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Biomedical subjects

L B Jensen

Publications and source records attributed to L B Jensen.

At least 73 records · Page 4Linked to original sources
PubMed1996

Sociological and behavioural characteristics of perimenopausal women with an express attitude to hormone substitution therapy.

OBJECTIVES: The objective of the study is to demonstrate differences in behaviour and in sociological characteristics between women wanting hormone replacement therapy (HRT) and women refusing such treatment. METHODS: From a study base of 6189 women, 413 perimenopausal women with an express positive or negative attitude towards the use of HRT were interviewed on sociological and behavioural characteristics. Checks against bias were performed by analysis of reluctant participants, identified as women who either did not agree to participate until they received at least one reminder, or who dropped out immediately after the interview. RESULTS: Women wanting HRT had higher levels of education, were less often childless, and were more frequent solarium users than women refusing this treatment. There were no differences in marital status, employment status, the average tea, coffee, wine and cigarette consumption, sun exposure, frequencies of travels abroad, or number of family cars, summer houses or boats. No difference in present smoking status was demonstrated but the estrogen users were more frequently past or present smokers. CONCLUSIONS: It is suggested that lack of knowledge of HRT may sometimes be the cause of rejecting it, or may influence on the compliance regarding its use. Familiarity with the use of the health system for other reasons than disease may promote the use of HRT. It is demonstrated that the observed patterns do not originate from self-selection bias.

Attitude↗
PubMed1996

Procollagen type I N-terminal propeptide (PINP) as an indicator of type I collagen metabolism: ELISA development, reference interval, and hypovitaminosis D induced hyperparathyroidism.

A sandwich enzyme-linked immunosorbent assay (ELISA) for quantification of the N-terminal propeptide of human procollagen type I (PINP) utilizing purified alpha 1-chain specific rabbit antibodies is described. The ELISA measured the content of the alpha 1-chain of PINP independent of the molecular form of the molecule. A parallelism was found between amniotic fluid (calibrator), normal and patient serum, and purified PINP (alpha 1), as well as the high and low molecular weight forms of PINP (alpha 1). The concentration of PINP in the calibrator (second trimester amniotic fluid) was determined to 25 micrograms/mL and the detection limit was 62 pg/mL measured in amniotic fluid, and 41 pg/mL measured in serum. The interassay coefficients of variation were 4.6% (low control) and 5.3% (high control), and the corresponding intraassay parameters were 2.9% and 4.9%. Recovery studies revealed an accuracy between 93% and 105%. The normal range (n = 57) for PINP was 56 ng/mL (median) the 10th and 90th centiles being 30 and 82 ng/mL, respectively. Patients with hyperparathyroidism due to hypovitaminosis D had median serum level of 168 ng/mL with a 10th centile of 44 ng/mL and a 90th centile of 450 ng/mL, these values being significantly different from the normal range (p < 0.001). The PINP-ELISA was superior to commercially available assays for PICP and osteocalcin in separation between healthy controls and patients with osteomalaci.

Adult↗
PubMed1996

Recent progress in the prevention of osteoporosis. To screen or not to screen?

Screening can be defined as: "Early detection of an asymptomatic condition which might develop to a symptomatic disease if not detected and treated". The purpose of a screening programme for osteoporosis is to identify individuals at risk and consequently to intervene in order to prevent future fractures. The principles of a screening test were outlined by William and Jungner in a WHO publication from 1968 (1). The 10 principles are still valid.

Economics, Medical↗
PubMed1995

Nail abnormalities in nondermatologic patients: prevalence and possible role as diagnostic aids.

BACKGROUND: Nail changes have traditionally been used as diagnostic aids. Their usefulness in general and predictive value in particular, however, is not known. OBJECTIVE: Our purpose was to survey nail changes and to clarify the potential of nail abnormalities to diagnose nondermatologic diseases. METHODS: The fingernails of 567 patients admitted to general medical and surgical wards were examined. The point prevalence rates were calculated on the basis of a binomial distribution. The results were compared with the diagnosis with logistic regression analysis correcting for age and sex. RESULTS: The most common findings were absence of lunulae (22.9% [19.5% to 26.6%]), white nails or apparent leukonychia (11.8% [9.3% to 14.8%]), and red lunulae (5.1% [3.5% to 7.3%]). The following significant associations were noted: pulmonary disease and clubbing (odds ratio[OR] = 4.1, 95% confidence interval [CI] = 1.7 to 9.5), hematologic disease and brittle nails (OR = 4.6, 95% CI = 1.6 to 13.7), hematologic disease and Terry nails (OR = 8.7, 95% CI = 2.7 to 27.0), gastrointestinal disease and pincer nails (OR = 33.6, 95% CI = 3.7 to 307.3), and gastrointestinal disease and subjective complaints (OR = 2.7, 95% CI = 1.4 to 5.0). CONCLUSION: Several significant associations were identified, suggesting that nail abnormalities can be diagnostic clues in the diagnosis of chronic nondermatologic diseases. An association between pincer nails and gastrointestinal disease has not been previously described.

Adolescent↗
PubMed1995

A stochastic killing system for biological containment of Escherichia coli.

Bacteria with a stochastic conditional lethal containment system have been constructed. The invertible switch promoter located upstream of the fimA gene from Escherichia coli was inserted as expression cassette in front of the lethal gef gene deleted of its own natural promoter. The resulting fusion was placed on a plasmid and transformed to E. coli. The phenotype connected with the presence of such a plasmid was to reduce the population growth rate with increasing significance as the cell growth rate was reduced. In very fast growing cells, there was no measurable effect on growth rate. When a culture of E. coli harboring the plasmid comprising the containment system is left as stationary cells in suspension without nutrients, viability drops exponentially over a period of several days, in contrast to the control cells, which maintain viability nearly unaffected during the same period of time. Similar results were obtained with a strain in which the killing cassette was inserted in the chromosome. In competition with noncontained cells during growth, the contained cells are always outcompeted. Stochastic killing obtained by the fim-gef fusion is at present relevant only as a containment approach for E. coli, but the model may be mimicked in other organisms by using species-specific stochastic expression systems.

Cloning, Molecular↗
PubMed1995

Construction and behavior of biologically contained bacteria for environmental applications in bioremediation.

The survival of microorganisms can be predicted through the use of active biological containment systems. We have constructed contained Pseudomonas putida strains that degrade alkylbenzoates. The modified strain carries a fusion of the Plac promoter to the gef gene, which encodes a killing protein. Expression from Plac is controlled through a regulatory cascade, so that Plac is switched on or off by the absence or presence of alkylbenzoates, respectively. Similar uncontained strains were also constructed and tested as a control. Contained and uncontained strains were genetically stable, and their survival and functionality in soil microcosms were as expected. Both contained and uncontained strains survived well in soils supplemented with alkylaromatics, whereas survival of the contained strain in soil microcosms without methylbenzoates was markedly reduced, in contrast to the control strain, which survived in these soils in the absence of alkylbenzoates. The TOL plasmid was transferred in soils between Pseudomonas strains but was not able to mobilize the elements of the containment system.

Bacteria↗
PubMed1994

Bone loss accompanying voluntary weight loss in obese humans.

Dual-energy x-ray absorptiometry was performed in 51 obese patients before and after 15 weeks on a low-calorie diet. Of these patients 39 were scanned 6 months later. Total and regional body bone mineral, fat mass, and fat free mass were measured. In the control group, 9 normal volunteers were scanned with up to 23 kg lard distributed anteriorly, and 9 volunteers were scanned with 15 kg lard posteriorly. The lard was then gradually removed to simulate the fat loss found in the patient group. In the patient group the mean weight loss was 12,273 g, the mean fat loss was 11,014 g, and the mean bone mineral loss was 171.6 g after 15 weeks. Close correlation between the fat loss and the bone loss was found and calculated to be 16.5 g bone mineral per kg fat in the patient group, in contrast with 0.5 g bone mineral per kg fat in the control group. In the control group, 15 kg lard placed posteriorly had no statistically significant effect on the bone measurements. If weight and fat were regained at the scanning time 6 months later, the bone mineral was regained as well. Patients with further weight loss continued to lose bone mineral. One patient lost 754 g bone mineral in 9 months. Her weight loss was 45 kg in that period, and the bone mineral content remained within the range for normal women at her age. Methodologic and pathogenetic problems are discussed. It is concluded that the observed bone loss should be regarded as physiologic normalization accompanying a diet-induced weight loss in the obese.

Absorptiometry, Photon↗
PubMed1994

Identification and removal of polymer- and aggregate-forming proteins in human plasma albumin preparations.

The presence of the glycoproteins haptoglobin and hemopexin in human plasma albumin (HPA) solutions were demonstrated to be responsible for the formation of polymers and aggregates during heat treatment for 10 h at 60 degrees C. Apart from haptoglobin and hemopexin three other contaminating proteins were identified as transferrin, Gc-globulin and beta 2-glycoprotein. During heat treatment the antigenicity of haptoglobin and hemopexin changed markedly and more than 90% of the antigens appeared as aggregates in the void volume during the following size chromatography. Without loss of albumin haptoglobin and hemopexin were removed from the HPA preparation by lectin (concanavalin A) affinity chromatography. The haptoglobin- and hemopexin-depleted HPA preparation did not form aggregates or polymers during heat treatment.

Biopolymers↗
PubMed1993

A substrate-dependent biological containment system for Pseudomonas putida based on the Escherichia coli gef gene.

A model substrate-dependent suicide system to biologically contain Pseudomonas putida KT2440 is reported. The system consists of two elements. One element carries a fusion between a synthetic lac promoter (PA1-04/03) and the gef gene, which encodes a killing function. This element is contained within a transposaseless mini-Tn5 transposon so that it can be integrated at random locations on the Pseudomonas chromosome. The second element, harbored by plasmid pCC102, is designed to control the first and bears a fusion between the promoter of the P. putida TOL plasmid-encoded meta-cleavage pathway operon (Pm) and the lacI gene, encoding the Lac repressor, plus xylS2, coding for a positive regulator of Pm. In liquid culture under optimal growth conditions and in sterile and nonsterile soil microcosms, P. putida KT2440 (pWWO) bearing the containment system behaves as designed. In the presence of a XylS effector, such as m-methylbenzoate, the LacI protein is synthesized, preventing the expression of the killing function. In the absence of effectors, expression of the PA1-04/03::gef cassette is no longer prevented and a high rate of cell killing is observed. Fluctuation test analyses revealed that mutants resistant to cell killing arise at a frequency of around 10(-5) to 10(-6) per cell per generation. Mutations are linked to the killing element rather than to the regulatory one. In bacteria bearing two copies of the killing cassette, the rate of appearance of mutants resistant to killing decreased to as low as 10(-8) per cell per generation.

Benzoates↗
PubMed1993

Suicidal genetic elements and their use in biological containment of bacteria.

The potential risks of unintentional releases of genetically modified organisms, and the lack of predictable behavior of these in the environment, are the subject of considerable concern. This concern is accentuated in connection with the next phase of gene technology comprising deliberate releases. The possibilities of reducing such potential risks and increasing the predictability of the organisms are discussed for genetically engineered bacteria. Different approaches towards designing disabled strains without seriously reducing their beneficial effects are presented. Principally two types of strain design are discussed: actively contained bacteria based on the introduction of controlled suicide systems, and passively contained strains based on genetic interference with their survival under environmental-stress conditions.

Bacteria↗
PubMed1991

An assay for complement factor B in species at different levels of evolution.

The alternative complement pathway is regarded as the evolutionary ancestral complement system. It is therefore of interest to analyze and characterize factor B of the alternative complement pathway in animals at different levels of evolution. We describe a functional assay which is based on the interaction of factor B from various animal species with Cobra Venom Factor, the snake C3b-analog. The signal system in the assay is C3-conversion in factor B-depleted chicken serum. The results show that a functional C3-convertase can be created with factor B from mammals, aves, and amphibians.

Animals↗
PubMed1990

[Referral of elderly patients with cerebral apoplexy to nursing homes].

A retrospective investigation was undertaken to investigate which factors are of significance in recommendation of patients with cerebral apoplexy in geriatric departments to nursing homes. The investigation includes 116 patients admitted during a period of two years. Thirty-five (30%) were recommended for nursing homes. Sixty-seven (58%) remained severely handicapped (corresponding to Rankin's groups IV and V). Logistic regression analysis revealed that marital status, dementia, lack of motivation and inability to walk were associated with recommendation for nursing homes whereas sex, degree of paresis, aphasia, focal cognitive disturbances, incontinence of urine and hemianopsia did not show any association. Sex was, similarly, of no significance for the functional result of rehabilitation. On the basis of the regression analysis, the probability of recommendation to a nursing home may be calculated with knowledge of the predisposing factors in any given patient.

Aged↗
PubMed1986

The endoscopic diagnosis of duodenal ulcer disease. A randomized clinical trial of bias and of interobserver variation.

In a randomized design we examined whether endoscopists are biased by knowledge of the radiologic diagnosis of duodenal ulcer and deformity of the duodenal bulb when recording the corresponding endoscopic diagnoses. A total of 156 patients had a barium meal and were subsequently randomized into 2 groups. In 74 of the cases the 2 endoscopists knew the result of the X-ray examination when doing the endoscopy; in 82 of the cases they did not. One endoscopist was significantly biased by his knowledge of the radiologic diagnosis of deformity of the duodenal bulb. Neither of the endoscopists was biased by his knowledge of the radiologic diagnosis of duodenal ulcer. In addition, the interobserver variation between the two endoscopists with regard to the endoscopic diagnoses of duodenal ulcer, deformity of the duodenal bulb, and duodenitis was examined. The interobserver variation was expressed by the overall agreement and by the kappa statistics, which adjusts the overall agreement for expected chance agreement. For duodenal ulcer, deformity of the duodenal bulb, and duodenitis, the overall agreements and kappa values were 0.91, 0.78, and 0.75, and 0.54, 0.42, and 0.33, respectively.

Adolescent↗
PubMed1982

Effect of acupuncture on tension headache and urinary catecholamine excretion.

Sixteen patients with tension headaches were treated with acupuncture, needles being inserted in the hand and foot and then electrostimulated. All patients were seen at four 2-h sessions with intervals of 1 week between each. The first two sessions were used for clinical examination only, thus serving as control, while acupuncture was administered during the last two sessions. Urine samples were collected immediately before and after each session and later analyzed for catecholamine content. During the 1-week intervals between sessions, records were kept of headache attacks and medicine intake. Following acupuncture two-thirds of the patients showed reduction in number of headache attacks, and about one half of the patients reduced their use of pain relieving drugs considerably. Urinary excretion of adrenaline and noradrenaline was always higher in samples collected before sessions than after sessions. However, this reduction in catecholamine excretion was significantly greater when acupuncture had been administered.

Acupuncture Therapy↗
PubMed1981

Mammography directed wire marking of nonpalpable breast lesions. A consecutive biopsy study of 100 patients.

Among 665 patients referred for breast complaints, 100 women (15%) had mammographically detected nonpalpable lesions suspected of malignancy. Using a mammography directed hook wire marking, 115 excisional biopsies were carried out. A correct biopsy containing the lesion was obtained in 113 instances. There were 2 failures, due to displacements of the wire in one case and surgical inexperience in another case. Two patients had minor wound complications. Invasive carcinoma was found in 12 and carcinoma in situ in 4 biopsies, i.e., a cancer rate of 16% of patients and 14% of biopsies. The biopsy procedure was simple, time saving, and acceptable of patients. The excisions were small and the cosmetic results excellent. During mammography for control of wire position, and during dressing and surgical manipulations the flexible hooked wire remained as originally placed in all cases but one.

Adult↗