Broken quantum symmetry and confinement phases in planar physics.

Many two-dimensional physical systems have symmetries which are mathematically described by quantum groups (quasitriangular Hopf algebras). In this Letter we introduce the concept of a spontaneously broken Hopf symmetry and show that it provides an effective tool for analyzing a wide variety of phases exhibiting many distinct confinement phenomena.

Effects of methotrexate on normal articular cartilage in vitro and in vivo.

OBJECTIVE: Methotrexate (MTX) has become the disease modifying drug of choice for the treatment of rheumatoid arthritis (RA). Direct effects of MTX on articular cartilage in vivo and in vitro were studied to determine possible adverse effects of the drug. METHODS: For in vitro experiments, adult bovine articular cartilage explants were cultured in the presence of MTX (0 to 100 microM), and effects on DNA and matrix metabolism were studied. For in vivo studies, 48 adult female rabbits were treated with MTX (30 mg/kg/week intramuscularly) or placebo, respectively, for up to 12 weeks, and effects on the cartilage of the femoral condyles were assessed. RESULTS: In vitro, MTX dose dependently increased the uptake of [3H]-thymidine, and decreased incorporation of [3H]-d-uridine into chondrocytes with a half maximal effect at 0.03 microM, suggesting inhibition of thymidylate-synthetase activity by the drug. MTX also dose dependently reduced the proportion of chondrocytes in S-phase, as determined by flow cytometry. MTX did not affect LDH release from chondrocytes or the proportion of viable cells, nor did it change the rate of protein synthesis, proteoglycan synthesis, proteoglycan breakdown, or the hydrodynamic size of newly synthesised proteoglycans. In vivo, MTX did not appreciably affect proteoglycan synthesis of the chondrocytes, proteoglycan content of the cartilage matrix, density of the chondrocyte population, or histological integrity of the cartilage. CONCLUSIONS: The data suggest the absence of major adverse effects by MTX on articular cartilage proteoglycan metabolism. Chondrocyte DNA metabolism seems to be changed by MTX only in concentrations and exposition periods clearly exceeding those found in synovial fluid of RA patients receiving the commonly prescribed doses of the drug.

The effects of high-dose methotrexate on the development of cartilage lesions in a lapine model of osteoarthrosis.

To determine whether systemic administration of methotrexate (MTX) can prevent joint destruction in experimental osteoarthrosis (OA) in rabbits, the disorder was induced unilaterally in the knee joints of 40 rabbits by partial medial meniscectomy and sectioning of the medial collateral and both cruciate ligaments. A sham operation (arthrotomy only) was performed in another four animals. Effects on the cartilage of the femoral condyles were studied after 6 and 12 weeks. Twelve weeks after induction, femoral and tibial osteophyte formation was demonstrated on radiographs in all cases. Marked cartilage damage was found histologically (median Mankin score 10 vs 1 for non-operated controls; P < 0.05, Wilcoxon test). Cartilage proteoglycan (GAG) content (dye binding assay) was reduced in operated joints [63 +/- 8 (mean +/- SEM) vs 75 +/- 6 micrograms chondroitin sulfate/mg cartilage wet weight], and the leukocyte count in the joints was elevated (226 +/- 14 vs 7 +/- 3 leukocytes per microliter joint aspirate after injection of 0.5 ml saline solution; both P < 0.05, Wilcoxon test). The rate of GAG synthesis was unchanged (ex vivo labelling with 35S-sulfate). Treatment with MTX (30 mg x kg body weight-1 x week-1 i.m., starting 12 h postoperatively) reduced cartilage damage (median Mankin score 8 vs 10 for placebo, P < 0.05, Mann-Whitney U-test), but had no significant effect on the other parameters tested. No significant MTX effects were observed on cartilage from nonoperated joints. Our data indicate that MTX may have a limited therapeutic effect in experimental OA in the rabbit.

[Sterility as a sequela of tubal schistosomiasis]. / Sterilität als Folge einer tubaren Schistosomiasis.

A 21-year old african women presented with primary sterility in the outpatient department of our university hospital. Screening examinations, including ultrasound, demonstrated a tumour of 5.8 x 4.1 cm diameter on the left ovary. While performing laparotomy to extirpate this tumour, bilateral occlusion of the tubes was discovered by chromopertubation.This diagnosis led us to perform bilateral salpingostomy and reimplantation of the Fallopian tubes. In addition to the ovarian tumour (dermoid), fragments of the Fallopian tubes were sent for histological examination, which revealed eggs of schistosomes probably of the species Schistosoma haematobium. Since tourism to and immigration from endemic areas is increasing, schistosomiasis should be considered when it is not possible to elucidate the cause of sterility by classical means.

[Primary hyperparathyroidism in the third trimester of pregnancy]. / Der primäre Hyperparathyreoidismus im 3. Schwangerschaftstrimenon.

A case of primary hyperparathyroidism in late pregnancy is described. After an initial conservative treatment surgery was performed in the 35th week of gestation. The further course of the pregnancy was uneventful, the newborn showed a normal development.

[Doppler ultrasound studies of breast tumors with the continuous wave technique]. / Dopplersonographische Untersuchungen von Mammatumoren in CW-Technik.

The aim of the study was to ascertain the reliability of continuous-wave Doppler signals in the diagnosis of breast cancer. CW-Doppler findings in a series of 63 cases of palpable breast tumors with histologic confirmation (24 malignancies and 39 benign tumors) are reported. Depending on the parameters used -20 -24 of 24 malignant nodes (83%-100%) and 20 -24 of 39 benign lesions (51%-62%) were correctly identified. Even benign tumors showed significant differences in systolic peak and diastolic frequencies compared to the contralateral breast. The Resistance-Index (RI) did not allow the differentiation of lesions when measured on one side only. Comparing the Resistance-Indices of both breasts helped improving the specificity of CW-Doppler-sonography to 89.7% and the positive predictive value to 73.3%. The CW-Doppler-sonography with the relevant parameters of diastolic and systolic peak frequency and the RI is considered a useful tool in the diagnosis of breast cancer.