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Biomedical subjects

Christoph Schmid

Publications and source records attributed to Christoph Schmid.

41 records · Page 3Linked to original sources
PubMed2003

Bone marrow edema of the mandibular condyle related to internal derangement, osteoarthrosis, and joint effusion.

PURPOSE: The purpose of this prospective study was to evaluate whether common magnetic resonance imaging (MRI) variables such as temporomandibular joint (TMJ) internal derangement, osteoarthrosis, and effusion may predict the diagnostic group of bone marrow edema of the mandibular condyle. MATERIALS AND METHODS: The relationship between bone marrow edema and TMJ disc displacement, osteoarthrosis, and effusion was analyzed in MRIs of 120 TMJs in 73 consecutive patients with TMJ pain and/or a clinical diagnosis of TMJ internal derangement type III (disc displacement without reduction). The diagnostic bone marrow edema group was comprised of 54 TMJs in 40 patients with a unilateral or bilateral MRI diagnosis of bone marrow edema. The control group consisted of 66 non-bone marrow edema TMJs in 33 patients with a bilateral MRI finding of an absence of bone marrow edema. A logistic regression analysis was used to compute the odds ratios for internal derangement, osteoarthrosis, and effusion for non-bone marrow edema TMJs (n = 66) versus TMJs with bone marrow edema (n = 54). RESULTS: Using Chi;(2) analysis for pair-wise comparison, the TMJ-related data showed a significant relationship between the MR imaging findings of TMJ bone marrow edema and those of internal derangement (P = .000), osteoarthrosis (P = .000), and effusion (P = .010). Of the MRI variables considered simultaneously in the multiple logistic regression analysis, osteoarthrosis (P = .107) and effusion (P = .102) dropped out as nonsignificant in the diagnostic bone marrow edema group when compared with the control group. The odds ratio for individuals with an internal derangement showing bone marrow edema was strong (3.6:1) and highly significant (P = .000). Significant increases in risk of bone marrow edema occurred with disc displacement without reduction and osteoarthrosis (9.2:1) (P = .000) and disc displacement without reduction and effusion (6.4:1) (P = .002). CONCLUSIONS: The results suggest that the MR imaging findings for TMJ bone marrow edema are related to those of internal derangement, osteoarthrosis, and effusion. However, the data re-emphasize the aspect that internal derangement, osteoarthrosis, and effusion may not be regarded as the unique and dominant factors in defining TMJ bone marrow edema instances.

Adolescent↗
PubMed2003

Adoptive immunotherapy in chimeras with donor lymphocytes.

Allogeneic stem cell transplantation has a well-defined indication in the treatment of hematological malignancies. The beneficial immune effect of allogeneic marrow transplantation has long been known, but only recently have methods been developed to separate the graft-versus-leukemia (GVL) effect from graft-versus-host disease (GVHD). Animal experiments have shown that lymphocytes from the marrow donor can be transfused without causing severe GVHD if stable chimerism and tolerance is established. First clinical studies have been preformed in patients with recurrent chronic myelogenous leukemia. In these patients complete molecular remissions were induced that persist without further maintenance treatment. These results have been confirmed in larger multicenter studies in Europe and the USA. The best results were obtained in chronic myelogenous leukemia (CML); repeated successes have been reported in relapsing acute myeloid leukemia (AML), myelodysplastic syndromes and multiple myeloma (MMY), and rare responses were reported for acute lymphoid leukemia. Contrary to animal experiments GVHD has been observed in human patients although to a lesser extent than expected in transplants not given immunosuppression. Secondly myelosuppression has been observed in patients treated with relapsing CML. In CML the incidence of GVHD could be reduced by depleting CD8+ T cells from the donor lymphocyte concentrate. Alternatively only small numbers of T lymphocytes can be transfused and in the case of failing responses, the numbers of donor lymphocytes may be increased. Results in recurrent AML have been improved by the use of low-dose cytosine arabinoside, granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor mobilized blood cells as compared to lymphocytes only. In MMY the response rate is higher than in AML, but the remissions are of limited duration in most patients. Several protocols have been designed to include preemptive donor lymphocyte transfusion in patients with a high relapse risk after transplantation. Problems remain to avoid chronic GVHD and to circumvent the immune escape mechanisms of leukemia.

Adoptive Transfer↗
PubMed2002

Osteoporosis before lung transplantation: association with low body mass index, but not with underlying disease.

Due to progress in lung transplantation, post-transplantation osteoporosis becomes an important problem. We determined bone mineral density (BMD) in 74 lung transplantation candidates, among them 24 patients with cysticfibrosis, 16 with chronic obstructive pulmonary disease, 14 with pulmonary fibrosis, and 11 with pulmonary hypertension. The mean T score (+/- SD) was -2.6 +/- 1.3 at femoral neck (FN), -2.2 +/- 1.6 at Ward's triangle (WT) and -2.3 +/- 1.5 at lumbar spine (LS). Osteoporosis was found in 61% of the patients at FN, 45% at WT and 50% at LS. Patients with different underlying lung diseases were similarly affected, not only those with cystic fibrosis but also others, including patients with pulmonary hypertension. No association was found between BMD and age, gender, menstrual condition in women and testosterone level in men. A negative correlation was found between chronic glucocorticoid use and T scores. Body mass index correlated positively (p < 0.01) with T scores at any site and the correlation was also significant for the 2 largest subgroups. Loss of lung function (FEV1) also was associated with lower T scores. No correlation was found between BMD and biochemical indices of bone turnover. Multivariate analysis revealed BMI and glucocorticoid use as independent risk factors. We conclude that osteoporosis is a very common condition in patients with end-stage pulmonary disease, independent of the underlying diagnosis. In view of additional bone loss under immunosuppressive treatment after lung transplantation, early diagnosis and prevention of osteoporosis in the pretransplant period should receive high priority.

Absorptiometry, Photon↗
PubMed2002

IGF-I and GH stimulate Phex mRNA expression in lungs and bones and 1,25-dihydroxyvitamin D(3) production in hypophysectomized rats.

OBJECTIVE: X-linked hypophosphatemia, a renal phosphate (Pi)-wasting disorder with defective bone mineralization, is caused by mutations in the PHEX gene (a Pi-regulating gene with homology to endopeptidases on the X chromosome). We wondered whether changes in Phex and neprilysin (NEP) (another member of the family of zinc endopeptidases) mRNA expression could be observed in relation to vitamin D and Pi metabolism during GH- and IGF-I-stimulated growth of hypophysectomized rats. DESIGN: Animals were infused s.c. for 2 days with vehicle, 200 mU (67 microg) GH or 300 microg IGF-I/rat per 24 h. We determined serum osteocalcin and osteocalcin mRNA in bone, Phex mRNA in bone and lungs, serum 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) and serum Pi levels, and renal expression of 25-hydroxyvitamin D(3)-1alpha-hydroxylase (1alpha-hydroxylase), of 25-hydroxyvitamin D(3)-24-hydroxylase (24-hydroxylase) and of the Na-dependent Pi-cotransporter type I and II (Na(d)Pi-I and -II). RESULTS: As compared with vehicle-treated controls, body weight and tibial epiphyseal width significantly increased in GH- and IGF-I-treated animals. Serum osteocalcin and osteocalcin mRNA levels in bone, Phex mRNA in bone and lungs, serum 1,25-(OH)(2)D(3) and renal 1alpha-hydroxylase mRNA rose concomitantly, whereas expression of NEP in lungs was barely affected and renal 24-hydroxylase mRNA decreased. Na(d)Pi-I and -II gene expression in the kidney and serum Pi levels remained unchanged. CONCLUSIONS: Our findings suggest a coordinate regulation of Phex mRNA expression in lungs and bone and vitamin D metabolism during GH- and IGF-I-stimulated growth.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗