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T K Jensen

Publications and source records attributed to T K Jensen.

At least 19 recordsLinked to original sources
PubMed2002

Time to pregnancy and semen parameters: a cross-sectional study among fertile couples from four European cities.

BACKGROUND: In fertile populations, little is known about the association between semen parameters and time to pregnancy (TTP). METHODS: Pregnant women from Copenhagen, Edinburgh, Paris and Turku who conceived without medical intervention were asked for their TTP (942 couples), and their partners provided a semen sample. The proportion of morphologically normal sperm and the multiple anomalies index (MAI, ratio of the total number of anomalies to the number of abnormal sperm) were centrally estimated. We estimated rate ratios for the occurrence of a pregnancy by a discrete survival model, adjusted for sexual activity and female factors affecting fecundity. RESULTS: Increasing sperm concentration influenced TTP up to 55 x 10(6)/ml. The proportion of morphologically normal sperm influenced TTP up to 39% according to David's criteria, and this association held among the subjects with a sperm concentration >55 x 10(6)/ml. For strict criteria, the threshold value was 19% normal sperm. An increase of 0.5 in MAI was associated with an adjusted rate ratio for the occurrence of a pregnancy of 0.68 (95% confidence interval: 0.54-0.85). CONCLUSIONS: These results highlight the importance of sperm morphology parameters and indicate that the effect of proportion of normal sperm on TTP may be independent of sperm concentration.

Cross-Sectional Studies↗
PubMed2002

Application of a 5' nuclease assay for detection of Lawsonia intracellularis in fecal samples from pigs.

A 5' nuclease assay was developed to detect Lawsonia intracellularis in porcine fecal samples. The specific probe and primers were chosen by using the 16S ribosomal DNA gene as a target. The 5' nuclease assay was used with a total of 204 clinical samples, and the results were compared to those of immunohistochemistry (IM) on ileal sections of the same animals. There was 91% agreement between the results of IM and the 5' nuclease assay. In the 5' nuclease assay, 111 (54%) of the pigs tested positive for L. intracellularis infection, with a mean cycle threshold (Ct) value of 27.2, whereas 98 (48%) of the pigs tested positive by IM. On average, the Ct and DeltaRn values for the positive samples were 27.2 (standard deviation [SD], 3.7) and 1.6 (SD, 0.7), respectively. A Ct value of 27.2 corresponds to a fecal excretion of approximately 10(7) L. intracellularis cells per g of feces. Furthermore, a total of 40 fecal samples derived from a herd known to be free from infection with L. intracellularis all tested negative, with a Ct value of 40. By using a Ct value of 36 as the cutoff limit, the detection limit of the assay was 1 L. intracellularis cell per PCR tube. In conclusion, the 5' nuclease assay that has been developed represents an applicable fast method for detection of L. intracellularis in fecal samples, with a sensitivity and specificity comparable to those of IM.

Animals↗
PubMed2001

Risk of adverse birth outcomes in populations living near landfill sites.

OBJECTIVE: To investigate the risk of adverse birth outcomes associated with residence near landfill sites in Great Britain. DESIGN: Geographical study of risks of adverse birth outcomes in populations living within 2 km of 9565 landfill sites operational at some time between 1982 and 1997 (from a total of 19 196 sites) compared with those living further away. SETTING: Great Britain. SUBJECTS: Over 8.2 million live births, 43 471 stillbirths, and 124 597 congenital anomalies (including terminations). MAIN OUTCOME MEASURES: All congenital anomalies combined, some specific anomalies, and prevalence of low and very low birth weight (<2500 g and <1500 g). RESULTS: For all anomalies combined, relative risk of residence near landfill sites (all waste types) was 0.92 (99% confidence interval 0.907 to 0.923) unadjusted, and 1.01 (1.005 to 1.023) adjusted for confounders. Adjusted risks were 1.05 (1.01 to 1.10) for neural tube defects, 0.96 (0.93 to 0.99) for cardiovascular defects, 1.07 (1.04 to 1.10) for hypospadias and epispadias (with no excess of surgical correction), 1.08 (1.01 to 1.15) for abdominal wall defects, 1.19 (1.05 to 1.34) for surgical correction of gastroschisis and exomphalos, and 1.05 (1.047 to 1.055) and 1.04 (1.03 to 1.05) for low and very low birth weight respectively. There was no excess risk of stillbirth. Findings for special (hazardous) waste sites did not differ systematically from those for non-special sites. For some specific anomalies, higher risks were found in the period before opening compared with after opening of a landfill site, especially hospital admissions for abdominal wall defects. CONCLUSIONS: We found small excess risks of congenital anomalies and low and very low birth weight in populations living near landfill sites. No causal mechanisms are available to explain these findings, and alternative explanations include data artefacts and residual confounding. Further studies are needed to help differentiate between the various possibilities.

Congenital Abnormalities↗
PubMed2001

Risk factors for intestinal pathogens in Danish finishing pig herds.

The objective of this investigation was to identify risk factors for infection with the intestinal bacteria: Lawsonia intracellularis, Brachyspira hyodysenteriae, Serpulina intermedia, Brachyspira innocens, Brachyspira pilosicoli and swine-pathogenic Escherichia coli (serogroups O138, O139, O141 and O149) in Danish finishing pig herds.A total of 79 herds was randomly selected and visited during 1998. From each herd, 20 faecal samples were collected from individual pigs weighing 30-50 kg. In total, 1580 faecal samples were collected and examined by polymerase chain reaction (L. intracellularis) or culture (all other agents). Information on feed and management procedures was collected by filling in questionnaires at the herd visits. The questionnaires included information on 29 dichotomous variables and three continuous variables. Variables with P<0.25 in a preliminary screening (chi2- or t-test) were selected for the statistical modelling. Our conclusions, based on the results of multifactorial logistic regression (cut-off: P=0.05), were the following: 1. Consistent batch production was associated with reduced prevalences of L. intracellularis and weakly -haemolytic spirochetes (S. intermedia, B. innocens, B. pilosicoli) (OR's=0.43 and 0.06, respectively). 2. Home-mixed (and/or non-pelleted) feed was associated with reduced prevalences of L. intracellularis and weakly -haemolytic spirochetes (OR's=0.6 and 0.4, respectively). 3. Providing straw to finishers was associated with a reduced prevalence of weakly -haemolytic spirochetes (OR=0.28-0.32). 4. Not using antimicrobial growth promoters for piglets was associated with an increased prevalence of S. intermedia (OR=11.11). 5. Rare occurrence of post-weaning diarrhoea (as opposed to common) was associated with an increased prevalence of weakly -haemolytic spirochetes (OR=8.3-13.7).

Animals↗
PubMed2001

In situ hybridisation for identification and differentiation of Mycoplasma hyopneumoniae, Mycoplasma hyosynoviae and Mycoplasma hyorhinis in formalin-fixed porcine tissue sections.

Oligonucleotide probes targeting 16S ribosomal RNA were designed for species-specific identification of the porcine mycoplasmas Mycoplasma hyopneumoniae, Mycoplasma hyorhinis and Mycoplasma hyosynoviae using a fluorescent in situ hybridisation assay. The specificity of the probes was evaluated using pure cultures as well as porcine tissue sections with artificial presence of mycoplasma, and the probes were found specific for the target organisms. The assay was applied on sections of 28 tissue samples from pigs infected with one or more of the three Mycoplasma species as determined by cultivation. M. hyopneumoniae and M. hyorhinis were identified in accordance with cultivation in lung sections from nine pigs affected by catarrhal to purulent bronchopneumonia. Likewise, in eight cases of fibrinous pericarditis, M. hyopneumoniae, M. hyorhinis and M. hyosynoviae were the infectious agents according to cultivation and were correctly identified by in situ hybridisation. Out of 11 joints cultivation positive for M. hyosynoviae, the probe was only able to identify M. hyosynoviae in eight cases probably due to a low number of microorganisms in the tissue sections. The in situ hybridisation assay is well suited for use in diagnostic and experimental work as well as a tool for pathogenesis studies.

Animals↗
PubMed2001

Regional differences in waiting time to pregnancy among fertile couples from four European cities.

BACKGROUND: A previous European study found a longer time to pregnancy (TTP) among fertile women from Paris compared with women from other Western European countries. A co-ordinated, cross-sectional study of pregnant couples from Denmark (Copenhagen), France (Paris), Scotland (Edinburgh) and Finland (Turku) was therefore undertaken to assess differences in waiting TTP among couples from these cities. METHODS: Pregnant women were invited to participate when they showed up for their first antenatal visit in one of the four centres. Inclusion criteria included that their partner was 20-45 years of age and born in the country in which he was currently living and that the pregnancy was achieved without fertility treatment. Both partners filled in a questionnaire and the man underwent a physical examination and delivered a semen sample (Turku: n = 237, Copenhagen: n = 302, Edinburgh: n = 212, Paris: n = 191). RESULTS: French couples had a decreased probability of conception compared with couples from the other three countries, although only after adjustment for confounders. No significant differences between couples from the three other countries were found. CONCLUSION: The observed geographical differences in TTP remain unexplained and were not due to differences in semen quality, but may be caused by varying exposures to environmental factors or psychological distress. In addition, selection bias due to the low participation rates cannot be ruled out. Future studies examining the causes for geographical differences in TTP are needed.

Adult↗
PubMed2001

Regional differences in semen quality in Europe.

Recent reports have indicated a decrease in semen quality of men in some countries, and suggested regional differences. A study was undertaken of semen samples from 1082 fertile men from four European cities (Copenhagen, Denmark; Paris, France; Edinburgh, Scotland; and Turku, Finland). Semen analysis was standardized, inter-laboratory differences in assessment of sperm concentration were evaluated, and morphology assessment centralized. Lowest sperm concentrations and total counts were detected for Danish men, followed by French and Scottish men. Finnish men had the highest sperm counts. Men from Edinburgh had the highest proportion of motile spermatozoa, followed by men from Turku, Copenhagen and Paris. Only the differences between Paris/Edinburgh and Paris/Turku were statistically significant (P < 0.003 and P < 0.002 respectively). No significant differences in morphology were detected. A general seasonal variation in sperm concentration (summer 70% of winter) and total sperm count (summer 72% of winter) was detected. Semen quality of a 'standardized' man (30 years old, fertile, ejaculation abstinence of 96 h) were estimated. Typically, sperm concentrations (x 10(6)/ml) for winter/summer were: Turku 132/93; Edinburgh 119/84; Paris 103/73; and Copenhagen 98/69. These differences in semen quality may indicate different environmental exposures or lifestyle changes in the four populations. However, it remains to be seen whether such changes can account for these differences. These data may also serve as a reference point for future studies on time trends in semen quality in Europe.

Adult↗
PubMed2001

Diagnostic examination of human intestinal spirochetosis by fluorescent in situ hybridization for Brachyspira aalborgi, Brachyspira pilosicoli, and other species of the genus Brachyspira (Serpulina).

Human intestinal spirochetosis, characterized by end-on attachment of densely packed spirochetes to the epithelial surface of the large intestines as a fringe has been associated with the weakly beta-hemolytic spirochetes Brachyspira aalborgi and Brachyspira (Serpulina) pilosicoli. In this study, fluorescent in situ hybridization with oligonucleotide probes targeting 16S or 23S rRNA of B. aalborgi, B. pilosicoli, and the genus Brachyspira was applied to 40 sections of formalin-fixed, paraffin-embedded intestinal biopsy specimens from 23 Danish and 15 Norwegian patients with histologic evidence of intestinal spirochetosis. Five biopsy specimens from patients without intestinal spirochetosis and three samples from pigs with experimental B. pilosicoli colitis were examined as well. In addition, the 16S ribosomal DNAs of two clinical isolates of B. aalborgi were sequenced, and a PCR procedure was developed for the identification of B. aalborgi in cultures. The genotypic characteristics of the two clinical isolates showed very high (99.5%) similarity with two existing isolates, the type strain of B. aalborgi and a Swedish isolate. Hybridization with the Brachyspira genus-specific probe revealed a brightly fluorescing fringe of spirochetes on the epithelia of 39 biopsy specimens, whereas 1 biopsy specimen was hybridization negative. The spirochetes in biopsy specimens from 13 Danish and 8 Norwegian patients (55.3%) were identified as B. aalborgi. The spirochetes in the biopsy specimens from the other 17 patients hybridized only with the Brachyspira probe, possibly demonstrating the involvement of as-yet-uncharacterized Brachyspira spirochetes in human intestinal spirochetosis.

Adolescent↗
PubMed2001

Application of fluorescent in situ hybridization for specific diagnosis of Pneumocystis carinii pneumonia in foals and pigs.

Fluorescent in situ hybridization, immunohistochemistry, and Grocott's methenamine-silver nitrate staining were compared as diagnostic methods for Pneumocystis carinii pneumonia in formalin-fixed lung tissue from foals and pigs. An oligonucleotide probe targeting 18S ribosomal RNA of P. carinii was designed for in situ hybridization, and a commercially available monoclonal antibody was used for immunohistochemistry. Samples from six foals and 10 pigs with P. carinii pneumonia, as verified by Grocott's methenamine-silver nitrate staining, were examined concurrently with samples from seven animals with pneumonia caused by other pathogens. Fluorescent in situ hybridization showed distinctive positive reactions for P. carinii in all test samples. The immunohistochemical procedure, however, only revealed P. carinii in the foals. The number of P. carinii organisms observed by fluorescent in situ hybridization and immunohistochemistry far exceeded the number of organisms stained by Grocott's methenamine-silver nitrate staining. The results show that fluorescent in situ hybridization targeting ribosomal RNA can provide a specific diagnosis of P. carinii pneumonia in foals and pigs.

Animals↗
PubMed2000

[Stress and fertility. A follow-up study among couples planning the first pregnancy].

Mental distress has often been suggested as a cause of unexplained infertility. However, the causal direction may well be from infertility to distress, and prospective data are needed. We therefore followed 393 couples, who were planning their first pregnancy, with prospective collection of information on distress from termination of birth control until pregnancy for a maximum of six menstrual cycles. The analyses included 1,475 menstrual cycles, and mental distress was measured in each cycle by the General Health Questionnaire (GHQ). Urine samples from each period of vaginal bleeding were analyzed for human chorionic gonadotrophic hormone, indicating early embryonal loss. We found that for cycles with the highest distress score (GHQ score above the 80 percentile) the probability of conception per cycle was 12.8% compared to 16.5% in other cycles (adjusted OR 0.6; 95% CI 0.4-1.0). The effect of distress was almost exclusively found among women with long menstrual cycles (OR 0.1; 95% CI 0.01-0.4 and OR 0.9; 0.5-1.4 for women with cycles > or = 35 and < 35 days, respectively). An increased incidence of early embryonal loss was also found among highly distressed women with long cycles, but was based on a small number of observations. It is concluded that psychological distress may be a risk factor for reduced fertility in women with long menstrual cycles.

Adult↗
PubMed2000

Selection bias in determining the age dependence of waiting time to pregnancy.

Many studies have found decreased fecundability, that is, the ability to conceive in a menstrual cycle, with increasing female age. To evaluate the effect of maternal age on waiting time to pregnancy, the authors reviewed hospital charts of all pregnant women attending prophylactic antenatal care at Odense University Hospital, Denmark, during 1972-1987. Only the first pregnancy of each woman and only planned pregnancies were included (n = 14,754). The fecundability odds ratio (FR) was calculated as the odds of a conception in a menstrual cycle among the older women divided by the odds among women aged 15-24 years. The FR for women aged 25-29 years was 1.12 (95% confidence interval (CI): 1.04, 1.20), for women aged 30-34 years it was 1.15 (95% CI: 1.01, 1.30), and for women above 34 years the FR was 2.44 (95% CI: 1.84, 3.22) after adjustment for confounders. The increased fecundability with age is contrary to previous studies and may be explained by selection bias, as sterile women were not included. In addition, some very fertile young women who became pregnant by accident before efficient birth control methods were available and therefore were excluded from time to pregnancy studies may now use oral contraceptives until they plan a pregnancy later in life and are included.

Adolescent↗
PubMed2000

Prevalence of intestinal pathogens in Danish finishing pig herds.

Our aim was to determine the prevalence of the intestinal bacteria: Lawsonia intracellularis, Brachyspira hyodysenteriae, Serpulina intermedia, Brachyspira innocens, Brachyspira pilosicoli, pathogenic Escherichia coli (serogroups O138, O139, O141 and O149) and Salmonella enterica in Danish finishing pig herds. A total of 79 herds was randomly selected and visited during 1998. From each herd, 20 faecal samples were collected from individual pigs weighing 30-50kg. Furthermore, 10 pooled pen samples were collected and examined for S. enterica. In total, 1580 faecal samples and 790 pen samples were collected and examined by polymerase chain reaction (PCR) or culture. L. intracellularis was found in 74 herds (93.7%), B. hyodysenteriae in two herds (2.5%), S. intermedia in 10 herds (12. 7%), B. innocens in 27 herds (34.2%), B. pilosicoli in 15 herds (19. 0%), pathogenic E. coli in 19 herds (24.1%) and S. enterica in eight herds (10.1%). The within-herd prevalences of L. intracellularis and B. hyodysenteriae were 25-30%; the within-herd prevalences of the other agents were 5-10%. Three herds (4%) were not infected with any of the bacteria and 25 herds (32%) were only infected with L. intracellularis.

Animals↗
PubMed2000

Diurnal scrotal skin temperature and semen quality. The Danish First Pregnancy Planner Study Team.

It is well established that heat is associated with reduced sperm production, but the role of physiological variation in temperature has never been scrutinized in humans. We studied diurnal scrotal temperature and markers of male fertility in a population of couples planning their first pregnancy. Sixty men from a cohort of couples who were planning their first pregnancy were included and scrotal skin temperature was monitored during 3 days using a portable data recorder. Working hours and working postures were recorded daily in a questionnaire. Each man provided a fresh semen sample and the couples were followed for six menstrual cycles or until a clinical pregnancy was recognized. The median value of scrotal skin temperature was 33.3 degrees C in the daytime and 34.8 degrees C at night. In periods of sedentary work, the median temperature was on average 0.7 degrees C higher (SE=0.2 degrees C). In addition, scrotal temperature was higher in the daytime, in summer, and in leisure time compared with working hours. Median sperm concentration among men with more than 75% of their daytime readings above 35 degrees C was 33.4 x 10(6)/mL, compared with 91.8 x 10(6)/mL for men with less than half of their readings above 35 degrees C (difference 58.4; 95% CI: 25.9-77.8 x 10(6)/mL). It is concluded that a sedentary position is a significant source of increased scrotal skin temperature, and even moderate and physiological elevation in scrotal skin temperature is associated with a substantially reduced sperm concentration. Sedentary work should be considered as an important potential confounder for reduced sperm count in epidemiological research.

Circadian Rhythm↗
PubMed2000

Detection of Lawsonia intracellularis in the tonsils of pigs with proliferative enteropathy.

The presence of Lawsonia intracellularis, the obligate intracellular bacterium causing proliferative enteropathy (PE), in the tonsils of pigs as a locus for infection or extraintestinal occurrence of the bacterium was investigated by PCR and immunohistochemistry. Tonsillar occurrence of L. intracellularis could be part of the pathogenesis of PE and an important risk factor in the spread of the disease. L. intracellularis was detected by only PCR in the tonsils of 2/32 pigs without PE at necropsy but with a clinical history of diarrhoea and detection of the bacterium in faeces 1 to 3 weeks prior to necropsy but not in four pigs with moderate PE lesions. However, L. intracellularis was detected in the tonsils of 4/9 pigs with PE complicated with necroses and in 4/4 pigs with proliferative haemorrhagic enteropathy in which L. intracellularis antigen also was demonstrated in tonsillar macrophages and as intact bacteria in the lumen of the crypts. The results show that L. intracellularis is detectable in the tonsils of pigs and that the tonsillar presence of L. intracellularis appears to be correlated to the severity of the intestinal lesions possibly as a result of local retention and not as part of the pathogenesis of PE.

Animals↗
PubMed2000

High frequency of sub-optimal semen quality in an unselected population of young men.

Male reproductive function seems to have deteriorated considerably during the past 4-5 decades. However, studies of the reproductive function in unselected populations have not previously been reported. As the large majority of young men in Denmark are subjected to a compulsory medical examination for military service, this provided a unique opportunity to study the reproductive function in an unbiased population. Altogether 891 young men delivered a blood sample in which reproductive hormones were measured. From 708 of these men data were also obtained on semen quality and testis size. The median sperm concentration was 41 x 10(6)/ml (mean 57.4 x 10(6)/ml). Men with ejaculation abstinence above 48 h had slightly higher sperm concentrations (median 45 x10(6)/ml, mean 63.2 x 10(6)/ml), but even in this subgroup, 21 and 43% respectively had sperm counts below 20 x 10(6)/ml and 40 x 10(6)/ml. Among men with no history of reproductive diseases and a period of abstinence above 48 h, as many as 18 and 40% respectively had concentrations below 20 and 40 x 10(6)/ml. Sperm counts were positively correlated with testis size, percentage normal spermatozoa and inhibin B, and negatively correlated with percentage immotile spermatozoa and follicle stimulating hormone. Possible causes for this high frequency of young men with suboptimal semen quality are obscure and need to be explored. Whether these findings apply for young male populations of comparable countries remains to be seen.

Analysis of Variance↗
PubMed2000

Computer-assisted semen analysis parameters as predictors for fertility of men from the general population. The Danish First Pregnancy Planner Study Team.

The predictive value of sperm motility parameters obtained by computer-assisted semen analysis (CASA) was evaluated for the fertility of men from general population. In a prospective study with couples stopping use of contraception in order to try to conceive, CASA was performed on semen samples from 358 men. A recently developed CASA system, Copenhagen Rigshospitalet Image house sperm Motility Analysis System (CRISMAS) was used for assessment of motility parameters. This system has an editing function which allows correction of tracks made by the computer. Probably due to this function, the concentration assessment made by CRISMAS was very close to that made by the technician (median difference <5%) in all concentration ranges. Correlation between CASA parameters and fertility of normal couples (measured as probability of achieving pregnancy) was examined by the Cox regression model. In univariate models ln(sperm concentration) [beta = 0.331, risk ratio (RR) = 1.392, P = 0.0001], ln(total sperm count) (beta = 0.252, RR = 1.286, P = 0.0007) and percentage motile spermatozoa (beta = 0.014, RR = 1.014, P = 0.0004) were most significant predictors for fertility. In a multivariate analysis ln(sperm concentration) (beta = 0.268, RR = 1.307, P = 0.0016) and percentage motile spermatozoa (beta = 0.010, RR = 1.010, P = 0.011) but even more significantly the combined parameter, ln(concentration of motile spermatozoa) (beta = 0.329, RR = 1.389, P = 0.0001), were the only parameters of predictive value for fertility of men in the general population. In conclusion, these parameters obtained by CASA measurements can be used for prediction of fertility potential in normal men. This appears to be the first study showing the value of CASA in prediction of fertility in the general male population.

Adult↗