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Biomedical subjects

W Becker

Publications and source records attributed to W Becker.

At least 757 records · Page 42Linked to original sources
PubMedDate not supplied

[Value of the plain roentgen image and arthrography in diagnosis of loosening of cemented hip endoprostheses].

Radiographic signs of suspected prosthetic hip component loosening were evaluated by comparing them with the intraoperative findings. In 59 surgical procedures for suspected loosening of cemented total hip prostheses preoperative radiographic signs of loosening in plain radiographs and radiographic arthrograms were compared with the intraoperative findings. Radiolucent lines between the interfaces prosthesis/cement and cement/bone in defined zones (Salvati et al. 1976, Gruen et al. 1979) were evaluated. For the acetabular component relevant radiolucent lines were observed only between the interface cement/bone. A radiolucent line > 2 mm in zone 1, > 1 mm in zone 2a, a fracture or a retroversion were shown to be reliable signs for loosening with a specificity of 92%, a sensitivity of 61% and a predictive value of 97% (p < 0.01). For the femoral component a radiolucent line at the cement/bone interface of > 1 mm in any of the single zones 2, 3, 6 or 7 and radiolucent lines of > 0 mm in the combined zones 1 + 2 + 6 + 7 proved to be reliable signs of loosening. At the cement/prosthesis interface of the femoral component a radiolucent line of any width in zone 6 and radiolucent lines in the combined zone 1 + 2 or 1 + 7 proved to be reliable signs for loosening as well as major defects within the cement. The above mentioned signs of femoral component loosening display a specificity of 79%, a sensitivity of 86% and a predictive value of 81% (p < 0.001). Arthrography may be useful as an additional diagnostic means for the acetabular component (7 out of 18 false negative results in the radiograms were true positive in the arthrography. Penetration of the contrast material through all 4 zones yields a specificity of 83%, a sensitivity of 48% and a predictive value of 90% with p > 0.05), whereas for the evaluation of the femoral component loosening the gain of information is marginal compared with plain radiographs (specificity 80%, sensitivity 69% and predictive value 78% with p < 0.01). Hip component loosening can be identified with the above mentioned signs even if there are no previous radiographs available.

Arthrography↗
PubMedDate not supplied

[Sonographic diagnosis of the juvenile tarsus. Clinical application possibilities demonstrated by examples].

Radiologic assessment of foot deformities in young children is limited especially by the ossification status. Ultrasonography proved to be a useful diagnostic supplement e.g. in idiopathic talipes equinovarus, vertical talus, and tarsal coalitions. Effects of treatment and three-dimensional movements of the tarsal joint complex can be delineated. Sonographic assessment of tarsal alignment is applicable already in the first months of life. This study deals with first experiences in clinical application of this new diagnostic technique.

Ankle↗
PubMedDate not supplied

[Dislocation following total hip endoprosthesis. Association with surgical approach and other factors].

During a period of eight years (1984 to 1992) we found 45 dislocations in 1734 patients treated by total hip arthroplasty. We compared this retrospectively evaluated group with a randomized control group of 61 patients. As a cause for an increasing number of dislocations in 1989 we found: age over 70 years, high CCD-stem-angle (142 degrees), dorsal approach, abduction of the acetabular component under certain circumstances (left side). Revision operations always are a high risk procedure. Acetabular anteversion, anaesthesia, way of component fixation did not induce an increased rate of dislocation. We now left the dorsal approach and use only stems with an CCD-angle of 135 degrees or less by now. Careful positioning of the acetabular components and a better patient-instruction helped to decrease the number of dislocations. Because of these measures we reduced the THA-dislocations rate from 5.6 to 0.17 per cent (first operations) and from 12.1 to 6.5 per cent (revision operations).

Aged↗
PubMedDate not supplied

[Experimental and clinical studies on the relevance of proton spin tomography in patients with coxarthrosis].

We examined 2 in formalin fixed hip specimens from a corpse, 27 patients with coxarthrosis and 3 healthy young volunteers with MRT concerning the illustration of the hip joint and pathological changes by coxarthrosis. Specimen of the femoral head after endoprosthetic operation could be achieved in 18 cases for comparison with MRT. All pathological alterations as cartilage alterations, sclerosis, cysts, effusion, edema, fibrosis were figured with high sensitivity. Cartilage was figured much better by gradient echo sequence with short echo time than by spin echo sequence. Gradient echo sequence made it possible to figure and quantify thinning of cartilage with high sensitivity. Both sequences showed artefacts because of the chemical shift in the area of the cartilage-bone boundary, which impaired especially the judgement of cartilage by spin echo sequence. Gradient echo sequence allowed because of the phase-contrast effect the distinction of hematopoietic and fatty bone marrow and possibly the delineation of bone marrow edema.

Adult↗
PubMedDate not supplied

[Diagnosis and therapy of bone tumors in the area of the pelvis].

Classical signs of tumour development are seldom observed with pelvic tumours: swelling is recognized only late because of the deep, hidden localization; in addition many pelvic tumours belong to the cartilage-dependent group, which grow slowly, producing little if any pain. X-ray appearance is unusual because of the flat bones, which produce different tumour reaction and are oblique in space. All those factors render diagnosis of pelvic tumours difficult and often delayed. Not infrequently mistakes are seen with the performance of biopsy, if the surgeon is not aware of the needs of definitive therapy. Tumours proximal of the acetabulum are usually better contained, whereas those of the pubic and ischial bones quickly gain access to the areolar tissues around the throughways of arteries and nerves. A clear concept of the margin of resection will decide whether amputation or resection can be performed preserving a useful extremity. Secondary tumours and tumorlike lesions are the aim of intralesional curettage or resection using tumour prosthesis if necessary and possible. The reported experience has been gathered from the personal surgical performance for 80 tumours of the pelvic region.

Amputation, Surgical↗
PubMedDate not supplied

[A case of bilateral isolated talonavicular synostosis in childhood--observations of tarsal joint function and functional adaptation of the proximal ankle joint].

A rare case of bilateral isolated coalition of the talonavicular joint with ball and socket ankle joint is presented. Range of motion of the subtalar joint and hindfoot mobility were measured intraoperatively. The following conclusions may be drawn on development and function of the ankle joint complex: Isolated talonavicular synostosis in the growing foot results in marked impairment of subtalar range of motion. The development of a ball and socket ankle joint may be caused thereby, if tarsal hypomobility becomes effective at an early stage of growth.

Ankle Joint↗
PubMedDate not supplied

[Differentiated thyroid gland carcinoma in children and adolescents].

Differentiated thyroid cancer is a rare disease in childhood and adolescence. Most frequently, thyroid cancer in children belongs to the papillary variant, whereas a follicular histological pattern is much less frequently encountered. Dedifferentiated (anaplastic) cancers are very rare at this age. Especially indolent cervical lymph node enlargement is suspicious for a thyroid cancer, even more when occurring together with a solitary, rapidly growing, and indurated thyroid nodule. Every nodule in the thyroid of children and adolescents, if not unequivocally cystic, is suspicious of a malignancy. In contrast to adults, multifocal tumor manifestations are frequently found in children and adolescents which often have spread beyond the capsule of the thyroid at the time of diagnosis. Regional lymph nodes are involved in up to 90%, and distant metastases are present in up to 20% of the cases. Despite these much more advanced stages as usually found in adults, the prognosis of children is better than at advanced age, since these tumors are highly differentiated, and, even in the case of distant metastases, a curative approach is still possible. The therapy (surgery/radioiodine) and the follow-up follows the same principles as those which have been established for older patients.

Adenocarcinoma, Follicular↗
PubMedDate not supplied

[Treatment of splay foot with the Helal metatarsal osteotomy].

Between 1983-1987 Helal's metatarsal II-IV osteotomy was performed on 135 feet because of painful splayfoot. Follow-up examinations of 93 feet 22 month post up on average showed subjectively and objectively good results in about 80% of the cases. In case of overlength of single metatarsalia we modified Helal's osteotomy by resecting a boneslice instead of performing a simple osteotomy. In order to reduce the incidence of the disturbance of wound healing and longlasting swelling we recommend a modification of post-op treatment.

Adult↗
PubMedDate not supplied

[Diagnosis of recurrence and therapy of recurrence with in situ bone cement filling in the treatment of giant cell tumor].

Bone-cement plugging allows immediate weight bearing and early detection in case of recurrence of giant cell tumor. A recurrence might be treated by either total or partial removal of the old plug and new curettage followed by a second cement plug. The method allows to plan the final surgery for a time which is likely free of risk of recurrence and which appears appropriate in terms of private time scheduling. In addition it saves the valuable autogenous graft.

Adolescent↗
PubMedDate not supplied

[111-In leukocyte scintigraphy in inflammatory diseases of the support and motor systems--initial results].

Acute osteomyelitis and arthritis, soft tissue infections as well as reactivated chronic osteomyelitis and septic total hip endoprostheses show positive scans in 111-In-Acetylaceton-Leucocyte-Scintigraphy. Negative results are found in chronic osteomyelitis and nonbacterial inflammations as rheumatic and degenerative diseases of the skeleton. Accuracy for all studies was 86%, specificity 100% and sensitivity 66%. False negative scans findings occurred especially in soft tissue infections and acute spondylitis. There have been no false positive scans. Typical case reports are illustrated.

Adolescent↗
PubMedDate not supplied

[Nuclear magnetic resonance tomography of meniscus lesions].

In magnetic resonance imaging (MR) the use of suitable surface coils combined with high resolution makes it possible to obtain differentiated information on the condition of the menisci. In particular, the course and extent of cracks, degenerative changes, and the attachment zones of the menisci can be assessed. This paper describes MR and clinical findings in 58 patients and compares them with those in seven healthy subjects.

Humans↗
PubMedDate not supplied

Sperm transport in the human female genital tract and its modulation by oxytocin as assessed by hysterosalpingoscintigraphy, hysterotonography, electrohysterography and Doppler sonography.

The transport function of the uterus and oviducts and its modulation by oxytocin has been examined using hysterosalpingoscintigraphy, recording of intrauterine pressure, electrohysterography and Doppler sonography of the Fallopian tubes. After application to the posterior vaginal fornix, a rapid (within minutes) uptake of the labelled particles into the uterus was observed during the follicular and during the luteal phase of the cycle in all patients. Transport into the oviducts, however, could only be demonstrated during the follicular phase. Transport was directed predominantly into the tube ipsilateral to the ovary bearing the dominant follicle; the contralateral oviduct appeared to be functionally closed. The proportion of patients exhibiting ipsilateral transport did increase concomitant with the increase of the diameter of the dominant follicle. That ipsilateral transport has biological significance is suggested by the observation that the pregnancy rate following spontaneous intercourse or insemination was significantly higher in those women in whom ipsilateral transport could be demonstrated than in those who failed to exhibit lateralization. Oxytocin administration was followed by a dramatic increase in the amount of material transported to the ipsilateral tube, as demonstrated by radionuclide imaging and by Doppler sonography following instillation of ultrasound contrast medium. Continuous recording of intrauterine pressure before and after oxytocin administration did show an increase in basal tonus and amplitude of contractions and a reversal of the pressure gradient from a fundo-cervical to a cervico-fundal direction. These actions of oxytocin were accompanied by an increase in amplitude of potentials recorded by electrohysterography. These data support the view that uterus and Fallopian tubes represent a functional unit that is acting as a peristaltic pump and that the increasing activity of this pump during the follicular phase of the menstrual cycle is reflected by an increased transport into the oviduct ipsilateral to the ovary bearing the dominant follicle. In addition, they strongly suggest a critical role of oxytocin in this process. Failure of this mechanism appears to be a cause of subfertility or infertility, as indicated by the low pregnancy rate following intrauterine insemination or normal intercourse in the presence of patent Fallopian tubes. It may be regarded as a new nosological entity for which we propose the term tubal transport disorder (TTD). Since pregnancy rate of such patients is normal when treated with in-vitro fertilization (IVF), hysterosalpingoscintigraphy seems to be useful for the choice of treatment modalities in patients with patent Fallopian tubes suffering from infertility.

Adult↗
PubMedDate not supplied

Effects of chronic ethanol treatment on lipid composition and prostaglandins in rats fed essential fatty acid deficient diets.

Rats of the third generation fed on a diet with 0.3 energy-% (low-essential fatty acids (EFA) or 3 energy-% (normal-EFA) essential fatty acids were given once-daily intraperitoneal injections of ethanol 3 g/kg or isocaloric glucose for 23 days. At the end of the experiment, organs were removed and their weight and lipid composition were determined. The postmortem accumulation of the prostaglandins PGE2, PGF2 alpha and 6-keto-PGF1 alpha was used to assess prostaglandin (PG) precursor availability in the organs. Ethanol was found to amplify the biochemical indicators of EFA-deficiency. The fatty acids 20:3 n-9 in brain phosphatidylethanolamine and phosphatidylinositol and 22:5 n-6 in brain phosphatidylethanolamine and phosphatidylserine were significantly higher in the ethanol group compared to the control group. In the kidney, the 20:3 n-9/20:4 n-6 ratio in phosphatidylinositol and phosphatidylserine was significantly higher in the ethanol group compared to the control group. The low-EFA animals had a lower output of urinary PGF2 alpha than the normal EFA animals. Chronic ethanol treatment gave a pronounced increase of urinary PGF2 alpha in both groups. Kidney levels of PGs were lower in the low EFA-animals. Chronic ethanol treatment gave a further decrease in kidney PGs. PG levels were the same in brains from low-EFA and normal-EFA animals with no effects of ethanol. The data are consistent with an increased utilization of EFA during chronic ethanol intoxication leading to a depletion of PG precursor stores in some but not all organs.

Alcoholism↗
PubMedDate not supplied

A comparative study of the organic acid content of the hemolymph of Schistosoma mansoni-resistant and susceptible strains of Biomphalaria glabrata.

The freshwater snail Biomphalaria glabrata is an intermediate host of the trematode Schistosoma mansoni. However, some strains of B. glabrata are resistant to successful infection by S. mansoni larvae. The present work examines the profile of organic acids present in S. mansoni-resistant and -susceptible strains of B. glabrata, in order to determine whether the type of organic acid present is related to susceptibility. The organic acids were extracted from the hemolymph of two susceptible B. glabrata strains (PR, Puerto Rico and Ba, Jacobina-Bahia from Brazil), and from the resistant strains 13-16-R1 and 10R2, using solid phase extraction procedures followed by high performance liquid chromatography. The organic acids obtained were analyzed and identified by comparison with known standards. Pyruvate, lactate, succinate, malate, fumarate, acetate, propionate, beta-hydroxybutyrate and acetoacetate were detected in all hemolymph samples. Under standard conditions, the concentration of each of these substances varied among the strains tested and appeared to be specific for each strain. An interesting variation was the low concentration of pyruvate in the hemolymph of PR-snails. Only the concentration of fumarate was consistently different (p < or = 0.05) between resistant and susceptible strains.

Animals↗
PubMedDate not supplied

Profile of organic acid concentrations in the digestive gland and hemolymph of Biomphalaria glabrata under estivation.

Using high performance liquid chromatography (HPLC) analysis it was possible to determine simultaneously the concentration of organic acids (pyruvate, lactate, succinate, fumarate, malate, acetate, propionate, acetoacetate, and ss-hydroxybutyrate) in the digestive gland and the extracellular concentration of these same acids in the hemolymph of estivating Biomphalaria glabrata, the intermediate host of Schistosoma mansoni. After a 7 day period of estivation, there was a significant increase in the tissue levels of lactate, succinate, malate and acetate compared to non-estivating snails. After 14 days of estivation, the levels of lactate and acetate were also significantly elevated. The hemolymph concentrations of pyruvate and acetate increased significantly after 7 days and acetate concentrations continued to be significantly increased up to 14 days of estivation. The other organic acids studied, such as ketone body acetoacetate and ss-hydroxybutyrate or the volatile acid propionate, did not accumulate. Their tissue concentrations, however, increased on the 7th day of estivation and reached normal levels within two weeks of estivation for some of them. One should take into consideration how the reduction in metabolism can be handled under aerobic conditions, and what role anaerobic pathways may play in both energy formation and redox balance processes.

Acids↗
PubMedDate not supplied

Evaluation of titanium implants placed into simulated extraction sockets: a study in dogs.

The purpose of this study was to evaluate the effect of gap width on bone healing around implants placed into simulated extraction socket defects of varying widths in 10 mongrel dogs. All premolars were removed and the alveolar ridges were reduced to a width of 7 mm. Nine weeks later, a total of 80 implants, 10 mm long by 3.3 mm wide, were placed into osteotomy sites prepared to 3 different diameters in the coronal half, simulating extraction sockets. Three experimental sites, with gap sizes of 0.5 mm, 1.0 mm, and 1.4 mm, were created; the control sites had no gap. The depth of each defect was measured at the time of implant placement. All implants were stable at the time of placement. The dogs were euthanized 12 weeks after implant placement, and blocks containing the implants and adjacent bone were submitted for histologic evaluation. Clinically, all control and test sites healed, with complete bone fill in the defect. Percentages of bone-to-implant contact were measured histologically. As the gap widened, the amount of bone-to-implant contact decreased, and the point of the highest bone-to-implant contact shifted apically. These changes were statistically significant (P < .001). No statistically significant differences in bone-to-implant contact were found between the sites when the apical 4 mm of implants were compared. Within the limits of this study, the simulated extraction socket defects healed clinically, with complete bone fill, regardless of the initial gap size. However, the width of the gap at the time of implant placement had a significant impact on the histologic percentage and the height of bone-to-implant contact.

Analysis of Variance↗
PubMedDate not supplied

Radioimmunotherapy of colorectal cancer in small volume disease and in an adjuvant setting: preclinical evaluation in comparison to equitoxic chemotherapy and initial results of an ongoing phase-I/II clinical trial.

The 5-year survival of colorectal cancer patients with distant metastases is below 30%, despite the development and use of a variety of chemotherapeutic regimens. Therefore, new therapeutic strategies are warranted. Whereas radioimmunotherapy (RIT) has shown disappointing results in bulky disease, it may be a promising therapeutic alternative in limited and small volume disease. The aim of this study was, therefore, to compare, in a preclinical study, the therapeutic efficacy of RIT in colorectal cancer to equitoxic chemotherapy, as well as to evaluate, in a pilot clinical trial, its efficacy in small volume disease. Nude mice, bearing subcutaneous or metastatic human colon cancer xenografts, were injected either with the unlabeled or 131I-labeled monoclonal antibodies (MAbs), CO17-1A (which is a murine IgG2a directed against a 41-kD membrane glycoprotein) or F023C5 (which is an anti-CEA MAb of murine IgG1 subtype), or were administered 5-fluorouracil/folinic acid (5-FU/LV) at equitoxic doses. In a pilot clinical study, 10 colorectal cancer patients with small volume metastatic disease (all lesions < or = 3 cm) have been entered so far in an ongoing mCi/m2-based dose escalation study with the 131I-labeled F023C5. In the animals, the maximum tolerated activities (MTD) of 131I-labeled CO17-1A and F023C5 were 300 microCi and 600 microCi, respectively, corresponding to blood doses of approximately 15 Gy each. Accordingly, myelotoxicity was dose-limiting. The MTD in the chemotherapy group was 0.6 mg 5-FU/1.8 mg LV, given as intravenous bolus 1 h apart for 5 subsequent days. Whereas no significant therapeutic effects were seen with both unlabeled MAbs or 5-FU/LV chemotherapy, tumor growth was retarded significantly with both radiolabeled antibodies. In the metastatic model, chemotherapy prolonged life for only a few weeks, whereas RIT led to cures in 35-55% of the animals. As was the case in the animals, myelotoxicity seems to be dose-limiting in patients as well. Encouraging anti-tumor effects were observed, lasting for up to more than 12 months. These data suggest that radioimmunotherapy may be a viable therapeutic option in colorectal cancer patients with limited disease. Myelotoxicity is the only dose-limiting organ toxicity. Although most patients were treated below the MTD, anti-tumor effects are encouraging. Further studies are ongoing.

Animals↗