences were seen.

CONCLUSIONS

We could not detect a clearly positive effect of fermented milk containing three probiotic bacteria on GI symptoms in IBS patients compared with the control treatment. However, a trend towards a more favourable effect during the first weeks was seen in the active group.

Transferability of a tetracycline resistance gene from probiotic Lactobacillus reuteri to bacteria in the gastrointestinal tract of humans

The potential of Lactobacillus reuteri as a donor of antibiotic resistance genes in the human gut was investigated by studying the transferability of the tetracycline resistance gene tet(W) to faecal enterococci, bifidobacteria and lactobacilli. In a double-blind clinical study, seven subjects consumed L. reuteri ATCC 55730 harbouring a plasmid-encoded tet(W) gene (tet(W)-reuteri) and an equal number of subjects consumed L. reuteri DSM 17938 derived from the ATCC 55730 strain by the removal of two plasmids, one of which contained the tet(W) gene. Faecal samples were collected before, during and after ingestion of 5 x 10(8) CFU of L. reuteri per day for 14 days. Both L. reuteri strains were detectable at similar levels in faeces after 14 days of intake but neither was detected after a two-week wash-out period. After enrichment and isolation of tetracycline resistant enterococci, bifidobacteria and lactobacilli from each faecal sample, DNA was extracted and analysed for presence of tet(W)-reuteri using a real-time PCR allelic discrimination method developed in this study. No tet(W)-reuteri signal was produced from any of the DNA samples and thus gene transfer to enterococci, bifidobacteria and lactobacilli during intestinal passage of the probiotic strain was non-detectable under the conditions tested, although transfer at low frequencies or to the remaining faecal bacterial population cannot be excluded.

Effect of rye bread breakfasts on subjective hunger and satiety: a randomized controlled trial

BACKGROUND

Several studies report that dietary fibre from different sources promotes the feeling of satiety and suppresses hunger. However, results for cereal fibre from rye are essentially lacking. The aim of the present study was to investigate subjective appetite during 8 h after intake of iso-caloric rye bread breakfasts varying in rye dietary fibre composition and content.

METHODS

The study was divided into two parts. The first part (n = 16) compared the satiating effect of iso-caloric bread breakfasts including different milling fractions of rye (bran, intermediate fraction (B4) and sifted flour). The second part (n = 16) investigated the dose-response effect of rye bran and intermediate rye fraction, each providing 5 or 8 g of dietary fibre per iso-caloric bread breakfast. Both study parts used a wheat bread breakfast as reference and a randomised, within-subject comparison design. Appetite (hunger, satiety and desire to eat) was rated regularly from just before breakfast at 08:00 until 16:00. Amount, type and timing of food and drink intake were standardised during the study period.

RESULTS

The Milling fractions study showed that each of the rye breakfasts resulted in a suppressed appetite during the time period before lunch (08:3012:00) compared with the wheat reference bread breakfast. At a comparison between the rye bread breakfasts the one with rye bran induced the strongest effect on satiety. In the afternoon the effect from all three rye bread breakfasts could still be seen as a decreased hunger and desire to eat compared to the wheat reference bread breakfast.In the Dose-response study both levels of rye bran and the lower level of intermediate rye fraction resulted in an increased satiety before lunch compared with the wheat reference bread breakfast. Neither the variation in composition between the milling fractions nor the different doses resulted in significant differences in any of the appetite ratings when compared with one another.

CONCLUSION

The results show that rye bread can be used to decrease hunger feelings both before and after lunch when included in a breakfast meal. Rye bran induces a stronger effect on satiety than the other two rye fractions used when served in iso-caloric portions.

TRIAL REGISTRATION

Trial registration number NCT00876785.

The osmotic link between hypoglycaemia and hypovolaemia

OBJECTIVE

Hypoglycaemia is regularly accompanied by hypovolaemia. To suggest a mechanism for this phenomenon, we reviewed data from eight studies conducted by our group and examined the circumstances under which rebound hypoglycaemia develops after intravenous infusion of glucose solutions.

MATERIAL AND METHODS

Forty healthy volunteers and 40 patients received a total of 122 infusions of glucose solutions at different rates, volumes and concentrations. Plasma glucose and the haemodilution were measured repeatedly during and for at least 2 h after the infusions ended. Glucose kinetics was calculated using a one-compartment turnover model and the plasma volume expansion was estimated from changes in Hb.

RESULTS

A strong linear correlation was found between the glucose level and the plasma volume expansion in all series of experiments (p<0.001). After infusion, there was a risk of hypoglycaemia and hypovolaemia developing in healthy volunteers with a high glucose clearance and when infusing glucose solutions of higher concentrations than 2.5 %. Few and mild hypoglycaemic events occurred in patients with insulin resistance, such as in diabetics and in those undergoing surgery. The immediate linear relationship between hypoglycaemia and hypovolaemia suggests an osmotic link between the two parameters. More specifically, infused fluid accompanies glucose during uptake into the cells, while volume expansion by the same fluid has already elicited an effective diuretic response.

CONCLUSION

Hypovolaemia is a consequence of hypoglycaemia after intravenous infusion of glucose solution and is caused by the osmotic translocation of fluid from the extracellular to the intracellular fluid space that occurs despite effective renal elimination.

Performance of principal component analysis and independent component analysis with respect to signal extraction from noisy positron emission tomography data - a study on computer simulated images

Multivariate image analysis tools are used for analyzing dynamic or multidimensional Positron Emission Tomography, PET data with the aim of noise reduction, dimension reduction and signal separation. Principal Component Analysis is one of the most commonly used multivariate image analysis tools, applied on dynamic PET data. Independent Component Analysis is another multivariate image analysis tool used to extract and separate signals. Because of the presence of high and variable noise levels and correlation in the different PET images which may confound the multivariate analysis, it is essential to explore and investigate different types of pre-normalization (transformation) methods that need to be applied, prior to application of these tools. In this study, we explored the performance of Principal Component Analysis (PCA) and Independent Component Analysis (ICA) to extract signals and reduce noise, thereby increasing the Signal to Noise Ratio (SNR) in a dynamic sequence of PET images, where the features of the noise are different compared with some other medical imaging techniques. Applications on computer simulated PET images were explored and compared. Application of PCA generated relatively similar results, with some minor differences, on the images with different noise characteristics. However, clear differences were seen with respect to the type of pre-normalization. ICA on images normalized using two types of normalization methods also seemed to perform relatively well but did not reach the improvement in SNR as PCA. Furthermore ICA seems to have a tendency under some conditions to shift over information from IC1 to other independent components and to be more sensitive to the level of noise. PCA is a more stable technique than ICA and creates better results both qualitatively and quantitatively in the simulated PET images. PCA can extract the signals from the noise rather well and is not sensitive to type of noise, magnitude and correlation, when the input data are correctly handled by a proper pre-normalization. It is important to note that PCA as inherently a method to separate signal information into different components could still generate PC1 images with improved SNR as compared to mean images.

Use of calcium channel blockers and beta blockers as antihypertensives in relation to mortality in type 2 diabetes patients: a population-based observational study

OBJECTIVES

In previous trials, patients with type 2 diabetes using calcium channel blockers (CCB) have suffered a less favourable outcome when compared with patients on other treatments. The present study was designed to compare mortality in type 2 diabetes patients using either CCB or beta blockers (BB) as antihypertensive agents.

DESIGN

Retrospective observational study. Patients were followed from the first day they were on either of the study drugs until 31 December 1996, or until death.

SETTINGS

Two Swedish municipalities.

SUBJECTS

All patients with type 2 diabetes who were using a CCB or a BB as an antihypertensive agent during 1984-1994.

MAIN OUTCOME MEASURES

Adjusted odds ratio for overall and cause-specific mortality in CCB users versus BB users.

RESULTS

Ninety-six users of CCB and 270 users of BB were included. The odds ratio for overall mortality, adjusted for age, sex, inclusion year and municipality was 1.78 (95% CI 1.17-2.71) in CCB users versus BB users. Corresponding odds ratios for mortality from IHD, stroke, cancer and other causes were 1.11, 2.41, 1.63 and 2.61, respectively. However, among those, only mortality due to other causes was significantly elevated.

CONCLUSIONS

This study adds support to the possibility of an adverse outcome in patients with diabetes using a CCB. An agent interfering with various cell functions such as calcium ion channels may also interfere with many pathways, increasing mortality. Therefore, a relation between blockade of calcium ion channels and miscellaneous causes of death should not be discarded. Our findings warrant careful examinations in other population-based studies. Copyright (c) 2000 John Wiley & Sons, Ltd.

Whole grain rye porridge breakfast improves satiety compared to refined wheat bread breakfast

Background

Previous studies show that dietary fibre-rich foods with low energy density have a stronger effect on satiety per calorie compared to more energy dense foods.

Objective

To investigate subjective appetite and voluntary energy intake (24 h) after consumption of rye porridge breakfast and pasta lunch made from whole grain compared to iso-energetic reference meals made from refined cereals: wheat bread breakfast and wheat pasta lunch.

Subjects

In all, 22 healthy subjects, 14 females and 8 males, aged 21–64 years, BMI ranging from 18.7 to 27.5 kg/m², participated.

Design

A randomised, crossover design was used. Appetite was rated by visual analogue scales (VAS) regularly from just before breakfast (08:00) until bedtime. An ad libitum dinner was served at 16:00. After leaving the clinic and in the morning day 2, subjects recorded foods consumed.

Results

Whole grain rye porridge gave a significantly prolonged satiety, lowered hunger and desire to eat (p<0.05 in most point estimates) up to 8 h after consumption compared to the refined wheat bread. The two pasta lunch meals did not vary in their effects on appetite ratings. There was no significant effect on ad libitum energy intake at 16:00 or self-reported energy and macronutrient intake in the evening and breakfast meal on day 2.

Conclusions

Whole grain rye porridge at breakfast has prolonged satiating properties up to 8 h after consumption compared to refined wheat bread, but did not diminish subsequent food intake.

Image analysis for monitoring the barley tempeh fermentation process

AIMS

To develop a fast, accurate, objective and nondestructive method for monitoring barley tempeh fermentation.

METHODS AND RESULTS

Barley tempeh is a food made from pearled barley grains fermented with Rhizopus oligosporus. Rhizopus oligosporus growth is important for tempeh quality, but quantifying its growth is difficult and laborious. A system was developed for analysing digital images of fermentation stages using two image processing methods. The first employed statistical measures sensitive to image colour and surface structure, and these statistical measures were highly correlated (r=0.92, n=75, P<0.001) with ergosterol content of tempeh fermented with R. oligosporus and lactic acid bacteria (LAB). In the second method, an image-processing algorithm optimized to changes in images of final tempeh products was developed to measure number of visible barley grains. A threshold of 5 visible grains per Petri dish indicated complete tempeh fermentation. When images of tempeh cakes fermented with different inoculation levels of R. oligosporus were analysed the results from the two image processing methods were in good agreement.

CONCLUSION

Image processing proved suitable for monitoring barley tempeh fermentation. The method avoids sampling, is nonintrusive, and only requires a digital camera with good resolution and image analysis software.

SIGNIFICANCE AND IMPACT OF THE STUDY

The system provides a rapid visualization of tempeh product maturation and qualities during fermentation. Automated online monitoring of tempeh fermentation by coupling automated image acquisition with image processing software could be further developed for process control.

Optoacoustic technique for continuous, noninvasive measurement of total hemoglobin concentration: an in vivo study

We used an optoacoustic technique to measure continuously and noninvasively total hemoglobin concentration in human blood in vivo. An optoacoustic probe, which combined illuminating fibers and a piezoelectric sensitive element, was placed in contact with the skin over the radial artery. Measurements in healthy volunteers agreed well with actual hemoglobin concentration.

Preserved leukocyte CD11b expression at the site of interstitial inflammation in patients with high-flux hemodiafiltration

The impact of high-flux hemodialysis on clinical outcomes remains controversial. We have previously shown that in vivo transmigrated leukocytes from patients with low-flux bioincompatible hemodialysis have an impaired capacity to upregulate CD11b at the site of interstitial inflammation. In the present study, we investigated the in vivo capacity of transmigrated monocytes and granulocytes to express CD11b at the site of interstitial inflammation in 10 patients on biocompatible high-flux hemodiafiltration or high-flux hemodialysis and 12 healthy subjects, and the in vitro response to a bacteria-related peptide (N-formyl-methionyl-leucyl-phenylalanine (fMLP)). Leukocyte formation of hydrogen peroxide (H(2)O(2)) and leukocyte apoptosis were also studied. In patients, both monocytes and granulocytes had a preserved capacity to express CD11b following in vivo transmigration to sites of interstitial inflammation, compared with cells from healthy subjects. Furthermore, monocytes and granulocytes from patients showed a preserved ability to respond to challenge with fMLP in the extravascular milieu. The intracellular killing capacity of leukocytes (H(2)O(2) production) in the interstitium was similar as of cells from healthy subjects both before and after stimulation with fMLP. Following maximal receptor independent stimulation (phorbol 12-myristate 13-acetate), leukocytes from patients showed lower H(2)O(2) production at the site of intense inflammation, compared with cells from healthy subjects. Finally, leukocyte apoptosis in interstitial inflammation was similar in patients and healthy subjects. We conclude that in vivo transmigrated leukocytes from patients on biocompatible high-flux hemodiafiltration or high-flux hemodialysis have a preserved capacity to express CD11b at the site of interstitial inflammation. This may have important biological implications.

Freeze-drying of Lactobacillus coryniformis Si3—effects of sucrose concentration, cell density, and freezing rate on cell survival and thermophysical properties

Freeze-drying is commonly used to stabilize lactic acid bacteria. Many factors have been reported to influence freeze-drying survival, including bacterial species, cell density, lyoprotectant, freezing rate, and other process parameters. Lactobacillus coryniformis Si3 has broad antifungal activity and a potential use as a food and feed biopreservative. This strain is considered more stress sensitive, with a low freeze-drying survival, compared to other commercialized antifungal lactic acid bacterial strains. We used a response surface methodology to evaluate the effects of varying sucrose concentration, cell density and freezing rate on Lb. coryniformis Si3 freeze-drying survival. The water activity of the dry product, as well as selected thermophysical properties of importance for freeze-drying; degree of water crystallization and the glass transition temperature of the maximally freeze concentrated amorphous phase (Tg') were determined. The survival of Lb. coryniformis Si3 varied from less than 6% to over 70% between the different conditions. All the factors studied influenced freeze-drying survival and the most important factor for survival is the freezing rate, with an optimum at 2.8 degrees C/min. We found a co-dependency between freezing rate and formulation ingredients, indicating a complex system and the need to use statistical tools to detect important interactions. The degree of water crystallization decreased and the final water activity increased as a function of sucrose concentration. The degree of water crystallization and Tg' was not affected by the addition of 10(8)-10(10) CFU/ml. At 10(11) CFU/ml, these thermophysical values decreased possibly due to increased amounts of cell-associated unfrozen water.

Microbial community growth and utilization of carbon constituents during thermophilic composting at different oxygen levels

Composting is characterized by dramatic changes in microbial community structure, to a high extent driven by changes in temperature and in the composition of the organic substrate. This study focuses on the interrelationships between decomposition of major classes in the organic material and dynamics in microbial populations during thermophilic composting of source-separated organic household waste. Experiments were performed in a 200-L laboratory reactor at 16, 2.5, and 1% O(2) in the compost atmosphere. Major classes of carbon constituents were analyzed by chemical methods, and the microbial biomass and community structure determined by fatty acid analyses with phospholipid fatty acids (PLFA) and total ester-linked fatty acids (EL) methods. At all three O(2) levels, the process was characterized by a rapid increase in microbial activity and biomass in the early thermophilic phase, although this period was delayed at the lower O(2) concentrations. Starch and fat were the main substrates utilized at all three O(2) levels during this period. The depletion of the starch fraction coincided with the beginning of a microbial biomass decrease, suggesting that starch is an important carbon substrate for the growth of thermophilic microorganisms during composting. Growth yields in the microbial community based on consumption of major carbon constituent classes in the high-activity period fell between 22 and 28%. Multivariate statistical analysis of changes in fatty acid composition revealed small, but statistically significant differences in the microbial community succession. At 16% O(2), 10 Me fatty acids from Actinomycetes and cyclopropyl fatty acids (from Gram-negative bacteria) became more important with time, whereas 18:1 omega 7t was characteristic at 2.5 and 1% O(2), indicating a more stressed bacterial community at the lower O(2) concentrations. Although adequate composting was achieved at O(2) levels as low as 2.5 and 1%, it is not recommended to compost at such low levels in large-scale systems, because the heterogeneous gas transport through the material in these systems might lead to anaerobic conditions and inefficient composting.

Antimicrobial actions of benzimidazoles against oral streptococci

BACKGROUND/AIM

Benzimidazoles, such as lansoprazole and omeprazole, are used extensively as proton-pump inhibitors to control stomach acid secretion and also have antimicrobial actions against Helicobacter pylori. Our objective was to determine whether they are potentially useful antimicrobials against oral bacteria.

METHODS

Streptococcus mutans was our main test organism. It was grown in suspension cultures and biofilms. Standard physiologic assays were used to assess inhibitory actions of benzimidazoles.

RESULTS

Benzimidazoles inhibited acid production by S. mutans in suspensions or biofilms. In pH-drop experiments, lansoprazole at a level of only 0.025 mm irreversibly inhibited acid production from glycolysis. Cell uptake of lansoprazole was found to be very pH sensitive and occurred mainly at pH values below about 5, indicating that the protonated form was taken up. Lansoprazole inhibition of glycolysis could be blocked by 2-mercaptoethanol, which suggests that disulfide bonds form between benzimidazoles and protein targets. Identified targets for benzimidazole inhibition included the phosphoenolpyruvate : sugar phosphotransferase system, the glycolytic enzymes aldolase, glyceraldehyde-3-phosphate dehydrogenase, and lactic dehydrogenase, and enzymes such as urease and arginine deiminase. Lansoprazole increased proton permeabilities of S. mutans cells but did not inhibit F-ATPases. Although cells in biofilms were somewhat less sensitive to the agents than those in suspensions, biofilm glycolysis was still markedly inhibited by 0.1 mm lansoprazole. Benzimidazoles are bactericidal, and the oral anaerobes Fusobacterium nucleatum and Prevotella intermedia were more sensitive to killing than was S. mutans.

CONCLUSION

Benzimidazoles appear to be useful inhibitors of oral bacteria in acid environments such as progressing caries lesions.

Modelling diffuse nutrient flow in eutrophication control scenarios

The Swedish Water Management Research Programme (VASTRA) focuses on the development and demonstration of tools for more efficient eutrophication control when implementing the EU water framework directive in Sweden. During the first half of the programme, models for nitrogen flow were developed, and at present, similar models for phosphorus are under construction (e.g. HBV-P). The programme is interdisciplinary, and scientists are collaborating in actor-games and focus group evaluations including scenario analysis. The scenarios modelled in VASTRA phase I, show that (i) changed agricultural practices can be the most effective and least expensive way to reduce nitrogen transport from land to the sea; (ii) constructed agricultural wetlands may only have small impact on riverine nitrogen transport in some regions, due to natural hydrometeorological dynamics; (iii) removing planktivorous fish may be an efficient way of reducing the algal concentrations in lakes without the undesired side-effect of increased nutrient load to the down-stream river system. In VASTRA phase II, one of the highlights will be interdisciplinary scenario-modelling of different measure strategies in a pilot catchment of southern Sweden (Rönne å).

Bacteria-binding plasma proteins in pellicles formed on hydroxyapatite in vitro and on teeth in vivo

Previous studies on dental pellicle formation and bacterial adherence have focussed on saliva and its components. The tooth surface is, however, also exposed to the plasma-derived crevicular fluid. In the present study, (i). plasma proteins in in vitro and in vivo pellicles were examined using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting and image analysis and (ii). the adherence of periodontopathogenic bacteria to experimental plasma and saliva pellicles was examined using radio-labelled bacteria and liquid scintillation counting. The plasma components fibrinogen, fibronectin, albumin and IgG were incorporated from plasma in the experimental pellicle and mediated the adherence of Porphyromonas gingivalis, Fusobacterium nucleatum and Actinomyces naeslundii. These proteins were also readily detected in in vivo pellicles and were found to a higher extent in pellicles formed at the gingival part of the tooth surface than at the incisal part.

Dental biofilms at healthy and inflamed gingival margins

OBJECTIVES

The increased plaque formation observed in gingival inflammation is not fully understood. Receptor proteins in the dental pellicle might influence bacterial adhesion and subsequent plaque formation. The purpose of the present study was to examine proteins and microorganisms in dental biofilms, at healthy and inflamed gingival margins.

MATERIAL AND METHODS

To see whether marginal inflammation affects the composition of the pellicle and the early dental plaque, samples were taken from the gingival and incisal parts of teeth in periodontally healthy subjects, both in gingival health and during experimental gingivitis. Pellicle proteins were analysed using gel-electrophoresis, immunoblotting and image analysis. Bacteria were analysed by culturing and the PCR technique.

RESULTS

During gingivitis, the rate of plaque formation increased significantly. The semiquantitative amounts of proteins and the numbers of bacteria varied considerably between individuals and surfaces. The amount of total and individual pellicle proteins and the total numbers of bacteria were, however, increased during gingivitis and the increase in proteins was statistically significant on the incisal parts of tooth surfaces. Compared to a healthy gingiva, reduced numbers for Actinomyces spp. (incisal parts only) and streptococci and increased numbers of periodontopathogens in the 4 h dental biofilms were seen at the inflamed gingiva.

CONCLUSION

Increased gingival crevicular fluid flow during gingivitis affects pellicle formation and increased plasma proteins in the pellicle may modify bacterial attachment and early dental plaque composition.