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F Luthi

Publications and source records attributed to F Luthi.

17 recordsLinked to original sources
PubMed2006

A new ambulatory system for comparative evaluation of the three-dimensional knee kinematics, applied to anterior cruciate ligament injuries.

The aim of this study was to develop an ambulatory system for the three-dimensional (3D) knee kinematics evaluation, which can be used outside a laboratory during long-term monitoring. In order to show the efficacy of this ambulatory system, knee function was analysed using this system, after an anterior cruciate ligament (ACL) lesion, and after reconstructive surgery. The proposed system was composed of two 3D gyroscopes, fixed on the shank and on the thigh, and a portable data logger for signal recording. The measured parameters were the 3D mean range of motion (ROM) and the healthy knee was used as control. The precision of this system was first assessed using an ultrasound reference system. The repeatability was also estimated. A clinical study was then performed on five unilateral ACL-deficient men (range: 19-36 years) prior to, and a year after the surgery. The patients were evaluated with the IKDC score and the kinematics measurements were carried out on a 30 m walking trial. The precision in comparison with the reference system was 4.4 degrees , 2.7 degrees and 4.2 degrees for flexion-extension, internal-external rotation, and abduction-adduction, respectively. The repeatability of the results for the three directions was 0.8 degrees , 0.7 degrees and 1.8 degrees . The averaged ROM of the five patients' healthy knee were 70.1 degrees (standard deviation (SD) 5.8 degrees), 24.0 degrees (SD 3.0 degrees) and 12.0 degrees (SD 6.3 degrees for flexion-extension, internal-external rotation and abduction-adduction before surgery, and 76.5 degrees (SD 4.1 degrees), 21.7 degrees (SD 4.9 degrees) and 10.2 degrees (SD 4.6 degrees) 1 year following the reconstruction. The results for the pathologic knee were 64.5 degrees (SD 6.9 degrees), 20.6 degrees (SD 4.0 degrees) and 19.7 degrees (8.2 degrees) during the first evaluation, and 72.3 degrees (SD 2.4 degrees), 25.8 degrees (SD 6.4 degrees) and 12.4 degrees (SD 2.3 degrees) during the second one. The performance of the system enabled us to detect knee function modifications in the sagittal and transverse plane. Prior to the reconstruction, the ROM of the injured knee was lower in flexion-extension and internal-external rotation in comparison with the controlateral knee. One year after the surgery, four patients were classified normal (A) and one almost normal (B), according to the IKDC score, and changes in the kinematics of the five patients remained: lower flexion-extension ROM and higher internal-external rotation ROM in comparison with the controlateral knee. The 3D kinematics was changed after an ACL lesion and remained altered one year after the surgery.

Adult↗
PubMed2006

Mixed testicular germ cell tumor presenting as metastatic pure choriocarcinoma involving the maxillary gingiva.

Gingival metastases are infrequent and invariably associated with a widespread disease and a poor prognosis. Because of their unremarkable clinical appearance, they can be difficult to distinguish from more common gingival hyperplastic or reactive lesions, such as pyogenic granuloma, peripheral giant cell granuloma, and peripheral ossifying granuloma. We are reporting here an unusual case of a 36-year-old man with a mixed testicular germ cell tumor presenting as a metastatic pure choriocarcinoma involving the maxillary gingiva, extending from the first left premolar to the left second maxillary molar, mimicking a 'benign looking' gingival mass. Gingival metastases may be the first manifestation of a widespread metastatic disease and therefore particular attention must be paid to gingival lesions associated with atypical clinical symptoms and/or signs.

Adult↗
PubMed2004

The value of PET, CT and in-line PET/CT in patients with gastrointestinal stromal tumours: long-term outcome of treatment with imatinib mesylate.

PURPOSE: Gastrointestinal stromal tumours (GIST) are mesenchymal neoplasms of the gastrointestinal tract that are unresponsive to standard sarcoma chemotherapy. Imaging of GIST patients is done with structural and functional methods such as contrast-enhanced helical computed tomography (ceCT) and positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG). The aim of this study was to compare the prognostic power of PET and ceCT and to evaluate the clinical role of PET/CT imaging. METHODS: All patients with GIST undergoing PET or PET/CT examinations were prospectively included in this study, and the median overall survival, time to progression and treatment duration were documented. The prognostic significance of PET and ceCT criteria of treatment response was assessed and PET/CT was compared with PET and ceCT imaging. Data for 34 patients (19 male, 15 female, 21-76 years) undergoing PET or PET/CT for staging or restaging were analysed. RESULTS: In 28 patients, PET/CT and ceCT were available after introduction of treatment with the tyrosine kinase inhibitor imatinib mesylate (Gleevec; Novartis, Basel, Switzerland). Patients without FDG uptake after the start of treatment had a better prognosis than patients with residual activity. In contrast, ceCT criteria provided insufficient prognostic power. However, more lesions were found on ceCT images than on PET images, and FDG uptake was sometimes very variable. PET/CT delineated active lesions better than did the combination of PET and ceCT imaging. CONCLUSION: Both PET and PET/CT provide important prognostic information and have an impact on clinical decision-making in GIST patients. PET/CT precisely delineates lesions and thus allows for the correct planning of surgical interventions.

Adult↗
PubMed2004

'Agglutination and flocculation' of stem cells collected by apheresis due to cryofibrinogen.

Collection of peripheral stem cells by apheresis is a well-described process. Here, investigations concerning 'agglutination and flocculation' of stem cells collected from two patients are described. In both cases, cryoproteins were observed and cryofibrinogen was identified using high-resolution two-dimensional electrophoresis. In one case, peripheral stem cells were collected after a second course of mobilization, and the cells were immediately washed at 37 degrees C before being frozen, allowing their use, despite the presence of cryofibrinogen. In the other case, 'agglutination' was reversed by warming the bag, and plasma was removed before freezing.

Agglutination↗
PubMed2000

Young children with Velo-Cardio-Facial syndrome (CATCH-22). Psychological and language phenotypes.

This is the first clinical description of a detailed psychological, speech, and language phenotype of four young children (< 5 years) with Velo-Cardio-Facial syndrome (VCFS) due to a deletion on chromosome 22 (22q11.2). The reported elevated risk of developing schizophrenia or bipolar disorder in adolescence for individuals with this chromosomal deletion led us to examine the psychiatric and cognitive status of young children with VCFS. Our observations suggest a phenotype comprised of a borderline to mildly retarded level of intellectual functioning, a language delay, a general deficit in social initiation, difficulties with attention/concentration, and a perturbed train of thought.

Child, Preschool↗
PubMed1999

B cell response after MMTV infection: extrafollicular plasmablasts represent the main infected population and can transmit viral infection.

The immune response to mouse mammary tumor virus (MMTV) relies on the presentation of an MMTV-encoded superantigen by infected B cells to superantigen-specific T cells. The initial extrafollicular B cell differentiation involved the generation of B cells expressing low levels of B220. These B220low B cells corresponded to plasmablasts that expressed high levels of CD43 and syndecan-1 and were CD62 ligand- and IgD-. Viral DNA was detected nearly exclusively in these B220low B cells by PCR, and retroviral type-A particles were observed in their cytoplasm by electron microscopy. An MMTV transmission to the offspring was also achieved after transfer of B220low CD62 ligand- CD43+ plasmablasts into noninfected females. These data suggest that B220low plasmablasts, representing the bulk of infected B cells, are capable of sustaining viral replication and may be involved in the transmission of MMTV.

Animals↗
PubMed1999

[Cardiac perforation by a gastric ulcer: an unusual cause of death, after an esophageal and gastric resection of an epidermoid esophageal carcinoma].

We report here the case of a 55 year old female that underwent surgery for a well differentiated squamous cell carcinoma of the esophagus (middle third). Four months after surgery, she complains of neck pain, for which she is prescribed non steroidal antiinflammatory drugs (NSAID). A CT-scan and a Barium swallow are then normal. After three weeks of treatment, the patient is admitted on emergency to the Intensive Care Unit for a resuscitation hematemesis and atrial fibrillation with a fast ventricular response. The symptoms are stabilized after the transfusion of a few packed red blood cells. A few hours later, however, a massive hematemesis recurs and the patient dies despite intense resuscitation measures. Autopsy reveals three gastric ulcers, one of which had perforated through the cardiac left ventricular wall.

Carcinoma, Squamous Cell↗
PubMed1997

Early neutralizing antibody response against mouse mammary tumor virus: critical role of viral infection and superantigen-reactive T cells.

Infectious mouse mammary tumor virus (MMTV) is a retrovirus that expresses a superantigen shortly after infection of B cells. The superantigen first drives the polyclonal activation and proliferation of superantigen-reactive CD4+ T cells, which then induce the infected B cells to proliferate and differentiate. Part of the MMTV-induced B cell response leads to the production of Abs that are specific for the viral envelope protein gp52. Here we show that this Ab response has virus-neutralizing activity and confers protection against superinfection by other MMTV strains in vivo as soon as 4 to 7 days after infection. A protective Ab titer is maintained lifelong. Viral infection as well as the superantigen-induced T-B collaboration are required to generate this rapid and long lasting neutralizing Ab response. Polyclonal or superantigen-independent B cell activation, on the contrary, does not lead to detectable virus neutralization. The early onset of this superantigen-dependent neutralizing response suggests that viral envelope-specific B cells are selectively recruited to form part of the extrafollicular B cell response and are subsequently amplified and maintained by superantigen-reactive Th cells.

Animals↗
PubMed1997

The nasal-associated lymphoid tissue of adult mice acts as an entry site for the mouse mammary tumor retrovirus.

Mouse mammary tumor virus (MMTV) is a B type retrovirus transmitted to the suckling offspring through milk. MMTV crosses the intestinal barrier of neonates, initially infects the lymphoid cells of the Peyer's patches, and later spreads to all lymphoid organs and to the mammary gland. Adult mice can be infected systemically, but not by oral MMTV administration. In this study, we show that nasal administration of infected milk induces the infection of adult mice. Nasal MMTV infection shared the main features of systemic and neonatal intestinal MMTV infections: deletion of the superantigen (SAg)-reactive T cell subset from the peripheral T cell population, presence of viral DNA in lymphoid cells, and transmission of MMTV from mother to offspring. Viral DNA was restricted to the lungs and nasal-associated lymphoid tissue (NALT) 6 d after nasal infection. Furthermore, SAg-induced T cell proliferation was only detected in NALT. These results demonstrate that MMTV crosses the intact epithelium of the upper respiratory tract of adult mice and infects the lymphoid follicles associated with these structures.

Animals↗
PubMed1997

Role of the immune response induced by superantigens in the pathogenesis of microbial infections.

Superantigens (SAgs) are microbial proteins which have potent effects on the immune system. They are presented by major histocompatibility complex (MHC) class II molecules and interact with a large number of T cells expressing specific T cell receptor V beta domains. Encounter of a SAg leads initially to the stimulation and subsequently to the clonal deletion of reactive T cells. SAgs are expressed by a wide variety of microorganisms which use them to exploit the immune system to their own advantage. Bacterial SAgs are exotoxins which are linked to several diseases in humans and animals. A classical example is the toxic shock syndrome in which the massive release of cytokines by SAg-reactive cells is thought to play a major pathogenic role. The best characterized viral SAg is encoded by mouse mammary tumour virus (MMTV) and has proved to have a major influence on the viral life cycle by dramatically increasing the efficiency of viral infection. In this paper, we review the general properties of SAgs and discuss the different types of microorganisms which produce these molecules, with a particular emphasis on the role played by the SAg-induced immune response in the course of microbial infections.

Animals↗
PubMed1997

Retrovirus-induced target cell activation in the early phases of infection: the mouse mammary tumor virus model.

Mouse mammary tumor virus (MMTV) infects B lymphocytes and expresses a superantigen on the cell surface after integration of its reverse-transcribed genome. Superantigen-dependent B- and T-cell activation becomes detectable 2 to 3 days after infection. We show here that before this event, B cells undergo a polyclonal activation which does not involve massive proliferation. This first phase of B-cell activation is T cell independent. Moreover, during the first phase of activation, when only a small fraction of B cells is infected by MMTV(SW), viral DNA is detected only in activated B cells. Such a B-cell activation is also seen after injection of murine leukemia virus but not after injection of vaccinia virus, despite the very similar kinetics and intensity of the immune response. Since retroviruses require activated target cells to induce efficient infection, these data suggest that the early polyclonal retrovirus-induced target cell activation might play an important role in the establishment of retroviral infections.

Animals↗
PubMed1996

[Is cancer a new disease? Apropos of diagnosis of tumor diseases in De Medicina by Celsus].

Cancer is a particularly common disease in modern societies. Moreover, epidemiology considers it typical of contemporary pathology. Nevertheless, the abundant ancient literature-in the De Medicina by Celsus, among others-leads us to believe that numerous benign and malignant tumours were observed if not identified as such. Hence, it is possible that both the change in medical conceptualization and the real increase in the prevalence are responsible for the actual importance of cancer.

History, Ancient↗
PubMed1995

[Anaphylactic shock].

Anaphylactic shock is an unexpected, sudden and sometimes deadly event that attacks the patient in 75% of the cases without pre-existent history of allergy. In general, drugs, hymenopteric poisons and nutrients (according to the recent concept) are responsible. Beside the classical IgE-mediated anaphylactic shock there exists another anaphylactic shock, identical in its clinical picture and treatment but not in the mechanism of development. Epinephrine is the only effective drug in case of respiratory (bronchial asthma, laryngeal edema) or cardiovascular (hypotension, arrhythmias, hypovolemic shock) manifestation. It has to be administered as rapidly as possible.

Anaphylaxis↗
PubMed1993

[Pain syndrome in the right iliac fossa and laparoscopy: routine appendectomy or not?].

Diagnostic laparoscopy is useful in the evaluation of patients with lower right quadrant pain when the diagnosis is uncertain. The object of this study was to determine whether a normal appendix should be routinely removed at laparoscopy. We have decided to do this in children, men under the age of 30 and women of childbearing age. However we do not perform appendectomy in men over the age of 30, women over 50 and in immunodeficient patients. This is a working hypothesis and is the basis of an on-going prospective study in our unit.

Abdominal Pain↗
PubMedDate not supplied

"Adolescent-onset Still's disease": characteristics and outcome in comparison with adult-onset Still's disease.

OBJECTIVES: To determine if adolescent onset systemic juvenile idiopathic arthritis (JIA) and adult onset Still's disease (AOSD) represent the same clinical continuum of disease. METHODS: Retrospective review of available clinical data on all pediatric and adult patients diagnosed with Still's disease within the last 10 years at a university hospital. Assessment of functional outcomes at last visit by clinical evaluation and HAQ or c-HAQ. RESULTS: Nine patients were identified as adolescent onset systemic JIA and were compared with 10 patients with AOSD (onset > 18 years old). No statistically significant differences were found between the two groups in terms of clinical presentation at onset and outcome at follow up. CONCLUSION: Adolescent patients presenting with systemic JIA have a disease onset and course undistinguishable from that of AOSD patients, suggesting that they represent a continuum of a single disease entity.

Adolescent↗