Search PubMed⌕ Search

Biomedical subjects

F Christensen

Publications and source records attributed to F Christensen.

At least 37 records · Page 2Linked to original sources

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↗

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↗

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↗

Ulnar variance determination.

Surgical procedures concerning the distal articular surfaces of the radius and ulna, demand an accurate method of measurement of ulnar variance. A new method, which is a modification of the method described by Palmer (1982), is introduced. 100 randomly selected healthy persons were submitted to X-ray of the wrist and the ulnar variance was determined independently by three observers using both methods. By "weighted kappa" statistics the results, expressed in intra- and interobserver agreement, showed a significantly higher reliability in favour of the Modified method.

Humans↗

Ulnar variance in Kienböck's disease.

Forty four patients with forty seven wrists suffering from Kienböck's disease were re-examined. The mean observation time was 20.5 years. In all forty seven wrists the treatment had been immobilization. Using a standard X-ray projection, and a reliable method of ulnar variance measuring, the ulnar variance was determined by three observers independently. Comparing the result with the ulnar variance in normal wrists we found the so-called "ulnar minus variant" overrepresented in patients with Kienböck's disease. However, comparing X-rays taken at the time of diagnosis with X-rays at re-examination, we found in eight out of forty seven wrists that a subchondral bone formation in the distal radium opposite the lunate bone had taken place. This bone formation will tend to enhance the negative value of ulnar variance measurements, and suggests an explanation of the overrepresentation of "ulnar minus variants" in Kienböck's disease. Excluding these eight wrists from the material and comparing the mean ulnar variance value in the remaining thirty nine wrists with the mean value in normal wrists no statistical difference was shown. Based on these observations it seems unlikely that the "ulnar minus variant" has any bearing on the cause of Kienböck's disease.

Adolescent↗

Wound infection after cesarean section.

A prospective multicenter study of 1,032 cesarean sections was performed to identify risk factors for postoperative wound infection. The overall rate of wound infection was 6.6% (3.8% in elective cases and 7.5% following nonelective operations), with considerable interhospital variation. Obesity was recognized as a patient-related risk factor, while risk factors inherent to the obstetric situation were duration of ruptured membranes prior to operation, fetal and labor monitoring by intrauterine devices, and omission of the use of plastic draping and redisinfection of the skin before closure. Logistic regression analysis was used to estimate the influence of these factors on the probability of wound infection. Certain risk factors associated with and over-represented in nonelective operations would explain the increased infection rates in these, and the observed interhospital variations did not differ from the expected rates when the distribution of other risk factors was considered.

Adolescent↗

The Catterall classification of Perthes' disease: an assessment of reliability.

The reliability of the Catterall grouping of Perthes' disease was examined by determining the agreement between pairs of observers using weighted kappa statistics. Anteroposterior and lateral radiographs of 100 hip joints were grouped independently by four experienced observers. There was a low, and in our opinion, unacceptable degree of inter-observer agreement even when Groups 2 and 3 were combined.

Hip Joint↗

Biosynthesis of ascorbate in yeast. Purification of L-galactono-1,4-lactone oxidase with properties different from mammalian L-gulonolactone oxidase.

An enzyme from Saccharomyces cerevisiae which catalyzes the reaction: L-galactonolactone + O2 leads to L-ascorbate + H2O2 has been purified 466-fold from the mitochondrial fraction of a yeast homogenate. The enzyme has several properties that are different from the L-galactonolactone oxidase described by Nishikimi et al. [Arch. Biochem. Biophys. 191, 479-486 (1978)]. By gel filtration in the presence of sodium deoxycholate an apparent Mr of 70 000 was obtained for the active enzyme. Polyacrylamide-gradient gel electrophoresis in the presence of deoxycholate gave an Mr of 74 000, whereas sodium dodecylsulfate/polyacrylamide gel electrophoresis showed only one protein band corresponding to an Mr of 18 000. A tetrameric structure of the enzyme is thereby suggested. The substrate specificity is confined to the aldonoacid lactones L-galactono-, D-altrono-, L-fucono-, D-arabino- and D-threono-1,4-lactones. Competitive inhibition was demonstrated with L-gulono- and D-galactono-1,4-lactones. p-Chloromercuriphenyl sulfonate, iodoacetamide, N-ethylmaleimide, sulfite and sulfide were all inhibitory to the enzyme. No effect was seen when cyanide, azide, EDTA, alpha, alpha'-bipyridyl or bathocuproine disulfonate was added. An apparent Km of 0.3 mM with L-galactonolactone as a substrate was found. The Km for oxygen was 0.18 mM. The pH/activity curve exhibited a maximum around pH 8.9 and a shoulder at pH 6.5. Evidence of a covalently bound flavin coenzyme and involvement of an iron-sulfur cluster was obtained from difference spectra of oxidized minus substrate-reduced enzyme with peaks or shoulders of the oxidized enzyme at 475, 445, 410, 375 and 350 nm. In sodium dodecylsulfate/polyacrylamide gels the enzyme subunit(s) had a bright yellow fluorescence after fixation in 7% acetic acid or 5% formaldehyde. The galactonolactone oxidase is stable with 50% activity being lost in 6 months at + 5 degrees C.

Animals↗

The relationship between the transport of glucose and cations across cell membranes in isolated tissues. X. Effect of glucose transport stimuli on the efflux of isotopically labelled calcium and 3-O-methylglucose from soleus muscles and epididymal fat pads of the rat.

(1) The relationship between Ca2+ and sugar transport has been studied by comparing the washout of 45Ca and 3-O-[14C]methylglucose from preloaded isolated rat soleus muscles and whole epididymal fat pads. (2) In soleus muscle, nine different agents with well established stimulating effects on glucose transport were all found to produce a marked increase in 3-O-[14C]methylglucose washout, which in each instance was preceded by or coincided with a rise in the washout of 45Ca. (3) Trypsin, 2,4-dinitrophenol, p-chloromercuriphenylsulfonic acid, H2O2 and hyperosmolarity all produced dose-dependent stimulation of the washout of 45Ca and 3-O-[3H]methylglucose. Regression analysis showed a highly significant correlation between the increases in the two parameters (P < 0.001). (4) Depolarization and Na+ influx induced by veratrine were found to be associated with a marked rise in 45Ca release followed by stimulation of 3-O-[14C]methylglucose washout. (5) In epididymal fat pads, six different agents known to stimulate glucose transport were found to produce a highly significant (P < 0.001) increase in the washout of 45Ca and 3-O-[14C]methylglucose. (6) It is concluded that in the major targets for insulin action, activation of the glucose transport system can be elicited by a rise in cytoplasmic Ca2+ concentration brought about by mobilization of Ca2+ from endogenous cellular pools.

4-Chloromercuribenzenesulfonate↗

Carbonic anhydrase isoenzyme determination: An aid to the diagnosis of "small-for-date" infants.

A specific and quantitative immunological method for the determination of human erythrocyte carbonic anhydrase isoenzymes B and C has been used to determine these enzymes in erythrocytes of umbilical cord blood. The investigations have shown a content of both isoenzymes less than a tenth of that in adults. The isoenzyme content correlated significantly with the estimated gestational age. The ratio between isoenzyme B and C rose with gestational age, reaching adult level at term. A group of 19 "small-for-date" infants had isoenzyme levels in the same range as normal full-term infants, significantly higher than the levels in the same range as normal full-term infants, significantly higher than the levels in truly premature infants. It is concluded that the determination of carbonic anhydrase isoenzymes is an aid in distinguishing "small-for-date" infants from the truly premature.

Carbonic Anhydrases↗