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C Jørgensen

Publications and source records attributed to C Jørgensen.

17 recordsLinked to original sources
PubMed2006

Naturally conceived twins with monochorionic placentation have the highest risk of fetal loss.

OBJECTIVE: The aim of this study was to estimate the rate of fetal loss in dichorionic (DC) and monochorionic (MC) twin pregnancies stratified according to zygosity and method of conception. METHODS: In a prospective multicenter observational study women with a twin pregnancy had an ultrasound scan before 14 + 6 weeks' gestation in order to determine chorionicity. The fetal loss rate, the perinatal, neonatal and infant mortality rates and the frequency of very preterm labor were estimated for the different types of twin. RESULTS: Among the 495 pregnancies (421 DC and 74 MC) 229 (46%) were conceived naturally and 266 (54%) by assisted reproduction (AR). Outcome data for 945 liveborn babies were obtained. The spontaneous miscarriage rate before 24 weeks' gestation was 10.9% (7/64) among naturally conceived MC compared to 3.0% (5/165) for naturally conceived DC twins (P < 0.05). For twins conceived by AR the corresponding figures were 0% (0/10) and 0.4% (1/256). The odds ratio (OR) for very preterm birth-before 28 weeks' gestation-was 4.2 for MC twins compared to DC twins. The relative risk of fetal loss or death among DC twins was 20% of the risk for MC twins. CONCLUSION: The risk of fetal loss, very preterm delivery and neonatal/infant death is significantly higher among twins with MC compared to DC placentation. Twins conceived by AR have a much lower risk of MC placentation. The risk of losing one or both twins seems higher among naturally conceived twins compared to twins conceived by AR, despite the fact that the maternal age was higher among the mothers of the AR twins.

Adult↗
PubMed2005

How to identify twins at low risk of spontaneous preterm delivery.

OBJECTIVE: The aim of this study was to evaluate transvaginal sonographic assessment of cervical length at 23 weeks as a screening test for spontaneous preterm delivery in order to define a cut-off value that could be used to select twin pregnancies at low risk of spontaneous preterm delivery. METHODS: In a prospective multicenter study of 383 twin pregnancies included before 14 + 6 weeks a cervical scan with measurement of the cervical length was performed at 23 weeks' gestation. The results were blinded for the clinicians if the cervical length was > or = 15 mm. The rates of spontaneous delivery at different cut-off levels of cervical length were determined. RESULTS: Eighty-nine percent of the twins had dichorionic placentation and 58% were conceived after assisted reproduction. The rate of spontaneous preterm delivery was 2.3% (1.5% for dichorionic (DC) and 9.1% for (MC) monochorionic twins) before 28 weeks and 18.5% (17.1% for DC and 29.5% for MC twins) before 35 weeks. The screen-positive rate was 5% for a cervical length < or = 20, 7-8% at < or = 25, 16-17% at < or = 30 and 34-48% at < or = 35 mm depending on chorionicity. The false-negative rate (1 - negative predictive value) ranged from 1.2% at 28 weeks to 18.6% at 35 weeks for all twins. Receiver-operating characteristics curves showed that the sensitivity increased with declining gestational age with cut-off levels of highest accuracy at 21 mm for 28 weeks and 29 mm for 33 weeks. CONCLUSIONS: Cervical length measurement at 23 weeks of gestation is a good screening test for predicting twins at low risk of preterm and very preterm delivery, especially in DC twins. The present results suggest that a cut-off of 25 mm should be recommended.

Cervical Ripening↗
PubMed2004

Smoking reduces breast tenderness during oral estrogen-progestogen therapy.

OBJECTIVE: We wished to study the influence of smoking upon the occurrence of breast tenderness during oral estrogen-progestogen therapy (EPT). METHODS: Data from 626 healthy postmenopausal women participating in three double-blind, randomized, controlled long-term trials of EPT versus placebo were included. The studies covered sequential, continuous and interrupted regimens of estradiol opposed by a selection of progestins. All studies were mono-center studies and performed in the period 1988-1997. Data on breast tenderness were collected from adverse event reporting and information on smoking status was obtained by interview. RESULTS: Smoking was associated with an earlier age at menopause (difference: 1.3 years, p < 0.001) and a slightly lower body mass index (difference: 0.8 kg/m2, p < 0.01). Smoking women in the EPT groups had significantly lower on-treatment estradiol levels compared to non-smoking women (p < 0.001), whereas no differences were observed in the placebo group. In parallel, the incidence of breast tenderness during EPT was reduced by about one-half (p < 0.001) in smokers compared to non-smokers, whereas no differences were seen on placebo. CONCLUSION: Current smoking reduces the incidence of breast tenderness in women receiving oral EPT. This may be caused by the increased degradation of estradiol during smoking.

Body Mass Index↗
PubMed2003

All-fiber, octave-spanning supercontinuum.

We present an all-fiber supercontinuum source based on a passively mode-locked erbium fiber laser and a small-effective-area, germanium-doped silica fiber. The parallels between this system and the continuum generated in microstructured fibers with 800-nm pulses are discussed, and the role of dispersion is investigated experimentally. We construct a hybrid fiber by fusion splicing lengths of different-dispersion fiber together, generating more than an octave of bandwidth.

Journal Article↗
PubMed2002

Heterotrophic bacteria growing in association with Methylococcus capsulatus (Bath) in a single cell protein production process.

The methanotrophic bacterium Methylococcus capsulatus (Bath) grows on pure methane. However, in a single cell protein production process using natural gas as methane source, a bacterial consortium is necessary to support growth over longer periods in continuous cultures. In different bioreactors of Norferm Danmark A/S, three bacteria consistently invaded M. capsulatus cultures growing under semi-sterile conditions in continuous culture. These bacteria have now been identified as a not yet described member of the Aneurinibacillus group, a Brevibacillus agri strain, and an acetate-oxidiser of the genus Ralstonia. The physiological roles of these bacteria in the bioreactor culture growing on natural, non-pure methane gas are discussed. The heterotrophic bacteria do not have the genetic capability to produce either the haemolytic enterotoxin complex HBL or non-haemolytic enterotoxin.

Bacillus↗
PubMed2001

Development and utilisation of a medium to isolate phenanthrene-degrading Pseudomonas spp.

In this study, we isolated phenanthrene degraders belonging to Pseudomonas spp. by combining the selective force of two previously described media. The two compounds, sodium lauryl sarcosine and trimethoprim, from the Gould S1 medium, were added to minimal agar plates sprayed with phenanthrene. Pseudomonas spp. that could produce clearing zones were isolated in one step from the rhizosphere without first selecting for Pseudomonas spp. and subsequently screening for degraders or vice versa. Enumeration and isolation of Pseudomonas spp. attached to the rhizosphere showed clear differences between two types of soil. Rhizosphere-attached phenanthrene degraders (from Pseudomonas spp.) were isolated from a former coal gasification site, but were absent in an agricultural soil subjected to organic farming. We isolated 23 phenanthrene degraders producing clearing zones from the rhizosphere of barley roots. All of these 23 isolates (of which 16 were fluorescent in UV light) proved to be members of the Pseudomonas RNA homology group I, on the basis of results of the analytical profile index (API) test system and classic taxonomic tests.

Bacteriological Techniques↗
PubMed2001

Diving development in nursing harbour seal pups.

This study investigated physiological and behavioural aspects of diving development in pups of the harbour seal Phoca vitulina. Behavioural data (4280 h, 6027 dives) from time/depth recorders (N=13) deployed on pups aged 0-19 days are presented concomitantly with physiological measurements (N=8, sampled both early and late in the nursing period) of blood oxygen stores and body composition. Pups grew from 12.6+/-1.8 kg (mean age 2 days, total body fat 16+/-4 %) to 22.2+/-2.5 kg (mean age 16 days, total body fat 35+/-5 %; means +/- S.D.) over the duration of the experiment. Pups less than 5 days of age had an elevated haematocrit and reduced plasma volume compared with older pups. Although plasma volume and blood volume increased, mass-specific blood oxygen stores (total haemoglobin) fell during the study period. Simultaneously, the following behavioural indicators of diving ability increased: the proportion of time spent in the water, dive depth, dive duration, bottom time and maximum daily swimming velocity. In addition, the proportion of dives that were identified by cluster analyses as being U-shaped increased significantly with age. On the basis of the measured blood oxygen stores, less than 1 % of the recorded dives exceeded the calculated aerobic dive limit. Thus, development in blood oxygen stores or rates of oxygen consumption did not seem to restrain the rate of neonatal dive development in harbour seals. It appears that behavioural modifications (experience and learning) may be the primary rate-limiting factors for ontogeny of diving skills in neonates of this species.

Animals↗
PubMed1999

Isolation and characterization of mutations in the Escherichia coli regulatory protein XapR.

In this work, the LysR-type protein XapR has been subjected to a mutational analysis. XapR regulates the expression of xanthosine phosphorylase (XapA), a purine nucleoside phosphorylase in Escherichia coli. In the wild type, full expression of XapA requires both a functional XapR protein and the inducer xanthosine. Here we show that deoxyinosine can also function as an inducer in the wild type, although not to the same extent as xanthosine. We have isolated and characterized in detail the mutants that can be induced by other nucleosides as well as xanthosine. Sequencing of the mutants has revealed that two regions in XapR are important for correct interactions between the inducer and XapR. One region is defined by amino acids 104 and 132, and the other region, containing most of the isolated mutations, is found between amino acids 203 and 210. These regions, when modelled into the three-dimensional structure of CysB from Klebsiella aerogenes, are placed close together and are most probably directly involved in binding the inducer xanthosine.

Base Sequence↗
PubMed1999

MULTISCAN--a Scandinavian multicenter second trimester obstetric ultrasound and serum screening study.

AIM: To study the detection rates of second trimester ultrasound screening for neural tube defects (NTD), abdominal wall defects (AWD) and Down's syndrome (DS) in low risk populations at tertiary centers, and to compare the ultrasound screening detection rates with those that were obtainable by biochemical serum screening (double test: alpha-fetoprotein/human chorion gonadotrophin/age test). STUDY DESIGN: Prospective multicenter study with a three year inclusion period: 1/1/1989-31/12/1991. SUBJECTS: 27,844 low-risk women at 18-34 years of age who had a second trimester ultrasound screening examination. Of these, 10,264 also had a serum test. METHODS: An ultrasound malformation scan and a serum test were carried out at 17-19 weeks of gestation. Risk calculations regarding DS were based on alpha-fetoprotein, human chorion gonadotrophin and maternal age; performed retrospectively for the first two years. RESULTS: In total 73 cases were identified in the study population: NTD (n=34), AWD (n=7) and DS (n=32). The detection rates, (%, with 95% confidence interval) for ultrasound screening were: NTD: 79.4 (62.1-91.3); AWD: 85.7 (42.1-99.6); DS: 6.3 (0.8-20.8). In the subgroup of women who had both tests, the detection rates for ultrasound screening vs double test were: NTD: 62.5 (24.5-91.5) vs 75.0 (34.9-96.8); AWD: 66.7 (9.4-99.2) vs 100 (29.2-100.0); DS: 7.7 (0.2-36.0) vs 46.2 (19.2-74.9). The false positive rates (%) for ultrasound screening vs double test were: NTD: 0.01/3.3; AWD: 0.01/3.3; DS: 0.1/4.0. CONCLUSION: Second trimester ultrasound screening in a low risk population gave a low detection rate for fetal DS (6.3%) and an acceptable detection rate for NTD (79.4%) and AWD (85.7%). In the subgroup of women who had both tests, serum screening performed better than ultrasound as applied in the present study, especially regarding DS.

Abdominal Muscles↗
PubMed1995

Transformation of o-xylene to o-methyl benzoic acid by a denitrifying enrichment culture using toluene as the primary substrate.

A highly enriched denitrifying mixed culture transformed o-xylene co-metabolically along with toluene by methyl group oxidation. o-Methyl benzaldehyde and o-methyl benzoic acid accumulated transiently as metabolic products of o-xylene transformation. Transformation of o-methyl benzyl alcohol and o-methyl benzaldehyde occurred independently of toluene degradation and resulted in the formation of a compound coeluting with o-methyl benzoic acid on a gas chromatograph. The co-metabolic relationship between toluene and o-xylene could be attributed to a mechanism linked to the initial oxidation of the methyl group.

Bacteria, Anaerobic↗
PubMed1995

Stoichiometry and kinetics of microbial toluene degradation under denitrifying conditions.

Batch experiments were carried out to investigate the stoichiometry and kinetics of microbial degradation of toluene under denitrifying conditions. The inoculum originated from a mixture of sludges from sewage treatment plants with alternating nitrification and denitrification. The culture was able to degrade toluene under anaerobic conditions in the presence of nitrate, nitrite, nitric oxide, or nitrous oxide. No degradation occurred in the absence of Noxides. The culture was also able to use oxygen, but ferric iron could not be used as an electron acceptor. In experiments with 14C-labeled toluene, 34% +/- 8% of the carbon was incorporated into the biomass, while 53% +/- 10% was recovered as 14CO2, and 6% +/- 2% remained in the medium as nonvolatile water soluble products. The average consumption of nitrate in experiments, where all the reduced nitrate was recovered as nitrite, was 1.3 +/- 0.2 mg of nitrate-N per mg of toluene. This nitrate reduction accounted for 70% of the electrons donated during the oxidation of toluene. When nitrate was reduced to nitrogen gas, the consumption was 0.7 +/- 0.2 mg per mg of toluene, accounting for 97% of the donated electrons. Since the ammonia concentration decreased during degradation, dissimilatory reduction of nitrate to ammonia was not the reductive process. The degradation of toluene was modelled by classical Monod kinetics. The maximum specific rate of degradation, k, was estimated to be 0.71 mg toluene per mg of protein per hour, and the Monod saturation constant, Ks, to be 0.2 mg toluene/l. The maximum specific growth rate, mu max, was estimated to be 0.1 per hour, and the yield coefficient, Y, was 0.14 mg protein per mg toluene.

Bacteria, Anaerobic↗
PubMed1993

Biodegradation of ortho-cresol by a mixed culture of nitrate-reducing bacteria growing on toluene.

A mixed culture of nitrate-reducing bacteria degraded o-cresol in the presence of toulene as a primary growth substrate. No degradation of o-cresol was observed in the absence of toluene or when the culture grew on p-cresol and 2,4-dimethylphenol. In batch cultures, the degradation of o-cresol started after toluene was degraded to below 0.5 to 1.0 mg/liter but continued only for about 3 to 5 days after the depletion of toluene since the culture had a limited capacity for o-cresol degradation once toluene was depleted. The total amount of o-cresol degraded was proportional to the amount of toluene metabolized, with an average yield of 0.47 mg of o-cresol degraded per mg of toluene metabolized. Experiments with [ring-U-14C]o-cresol indicated that about 73% of the carbon from degraded o-cresol was mineralized to CO2 and about 23% was assimilated into biomass after the transient accumulation of unidentified water-soluble intermediates. A mathematical model based on a simplified Monod equation is used to describe the kinetics of o-cresol degradation. In this model, the biomass activity toward o-cresol is assumed to decay according to first-order kinetics once toluene is depleted. On the basis of nonlinear regression of the data, the maximum specific rate of o-cresol degradation was estimated to be 0.4 mg of o-cresol per mg of biomass protein per h, and the first-order decay constant for o-cresol-degrading biomass activity was estimated to be 0.15 h-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Biodegradation, Environmental↗
PubMed1990

Ultrasound examination for detection of ovarian carcinoma in risk groups.

Ovarian ultrasound scanning was carried out as an adjunct to pelvic examination in 801 women between 40-70 years of age presenting at the outpatient Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden for a variety of gynecologic complaints. All belonged to a high-risk category for ovarian carcinoma because of nulliparity; family history of ovarian, breast, or endometrial carcinoma; previous cancer; or unspecified abdominal complaints. Of 638 patients with normal scans, findings at pelvic examination had been abnormal in 51 cases, and all were normal at subsequent clinical follow-up. Among 163 patients with abnormal ultrasound scans, one case of borderline ovarian tumor and two cases of endometrial cancer were found for which the pelvic examination had been considered normal. Clinical symptoms probably would have led to detection within a short time in these cases anyway, even if ultrasound had not been performed. Based on the findings in this study and the previous experience with gynecologic ultrasound in several thousand patients, it would not seem that ultrasound has a role in screening for ovarian carcinoma.

Adult↗
PubMed1989

[Occurrence of the yeast, Cryptococcus (Cr) neoformans, in pigeon droppings].

Pigeon droppings were collected in Copenhagen and Odense. In samples from pigeon lofts, cryptococci were found in 33% from Copenhagen and in 16% from Odense. All of the species of cryptococci found were Cr. neoformans. These findings are compared with the previous Danish investigations. The frequent occurrence of cryptococci in AIDS patients is mentioned.

Animals↗
PubMedDate not supplied

Potential mineralization of four herbicides in a ground water--fed wetland area.

Herbicides may leach from agricultural fields into ground water feeding adjacent wetlands. However, only little is known of the fate of herbicides in wetland areas. The purpose of the study was to examine the potential of a riparian fen to mineralize herbides that could leach from an adjacent catchment area. Slurries were prepared from sediment and ground water collected from different parts of a wetland representing different redox conditions. The slurries were amended with O2, NO3-, SO4(2-), and CO2, or CO2 alone as electron acceptors to simulate the in situ conditions and their ability to mineralize the herbides mecoprop, metsulfuron-methyl, isoproturon and atrazine. In addition, the abundance of bacteria able to utilize O2, NO3-, SO4(2-) + CO2, and CO2 as electron acceptors was investigated along with the O2-reducing and methanogenic potential of the sediment. The recalcitrance to bacterial degradation depended on both the type of herbicide and the redox conditions pertaining. Mecoprop was the most readily degraded herbicide, with 36% of [ring-U-14C]mecoprop being mineralized to 14CO2 under aerobic conditions after 473 d. In comparison, approximately 29% of [phenyl-U-14C]metsulfuron-methyl and 16% of [ring-U-14C]isoproturon mineralized in aerobic slurries during the same period. Surprisingly, 8 to 13% of mecoprop also mineralized under anaerobic conditions. Neither metsulfuron-methyl nor isoproturon were mineralized under anaerobic conditions and atrazine was not mineralized under any of the redox conditions examined. The present study is the first to report mineralization of meco-prop in ground water in a wetland area, and the first to report mineralization of a phenoxyalcanoic acid herbicide under both aerobic and anaerobic conditions.

2-Methyl-4-chlorophenoxyacetic Acid↗