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Biomedical subjects

F Christensen

Publications and source records attributed to F Christensen.

At least 19 recordsLinked to original sources
PubMed1994

Method validation in relation to accuracy and precision for the gas chromatography-mass spectrometric analysis of 19-nortestosterone in urine with heptafluorobutyric anhydride and N-methyl-N-(trimethylsilyl)trifluoroacetamide.

Method validation for all the analytical methods used in food control is of the highest priority. For this control there is a lack of reference materials, thus, it is necessary to validate the methods each time they are used for new applications. Among the many aspects of validation, this report pays particular attention to repeatability and reproducibility. The within-assay variability gives a good indication of the precision of the method shown by the repeatability. The between-assay variability gives no indication on the accuracy (or trueness) because no certified reference material is available. The reproducibility however, also gives an indication of the precision of the method. In this work the limit of detection, also an aspect of validation, was found to be below 0.375 micrograms 1-1 for both derivatization methods; however, the precision of the heptafluorobutyric anhydride method was found to be better than that of the N-methyl-N-(trimethylsilyl)trifluoroacetamide method.

Acetamides↗
PubMed1993

Fallopian tube sperm perfusion (FSP) versus intra-uterine insemination (IUI) in the treatment of unexplained infertility: a prospective randomized study.

Prospective randomization of 60 couples with unexplained infertility was performed for treatment either with intrauterine insemination (IUI), using a volume of 0.5 ml of the inseminate, or Fallopian tube sperm perfusion (FSP), using a volume of 4 ml of inseminate. The protocols for ovarian stimulation and induction of ovulation were the same in the two groups. The two groups were similar concerning age of the female at the start of treatment and the number of follicles > 15 mm diameter, the serum oestradiol concentrations and the endometrial thickness on the day of human chorionic gonadotrophin (HCG) administration. The mean (+/- SD) number of motile spermatozoa inseminated was significantly higher in the FSP group than in the IUI group (52 +/- 5 x 10(6) and 28 +/- 3 x 10(6) respectively). In the FSP group, 30 women were given a total of 52 treatment cycles; 14 clinical pregnancies occurred in this group, giving a pregnancy rate of 26.9% per cycle and 46.7% per woman. In the IUI group, 28 women were given a total of 51 treatment cycles; five clinical pregnancies occurred, giving a pregnancy rate of 9.8% per cycle and 17.9% per woman. The pregnancy rates per cycle and per woman in the FSP group were significantly higher than in the IUI group (P < 0.05, chi-square test). This study indicates that in the treatment of couples with unexplained infertility, Fallopian tube sperm perfusion (FSP) is more successful than intra-uterine insemination (IUI).

Adult↗
PubMed1992

Treatment of peanut allergy with rush immunotherapy.

Peanut and peanut products are a common food in the diet. Peanuts are also one of the most common foods responsible for food-induced anaphylaxis. Patients rarely lose sensitivity to peanuts. Although the ideal treatment is avoidance, this is often not possible because of hidden exposures; therefore, a more effective treatment is needed. Subjects with confirmed peanut allergy were treated in a double-blind, placebo-controlled study with peanut immunotherapy or placebo. Objective measures of efficacy included changes in symptom score during double-blind placebo-controlled peanut challenge (DBPCPC) and titrated end point prick skin tests (PST). Three subjects treated with peanut immunotherapy completed the study. These subjects displayed a 67% to 100% decrease in symptoms induced by DBPCPC. Subjects also had a 2- to 5-log reduction in end point PST reactivity to peanut extract. One placebo-treated subject completed the study. This subject had essentially no change in DBPCPC symptom scores or PST sensitivity to peanut. Two other placebo-treated subjects underwent a second PST session. These subjects had a 1- to 2-log increase in skin test sensitivity to peanut. All peanut-treated subjects were able to reach maintenance dose, and in no case did an anaphylactic reaction occur secondary to the peanut immunotherapy. The current study provides preliminary data demonstrating the efficacy of injection therapy with peanut extract and provides a future line of clinical investigation for the treatment of this potentially lethal disease. It should be noted, however, that the rate of systemic reactions with rush immunotherapy was 13.3%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[In vitro fertilization and embryo transfer in a Deaconess Institution. Experience from the first years].

Eighty-one women suffering from occluded Fallopian tubes and 29 women with unexplained infertility were treated with in vitro fertilization and embryo transfer (IVF-ET). All procedures were carried out on outpatients. A total of 24 pregnancies were achieved in the group of patients with occluded tubes whereas eight became pregnant in the group of patients treated for unexplained infertility. From these results, it is expected that 30% of women suffering from occluded tubes or unexplained infertility can achieve pregnancy following two IVF-ET treatment cycles.

Adult↗
PubMed1988

A new method of estimation of interobserver variation and its application to the radiological assessment of osteoarthrosis in hip joints.

Four frequently referenced radiological methods for assessment of osteoarthrosis in hip joints are compared with respect to their interobserver variation. One hundred hip joints were rated by four observers. Each observer applied all four methods to all the radiographs. The results were analysed by a new statistical method, which allowed detailed assessment of the nature and extent of interobserver variation. Significant differences in terms of intraobserver disagreement were found, and Heripret's method was the best in this respect. All four methods showed a significant degree of systematic disagreement among the observers. This suggests that the interobserver variation might be reduced by confronting the observers with the results of the statistical analysis of their judgements.

Bone Diseases↗
PubMed1988

Improved cementation in total hip replacement.

Insufficient cementation has been suggested to be the most common cause of loosening of the femoral component after total hip arthroplasty. A clinical and radiographic study of 129 consecutive, primary total hip replacements was performed 5 years after surgery, in order to evaluate the significance of femoral plugging, special attention being focused on cementation and radiographic loosening. A polyethylene medullary plug was used in 78 hips which were compared with 51 non-plugged hips with respect to the clinical course and radiographic appearance. The cement mantle around the femoral component was thicker, and the packing of cement significantly improved when the plug was used. The frequency of radiographic loosening was smaller in the plugged group but with no statistical significance. There was no difference in clinical results between the compared groups. Our results indicate that medullary plugging improves the cementation and in particular prevents insufficient cementation of the femoral component.

Adult↗
PubMed1988

Calcar resorption after total hip arthroplasty.

Calcar resorption is a significant complication after total hip arthroplasty and may result in technical problems at revision of failed hip arthroplasties. Radiographs and patient data from a series of 129 consecutive primary total hip arthroplasties were evaluated 5 years after surgery to study factors associated with calcar resorption. The incidence of calcar resorption was 21%. Primary positive calcar-collar contact reduced the incidence of calcar resorption. Sufficient cementation of the medullary canal significantly reduced the incidence of calcar resorption, as did neutral and valgus positioning of the femoral component. Loosening of the acetabular component occurred more often in the group with calcar resorption. Middle-aged patients and men were more prone to develop resorption of the calcar. Calcar resorption may be influenced by surgical technique. Alteration of the operative technique is recommended, with emphasis on correct valgus or neutral position of the femoral component, a positive calcar-collar contact, and improved cementation.

Aged↗
PubMed1988

Ectopic bone formation after total hip arthroplasty.

Ectopic bone formation (EBF) is a well-known complication of total hip arthroplasty (THA). The etiology and pathogenesis are still obscure. An analysis of 119 consecutive patients with 129 primary THAs was performed to identify factors predisposing to ectopic bone formation, its frequency, and its effect on the results. Gender (male) and the duration of the operative procedure were statistically significant factors in the development of ectopic bone, which occurred in 63% of hips. The effect of grade III EBF on THA was a limited range of movement. Both local and systemic factors seem to play a role in the development of ectopic bone. Gentle handling of tissues may be important if the rate of ectopic bone is to be reduced.

Female↗
PubMed1988

Treatment of chondromalacia patellae by lateral retinacular release of the patella.

A series of 59 knees in 58 patients were surgically treated from 1977 to 1982 for chondromalacia patellae, and were followed for an average of 1.2 to 4.6 years after the operation. The operative procedure was open lateral retinacular release in all knees. In knees with recurrent patellar subluxation, the number of poor results increased from 24% to 70%, and in knees with no subluxation from 21% to 24%. The difference after 4.6 years was statistically significant. No correlation between the severity or location of the cartilage changes and the operative effect was found. Open lateral retinacular release is an acceptable treatment of chondromalacia patellae without subluxation of the patella, whereas in the presence of recurrent subluxation, the release does not correct the basic biomechanical disturbance.

Adolescent↗
PubMed1987

Total hip replacement ad modum Lubinus: five- to seven-year follow-up.

A study of 141 total hip replacements with the Lubinus prosthesis is presented. The complications in the total patient group and the results in 129 hips with follow-up times from 5 to 7 years are described. Three prostheses (2.1%) have been reoperated because of loosening. There were radiographic signs of definitive loosening in 2.3%. Varus positioning was associated with an increased loosening rate. No infections have been encountered, and none of the hips have undergone excision arthroplasty. Ninety-two percent of the hips were free from significant pain and 78% had a total range of motion exceeding 160 degrees. THR was performed, without subsequent infections, in a conventional operating room using prophylactic penicillin and gentamicin cement. We propose that the surgical technique of exposure and the cement injection technique with a partial vacuum in the medullary canal may be responsible for the low incidence of femoral prosthesis loosening (0.7%).

Aged↗
PubMed1987

Hip replacement in obese patients.

In a 5-year follow-up study of 125 hip replacements a. m. Lubinus, 41 obese and 84 nonobese patients were compared. Peroperative blood loss was greater in the obese patients. There was, however, no difference in the operation or hospitalization times between the compared groups. There was no infection, wound dehiscence, or delay in wound healing. No deaths occurred during the immediate postoperative period. The obese patients had a lower preoperative walking-ability score. At follow-up, this difference was eliminated. Radiographic signs of loosening were equally common in the compared groups. Three patients, two of whom were in the nonobese group, had been reoperated on because of prosthetic loosening. Our results indicate that obesity does not increase the risk of surgical complication or prosthetic loosening in hip replacement.

Adult↗
PubMed1987

Revision of the uncemented hip prosthesis.

In a series of 213 consecutive total hip replacements a.m. Lubinus, the clinical course after 72 revisions and 141 primary procedures was compared after 5 years. The revised THRs were uncemented Ring prostheses. Dislocation and peroperative fracture were more common in the revision group. Two failures because of aseptic loosening occurred in the revision group and 3 in the control group. No excisional arthroplasty was required, and no infections occurred. Radiographic evaluation of prosthetic positioning, component loosening, calcar resorption, and paraarticular ossification disclosed only slightly inferior results in the revision group. Clinically, the revised cases were not inferior to the primary ones. Revision of the uncemented hip seems less difficult than of the cemented hip.

Adult↗
PubMed1986

Kienböck's disease--late results by non-surgical treatment. A follow-up study.

Two groups of patients with Kienböck's disease were followed. Twenty-three wrists had been immobilised with plaster and twenty-six had no treatment. At follow up there was a marked improvement in both groups. Eighty-three percent of the wrists in the new treated group were pain free, or reported pain only on heavy work, and in the nontreated group this was valid for 77%. Examining X-rays at follow up we did not find a single wrist in which the lunate was normal or less deformed than at the time of diagnosis. In all forty-nine wrists the lunate was deformed and in 67% osteoarthrosis in the radiocarpal joint was evident. It is concluded, that Kienböck's disease has a naturally benign course, the remaining symptoms at follow-up might be caused by osteoarthrosis and nothing seems to be gained by rigorous immobilisation. If pain persists efficient treatment must be based on surgical methods.

Adolescent↗