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Biomedical subjects

A Eliasson

Publications and source records attributed to A Eliasson.

At least 19 recordsLinked to original sources

Incidence and risk of venous thromboembolism in patients with verified arterial thrombosis: a population study based on 23,796 consecutive autopsies.

BACKGROUND: The relationship between atherothrombotic disease and venous thromboembolism (VTE) remains unclear. PATIENTS AND METHODS: In a cohort of 23,796 consecutive autopsies, performed using a standardized procedure and representing 84% of all in-hospital deaths between 1970 and 1982 in an urban Swedish population, we investigated the relationship between verified arterial thrombosis and VTE, with the hypothesis that patients with thrombosis in major artery segments have increased odds of VTE. RESULTS: We found an increased risk of VTE in patients with arterial thrombosis (Odds ratio; OR adjusted for gender and age 1.4, 95% confidence interval; CI 1.3-1.5) (P < 0.001). Patients with cervico-cranial and peripheral artery thrombosis had an excess risk even when controlling for age and major concomitant diseases. A negative association between coronary thrombosis and VTE in the univariate analysis (OR 0.7; 95% CI 0.6-0.8) (P < 0.001), was less pronounced in the multivariate analysis (OR 0.8; 95% CI 0.7-1.0) (P = 0.016). CONCLUSIONS: A positive association between atherothrombosis and VTE was confirmed, except in patients with coronary thrombosis, where IHD as competing death cause is a possible confounder. Our findings indicate a potential for directed prevention, but may also imply similarities in etiology.

Aged↗

Intracellular fluxes in a recombinant xylose-utilizing Saccharomyces cerevisiae cultivated anaerobically at different dilution rates and feed concentrations.

A metabolic flux model was constructed for the yeast Saccharomyces cerevisiae comprising the most important reactions during anaerobic metabolism of xylose and glucose. The model was used to calculate the intracellular fluxes in a recombinant, xylose-utilizing strain of S. cerevisiae (TMB 3001) grown anaerobically in a defined medium at dilution rates of 0.03, 0.06, and 0.18 h(-1). The feed concentration was varied from 0 g/L xylose and 20 g/L glucose to a mixture of 15 g/L xylose and 5 g/L glucose, so that the total concentration of carbon source was kept at 20 g/L. The specific uptake of xylose increased with the xylose concentration in the feed and with increasing dilution rate. The excreted xylitol was less than half of the xylose consumed. With increasing xylose concentration in the feed, the fluxes in the pentose phosphate pathway increased, whereas the flux through glycolysis decreased. Under all cultivation conditions, nicotinamide adenine dinucleotide (NADH) was the preferred cofactor for xylose reductase. The model showed that the flux through the reaction from ribulose 5-phosphate to xylulose 5-phosphate was very low under all cultivation conditions.

Aldehyde Reductase↗

Tonsillotomy in children with tonsillar hypertrophy.

Tonsillectomy is one of the most frequent surgical procedures carried out on children. Obstructive sleep apnea syndrome, caused by tonsillar hypertrophy, has been attracting increasing interest and tonsillectomy is often performed as a result of this indication. Regardless of the indication, the main aim of tonsillectomy has always been to remove the tonsils completely. The present study was undertaken in order to investigate the effect of two different surgical techniques, tonsillectomy and tonsillotomy, on clinical symptoms in children with symptoms of obstructive sleep apnea syndrome due to tonsillar hypertophy. The study was conducted as a prospective, randomized trial comparing the clinical effects of standard tonsillectomy and tonsillotomy using a CO2 laser. Forty-three children aged 2-9 years were included. Both groups of patients experienced comparable relief from symptoms of snoring and apneas at follow-up after 3 months and 2 years. There was no significant statistical difference between the two groups of patients in terms of both short- and long-term effects on clinical symptoms. Tonsillotomy caused no measurable bleeding during surgery. Postoperative pain and distress were less pronounced in the tonsillotomy group according to visual analog scale evaluations made by patients, parents and nursing staff. In conclusion tonsillotomy appears to be the less traumatic surgical method in cases of upper airway obstruction in children caused by tonsillar hypertrophy.

Child↗

Xylulose fermentation by mutant and wild-type strains of Zygosaccharomyces and Saccharomyces cerevisiae.

Anaerobic xylulose fermentation was compared in strains of Zygosaccharomyces and Saccharomyces cerevisiae, mutants and wild-type strains to identify host-strain background and genetic modifications beneficial to xylose fermentation. Overexpression of the gene (XKS1) for the pentose phosphate pathway (PPP) enzyme xylulokinase (XK) increased the ethanol yield by almost 85% and resulted in ethanol yields [0.61 C-mmol (C-mmol consumed xylulose)(-1)] that were close to the theoretical yield [0.67 C-mmol (C-mmol consumed xylulose)(-1)]. Likewise, deletion of gluconate 6-phosphate dehydrogenase (gnd1delta) in the PPP and deletion of trehalose 6-phosphate synthase (tps1delta) together with trehalose 6-phosphate phosphatase (tps2delta) increased the ethanol yield by 30% and 20%, respectively. Strains deleted in the promoter of the phosphoglucose isomerase gene (PGI1) - resulting in reduced enzyme activities - increased the ethanol yield by 15%. Deletion of ribulose 5-phosphate (rpe1delta) in the PPP abolished ethanol formation completely. Among non-transformed and parental strains S. cerevisiae ENY. WA-1A exhibited the highest ethanol yield, 0.47 C-mmol (C-mmol consumed xylulose)(-1). Other non-transformed strains produced mainly arabinitol or xylitol from xylulose under anaerobic conditions. Contrary to previous reports S. cerevisiae T23D and CBS 8066 were not isogenic with respect to pentose metabolism. Whereas, CBS 8066 has been reported to have a high ethanol yield on xylulose, 0.46 C-mmol (C-mmol consumed xylulose)(-1) (Yu et al. 1995), T23D only formed ethanol with a yield of 0.24 C-mmol (C-mmol consumed xylulose)(-1). Strains producing arabinitol did not produce xylitol and vice versa. However, overexpression of XKS1 shifted polyol formation from xylitol to arabinitol.

Anaerobiosis↗

Molecular and expression analysis of a LIM protein gene family from flowering plants.

LIM-domain proteins participate in important cellular processes in eukaryotes, including gene transcription and actin cytoskeleton organization. They are predominantly found in animals, but have also been identified in yeast and plants. Following the characterization ofa LIM-domain protein in sunflower pollen, we carried out an extensive search for these proteins in flowering plants. We have isolated and studied cDNAs and/or genomic sequences for two novel LIM-domain proteins from sunflower, three from tobacco, and one from Arabidopsis. The plant proteins are structurally related to the cytoskeleton-associated CRP class of LIM proteins in animals, but show several distinctive features, including a second, atypical, LIM domain. We have performed comparative expression studies of these genes, as well as of one other gene from tobacco and two additional Arabidopsis genes whose sequences are available from databases. These studies, carried out by RT-PCR in the presence of gene-specific primers, showed that, in sunflower and tobacco, pollen grains and sporophytic tissues express different sets of LIM proteins. With the exception of one Arabidopsis gene--which has two introns--all the genes analyzed contain four introns at conserved positions, indicating that the ancestral gene from which the various copies evolved in higher plants allready had this split structure.

Amino Acid Sequence↗

A LIM-domain protein from sunflower is localized to the cytoplasm and/or nucleus in a wide variety of tissues and is associated with the phragmoplast in dividing cells.

LIM proteins are important eucaryotic developmental regulators characterized by the presence of one or several double zinc finger motifs, the LIM domains, which are protein-interacting domains. Using the cDNA of the previously described pollen LIM protein PLIM1 from sunflower as a hybridization probe we have isolated the coding sequence for a related protein from cDNA libraries from various sunflower organs. This protein, WLIM1, is 188 amino acids long and, like the pollen protein PLIM1, contains two LIM domains, separated by a 48 residue spacer region. The two sunflower proteins are structurally related to the animal LIM proteins CRP and MLP. A WLIM1 gene transcript was detected by RT-PCR in all vegetative and reproductive plant organs tested. Polyclonal antibodies raised against the bacterially expressed and affinity-purified protein recognize a polypeptide of ca. 50 kDa in these organs. Immunocytochemical studies detect the protein in many cell types in each of these organs where it is localized either to the cytoplasm, the nucleus, or both. The protein is often associated with plastids and smaller cellular structures or organelles. In late anaphase and early telophase of dividing cells from ovaries, stems and roots it accumulates in the phragmoplast, and may therefore also play a role in cytokinesis.

Adaptor Proteins, Signal Transducing↗

Anaerobic xylose fermentation by recombinant Saccharomyces cerevisiae carrying XYL1, XYL2, and XKS1 in mineral medium chemostat cultures.

For ethanol production from lignocellulose, the fermentation of xylose is an economic necessity. Saccharomyces cerevisiae has been metabolically engineered with a xylose-utilizing pathway. However, the high ethanol yield and productivity seen with glucose have not yet been achieved. To quantitatively analyze metabolic fluxes in recombinant S. cerevisiae during metabolism of xylose-glucose mixtures, we constructed a stable xylose-utilizing recombinant strain, TMB 3001. The XYL1 and XYL2 genes from Pichia stipitis, encoding xylose reductase (XR) and xylitol dehydrogenase (XDH), respectively, and the endogenous XKS1 gene, encoding xylulokinase (XK), under control of the PGK1 promoter were integrated into the chromosomal HIS3 locus of S. cerevisiae CEN.PK 113-7A. The strain expressed XR, XDH, and XK activities of 0.4 to 0.5, 2.7 to 3.4, and 1.5 to 1.7 U/mg, respectively, and was stable for more than 40 generations in continuous fermentations. Anaerobic ethanol formation from xylose by recombinant S. cerevisiae was demonstrated for the first time. However, the strain grew on xylose only in the presence of oxygen. Ethanol yields of 0.45 to 0.50 mmol of C/mmol of C (0.35 to 0.38 g/g) and productivities of 9.7 to 13.2 mmol of C h(-1) g (dry weight) of cells(-1) (0.24 to 0.30 g h(-1) g [dry weight] of cells(-1)) were obtained from xylose-glucose mixtures in anaerobic chemostat cultures, with a dilution rate of 0.06 h(-1). The anaerobic ethanol yield on xylose was estimated at 0.27 mol of C/(mol of C of xylose) (0.21 g/g), assuming a constant ethanol yield on glucose. The xylose uptake rate increased with increasing xylose concentration in the feed, from 3.3 mmol of C h(-1) g (dry weight) of cells(-1) when the xylose-to-glucose ratio in the feed was 1:3 to 6.8 mmol of C h(-1) g (dry weight) of cells(-1) when the feed ratio was 3:1. With a feed content of 15 g of xylose/liter and 5 g of glucose/liter, the xylose flux was 2.2 times lower than the glucose flux, indicating that transport limits the xylose flux.

Anaerobiosis↗

Xylose utilisation by recombinant strains of Saccharomyces cerevisiae on different carbon sources.

Autoselective xylose-utilising strains of Saccharomyces cerevisiae expressing the xylose reductase (XYL1) and xylitol dehydrogenase (XYL2) genes of Pichia stipitis were constructed by replacing the chromosomal FUR1 gene with a disrupted fur1::LEU2 allele. Anaerobic fermentations with 80 g l-1 D-xylose as substrate showed a twofold higher consumption of xylose in complex medium compared to defined medium. The xylose consumption rate increased a further threefold when 20 g l-1 D-glucose or raffinose was used as co-substrate together with 50 g l-1 D-xylose. Xylose consumption was higher with raffinose as co-substrate than with glucose (85% versus 71%, respectively) after 82 h fermentations. A high initial ethanol concentration and moderate levels of glycerol and acetic acid accompanied glucose as co-substrate, whereas the ethanol concentration gradually increased with raffinose as co-substrate with no glycerol and much less acetic acid formation.

Acetic Acid↗

Hypersensitivity to sound--questionnaire data, audiometry and classification.

This study included consecutive case histories and audiometry of 100 patients with hypersensitivity to sounds. There are several different conditions with the symptom of hypersensitivity to sounds. Hyperacusis is one of those and is seldom described in the literature. The term hyperacusis is often used synonymously with hypersensitivity to sound. We propose that there is a specific condition that could be termed hyperacusis. Hyperacusis is often elicited by loud sounds or by a number of other traumata or diseases. It is not typical of occupational noise exposure (with the exception of exposure to music). The typical patient is relatively young, the mean age being approximately 10 years less than for a population of patients with tinnitus or noise-induced hearing loss. In addition to hypersensitivity to sound, the patients often suffer from tinnitus (86%). Sounds are frequently painful and exposure to loud sounds worsens the condition for some time. The patients often have headaches. Pure tone audiograms show normal hearing or a slight high tone loss. The uncomfortable loudness level is markedly decreased, mostly less than 90 dB HL. Patients with hyperacusis may also be divided into those hypersensitive to the loudness of sounds with a decreased pure tone uncomfortable loudness level and those hypersensitive to certain specific sounds irrespective of loudness showing relatively high pure tone uncomfortable loudness levels and decreased uncomfortable loudness levels to specific sounds. With a careful history other conditions with the symptom of hypersensitivity to sound can be excluded.

Adolescent↗

Replication of minichromosomes in a host in which chromosome replication is random.

Minichromosomes are plasmids with the origin of chromosome replication, oriC, as their only origin of replication. In Escherichia coli, minichromosomes are compatible with the chromosome and replicate in a cell-cycle-specific manner at the same time as oriC located on the chromosome initiates replication. In int strains, oriC has been inactivated and replaced by a plasmid origin. Because plasmids control their own replication, chromosome replication is uncoupled from the normal cell-cycle control and is random with respect to the cell cycle in the int strains. We have used an intP1 strain to address the question of whether minichromosome replication is coupled to the replication of the chromosome or is governed by cell-cycle-specific signals. Minichromosome replication was analysed by density-shift experiments and found not to be random in the randomly replicating intP1 host. This suggests that the cell-cycle-specific control functions of oriC replication are operating also in the intP1 strain.

Bacterial Proteins↗

Escherichia coli strains in which chromosome replication is controlled by a P1 or F replicon integrated into oriC.

We report the construction of intP1 and intFs strains, in which the basic replicon from either plasmid P1 or plasmid F (oriS) has been integrated in both orientations into the origin of replication, oriC, of the Escherichia coli chromosome. In these strains, oriC is no longer functional and chromosome-replication is instead controlled by the integrated plasmid replicon. The strains were viable, showing that the deviation from normal chromosome-replication control was not large enough to prohibit cell survival. The strains showed a broader cell-size distribution than a wild-type strain and were more filamentous in rich than in minimal media, although cells of wild-type size were also present. Cells which contained aberrantly shaped or aberrantly distributed nucleoids were also observed. Marker-frequency analysis indicated that chromosome replication was predominantly bidirectional in both intFs strains. In the intP1 strains, the degree of bidirectionality depended upon the orientation of the integrated replicon.

Chromosomes, Bacterial↗

Random initiation of replication of plasmids P1 and F (oriS) when integrated into the Escherichia coli chromosome.

We have constructed intP1 and intFs strains of Escherichia coli in which the basic replicons of either plasmid P1 or plasmid F (oriS) were integrated into an inactivated oriC, such that chromosome replication is controlled by the integrated plasmid replicon. In this study, we have further analysed these strains, and density-shift experiments revealed that chromosome replication occurred randomly during the cell cycle. Flow-cytometry analyses of exponentially growing populations supported this conclusion, and also showed that the DNA/mass ratio of the strains decreased with increasing growth rate. Flow cytometry of exponentially growing cultures treated with rifampicin demonstrated that initiation of replication was uncoordinated in cells containing multiple replication origins.

Chromosomes, Bacterial↗

Hearing in pop/rock musicians: a follow-up study.

In 1975, the threshold hearing levels (HLs) of 83 Swedish and British pop/rock musicians were examined with pure tone audiometry. At that time we found 13% of the musicians with a hearing loss > 20 dB HL at a high frequency pure tone average (3, 4, 6, and 8 kHz). The aim of the present investigation was to conduct an audiometric follow-up study of these musicians 16 years after the first examination. Fifty-three of the 83 pop/rock musicians were retested in 1991 to 1992. They also filled in a questionnaire concerning occupational noise activities, leisure noise activities, general health problems and subjective symptoms related to loud music exposure. The median pure tone audiogram was within 20 dB HL at all test frequencies. On an individual basis, 63% had normal high high frequency pure tone average scores and another 15% had a very limited high frequency hearing loss (< or = 25 dB HL). It seems surprising that pop/rock musicians after performing for 26 years have such well-preserved hearing. There might be a protective effect by the generally positive attitude from the musicians toward their performance and their audience. Regarding the loud and more or less continuous sound levels over 85 dBA there might also be a protective effect from a continuous contraction of the stapedius muscle.

Acoustic Stimulation↗

Direct visualization of plasmid DNA in bacterial cells.

The direct visualization of plasmid DNA inside Escherichia coli cells is demonstrated using phase-fluorescence microscopy of DAPI (4',6-diamidino-2-phenylindole)-stained bacteria. Small as well as large plasmids could be detected, both in minicells and in cells of larger size. For large plasmids, even single molecules appeared to be within the detection limit. The fluorescence generated from monomers of small plasmids was probably below this limit, and for these plasmids the observed signals may represent aggregates. The distribution of the fluorescence foci might reflect specific plasmid positioning during partition and/or replication.

Cell Division↗

Cutaneous myiasis caused by the African tumbu fly (Cordylobia anthropophaga).

We describe a patient with cutaneous myiasis caused by the African tumbu fly (Cordylobia anthropophaga). This case demonstrates the need for a detailed travel history and an understanding of the fly life cycle to prevent erroneous diagnosis and to expedite prompt treatment. The nature of the lesions, larval morphological features, histological characteristics, and immune response directed toward fly maggots are described.

Abdomen↗

Fetal blood velocity waveforms in normal pregnancies. A longitudinal study.

Blood velocity in the umbilical artery, fetal descending aorta and fetal middle cerebral artery was recorded by means of 3.5 MHz pulsed Doppler ultrasound in 22 normal pregnancies. The measurements were performed longitudinally between 25 and 42 weeks of gestation. The maximum blood velocity curves were analysed for pulsatility index (PI), systolic/diastolic velocity ratio (S/D ratio) and in the middle cerebral artery also for the resistance index according to Pourcelot (RI). In the umbilical artery, all variables decreased significantly with increasing gestational age as an expression of the decreasing placental vascular resistance. PI in the descending aorta remained fairly constant during the examined period of gestation. In the middle cerebral artery, all three variables (PI, S/D ratio, RI) decreased significantly as gestation advanced. With the exception of the umbilical artery at 28-32 weeks, PI and S/D ratio were not influenced by the heart rate in any of the vessels examined. Diagrams of the gestational age-related reference values (means +/- 2 SD) for the variables of the blood velocity waveforms were established. Additionally, a ratio of the PI and S/D was calculated for the umbilical artery and middle cerebral artery.

Blood Flow Velocity↗