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Biomedical subjects

E Arendt

Publications and source records attributed to E Arendt.

10 recordsLinked to original sources

Enhanced matrix degradation after withdrawal of TGF-beta1 triggers hepatocytes from apoptosis to proliferation and regeneration.

TGF-beta1 is a profibrogenic cytokine participating in deposition of extracellular matrix in fibrotic disorders. In liver, its anti-proliferative/apoptotic effect on hepatocytes promotes fibrosis. The tetracycline-controlled double-transgenic TA(LAP-2)/p(tet)TGF-beta1 mouse provides a model for reversible liver fibrosis. In livers of TGF-beta1-expressing mice, hepatocytes showed synchronous apoptosis detected by DNA laddering and active caspase-3 staining that disappeared when expression of transgenic TGF-beta1 was switched off. In these 'off' mice, perisinusoidal liver fibrosis resolved within 21 days accompanied by elevated proliferation of hepatocytes. Here, we have specified the intermediary stages (2-3 days off and 6 days off) in terms of (i) proliferation (by immunohistochemical staining of proliferating cell nuclear antigen and expression of cyclin D1 mRNA) and (ii) extracellular matrix remodelling processes (by measuring mRNA expression of matrix metalloproteinases-2 and -13 (mmp-2 and mmp-13) and tissue inhibitor of matrix metalloproteinases 1 (timp-1) and quantitative morphometric analysis. In summary, we show a rapidly declining timp-1 mRNA level together with lastingly high mmp-2 and mmp-13 mRNA levels after 2-3 days, suggesting that high matrix-degrading potential represents a prerequisite for the markedly enhanced proliferation of hepatocytes in the early stages after switching off transgenic TGF-beta1.

Animals↗

Use of a broad-host-range bacteriocin-producing Lactococcus lactis transconjugant as an alternative starter for salami manufacture.

Lactococcus lactis DPC4268 is widely used for Cheddar cheese manufacture in Ireland where it is recognised for its reliable fast acid producing ability in dairy environments. A transconjugant of this strain, L. lactis DPC4275, was generated which produces the broad spectrum, two-component bacteriocin lacticin 3147, which is inhibitory to a variety of undesirable gram-positive bacteria including Clostridium, Bacillus, Enterococcus, Listeria, Staphylococcus and Streptococcus. Both DPC4268 and DPC4275 were used as single strain starters for manufacture of salamis. These products were compared with a salami manufactured with a conventional starter (Lactobacillus sake and Staphylococcus carnosus) in terms of pH development, a(w)-value, weight loss, colour development and sensory characteristics. Salamis produced with either lactococcal culture exhibited pH values below 5.1 and a(w)-values below 0.90 which is favourable for preservation and hygienic stability. In addition, these salamis had good sensory and colorimetric qualities. A minimum lacticin 3147 concentration of 640 AU/g was detected in the salamis which were produced with L. lactis DPC4275.

Animals↗

Osteochondral lesions and cruciate ligament injuries. MRI in 18 knees.

Magnetic resonance images were obtained prior to arthroscopy and surgery in 18 knees with acute anterior cruciate ligament injury. The incidence of osseous lesions was assessed and the findings were compared with those at arthroscopy. A total of 28 osseous lesions were detected by MRI in 15 knees, but none of these were detected by radiographs or arthroscopy.

Adolescent↗

Pregnancy outcome after expectant management of premature rupture of the membranes in the second trimester.

Because management of premature rupture of the membranes (PROM) at or before 26 weeks is controversial, we examined maternal and perinatal outcome after expectant management of 44 pregnancies complicated by this problem. Mean gestational age at preterm PROM was 23.9 +/- 1.7 (SD) weeks. The latency period between preterm PROM and delivery ranged from 1 to 68 days, with a medium of 6. Of the patients, 54.6% delivered within a week of PROM, and 79.5% delivered by four weeks; 77.2% developed chorioamnionitis, but despite this high incidence, there was no maternal sepsis or pelvic thrombophlebitis, and no maternal surgery was necessary. Perinatal outcome was 60.5% neonatal survival, 54.2% perinatal survival and a stillbirth rate of 10.4%. Respiratory distress syndrome, bronchopulmonary dysplasia, sepsis and intraventricular hemorrhage were common types of neonatal morbidity. There was no pulmonary hypoplasia, and limb deformity was seen in only two neonates. Costs of expectant management in pregnancies complicated by second-trimester PROM were estimated, and a strategy to reduce cost is suggested.

Adult↗

Biomechanical effect of a two-segment anterior cruciate ligament graft with separate femoral attachments and differing levels of prescribed load sharing.

The objective of this study was to analyze the biomechanical effect of varying the level of prescribed load sharing between two segments of an anterior cruciate ligament (ACL) graft, and of separating the femoral attachments of these segments. Total anterior-posterior (AP) laxity was measured using an instrumented spatial linkage. Forces in graft segments were measured using buckle transducers. The two-segment graft was formed using the middle third of the patellar tendon with bone blocks and a synthetic augmentation device. Proximal fixation was obtained using a fixture which allowed changing the individual locations of the femoral attachments of the tendon and augmentation segments. Distal fixation was achieved using a force-setting device which allowed the loads in each segment to be set to prescribed levels. Total graft force, load sharing, and total AP laxity were recorded during the application of 100-N AP tibial loads at 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 110 degrees flexion, for various combinations of load sharing set at extension and locations of femoral attachment sites. The load sharing, total graft force, and AP laxity during AP loading at the five test flexion angles were not significantly affected by changing the prescribed level of load sharing set at extension for a given femoral attachment configuration. However, varying the separate hole locations of the graft segments for a given level of load sharing significantly affected load sharing, total graft force, and AP laxity. If the tendon graft was located posteriorly (on the medial surface of the lateral femoral condyle) and the augmentation segment proximally, the augmentation carried a greater portion of the total force in flexion. If the augmentation segment was changed to a more posterosuperior location and the tendon posteroinferior, the tendon carried a higher percentage of the total force in flexion. AP laxity in most reconstruction states was significantly greater than in the normal joint with an intact ACL. The nature of the load sharing between the graft segments under AP tibial load over the flexion range can be controlled by the appropriate choice of the segments' femoral attachment locations.

Analysis of Variance↗

[Patellofemoral pain. Diagnosis and treatment].

Patellofemoral pain is a frequent complaint among recreational and competitive athletes. Studies from Sweden and Norway among junior and senior high school students showed that every third to fourth student currently suffers, or has previously suffered, from patellofemoral pain. This paper presents current trends in diagnosis and treatment of patellofemoral pain. It describes the clinical examination, and discusses the additional information obtained from tests like radiography, CT and MT. Arthroscopy can establish the degree of cartilage damage and joint articulation, but should not be used as a general diagnostic tool. Treatment of patellofemoral pain should consist of patient education and a carefully designed rehabilitation programme emphasizing eccentric quadriceps exercises, primarily in close chain modes. A knee sleeve with a lateral cushion seems to alleviate symptoms in some patients. If the problems are not reduced by a well executed exercise programme over six months, surgical intervention should be discussed on the basis of a specific diagnosis. The article includes a review of recent studies on patellar shaving, spongialization, lateral release, proximal/distal realignment, tibial tubercle elevation and medialization, and patellectomy.

Athletic Injuries↗

Knee injury patterns among men and women in collegiate basketball and soccer. NCAA data and review of literature.

Women's participation in intercollegiate athletics has increased dramatically in recent years. Greater participation has increased awareness of health and medical issues specific to the female athlete. Some reports have noted a higher susceptibility to knee injury, specifically injuries to the anterior cruciate ligament, in female athletes as compared with their male counterparts. We performed a 5-year evaluation of anterior cruciate ligament injuries in collegiate men's and women's soccer and basketball programs using the National College Athletic Association Injury Surveillance System. Results showed significantly higher anterior cruciate ligament injury rates in both female sports compared with the male sports. Noncontact mechanisms were the primary cause of anterior cruciate ligament injury in both female sports. Possible causative factors for this increase in anterior cruciate ligament injuries among women may be extrinsic (body movement, muscular strength, shoe-surface interface, and skill level) or intrinsic (joint laxity, limb alignment, notch dimensions, and ligament size).

Anterior Cruciate Ligament Injuries↗