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H Andersson

Publications and source records attributed to H Andersson.

At least 19 recordsLinked to original sources
PubMed2006

Transcriptional profiling of the peripheral blood response during tularemia.

Tularemia is a febrile disease caused by the highly contagious bacterium Francisella tularensis. We undertook an analysis of the transcriptional response in peripheral blood during the course of ulceroglandular tularemia by use of Affymetrix microarrays comprising 14,500 genes. Samples were obtained from seven individuals at five occasions during 2 weeks after the first hospital visit and convalescent samples 3 months later. In total, 265 genes were differentially expressed, 95 of which at more than one time point. The differential expression was verified with real-time quantitative polymerase chain reaction for 36 genes (R(2)=0.590). The most prominent changes were noted in samples drawn on days 2-3 and a considerable proportion of the upregulated genes appeared to represent an interferon-gamma-induced response and also a proapoptotic response. Genes involved in the generation of innate and acquired immune responses were found to be downregulated, presumably a pathogen-induced event. A logistic regression analysis revealed that seven genes were good predictors of the early phase of tularemia. This is the first description of the transcriptional host response to ulceroglandular tularemia and the study has identified gene subsets relevant to the pathogenesis of the disease and subsets that may serve as early diagnostic biomarkers.

Aged↗
PubMed2006

Phytosterol and phytostanol esters are effectively hydrolysed in the gut and do not affect fat digestion in ileostomy subjects.

BACKGROUND: Hydrolysis of phytosterol ester (PSTE) and phytostanol ester (PSTA) during fat digestion is not well characterised under controlled dietary conditions. AIMS: The main aims of this study were therefore to quantify the PSTE and PSTA hydrolysis after gut passage and to assess whether or not PSTE and PSTA induce fat malabsorption by measuring the fatty acid excretion following PSTE/PSTA consumption. METHODS: Ileostomy subjects (n = 7) were investigated in a randomised crossover study with one control and two intervention periods, when either 2.5 g of PSTE or PSTA corresponding to 1.5 g free sterol or stanol equivalents were added to a controlled diet. Ileostomy bags were collected and immediately frozen for analysis of nutrients, fatty acids and sterols. RESULTS: The study showed that 88.4 +/- 5.9% PSTE and 85.7 +/- 6.5% PSTA were hydrolysed following small bowel passage in the ileostomy subjects. The total excretion of fatty acids was similar in all three periods. CONCLUSIONS: A majority of the 2.5 g PSTE and PSTA was hydrolysed during small bowel passage,which did not affect fat absorption as indicated by similar excretions of fatty acids in all periods. Consumption of increasing amounts of esterified phytosterols and phytostanols from enriched food formats should thereby have no adverse effects in this regard.

Adult↗
PubMed2006

9p subtelomere deletion: pathogenic mutation or normal variant?

We report an apparently benign familial 9p subtelomere deletion identified using chromosome-arm-specific subtelomere probes in a patient with multiple congenital anomalies. Our experience demonstrated that the discovery of a subtelomeric deletion and/or duplication does not always guarantee the identification of the etiology for the patients phenotype and a positive finding with subtelomere probes should always be followed by parental study with the same probe in order to distinguish a disease causing alteration from a benign familial polymorphism.

Chromosome Deletion↗
PubMed2005

Small bowel absorption of magnesium and calcium sulphate from a natural mineral water in subjects with ileostomy.

BACKGROUND: In many developed countries, magnesium and calcium intakes do not reach recommendations for a large part of the population. Mineral water may be a useful alternative source of dietary minerals, especially in groups of people at risk for developing deficiency due to low intakes. AIM: To assess if the addition of a natural and mineral-rich water increased small bowel mineral absorption in people with ileostomy. METHODS: A controlled randomised crossover study with two periods of two days each and a minimum 5 days of washout was performed in six ileostomy subjects. Apparent mineral absorption from 0.5 L of natural mineral water with either a high or a low mineral content consumed in the fasting state was compared. The daily addition of minerals corresponded to 2.3mmol magnesium, 6.9 mmol calcium and 7.7mmol sulphate. Ileostomy effluents were sampled and analysed for magnesium, calcium and total sulphate. RESULTS: When compared with the control, the median absorbed amount of magnesium increased from 0.8 (0-1.34) mmol/d to 1.2 (0.8-1.9) mmol/d,which corresponded to a 30% increase (P = 0.028). Median amount of calcium absorbed increased from 8.3 (6.7-13.6) mmol/d to 14.8 (8.3-20.4) mmol/d, i. e. a 45% increase (P = 0.027). The sulphate absorption increased from 1.9 (1.3-2.2) mmol/d to 5.1 (4.2-6.8) mmol/d,which corresponded to 197 % increase (P = 0.028). CONCLUSIONS: The mineral-rich water increased absorption of both magnesium and calcium and can therefore be used as an additional source of minerals. However, consumption with meals may be preferred.

Adult↗
PubMed2005

Rapeseed oil, olive oil, plant sterols, and cholesterol metabolism: an ileostomy study.

OBJECTIVE: To study whether olive oil and rapeseed oil have different effects on cholesterol metabolism. DESIGN: Short-term experimental study, with controlled diets. SETTING: Outpatients at a metabolic-ward kitchen. SUBJECTS: A total of nine volunteers with conventional ileostomies. INTERVENTIONS: Two 3-day diet periods; controlled diet including 75 g of rapeseed oil or olive oil. MAIN OUTCOME MEASURES: Cholesterol absorption, ileal excretion of cholesterol, and bile acids. Serum levels of cholesterol and bile acid metabolites. Differences between diets evaluated with Wilcoxon's signed rank sum test. RESULTS: Rapeseed oil diet contained 326 mg more plant sterols than the olive oil diet. Rapeseed oil tended to decrease cholesterol absorption by 11% (P = 0.050), and increased excretion of cholesterol, bile acids, and their sum as sterols by 9% (P = 0.021), 32% (P = 0.038), and 51% (P = 0.011) compared to olive oil. A serum marker for bile acid synthesis (7alpha-hydroxy-4-cholesten-3-one) increased by 28% (P = 0.038) within 10 h of consumption, and serum cholesterol levels decreased by 7% (P = 0.024), whereas a serum marker for cholesterol synthesis (lathosterol) as well as serum levels of plant sterols remained unchanged. CONCLUSIONS: Rapeseed oil and olive oil have different effects on cholesterol metabolism. Rapeseed oil, tends to decrease cholesterol absorption, increases excretion of cholesterol and bile acids, increases serum marker of bile acid synthesis, and decreases serum levels of cholesterol compared to olive oil. This could in part be explained by different concentrations of natural plant sterols. SPONSORSHIP: Supported by the Göteborg Medical Society, the Swedish Medical Society, the Swedish Board for Agricultural Research (SJFR) grant 50.0444/98 and by University of Göteborg.

Adult↗
PubMed2005

Autofluorescence characterisation of isolated whole crypts and primary cultured human epithelial cells from normal, hyperplastic, and adenomatous colonic mucosa.

BACKGROUND/AIMS: In vivo autofluorescence endoscopic imaging and spectroscopy have been used to detect and differentiate benign (hyperplastic) and preneoplastic (adenomatous) colonic lesions. This fluorescence is composed of contributions from the epithelium, lamina propria, and submucosa. Because epithelial autofluorescence in normal and diseased tissues is poorly understood, this was the focus of the present study. METHODS: Whole colonic crypts were isolated, and short term primary cultures of epithelial cells were established from biopsies of normal, hyperplastic, and adenomatous colon. Autofluorescence (488 nm excitation) was examined by confocal fluorescence microscopy. Fluorescently labelled organelle probes and transmission electron microscopy were used to identify subcellular sources of fluorescence. RESULTS: Mitochondria and lysosomes were identified as the main intracellular fluorescent components in all cell types. Normal and hyperplastic epithelial cells were weakly autofluorescent and had similar numbers of mitochondria and lysosomes, whereas adenomatous (dysplastic) epithelial cells showed much higher autofluorescence, and numerous highly autofluorescent lysosomal (lipofuscin) granules. CONCLUSIONS: Short term primary cell cultures from endoscopic biopsies provide a novel model to understand differences in colonic tissue autofluorescence at the glandular (crypt) and cellular levels. The differences between normal, hyperplastic, and adenomatous epithelial cells are attributed in part to differences in the intrinsic numbers of mitochondria and lysosomes. This suggests that the detection of colonic epithelial fluorescence alone, if possible, may be sufficient to differentiate benign (hyperplastic) from preneoplastic and neoplastic (adenomatous) colonic intramucosal lesions during in vivo fluorescence endoscopy. Furthermore, highly orange/red autofluorescent intracellular granules found only in dysplastic epithelial cells may serve as a potential biomarker.

Adenomatous Polyps↗
PubMed2005

Wounds scrutiny in a Swedish hospital: prevalence, nursing care and bacteriology, including MRSA.

OBJECTIVE: To identify all wounds, wound types and wound characteristics; to identify bacteria in all wounds, particularly MRSA, VRE and multi-resistant Gram-negative rods;. METHOD: All patients admitted to or visiting hospital clinics were examined. If the patient had a wound, a questionnaire was filled in by a nurse, and if the wound met the inclusion criteria swabs were taken. RESULTS: A total of 2172 patients were admitted to or visited the hospital; 408 (19%) had a total of 668 wounds. Of this number, 248 were cultured. Thirty-seven patients had pressure ulcers, 83 had leg and foot ulcers and 288 patients had other types of wounds. Nursing care varied according to wound type and ward. Fifty-eight different types of wound dressings were used. Cleansing was performed with saline in 58% of the wounds. The mean number of dressing changes was once daily. Wounds were painful in 37% of the cases, with a predominance of leg and foot ulcers (51%). Many patients did not receive analgesia. MRSA was identified in two patients. No VRE was identified, and there was a low prevalence of multi-resistance in Enterobacteriaceae and Pseudomonas aeruginosa. CONCLUSION: The study provided important information for future improvement of wound care in a university hospital. Fewer resistant bacteria, particularly MRSA, were identified than expected.

Adolescent↗
PubMed2004

Solar wind-induced atmospheric erosion at Mars: first results from ASPERA-3 on Mars Express.

The Analyzer of Space Plasma and Energetic Atoms (ASPERA) on board the Mars Express spacecraft found that solar wind plasma and accelerated ionospheric ions may be observed all the way down to the Mars Express pericenter of 270 kilometers above the dayside planetary surface. This is very deep in the ionosphere, implying direct exposure of the martian topside atmosphere to solar wind plasma forcing. The low-altitude penetration of solar wind plasma and the energization of ionospheric plasma may be due to solar wind irregularities or perturbations, to magnetic anomalies at Mars, or both.

Journal Article↗
PubMed2004

Rhythmic melatonin secretion does not correlate with the expression of arylalkylamine N-acetyltransferase, inducible cyclic amp early repressor, period1 or cryptochrome1 mRNA in the sheep pineal.

The pineal gland, through nocturnal melatonin, acts as a neuroendocrine transducer of daily and seasonal time. Melatonin synthesis is driven by rhythmic activation of the rate-limiting enzyme, arylalkylamine N-acetyltransferase (AA-NAT). In ungulates, AA-NAT mRNA is constitutively high throughout the 24-h cycle, and melatonin production is primarily controlled through effects on AA-NAT enzyme activity; this is in contrast to dominant transcriptional control in rodents. To determine whether there has been a selective loss of circadian control of AA-NAT mRNA expression in the sheep pineal, we measured the expression of other genes known to be rhythmic in rodents (inducible cAMP early repressor ICER, the circadian clock genes Period1 and Cryptochrome1, as well as AA-NAT). We first assayed gene expression in pineal glands collected from Soay sheep adapted to short days (Light: dark, 8-h: 16-h), and killed at 4-h intervals through 24-h. We found no evidence for rhythmic expression of ICER, AA-NAT or Cryptochrome1 under these conditions, whilst Period1 showed a low amplitude rhythm of expression, with higher values during the dark period. In a second group of animals, lights out was delayed by 8-h during the final 24-h sampling period, a manipulation that causes an immediate shortening of the period of melatonin secretion. This did not significantly affect the expression of ICER, AA-NAT or Cryptochrome1 in the pineal, whilst a slight suppressive effect on overall Per1 levels was observed. The attenuated response to photoperiod change appears to be specific to the ovine pineal, as the first long day induced rapid changes of Period1 and ICER expression in the hypothalamic suprachiasmatic nuclei and pituitary pars tuberalis, respectively. Overall, our data suggest a general reduction of circadian control of transcript abundance in the ovine pineal gland, consistent with a marked evolutionary divergence in the mechanism regulating melatonin production between terrestrial ruminants and fossorial rodents.

Animals↗
PubMed2004

Apoptosis induced kinetic changes in autofluorescence of cultured HL60 cells-possible application for single cell analysis on chip.

INTRODUCTION: This paper presents a new method using natural cellular fluorescence (autofluorescence, AF) to study apoptosis. Measurement of AF reduces sample preparation time and avoids cellular toxicity due to the fact that no labelling is required. METHODS: Human promyelocytic leukemic HL60 cells were incubated with camptothecin (CPT), tumour necrosis factor (TNF)-alpha in combination with cycloheximide (CHX), or irradiated with 6 or 10 Gray, during varying time periods, to initiate apoptosis. AF was measured at the flow cytometer. RESULTS: Induction of apoptosis results in the shrinkage of the cell and the fragmentation into apoptotic bodies. With flow cytometry, 4 subpopulations, viable, early apoptotic, late apoptotic and the necrotic cells, can be distinguished. Induction of apoptosis results in a decrease in AF intensity compared to untreated HL60 cells, especially seen in the late apoptotic subpopulation. The AF intensity is found to decrease significantly in time (between 2 h and 24 h) for all the four apoptotic inducers used. CONCLUSIONS: Our results show that it is possible to specifically measure the apoptotic-induced kinetic changes in AF in HL60 cells. A decrease in AF intensity is seen from 2 h till 24 h. These results open a door for future developments in single-cell analysis.

Apoptosis↗
PubMed2004

Intake of dietary plant sterols is inversely related to serum cholesterol concentration in men and women in the EPIC Norfolk population: a cross-sectional study.

OBJECTIVE: We examined the relation between intake of natural dietary plant sterols and serum lipid concentrations in a free-living population. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional population-based study of 22,256 men and women aged 39-79 y resident in Norfolk, UK, participating in the European Prospective Investigation into Cancer (EPIC-Norfolk). MAIN EXPOSURE AND OUTCOME MEASURES: Plant sterol intake from foods and concentrations of blood lipids. RESULTS: Mean concentrations of total cholesterol and low-density lipoprotein cholesterol, adjusted for age, body mass index and total energy intake, decreased with increasing plant sterol intake in men and women. Mean total serum cholesterol concentration for men in the highest fifth of plant sterol intake (mean intake 463 mg daily) was 0.25 mmol/l lower and for low-density lipoprotein cholesterol 0.14 mmol/l lower than those in the lowest fifth of plant sterol consumption (mean intake 178 mg daily); the corresponding figures in women were 0.15 and 0.13 mmol/l. After adjusting for saturated fat and fibre intakes, the results for total cholesterol and low-density lipoprotein cholesterol were similar, although the strength of the association was slightly reduced. CONCLUSIONS: In a free-living population, a high intake of plant sterols is inversely associated with lower concentrations of total and low-density lipoprotein serum cholesterol. The plant sterol content of foods may partly explain diet-related effects on serum cholesterol concentration.

Adult↗
PubMed2003

Prolactin cycles in sheep under constant photoperiod: evidence that photorefractoriness develops within the pituitary gland independently of the prolactin output signal.

The present study investigated photorefractoriness in the prolactin (PRL) axis in hypothalamopituitary-disconnected (HPD) sheep exposed to prolonged long days. In experiment 1, HPD Soay rams transferred from short (8L:16D) to long (16L:8D) days for 48 wk to induce a cycle of activation, decline (photorefractoriness), and reactivation in PRL secretion were treated chronically with bromocriptine (dopamine-receptor agonist) or vehicle from the onset of photorefractoriness. Bromocriptine (0.01-0.04 mg kg-1 day-1; 12-24 wk of long days) blocked PRL release and caused a rebound response after the treatment, but it had no effect on the long-term PRL cycle (posttreatment PRL minimum, mean +/- SEM, 35.3 +/- 0.6 and 37.0 +/- 0.4 wk for bromocriptine and control groups, respectively; not significant). In experiment 2, HPD rams were treated with sulpiride (dopamine-receptor antagonist) during photorefractoriness. Sulpiride (0.6 mg/kg twice daily; 22-30 wk of long days) induced a marginal increase in blood PRL concentrations, but again, it had no effect on the long-term PRL cycle (PRL minimum, 37.9 +/- 0.4 and 37.6 +/- 0.9 wk for sulpiride and control groups, respectively; not significant). The 24-h blood melatonin profile consistently reflected the long-day photoperiod throughout, and blood FSH concentrations were minimal, confirming the effectiveness of the HPD surgery. The results support the conclusion that photorefractoriness is regulated at the level of the pituitary gland independently of the PRL output signal.

Animals↗
PubMed2003

Clock genes and the long-term regulation of prolactin secretion: evidence for a photoperiod/circannual timer in the pars tuberalis.

Prolactin secretion is regulated by photoperiod through changes in the 24-h melatonin profile and displays circannual rhythmicity under constant photoperiod. These two processes appear to occur principally within the pituitary gland, controlled by the pars tuberalis. This is evident because: (i) hypothalamic-pituitary disconnected (HPD) sheep show marked changes in prolactin secretion in response to switches in photoperiod and manipulations of melatonin, similar to brain-intact controls; (ii) HPD sheep also show photoperiod-specific, long-term cycles in prolactin secretion under constant long or short days, with the timing maintained even when prolactin secretion is blocked for 2-3 months; and (iii) pars tuberalis cells, but not lactotrophs, express high concentrations of melatonin (MT1) receptor, and exhibit a duration-sensitive, cAMP-dependant, inhibitory response to physiological concentrations of melatonin. This suggests the existence of an intrinsic, reversible photoperiod-circannual timer in pars tuberalis cells. A full complement of clock genes (Bmal1, Clock, Per1, Per2, Cry1 and Cry2) are expressed in the ovine pars tuberalis, and undergo 24-h cyclical expression as observed in a cell autonomous, circadian clock. Activation of Per genes occurs in the early day (melatonin off-set), while activation of Cry genes occurs in the early night (melatonin on-set). This temporal association is evident under both long and short days, thus the Per-Cry interval varies directly with photoperiod. Because, PER : CRY, protein : protein interactions affect stability, nuclear entry and gene transcription based on rodent data, the change in phasing of Per/Cry expression provides a potential mechanism for decoding the long day/short day melatonin signal. A speculative, but testable, extension of this hypothesis is that intrinsically regulated changes in the phase of Per/Cry rhythms, regulates both photorefractoriness and the generation of circannual rhythms in prolactin secretion.

Animals↗
PubMed2003

Clock genes in calendar cells as the basis of annual timekeeping in mammals--a unifying hypothesis.

Melatonin-based photoperiod time-measurement and circannual rhythm generation are long-term time-keeping systems used to regulate seasonal cycles in physiology and behaviour in a wide range of mammals including man. We summarise recent evidence that temporal, melatonin-controlled expression of clock genes in specific calendar cells may provide a molecular mechanism for long-term timing. The agranular secretory cells of the pars tuberalis (PT) of the pituitary gland provide a model cell-type because they express a high density of melatonin (mt1) receptors and are implicated in photoperiod/circannual regulation of prolactin secretion and the associated seasonal biological responses. Studies of seasonal breeding hamsters and sheep indicate that circadian clock gene expression in the PT is modulated by photoperiod via the melatonin signal. In the Syrian and Siberian hamster PT, the high amplitude Per1 rhythm associated with dawn is suppressed under short photoperiods, an effect that is mimicked by melatonin treatment. More extensive studies in sheep show that many clock genes (e.g. Bmal1, Clock, Per1, Per2, Cry1 and Cry2) are expressed in the PT, and their expression oscillates through the 24-h light/darkness cycle in a temporal sequence distinct from that in the hypothalamic suprachiasmatic nucleus (central circadian pacemaker). Activation of Per1 occurs in the early light phase (dawn), while activation of Cry1 occurs in the dark phase (dusk), thus photoperiod-induced changes in the relative phase of Per and Cry gene expression acting through PER/CRY protein/protein interaction provide a potential mechanism for decoding the melatonin signal and generating a long-term photoperiodic response. The current challenge is to identify other calendar cells in the central nervous system regulating long-term cycles in reproduction, body weight and other seasonal characteristics and to establish whether clock genes provide a conserved molecular mechanism for long-term timekeeping.

Animals↗
PubMed2001

The photophase light intensity does not affect the scotophase melatonin response in the domestic pig.

This study investigated the effects of the photophase light intensity on the scotophase melatonin response. Twelve, 8-month-old crossbred gilts were allocated to three groups of four and housed in temperature- and lighting-controlled climate rooms. The rooms had a light intensity of 40, 200 or 10,000 lx and a light-dark cycle of 12 L:12 D. The gilts were allowed to acclimatize to a new lighting regimen for 1 week before being sampled at 2h intervals for 24h. Following the sampling, pigs were transferred under a different light intensity, allowed to adjust for 1 week and sampled again. The procedure was repeated three times so that all the groups went through all three lighting regimens (light intensities). All the gilts exhibited a clear circadian serum melatonin rhythm under each lighting regimen with high melatonin concentrations occurring during the scotophase. There was no difference in the scotophase melatonin response in terms of mean concentrations or duration of increased melatonin levels within or between the groups under different lighting regimens. There was considerable inter-individual variation in the dark phase melatonin response but the individual profiles were consistent under the different lighting regimens. It is concluded that when a certain threshold light intensity (<40lx) is exceeded, the photophase light intensity has no effect on the scotophase melatonin response. These results imply that extremely high light intensities during the photophase would provide no additional benefits compared with normal comfortable light intensity, if artificial lighting programs were introduced to commercial piggeries in order to reduce seasonal effects on reproduction.

Animals↗
PubMed2001

Micromachined filter-chamber array with passive valves for biochemical assays on beads.

The filter-chamber array presented here enables a real-time parallel analysis of three different samples on beads in a volume of 3 nL, on a 1 cm2 chip. The filter-chamber array is a system containing three filter-chambers, three passive valves at the inlet channels and a common outlet. The design enables parallel sample handling and time-controlled analysis. The device is microfabricated in silicon and sealed with a Pyrex lid to enable real-time analysis. Single nucleotide polymorphism analysis by using pyrosequencing has successfully been performed in single filter-chamber devices. The passive valves consist of plasma-deposited octafluorocyclobutane and show a much higher resistance towards water and surface-active solutions than previous hydrophobic patches. The device is not sensitive to gas bubbles, clogging is rare and reversible, and the filter-chamber array is reusable. More complex (bio)chemical reactions on beads can be performed in the devices with passive valves than in the devices without valves.

Biochemistry↗
PubMed2001

Patterned self-assembled beads in silicon channels.

A novel technique enabling selective bead trapping in microfluidic devices without the use of physical barriers is presented in this paper. It is a fast, convenient and simple method, involving microcontact printing and self-assembly, that can be applied to silicon, quartz or plastic substrates. In the first step, channels are etched in the substrate. The surface chemistry of the internal walls of the channels is then modified by microcontact printing. The chip is submerged in a bead slurry where beads self-assemble based on surface chemistry and immobilize on the internal walls of the channels. Silicon channels (100 microm wide and 50 microm deep) have been covered with monolayers of streptavidin-, amino- and hydroxy-functionalized microspheres and resulted in good surface coverage of beads on the channel walls. A high-resolution pattern of lines of self-assembled streptavidin beads, as narrow as 5 microm, has also been generated on the bottom of a 500 microm wide and 50 microm deep channel. Flow tests were performed in sealed channels with the different immobilized beads to confirm that the immobilized beads could withstand the forces generated by water flowing in the channels. The presented results indicate that single beads can be precisely positioned within microfluidic devices based on self-assembly which is useful as screening and analysis tools within the field of biochemistry and organic chemistry.

Animals↗