Normal tendons and palmar aponeuroses from patients with carpal tunnel syndrome and tissues of the palmar aponeuroses from patients with Dupuytren's contracture were subjected to biomechanical tests. Several parameters characterizing the viscoelastic load response of the tissues were investigated. The tissues from patients with Dupuytren's contracture were classified according to their macroscopic and histological appearance into apparently normal palmar aponeuroses, thickened fibre bundles and contracture bands. There were biomechanical differences between the normal palmar aponeuroses and the apparently normal palmar aponeuroses indicating that biomechanical changes occur before thickening of fibres or cellular proliferation can be observed. Significant biomechanical changes occurred between apparently normal palmar aponeuroses and thickened fibre bundles. Journal of Hand Surgery (British and European Volume, 1997) 22B: 4:510 517
Purpose: To compare the effect of erbium:YAG laser photocapsulotomy (ELC), continuous curvilinear capsulorhexis (CCC), and high-frequency capsulotomy (HFC) on anterior capsule edges using light microscopy (LM) and transmission electron microscopy (TEM). Setting: Department of Ophthalmology, Department of Histology and Embryology II, University of Vienna, Vienna, Austria. Methods: Five anterior capsule membranes were obtained experimentally by ELC, which was performed with the Oertli MicroLaser photoemulsification tip in eyes from 5 human cadavers. Thirty anterior capsule membranes were obtained during cataract surgery by CCC (n = 15) or, in cases with poor or missing red fundus reflexes, by HFC (n = 15). Continuous curvilinear capsulorhexis was performed conventionally with a manual, bent, 27-gauge cannula, and HFC was performed according to Klöti. Membranes were processed and examined by LM and TEM according to standard procedures. Results: The edges obtained by ELC showed mild signs of denaturation and mechanical disruption, tears, and micro-tears. Lens capsule edges obtained by CCC were smooth with no irregularities in any specimen; the edges were beveled anteriorly to posteriorly with no evidence of tearing. Edges produced by HFC were considerably wider; the surfaces showed distinct denaturation, preformed tears, and micro-tears. The edges were surrounded by a nonhomogeneous mass, which consisted mainly of denatured lens capsule material. Conclusions: Of the 3 techniques, CCC produced the mildest tissue damage. The histological damage at ELC edges was relatively mild and intermediate compared with that seen at CCC and HFC edges. These observations suggest that ELC is an appropriate option for anterior capsulotomy in cataract surgery.
Prostate carcinoma-derived factors induce a proliferative response in osteoblasts. The present study investigated the involvement of MAP kinase in the osteoblastic reaction of osteocytes and the response of 1alpha,25-hydroxy-vitamin D3 (1,25-vitD3)-pretreated osteoblasts. Conditioned media (CM) from prostate, colon, pancreatic, renal cell and breast cancer cell lines were tested on their proliferative activity using murine osteoblast-like MC3T3-E1 cells, MG63 human osteosarcoma cells and immortalized human osteoblasts (AHTO-7). Changes in osteoblastic activities of the supernantants were measured in the presence of MAP kinase inhibitors and following 1,25-vitD3-induced differentiation of the target osteoblasts. Supernatants of prostate cancer cells stimulated proliferation of osteoblasts in all three indicator cell lines, with AHTO-7 exhibiting the most significant correlation to human primary osteoblast cultures. 1,25-vitD3 induced the differentiation marker alkaline phosphatase (ALP) in MC3T3-E1 and AHTO-7, but only to a minor degree in MG63 cells. 1,25-vitD3-induced differentiation reduced the proliferative response to CM from several cell lines in MC3T3-E1 and MG63 to a minor degree, whereas in AHTO-7 cells the osteoblastic reaction was reduced for 2/4 pancreatic, 3/3 colon and 1/1 renal cancer CMs, however not for 3/3 prostate cancer CMs. Stimulation of AHTO-7 cells by CM from prostate cancer lines is inhibited significantly by MEK1 kinase inhibitor PD 98059 in contrast to CMs derived from other carcinomas, except ACHN renal cancer cells. The findings in the present study demonstrate that human AHTO-7 cells seem to represent a valid human system to monitor osteoblastic activity, especially in respect to 1,25-vitD3-induced differentiation. Vitamin D3-induced differentiation has no direct effect on prostate cancer-derived osteoblastic activity in the same cell line in vitro, which however, could be reversed by disruption of the signal transduction at the MAP kinase level, revealing a new target for the inhibition of prostate cancer-associated bone formation.
OBJECTIVES This study evaluated intracardiac angiotensin-converting enzyme inhibition as an adjuvant to cardioplegia and examined its effects on hemodynamic, metabolic, and ultrastructural postischemic outcomes. METHODS The experiments were performed with an isolated, erythrocyte-perfused, rabbit working-heart model. The hearts excised from 29 adult New Zealand White rabbits (2950 +/- 200 g) were randomly assigned to four groups. Two groups received quinaprilat (1 microg/mL), initiated either with cardioplegia (n = 7) or during reperfusion (n = 7). The third group received l-arginine (2 mmol/L) initiated with cardioplegia (n = 7). Eight hearts served as a control group. Forty minutes of preischemic perfusion were followed by 60 minutes of hypothermic arrest and 40 minutes of reperfusion. RESULTS All treatments substantially improved postischemic recovery of external heart work (62% +/- 6%, 69% +/- 3%, and 64% +/- 5% in quinaprilat during cardioplegia, quinaprilat during reperfusion, and l-arginine groups, respectively, vs 35% +/- 5% in control group, P <.001) with similarly increased external stroke work and cardiac output. When administered during ischemia, quinaprilat significantly improved recovery of coronary flow (70% +/- 8%, P =.028 vs quinaprilat during reperfusion [49% +/- 5%] and P =.023 vs control [48% +/- 6%]). l-Arginine (55% +/- 7%) showed no significant effect. Postischemic myocardial oxygen consumption remained low in treatment groups (4.6 +/- 1.2 mL. min(-1). 100 g(-1), 6.0 +/- 2.2 mL. min(-1). 100 g(-1), and 4.7 +/- 1.6 mL. min(-1). 100 g(-1) in quinaprilat during cardioplegia, quinaprilat during reperfusion, and l-arginine groups, respectively, vs 4.2 +/- 0.8 mL. min(-1). 100 g(-1) in control group), even though cardiac work was markedly increased. High-energy phosphates, which were consistently elevated in all treatment groups, showed a significant increase in adenosine triphosphate with quinaprilat during ischemia (2.24 +/- 0.14 micromol/g vs 1.81 +/- 0.12 micromol/g in control group, P =.040). Ultrastructural grading of mitochondrial damage revealed best preservation with quinaprilat during ischemia (100% [no damage], P =.001 vs control). CONCLUSION These experimental findings have clinical relevance regarding prevention of postoperative myocardial stunning and low coronary reflow in patients undergoing heart surgery.
Objective: This study evaluates the effects of diltiazem administered during reperfusion on hemodynamic, metabolic, and ultrastructural postischemic outcome. Methods: Hearts of 38 adult White New Zealand rabbits underwent 60 min of global cold ischemia followed by 40 min of reperfusion in an erythrocyte perfused isolated working heart model. Hearts were randomly assigned to four groups and received diltiazem (0.1, 0.25, and 0.5 mumol/l) during reperfusion only, or served as control. Results: The postischemic time courses of heart rate, aortic flow, and external stroke work clearly reflected the dose-dependent negative chronotropic and inotropic efficacy of diltiazem in the two higher concentrations. High energy phosphates (HEP) determined from myocardial biopsies taken after 40 min of reperfusion were significantly better preserved in all treatment groups compared to control hearts. Similarly ultrastructural grading of mitochondria and myofilaments revealed a significant reduction of reperfusion injury in hearts that received diltiazem compared to control. Conclusions: Diltiazem protects mitochondrial integrity and function, thereby preserving myocardial HEP levels. Only low dose diltiazem (.0.1 mumol/l) during reperfusion combines both, optimal mitochondrial preservation with minimal changes in hemodynamics. (C) 2002 Elsevier Science B.V. All rights reserved.
Aromatic fatty acids such as phenylbutyrate (PB) and its metabolite phenylacetate (PA) induce growth arrest, differentiation and apoptosis in solid tumor cells. Despite their antiproliferative action they were reported to exhibit a synergistic effect in combination with cytotoxic drugs like topotecan, and others. Since the activity of the camptothecines (CPTs) depends on local pH conditions, we investigated, whether PB/PA modulate CPT effects indirectly by affecting intracellular pH in SW620 and SW480 colon cancer cells. The results for the colon carcinoma cells show an antagonistic interaction for the combination of CPT and 0.25-5 mM PA in viability assays, resulting in an approximately 3-fold increase in IC50 (control: 20+/-7 nM). A synergistic effect with significantly increased numbers of late apoptotic/necrotic cancer cells (difference +21+/-4%) and 1.4-fold sensitization were detected upon inclusion of 2.5 mM PA during a 4-h CPT (10 micro;M) loading phase. In response to 0.25-1 mM PA/PB the cells exhibit a reversible decrease of pHi (0.1-0.31 pH units) in HEPES- or bicarbonate-buffered media. Dose-dependent acidification and pHi-recovery occurred following addition of PA and PB after an acid load and inhibition of the Na+/H+-antiporter and bicarbonate exchangers, pointing to a possible intracellular mechanism of cytoplasmic acidification. It is concluded that the synergistic modulation of CPT toxicity by short-term PA/PB treatment in colon carcinoma cells is caused by changes in intracellular pH, possibly affecting quantity and localization of the active closed lactone form of this drug.
BACKGROUND:Prostate cancer metastases induce a predominantly osteoblastic response in bone tissue, resulting in new bone formation and associated morbidity; however, the mechanisms of these tumor-host responses are not fully understood.MATERIALS AND METHODS:Supernatants of prostate (PC3, DU145, LNCaP), breast (BT20, ZR-75-1), colon (SW620, Colo 320DM), pancreatic (ASPC1, Capan-1), renal cell (ACHN) and hepatoma (HepG2) cell lines were tested for their capacity to modulate proliferation, activity of alkaline phosphatase (ALP) and CD99/MIC2 expression in AHTO-7 (large T antigen transfected human trabecular osteoblasts) cells in vitro.RESULTS:Osteoblastic stimulation is not restricted to prostate cancer derived conditioned media CM and high activity is found in CM from Capan-1, HepG2 and ACHN lines. Furthermore these CM down-regulate the expression of the CD99/MIC2 antigen in comparison to medium by AHTO-7 cells as detected by HBA-71 immunofluorescence, with the exception of prostate cancer-derived CM. Induction of the differentiation marker ALP was detected in response to CM derived from Capan-1, BT-20 and Colo320DM. Stimulation of the proliferation of AHTO-7 cells (105-138% of control), induction of ALP (1.17-5.29-fold) and down-regulation of CD99 (13.6-57.5%) exhibited no correlation. CM derived from PC3 and LNCaP metastatic prostate cancer cell lines specifically resulted in the retention/stimulation of the expression of CD99/MIC2 in AHTO-7 cells in contrast to all other cell lines tested.CONCLUSION:The CD99/MIC2 antigen, which is expressed on human osteoblasts and osteosarcoma cells, seems to constitute a new and independent response marker of osteoblasts in the triggering of osteoblastic reaction by prostate cancer cells.
In this second part of our study, the histomorphologic changes occurring in the patellar tendon (PT) of rats after sole stress-shielding were evaluated. In seven adult albino rats, both PTs were exposed by straight skin incision and then stress-shielded on one side by a cerclage, while the contralateral PT served as the sham-operated control. One animal died after the operation and was used as a negative control. After 10 weeks of otherwise unrestricted motion, the rats were killed, and the histomorphology of all PT specimen pairs compared by light and transmission electron microscopy. Light microscopy showed mid-portion thickening and irregularity of collagen bundles in the stress-shielded tendons. Intense remodelling was demonstrated by increased cellularity and vascularity, as well as by enrichment in acidic proteoglycans. Ultrastructural evaluation and morphometry revealed a predominance of large diameter (peak between 180 and 260 nm) collagen fibrils in the sham-operated controls, while in the stress-shielded tendons the number of apparently new, small-diameter (peak between 40 and 60 nm) collagen fibrils increased (up to 77% per cross-sectional field of view). The difference in peak diameters was statistically significant (p < 0.0005). This rat model demonstrated that sole stress-shielding not only causes biomechanical alterations, but also intense tissue remodelling and significant morphological changes in the collagen fibrils in the patellar tendon, comparable to so-called 'ligamentization' in experimental and clinical patellar tendon grafts for anterior cruciate ligament reconstruction.
Previous studies demonstrated the disinfecting potential of Nd:YAG laser irradiation on the root canal system from an overall quantitative viewpoint. The aim of this study was to evaluate the specific effect of irradiation through dentin on gram‐negative and gram‐positive bacteria with regard to their cell structure.
Due to the limited number of donor organs, death on the waiting list and waiting time for cardiac transplantation have markedly increased. A pressing need of appropiate selection criteria for patients who would benefit most from transplantation is apparent. The purpose of this study is to identify pre- and early postoperative risk factors that influence long term survival after cardiac transplantation. 702 consecutive patients who underwent cardiac transplantation between 3/1984 and 12/1997 were analyzed retrospectively for the influence of different pre- and early postoperative risk factors on early (30 days) and late death (5 years). Univariate and multivariate regression analysis revealed risk factors for early as well as late death. Predictors of early death were higher preoperative PVR, retransplantation, longer ischemic time, postoperative acute kidney failure and longer intubation time. Risk factors for late death were early transplant era, previous cardiac surgery, patients awaiting transplantation in a hospital, prolonged stay in an intensive care unit, and any rejection during the first month after transplantation. These results demonstrate that pre- and early postoperative risk factors have significant inluence on early and long term survival.
Zuckermann, Andreas1; Ploner, Meinhard1; Mallinger, Robert1; Czerny, Martin1; Riha, Marcus1; Wolner, Ernst1; Grimm, Michael1; Laufer, Günther1 Author Information
In recent years a series of trials has sought to define the optimal protocol for everolimus-based immunosuppression in heart transplantation, with the goal of minimizing exposure to calcineurin inhibitors (CNIs) and harnessing the non-immunosuppressive benefits of everolimus. Randomized studies have demonstrated that immunosuppressive potency can be maintained in heart transplant patients receiving everolimus despite marked CNI reduction, although very early CNI withdrawal may be inadvisable. A potential renal advantage has been shown for everolimus, but the optimal time for conversion and the adequate reduction in CNI exposure remain to be defined. Other reasons for use of everolimus include a substantial reduction in the risk of cytomegalovirus infection, and evidence for inhibition of cardiac allograft vasculopathy, a major cause of graft loss. The ongoing MANDELA study is a 12-month multicenter, randomized, open-label, parallel-group study in which efficacy, renal function and safety are compared in approximately 200 heart transplant patients. Patients receive CNI therapy, steroids and everolimus or mycophenolic acid during months 3 to 6 post-transplant, and are then randomized at month 6 post-transplant (i) to convert to CNI-free immunosuppression with everolimus and mycophenolic acid or (ii) to continue reduced-exposure CNI, with concomitant everolimus. Patients are then followed to month 18 post-transplant The rationale and expectations for the trial and its methodology are described herein.
AIM Different trephination methods may lead to differences in degree of tissue damage and endothelial cell loss, which both influence the outcome of penetrating keratoplasty. Light, transmission, and scanning electron microscopy were used to compare the ultrastructural appearance of the cut edges and the endothelial cell loss in 26 human corneal donor buttons obtained by trephination with the suction fixated guided trephine system (GTS) and with the free hand posterior punch technique (PPT). METHODS Human corneas were stored between 5 and 14 days in Optisol. One cornea from each pair was used for each technique. Trephinations (7.5 mm) were performed either from the anterior direction with the GTS (n=13) or from the posterior direction with the PPT (n=13) using Pharmacia Superblade trephines. Light microscopy, transmission electron, and scanning electron microscopy were performed according to standard procedures. Widening of the cut edges and the extent of endothelial cell loss were measured at three different areas per corneal button and analysed statistically. RESULTS In contrast with the PPT, the GTS trephine produced considerable fibrillar disorder at the cut edges of the corneal buttons. The distance to which the endothelial cell loss extended from the edges of the cuts was significantly (p<0.001) lower for the GTS (42.2 (SD 50.8) μm from the edge) than for the PPT (109.3 (68.1) μm). Stromal widening at the edges (measured as percentage increase in stromal thickness, compared with the thickness of the central cornea) was observed with both techniques. However, the mean stromal widening produced by the GTS was significantly greater than that produced by PPT (106% (24%)v 69% (21%); p<0.002). CONCLUSION Both trephination techniques produced only minor tissue damage. Nevertheless, there were distinct differences in the fine appearance of the cuts produced by the GTS and the PPT techniques. The extent of the fibrillar dislocation and stromal widening was greater at the edges of the GTS buttons. The GTS technique produced significantly less endothelial cell loss at the cut edges than did the free hand punching technique, PPT.
Resveratrol, a natural phytoestrogen, has been reported to promote differentiation of murine MC3T3-E1 osteoblasts and to inhibit proliferation of prostate cancer cell lines. In the present study we tested the effects of resveratrol on the increased proliferation of human AHTO-7 osteoblastic cell line induced by conditioned media (CM) from a panel of carcinoma cell lines. This compound was found to modulate AHTO-7 proliferation in a tamoxifen-sensitive mechanism at lower concentrations, but failed to induce the osteoblast differentiation marker alkaline phosphatase (ALP) in contrast to vitamin D3. The proliferative response of AHTO-7 cells to conditioned media from carcinoma cell lines was diminished (30-71.4% inhibition) upon pretreatment with 0.5 microM resveratrol. Highest inhibition was demonstrated for pancreas (BxPC3, Panc-1), breast (ZR75-1) and renal (ACHN) carcinoma cell line supernatants whereas the effect on colon carcinoma (SW620, Colo320DM) cell CM and prostate cancer (PC3, DU145 and LNCaP) CM was less pronounced. Direct addition of resveratrol affected only supernatants of cell lines (<25% inhibition) exhibiting growth stimulatory activity for normal WI-38 lung fibroblasts. Resveratrol inhibited proliferation of DU145 and LNCaP cells in concentrations exceeding 5 microM, altered cell cycle distribution of all prostate cancer cell lines in concentrations as low as 0.5 microM, but did not inhibit the production of osteoblastic factors by these lines. In conclusion, resveratrol failed to induce ALP activity as marker of osteoblast differentiation in human osteoblastic AHTO-7 cells, however, inhibited their response to osteoblastic carcinoma-derived growth factors in concentrations significantly lower than those to reduce growth of cancer cells, thus effectively modulating tumor - osteoblast interaction.
Abstract Mycophenolic acid (MPA) is nowadays in broad clinical use as a substitute for azathioprine. An immunoassay for MPA recently received approval for clinical applications. The high performance liquid chromatography (HPLC) assay for measuring MPA and its glucuronide conjugate (MPAG) we describe here is not only rapid and simple but also extremely sensitive at plasma levels obtained during standard immunosuppressive regimens. The determination of MPAG is possible without any change of the chromatographic conditions (detection wavelength of 214 nm, mobile phase: acetonitrile and 50 mmol/l o-phosphoric acid (50:50, V/V), run time: 15 min). The required equipment is a standard HPLC system including a simple UV-detector. Sample volume of 400 μl is required for both determinations. Detection limit is 0.25 μmol/l for MPA and 5 μmol/l for MPAG. Linearity is excellent for serial dilutions (0.5–25 μmol/l for MPA, 25–500 μmol/l for MPAG) and high accuracies favour the method described. More than 2000 plasma samples tested for MPA in patients after heart transplantation within one year and more than 500 samples for MPAG underline the clinical applicability of this assay.
Limited data exist that compare the predominant cardiac preservation solutions (CPSs).The United Network for Organ Sharing database was retrospectively reviewed from January 1, 2004 to March 31, 2018, for donor hearts. Of 34,614 potential donors, 21,908 remained after applying the exclusion criteria. The CPS analyzed included saline, the University of Wisconsin (UW), cardioplegia, Celsior, and Custodiol. The primary endpoints were recipient survival and posttransplant rejection. Logistic and Cox models were used to quantify survival endpoints.Saline was used as the CPS in 2549 patients (12%), UW in 10,549 (48%), cardioplegia in 1307 (6%), Celsior in 5081 (23%), and Custodiol in 2422 (11%). Donor age ranged from 15 to 68 y (mean = 32.0 y, median = 30.0 y), and 71% were male. Adjusted survival probabilities of recipients whose donor hearts were procured with saline was 96% 30 d, 90% 1 y, UW: 97% 30 d, 92% 1 y, cardioplegia: 95% 30 d, 87% 1 y, Celsior: 96% 30 d, 90% 1 y, and Custodiol: 97% 30 d, 92% 1 y. When these comparisons were adjusted for donor age, sex, ethnicity, ischemic time, recipient age, sex, ethnicity, creatinine, ventricular assist device (VAD), length of stay, region and days on waiting list, cardioplegia solution was demonstrated to have a higher risk of death (30 d, 1 y, overall) and posttransplant rejection versus UW (odds ratio 1.70, P = 0.001; odds ratio 1.63, P < 0.001; hazard ratio 1.22, P < 0.001; hazard ratio 1.21, P < 0.001, respectively).Cardioplegia solutions for cardiac preservation are associated with a higher mortality in heart transplant recipients.