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Biomedical subjects

M Schweitzer

Publications and source records attributed to M Schweitzer.

At least 19 recordsLinked to original sources
PubMed2004

Advancements in the diagnosis of acute appendicitis in children and adolescents.

The aim of our study was to further improve the preoperative diagnosis of acute appendicitis in children and adolescents. All diagnostic parameters from the patients' medical history (duration and quality of abdominal pain, stool behaviour), the laboratory (leukocytes, C-reactive protein), the clinic (defense, tenderness on percussion, nausea, vomiting, dry tongue) and repeated ultrasound investigations (visualisation of the appendix, indirect signs of an inflammatory process in the appendix region) were documented prospectively and were re-assessed with regard to their diagnostic value. As an additional parameter, procalcitonin was determined. 1156 patients (593 male/563 female) with a mean age of 9.51 years (+/- 1.2 yrs) (max. 15 yrs/min. 2.3 yrs), referred to the department with acute abdominal pain, were examined. 233 (141 male/92 female; 20.1 %) of these patients with a mean age of 10.47 years (+/- 1.1 yr) had appendicitis. Based on the patients' medical history, laboratory findings, the initial clinical investigation and the initial ultrasound investigation, 173 patients (74.3 % of the later operated 233 children with appendicitis) were diagnosed with certainty. The diagnosis of 60 patients (25.7 %) of this group remained uncertain. These patients received a saline enema (Clysmol, Pharmacia & Upjohn Company) and were subjected to a second clinical and sonographic investigation after approximately four hours of parenteral fluid substitution (Ringer's lactate, Mayrhofer Pharmazeutika Company, 4 ml/kg/h). The other 923 patients (79.83 %) were discharged and were followed up as outpatients in the following days. Based on this stepwise procedure, the percentage of correctly diagnosed appendicitis could be increased to 97.4 %. The measurement of procalcitonin proved to be of no value in the diagnosis of acute appendicitis. It may be concluded that in children with abdominal pain, high diagnostic accuracy can only be achieved by a carefully combined evaluation of all individual diagnostic parameters and repeated investigations.

Acute Disease↗
PubMed2001

The incisor-lip relationship in Herbst/multibracket appliance treatment of Class II, Division 2 malocclusions.

The purpose of this investigation was to examine the effect of Herbst/multibracket appliance treatment on the upper incisor-lower lip relationship in the management of Class II, division 2 malocclusions. The study evaluated 19 successfully treated subjects using lateral head films analyzed at 3 occasions: before (T1) and after (T2) Herbst/multibracket appliance treatment and 1-year posttreatment (T3). The average treatment (T1-T2) changes showed (1) the lower lip overlap on the upper incisors was reduced from 6.0 mm to 4.2 mm (P < .001), (2) the upper incisors were proclined 15.3 degrees (P < .001) and the lower incisors were proclined 9.6 degrees (P < .001), (3) the overbite was reduced from 7.3 mm to 1.7 mm (P < .001), and (4) the sagittal jaw base relationship (Wits) improved from +3.5 to +0.5 mm (P < .001). The average posttreatment (T2-T3) changes showed (1) the upper incisor-lower lip relationship remained stable, (2) the upper (0.6 degrees; P < .001) and lower (2.3 degrees; P < .001) incisors retroclined, (3) the overbite increased (1.2 mm; P < .001), and (4) the sagittal jaw base relationship remained unchanged. In conclusion, it was found that the upper incisor-lower lip relationship was improved by Herbst/multibracket appliance treatment and remained stable during a 1-year posttreatment period in spite of minor relapses of incisor tooth positions and relationships.

Cephalometry↗
PubMed2001

[Prevention of congenital toxoplasmosis in France. Risk assessment. Results and perspectives of prenatal screening and newborn follow up].

In France, a national program for the prevention of congenital toxoplasmosis has been set up 25 years ago. This program is here presented and discussed in details. It is based on a decision tree well defined, with pre and/or per gravidic serological screening with several different tests, completed, if necessary, by ultrasounds examinations of the fetus, biomolecular tests (PCR) on amniotic fluid, and by clinical, biological, and radiological surveillance of neo-nates. The purpose of this prevention program is to: 1/identify nonimmune young women and limit their contamination risk during pregnancy by appropriate counseling on hygiene and diet; 2/screen and treat per gravidic toxoplasmosis as early as possible so as to prevent or limit transmission to the fetus and its consequences. 3/in utero diagnose and treat infestation of the fetus; 4/diagnose and treat asymptomatic congenital toxoplasmosis in neonates, to prevent risks of reactivation and late complications, especially ocular. Such a prevention program has a cost validated by the prevalence of acquired toxoplasmosis in adults in France (over 50% of the population) and by the yearly incidence of congenital toxoplasmosis (at least 0.1% of births according to the best hypothesis). These 6 to 700 congenital toxoplasmosis cases per year may be compared to the 6 to 7,000 per gravidic seroconversions which could lead to fetal contamination if no preventive measures are taken. Nevertheless, as it is often the case in the field of prevention, it is very difficult to statistically assess the efficacy of this program even though several arguments show that it allows to eliminate the most serious toxoplasmosis, sources of serious handicaps at birth, and to limit the frequency of late complications (especially retino-choroiditis) of asymptomatic infections in neonates. The position of European countries varies as to prevention of congenital toxoplasmosis. Some countries (Austria, Belgium) have national prevention programs similar to the French one, whereas others have set up only limited programs or set up no systematic prevention. These differences may be accounted for by the different frequencies of toxoplasmic risk. It seems mandatory to forget all dogmatism and not to stick to a strictly statistical approach for a disease with not only medical but also social and human consequences.

Female↗
PubMed1999

Efficacy of magnetic resonance imaging in the evaluation of posterior cervical spine fractures.

STUDY DESIGN: A retrospective study using two independent, blinded musculoskeletal radiologists to evaluate the sensitivity, specificity, and predictive value of cervical spine magnetic resonance imaging in detecting posterior element fractures of the cervical spine. OBJECTIVE: To evaluate the sensitivity, specificity, and predictive value of magnetic resonance imaging, using computed tomographic scanning as the gold standard, in the diagnosis of posterior element cervical spine fractures. SUMMARY OF BACKGROUND DATA: Few investigators have evaluated the accuracy of magnetic resonance imaging in the determination of cervical spine fractures. METHODS: From January 1994 through June 1996, 75 cervical spine fractures in 32 patients were confirmed by computed tomography. Two musculoskeletal radiologists who were blinded to the clinical history and presence or absence of cervical injury among the study population, independently evaluated each cervical magnetic resonance image recording the presence or absence of soft tissue or bony injury. RESULTS: The overall sensitivity and specificity rates for the diagnosis of a posterior element fracture by magnetic resonance imaging was 11.5% and 97.0%, respectively. The positive predictive value for this group was 83%, and the negative predictive value was 46%. In reference to anterior fractures, the sensitivity was 36.7% and the specificity 98%. Positive and negative predictive values were 91.2% and 64%, respectively. CONCLUSIONS: Magnetic resonance imaging was not effective in recognizing bony injury to the cervical spine and in particular was not as sensitive or as specific as computed tomography in identifying cervical spinal fractures. Computed tomography remains the study of choice for the detection and precise classification of bony injuries to the cervical region, especially when plain radiographs are difficult to evaluate. Magnetic resonance imaging, although not as effective as computed tomography in defining specific bony disorders, remains the gold standard in the evaluation of spinal cord injury, occult vascular injury, and intervertebral disc disruption (hyperextension injury), including herniation and other soft tissue disorders (hematoma, ligament tear).

Adolescent↗
PubMed1999

Post-traumatic and stress-induced osteolysis of the distal clavicle: MR imaging findings in 17 patients.

OBJECTIVE: To describe the MR imaging findings in patients with osteolysis of the distal clavicle and to compare the MR imaging appearance of clavicular osteolysis following acute injury with that related to chronic stress. DESIGN AND PATIENTS: MR imaging examinations were reviewed in 17 patients (14 men, 3 women; ages 16-55 years) with the diagnosis of post-traumatic or stress-induced osteolysis of the clavicle. A history of a single direct injury was present in seven patients and a history of weight-lifting, participation in sports, or repetitive microtrauma was present in 10 patients. RESULTS: MR imaging showed edema in the distal clavicle in 17 patients and, of these, eight also had edema in the acromion. The edema was most evident in STIR and fat-suppressed T2-weighted pulse sequences. Other findings about the acromioclavicular (AC) joint were prominence of the joint capsule in 14, joint fluid in eight, cortical irregularity in 12, and bone fragmentation in six patients. No differences in the MR imaging features of post-traumatic and stress-induced osteolysis of the distal clavicle were observed. CONCLUSION: Post-traumatic and stress-induced osteolysis of the distal clavicle have similar appearances on MR imaging, the most common and conspicuous MR imaging feature being increased T2 signal intensity in the distal clavicle.

Acromioclavicular Joint↗
PubMed1999

Chronic eosinophilic pneumonia with pleural effusion.

The case history of a 77-year-old lady with chronic eosinophilic pneumonia is presented. The diagnosis was difficult due to the simultaneous presence of a pleural effusion and congestive heart failure. Radiological findings and treatment are discussed.

Aged↗
PubMed1999

Sequence specific hybridization properties of methylphosphonate oligodeoxynucleotides.

Methylphosphonate oligodeoxynucleotides (MPO's) with isomerically pure Rp-configurated methylphosphonates (MP's) were synthesized by block coupling of ApT and TpA dinucleoside methylphosphonates (DMP's, p indicating MP-linkage). Oligonucleotide duplexes (20 mers) with these Rp-MP's showed almost the same melting temperatures (Tm) as those with phosphorodiester bonds. Further a dependence of the duplex stability from the nucleosides (bases) adjacent to the MP moiety was observed. For the first time thermodynamic parameters for the duplex to coil transition of isomerically pure MP's were determined from the concentration dependence of the Tm. CD-spectra of the duplexes show structural changes which can be associated with the transition to a compact helix with higher helix winding angle.

Nucleic Acid Conformation↗
PubMed1999

Iliotibial band friction syndrome: MR imaging findings in 16 patients and MR arthrographic study of six cadaveric knees.

PURPOSE: To define magnetic resonance (MR) imaging findings in patients with the iliotibial band friction syndrome (ITBFS) and to correlate these findings with anatomic features defined at magnetic resonance (MR) arthrography in cadavers. MATERIALS AND METHODS: The anatomic relationship of the iliotibial tract (ITT) to the lateral recesses of the knee joint and the lateral femoral epicondyle was investigated with MR arthrography at full extension and at 30 degrees and 60 degrees of knee flexion in six cadaveric knees. Seventeen MR imaging studies in 16 patients with ITBFS were evaluated. RESULTS: In the cadaveric study, no interference of the lateral synovial recess with the lateral femoral epicondyle at full extension and at 30 degrees and 60 degrees of knee flexion was observed. In all specimens, correlation of MR images with macroscopic and microscopic sections revealed no primary bursa between the lateral femoral epicondyle and the ITT. In clinical studies, MR imaging findings of poorly defined signal intensity abnormalities or circumscribed fluid collections were located in a compartmentlike space confined laterally by the ITT and medially by the meniscocapsular junction, the lateral collateral ligament, and the lateral femoral epicondyle. CONCLUSION: MR imaging accurately depicts the compartmentlike distribution of signal intensity abnormalities in patients with ITBFS.

Adolescent↗
PubMed1999

Pericruciate meniscal cysts arising from tears of the posterior horn of the medial meniscus: MR imaging features that simulate posterior cruciate ganglion cysts.

OBJECTIVE: The purpose of this study is to describe MR imaging features of an unusual type of meniscal cyst arising from tears of the posterior horn of the medial meniscus in 10 patients. MATERIALS AND METHODS: Retrospective review of MR examinations of the knee was performed of 10 patients (nine men, one woman; mean age, 39 years) in whom evidence of a meniscal tear and a cyst-like structure around the posterior cruciate ligament (PCL) was seen. RESULTS: An oval mass with low signal intensity on T1-weighted MR images and increased signal intensity on T2-weighted MR images posterior to the PCL, simulating a PCL ganglion cyst, was seen in all 10 patients. A tear of the posterior horn of the medial meniscus was also seen in all patients. The sites of communication between the cyst and meniscal tear were observed in sagittal MR images in eight patients. Septation within the cyst and associated joint effusion were seen in eight and four patients, respectively. Arthroscopy in eight patients and transmeniscal needle drainage in the other two patients confirmed both the meniscal tear and the pericruciate meniscal cyst. CONCLUSION: Pericruciate meniscal cysts cause fluid collections posterior to the PCL, simulating a PCL ganglion cyst. Careful analysis of the posterior horn of the medial meniscus should be performed when a cyst-like structure is seen adjacent to the PCL.

Adolescent↗
PubMed1998

Silicone synovitis: MR imaging in five patients.

Silicone synovitis is a known complication of silicone implants used in orthopedic surgery for joint reconstruction. It has been studied with routine radiography; however, no report on magnetic resonance imaging abnormalities of this condition exist in the literature. This article reports on five patients with silicone synovitis studied by magnetic resonance imaging. All patients showed hypointense implants that were deformed, fragmented or subluxed, and intra- and periarticular silicone particles were evident on T1- and T2-weighted images.

Adult↗
PubMed1998

Evidence of the subperiosteal origin of osteoid osteomas in tubular bones: analysis by CT and MR imaging.

OBJECTIVE: A large series of patients with pathologically proven osteoid osteoma of tubular bones was reviewed to determine the frequency of a subperiosteal site of origin. MATERIALS AND METHODS: Thirty-eight cases that were included met two criteria: the tumor was located in a tubular bone, and the lesion had been evaluated by CT scanning or MR imaging, or both. The location of the osteoid osteoma was categorized as intracortical, sub-periosteal, endosteal, or medullary. RESULTS: Among the 38 cases, 19 were imaged with CT scanning, 14 with MR imaging, and five with both techniques. The most common affected sites were the femur (n = 13), tibia (n = 15), and humerus (n = 4). Among these 38 cases, 18 were intracortical, two were intramedullary, and 18 were subperiosteal. CONCLUSION: Osteoid osteomas occurring in a subperiosteal or surface location are not rare. Indeed, many osteoid osteomas arising in a tubular bone possibly originate in a subperiosteal site and later appear as an intracortical lesion. This site of origin appears to relate principally to continual remodeling of bone with subperiosteal deposition and endosteal erosion.

Adult↗
PubMed1998

[Prenatal diagnosis of a pancreatic cyst due to Ivemark II syndrome].

We present a case of pancreatic cyst associated with other malformations which was diagnosed at antenatal ultrasound. Renal, hepatic, and pancreatic dysplasia as described by Ivemark in 1959 was confirmed by the pathology examination. This uncommon and lethal syndrome demonstrates autosomic recessive transmission. Ultrasound evidence of renal, hepatic and pancreatic dysplasia, associated with femoral abnormalities is suggestive of Meckel's syndrome. Other differential diagnoses are more easily distinguished (chondrodysplasia, chromosomal or metabolic abnormalities).

Abnormalities, Multiple↗
PubMed1997

Acromegaly with normal basal growth hormone levels.

BACKGROUND: The most common cause of acromegaly is excess of growth hormone (GH) secretion. METHODS: We report a 42-year-old male patient, who had become acromegalic over the past 5 years. There were no visual changes or change in sexual function, no gynaecomastia or galactorrhoea. Both CT and MRI scans showed a large mass measuring 2.5 x 2.5 x 3.5 cm, originating from the sella turcica and extending into and totally filling up the sphenoid sinus with diffusely invasive features. RESULTS: Basal serum GH level was within normal range, but insulin-like growth factor 1 (IGF-1) was elevated with slightly increased prolactin (PRL) and impaired GH secretory regulation as well. A pituitary adenoma was partially removed through transsphenoidal microsurgery. Pathology confirmed a mammo-somatotrophic adenoma but immunocytochemistry study of the tumour showed only positivity for PRL but not GH. CONCLUSIONS: When acromegaly occurs without GH level elevation, one should pay attention that: 1) IGF-1 might be the cause of the clinical feature of acromegaly; 2) The tumour might undergo morphological transformation; and 3) Hyperinsulinemia or GH receptor antibody formation could also be the cause of the acromegalic appearance.

Acromegaly↗
PubMed1997

MR imaging of dislocation of the posterior tibial tendon.

OBJECTIVE: The purpose of this article is to describe the MR imaging appearance of seven cases of posterior tibial tendon dislocation and subluxation. CONCLUSION: Posterior tibial tendon dislocation is a rare but important entity usually related to a previous traumatic event. The clinical diagnosis is often missed because of its rarity. MR imaging provides important clues to the diagnosis and preoperative evaluation of this condition.

Adult↗
PubMed1997

Arthropathies and inflammatory conditions of the elbow.

MR imaging of arthropathies and inflammatory conditions affecting the elbow are presented. Noninfectious conditions discussed include osteoarthritis, disorders characterized by synovial proliferation, pigmented villo- nodular synovitis, synovial osteochondromatosis, crystal deposition disorders, and neuropathic osteoarthropathy. Infectious conditions discussed include septic olecranon bursitis, septic arthritis, osteomyelitis, and pyomyositis. Clinical aspects of these entities are discussed, including utility of MR imaging for diagnosis and clinical management.

Arthritis↗