Eliminating exposure to aqueous solvents is necessary for the early detection and ultrastructural elemental analysis of sites of calcium and phosphorus enrichment in mineralizing UMR106-01 osteoblastic cultures

The mechanism underlying the mineralization of bone is well studied and yet it remains controversial. Inherent difficulties of imaging mineralized tissues and the aqueous solubility of calcium and phosphate, the 2 ions which combine to form bone mineral crystals, limit current analyses of labile diffusible, amorphous, and crystalline intermediates by electron microscopy. To improve the retention of calcium and phosphorus, we developed a pseudo nonaqueous processing approach and used it to characterize biomineralization foci, extracellular sites of hydroxyapatite deposition in osteoblastic cell cultures. Since mineralization of UMR106-01 osteoblasts is temporally synchronized and begins 78 h after plating, we used these cultures to evaluate the effectiveness of our method when applied to cells just prior to the formation of the first mineral crystals. Our approach combines for the first time 3 well-established methods with a fourth one, i.e. dry ultrathin sectioning. Dry ultrathin sectioning with an oscillating diamond knife was used to produce electron spectroscopic images of mineralized biomineralization foci which were high-pressure frozen and freeze substituted. For comparison, cultures were also treated with conventional processing and wet sectioning. The results show that only the use of pseudo nonaqueous processing was able to detect extracellular sites of early calcium and phosphorus enrichment at 76 h, several hours prior to detection of mineral crystals within biomineralization foci.

Expression and localization pattern of ABCA1 in diverse human placental primary cells and tissues

The ATP-binding cassette transporter A1 (ABCA1) mediates the transport of cholesterol, phospholipids, and other lipophilic molecules across cellular membranes. Recent data provide evidence that ABCA1 plays an important role in placental function but the exact cellular sites of ABCA1 action in the placenta remain controversial. To clarify this issue, we analyzed the cellular and subcellular localization of ABCA1 with immunocytochemistry, immunofluorescence and subsequent confocal or immunofluorescence microscopy in different types of isolated primary placenta cells: cytotrophoblast cells, amnion epithelial cells, villous macrophages (Hofbauer cells), and mesenchymal cells isolated from chorionic membrane and placental villi. After 12 h of cultivation, primary cytotrophoblast cells showed intensive membrane and cytoplasmic staining for ABCA1. After 24 h, with progressive syncytium formation, ABCA1 staining intensity was markedly reduced and ABCA1 was dispersed in the cytoplasm of the forming syncytial layer. In amnion epithelial cells, placental macrophages and mesenchymal cells, ABCA1 was predominantly localized at the cell membrane and cytoplasmic compartments partially corresponding to the endoplasmic reticulum. In these cell types, the ABCA1 staining intensity was not dependent on the cultivation time. In conclusion, ABCA1 shows marked expression levels in diverse placental cell types. The multitopic localization of ABCA1 in diverse human placental cells not all directly involved in materno-fetal exchange suggests that this protein may not only participate in transplacental lipid transport but could have additional regulatory functions.

Impact of CD39 and purinergic signalling on the growth and metastasis of colorectal cancer

Despite improvements in prevention and management of colorectal cancer (CRC), uncontrolled tumor growth with metastatic spread to distant organs remains an important clinical concern. Genetic deletion of CD39, the dominant vascular and immune cell ectonucleotidase, has been shown to delay tumor growth and blunt angiogenesis in mouse models of melanoma, lung and colonic malignancy. Here, we tested the influence of CD39 on CRC tumor progression and metastasis by investigating orthotopic transplanted and metastatic cancer models in wild-type BALB/c, human CD39 transgenic and CD39 deficient mice. We also investigated CD39 and P2 receptor expression patterns in human CRC biopsies. Murine CD39 was expressed by endothelium, stromal and mononuclear cells infiltrating the experimental MC-26 tumors. In the primary CRC model, volumes of tumors in the subserosa of the colon and/or rectum did not differ amongst the treatment groups at day 10, albeit these tumors rarely metastasized to the liver. In the dissemination model, MC-26 cell line-derived hepatic metastases grew significantly faster in CD39 over-expressing transgenics, when compared to CD39 deficient mice. Murine P2Y2 was significantly elevated at both mRNA and protein levels, within the larger liver metastases obtained from CD39 transgenic mice where changes in P2X7 levels were also noted. In clinical samples, lower levels of CD39 mRNA in malignant CRC tissues appeared associated with longer duration of survival and could be linked to less invasive tumors. The modulatory effects of CD39 on tumor dissemination and differential levels of CD39, P2Y2 and P2X7 expression in tumors suggest involvement of purinergic signalling in these processes. Our studies also suggest potential roles for purinergic-based therapies in clinical CRC.

Stereoselective determination of drugs and metabolites in body fluids, tissues and microsomal preparations by capillary electrophoresis (2000-2010)

During the past two decades, chiral capillary electrophoresis (CE) emerged as a promising, effective and economic approach for the enantioselective determination of drugs and their metabolites in body fluids, tissues and in vitro preparations. This review discusses the principles and important aspects of CE-based chiral bioassays, provides a survey of the assays developed during the past 10 years and presents an overview of the key achievements encountered in that time period. Applications discussed encompass the pharmacokinetics of drug enantiomers in vivo and in vitro, the elucidation of the stereoselectivity of drug metabolism in vivo and in vitro, and bioanalysis of drug enantiomers of toxicological, forensic and doping interest. Chiral CE was extensively employed for research purposes to investigate the stereoselectivity associated with hydroxylation, dealkylation, carboxylation, sulfoxidation, N-oxidation and ketoreduction of drugs and metabolites. Enantioselective CE played a pivotal role in many biomedical studies, thereby providing new insights into the stereoselective metabolism of drugs in different species which might eventually lead to new strategies for optimization of pharmacotherapy in clinical practice.

Postreperfusion cardiac arrest and resuscitation during orthotopic liver transplantation: dynamic visualization and analysis of physiologic recordings

We recently reported on the Multi Wave Animator (MWA), a novel open-source tool with capability of recreating continuous physiologic signals from archived numerical data and presenting them as they appeared on the patient monitor. In this report, we demonstrate for the first time the power of this technology in a real clinical case, an intraoperative cardiopulmonary arrest following reperfusion of a liver transplant graft. Using the MWA, we animated hemodynamic and ventilator data acquired before, during, and after cardiac arrest and resuscitation. This report is accompanied by an online video that shows the most critical phases of the cardiac arrest and resuscitation and provides a basis for analysis and discussion. This video is extracted from a 33-min, uninterrupted video of cardiac arrest and resuscitation, which is available online. The unique strength of MWA, its capability to accurately present discrete and continuous data in a format familiar to clinicians, allowed us this rare glimpse into events leading to an intraoperative cardiac arrest. Because of the ability to recreate and replay clinical events, this tool should be of great interest to medical educators, researchers, and clinicians involved in quality assurance and patient safety.

Binding sites of muscarinic and adrenergic receptors in gastrointestinal tissues of dairy cows suffering from left displacement of the abomasum

Muscarinic acetylcholine (M) and adrenergic (AR) receptors mediate gastrointestinal motility. Using radioligand binding assays and real-time polymerase chain reaction, the densities of binding sites and mRNA levels of M(2), M(3), alpha(2AD)- and beta(2)-AR were compared in muscle tissues from the abomasal fundus, pylorus, duodenum, caecum, and external loop of the spiral colon of eight cows with left displacement of abomasum (LDA), and of eight healthy cows. Specific binding of the [(3)H]-ligands to each of the four receptors was competitive and saturable. Binding sites of M(2) (all intestinal sites), M(3) (duodenum and caecum), and of alpha(2AD)-AR (abomasal fundus) were lower (P<0.05) in cows with LDA than in healthy cows. The coefficients of correlation between binding sites and mRNA transcripts of receptors were dissimilar in cows with LDA and healthy cows. The decrease in densities of M (intestine) and of alpha(2AD)-AR (abomasum) receptors suggests their implication in the impairment of motility associated with or leading to LDA.

Immediate and delayed transplantation of mesenchymal stem cells improve muscle force after skeletal muscle injury in rats

Mesenchymal stem cell (MSC) therapy is a promising approach for regaining muscle function after trauma. Prior to clinical application, the ideal time of transplantation has to be determined. We investigated the effects of immediate and delayed transplantation. Sprague-Dawley rats received a crush trauma to the left soleus muscle. Treatment groups were transplanted locally with 2 × 10(6) autologous MSCs, either immediately or 7 days after trauma. Saline was used as sham therapy. Contraction force tests and histological analyses were performed 4 weeks after injury. GFP-labelled MSCs were followed after transplantation. The traumatized soleus muscles of the sham group displayed a reduction of twitch forces to 36 ± 17% and of tetanic forces to 29 ± 11% of the non-injured right control side, respectively. Delayed MSC transplantation resulted in a significant improvement of contraction maxima in both stimulation modes (twitch, p = 0.011; tetany, p = 0.014). Immediate transplantation showed a significant increase in twitch forces to 59 ± 17% (p = 0.043). There was no significant difference in contraction forces between muscles treated by immediate and delayed cell transplantation. We were able to identify MSCs in the interstitium of the injured muscles up to 4 weeks after transplantation. Despite the fundamental differences of the local environment, which MSCs encounter after transplantation, similar results could be obtained with respect to functional muscle regeneration. We believe that transplanted MSCs residing in the interstitial compartment evolve their regenerative capabilities through paracrine pathways. Our data suggest a large time window of the therapeutical measures.

Six-year follow-up of azathioprine and mycophenolate mofetil use during the first 6 months of renal transplantation

Long-term follow-up examination to test whether therapy with mycophenolate mofetil (MMF) or azathioprine (AZA) during the first year translates into different graft or patient survival and graft function is important. Therefore, 6-year follow-up data of a group of 80 consecutive renal transplant recipients were analyzed. The first group of 40 patients was treated with AZA, cyclosporine and prednisone and the second group with MMF, cyclosporine and prednisone for the first 6 months. Graft failure rates were compared during follow-up. Creatinine, inverse slope of creatinine (delta/creatinine) and 24-hour proteinuria at 6 years post transplantation were compared. The Kaplan-Meier analyses for death-censored and non-censored graft failure showed no difference between the groups. Creatinine values at 6 years for the AZA Group were 139 +/- 36 micromol/l (95% CI 125.9-151.2 micromol/l) and for the MMF Group 149 +/- 52 micromol/l (95% CI 133.9-164.9 micromol/l). Delta/creatinine and 24-hour proteinuria at 6 years did not differ between the two groups. We conclude that an initial 6-month treatment with MMF as opposed to AZA reduced the early rejection rate, but did not result in superior long-term graft function or survival after 6 years of follow-up observation.

Hypothetical mortality risk associated with spiral tomography of the maxilla and mandible prior to endosseous implant treatment

Radiation dose delivered from the SCANORA radiography unit during the cross-sectional mode for dentotangential projections was determined. With regard to oral implantology, patient situations of an edentulous maxilla and mandible as well as a single tooth gap in regions 16 and 46 were simulated. Radiation doses were measured between 0.2 and 22.5 mGy to organs and tissues in the head and neck region when the complete maxilla or mandible was examined. When examining a single tooth gap, only 8% to 40% of that radiation dose was generally observed. Based on these results, the mortality risk was estimated according to a calculation model recommended by the Committee on the Biological Effects of Ionizing Radiations. The mortality risk ranged from 31.4 x 10(-6) for 20-year-old men to 4.8 x 10(-6) for 65-year-old women when cross-sectional imaging of the complete maxilla was performed. The values decreased by 70% when a single tooth gap in the molar region of the maxilla was radiographed. The figures for the mortality risk for examinations of the complete mandible were similar to those for the complete maxilla, but the mortality risk decreased by 80% if only a single tooth gap in the molar region of the mandible was examined. Calculations according to the International Commission on Radiological Protection carried out for comparison did not reveal the decrease of the mortality risk with age and resulted in a higher risk value in comparison to the group of 35-year old individuals in calculations according to the Committee on the Biological Effects of Ionizing Radiations.

Hypothetical mortality risk associated with spiral computed tomography of the maxilla and mandible

In the present study, dose measurements have been conducted following examination of the maxilla and mandible with spiral computed tomography (CT). The measurements were carried out with 2 phantoms, a head and neck phantom and a full body phantom. The analysis of applied thermoluminescent dosimeters yielded radiation doses for organs and tissues in the head and neck region between 0.6 and 16.7 mGy when 40 axial slices and 120 kV/165 mAs were used as exposure parameters. The effective dose was calculated as 0.58 and 0.48 mSv in the maxilla and mandible, respectively. Tested methods for dose reduction showed a significant decrease of radiation dose from 40 to 65%. Based on these results, the mortality risk was estimated according to calculation models recommended by the Committee on the Biological Effects of Ionizing Radiations and by the International Commission on Radiological Protection. Both models resulted in similar values. The mortality risk ranges from 46.2 x 10.6 for 20-year-old men to 11.2 x 10(-6) for 65-year-old women. Using 2 methods of dose reduction, the mortality risk decreased by approximately 50 to 60% to 19.1 x 10(-6) for 20-year-old men and 5.5 x 10(-6) for 65-year-old women. It can be concluded that a CT scan of the maxillofacial complex causes a considerable radiation dose when compared with conventional radiographic examinations. Therefore, a careful indication for this imaging technique and dose reduction methods should be considered in daily practice.

Posttraumatic stress disorder after implantation of a mechanical assist device followed by heart transplantation: evaluation of patients and partners

AIM: We sought to investigate the prevalence of posttraumatic stress disorder, anxiety, and depression in patients and their partners after implantation of a mechanical assist device as a bridge to heart transplantation. METHODS: This was a retrospective assessment of 41 patients (age 46.3 +/- 12.0 years; male-female ratio, 38:3; time since transplantation, 55.3 +/- 34.2 months [range, 7-122 months) and 27 partners (male-female ratio 2:25) by standardized instruments (Impact of Event Scale, Hospital Anxiety and Depression Scale), in 2 University Heart Transplant Centers (Vienna, Austria, Munster, Germany). The duration of the support systems (MicroMed DeBakey-VAD in 17 patients, Novacor in 10, Thoratec in 8, TCI HeartMate in 5, and Berlin Heart Incor in 1 patient) ranged from 28 to 711 (176 +/- 146) days. RESULTS: None of the patients, but 23% of the partners (n = 6), met the criteria for posttraumatic stress disorder (Maercker cutoff >0). The Impact of Event Scale (IES) sum scales differed significantly between the 2 groups (21.2 +/- 15.1, mean +/- SD) for the patients versus 38.1 +/- 27.8 for the partners, respectively; P = .001). Two percent of the patients, but 19% of the partners, showed mild to moderate depression; 4% of patients, but 23% of their partners, reported mild to moderate anxiety. None of the results were significantly influenced by the time since transplantation, patient age, diagnoses, type of assist device, or indication for heart transplantation. CONCLUSIONS: Despite patients being much closer to a life threat, their partners experience significantly more psychologic distress even in the long run. Our findings highlight the need for attention to the supporting persons.