Cell therapy prevents structural, functional and molecular remodeling of remote non-infarcted myocardium

Background/objectives: Therapy using bone marrow (BM) cells has been tested experimentally and clinically due to the potential ability to restore cardiac function by regenerating lost myocytes or increasing the survival of tissues at risk after myocardial infarction (MI). In this study we aimed to evaluate whether BM-derived mononuclear cell (MNC) implantation can positively influence the post-MI structural remodeling, contractility and Ca(2 +)-handling proteins of the remote non-infarcted tissue in rats. Methods and results: After 48 h of MI induction, saline or BM-MNC were injected. Six weeks later, MI scars were slightly smaller and thicker, and cardiac dilatation was just partially prevented by cell therapy. However, the cardiac performance under hemodynamic stress was totally preserved in the BM-MNC treated group if compared to the untreated group, associated with normal contractility of remote myocardium as analyzed in vitro. The impaired post-rest potentiation of contractile force, associated with decreased protein expression of the sarcoplasmic reticulum Ca2 +-ATPase and phosphorylated-phospholamban and overexpression of Na(+)/Ca(2 +) exchanger, were prevented by BM-MNC, indicating preservation of the Ca(2 +) handling. Finally, pathological changes on remodeled remote tissue such as myocyte hypertrophy, interstitial fibrosis and capillary rarefaction were also mitigated by cell therapy. Conclusions: BM-MNC therapy was able to prevent cardiac structural and molecular remodeling after MI, avoiding pathological changes on Ca(2 +)-handling proteins and preserving contractile behavior of the viable myocardium, which could be the major contributor to the improvements of global cardiac performance after cell transplantation despite that scar tissue still exists.

Giant cell tumor of bone: risk factors for recurrence

Many surgeons treat giant cell tumor of bone (GCT) with intralesional curettage. Wide resection is reserved for extensive bone destruction where joint preservation is impossible or when expendable sites (eg, fibular head) are affected. Adjuvants such as polymethylmethacrylate and phenol have been recommended to reduce the risk of local recurrence after intralesional surgery. However, the best treatment of these tumors and risk factors for recurrence remain controversial.

Close-to-native ultrastructural preservation by high pressure freezing

The objective of modern transmission electron microscopy (TEM) in life science is to observe biological structures in a state as close as possible to the living organism. TEM samples have to be thin and to be examined in vacuum; therefore only solid samples can be investigated. The most common and popular way to prepare samples for TEM is to subject them to chemical fixation, staining, dehydration, and embedding in a resin (all of these steps introduce considerable artifacts) before investigation. An alternative is to immobilize samples by cooling. High pressure freezing is so far the only approach to vitrify (water solidification without ice crystal formation) bulk biological samples of about 200 micrometer thick. This method leads to an improved ultrastructural preservation. After high pressure freezing, samples have to be subjected to follow-up procedure, such as freeze-substitution and embedding. The samples can also be sectioned into frozen hydrated sections and analyzed in a cryo-TEM. Also for immunocytochemistry, high pressure freezing is a good and practicable way.

Preserving middle lobe to improve lung function in non-small-cell lung cancer

When a lung tumor arises in segment 6, the close anatomical relationship to the middle lobe bronchus may make a lower bilobectomy necessary. Sleeve lobectomy may be an alternative. These procedures were compared retrospectively in 36 patients operated on between January 2005 and December 2006 with non-small-cell lung cancer (stage I-IIIB) of the right lower lobe. Sleeve lobectomy was performed in 21 patients and bilobectomy in 15 (41%). Preoperative lung function was comparable in both groups. Radical resection was achieved in 34/36 patients. Operation time was 121 min for sleeve lobectomy and 144 min for bilobectomy. Chest tubes were removed after 5 days in both groups. Postoperative lung function was better after sleeve lobectomy than bilobectomy (forced expiratory volume in 1st sec: 78% vs. 69%). Preservation of the middle lobe by sleeve lobectomy is feasible. There was no evidence that this resection was less radical, and complication rates were similar in both groups.

Elevated levels of endocannabinoids in chronic hepatitis C may modulate cellular immune response and hepatic stellate cell activation.

The endocannabinoid (EC) system is implicated in many chronic liver diseases, including hepatitis C viral (HCV) infection. Cannabis consumption is associated with fibrosis progression in patients with chronic hepatitis C (CHC), however, the role of ECs in the development of CHC has never been explored. To study this question, anandamide (AEA) and 2-arachidonoyl glycerol (2-AG) were quantified in samples of HCV patients and healthy controls by gas and liquid chromatography mass spectrometry. Fatty acid amide hydrolase (FAAH) and monoaclyglycerol lipase (MAGL) activity was assessed by [3H]AEA and [3H]2-AG hydrolysis, respectively. Gene expression and cytokine release were assayed by TaqMan PCR and ELISpot, respectively. AEA and 2-AG levels were increased in plasma of HCV patients, but not in liver tissues. Hepatic FAAH and MAGL activity was not changed. In peripheral blood mononuclear cells (PBMC), ECs inhibited IFN-γ, TNF-α, and IL-2 secretion. Inhibition of IL-2 by endogenous AEA was stronger in PBMC from HCV patients. In hepatocytes, 2-AG induced the expression of IL-6, -17A, -32 and COX-2, and enhanced activation of hepatic stellate cells (HSC) co-cultivated with PBMC from subjects with CHC. In conclusion, ECs are increased in plasma of patients with CHC and might reveal immunosuppressive and profibrogenic effects.

Retinal Cell Death Caused by Sodium Iodate Involves Multiple Caspase-Dependent and Caspase-Independent Cell-Death Pathways

Herein, we have investigated retinal cell-death pathways in response to the retina toxin sodium iodate (NaIO3) both in vivo and in vitro. C57/BL6 mice were treated with a single intravenous injection of NaIO3 (35 mg/kg). Morphological changes in the retina post NaIO3 injection in comparison to untreated controls were assessed using electron microscopy. Cell death was determined by TdT-mediated dUTP-biotin nick end labeling (TUNEL) staining. The activation of caspases and calpain was measured using immunohistochemistry. Additionally, cytotoxicity and apoptosis in retinal pigment epithelial (RPE) cells, primary retinal cells, and the cone photoreceptor (PRC) cell line 661W were assessed in vitro after NaIO3 treatment using the ApoToxGlo™ assay. The 7-AAD/Annexin-V staining was performed and necrostatin (Nec-1) was administered to the NaIO3-treated cells to confirm the results. In vivo, degenerating RPE cells displayed a rounded shape and retracted microvilli, whereas PRCs featured apoptotic nuclei. Caspase and calpain activity was significantly upregulated in retinal sections and protein samples from NaIO3-treated animals. In vitro, NaIO3 induced necrosis in RPE cells and apoptosis in PRCs. Furthermore, Nec-1 significantly decreased NaIO3-induced RPE cell death, but had no rescue effect on treated PRCs. In summary, several different cell-death pathways are activated in retinal cells as a result of NaIO3.

Comparative Cytotoxicity Study of Silver Nanoparticles (AgNPs) in a Variety of Rainbow Trout Cell Lines (RTL-W1, RTH-149, RTG-2) and Primary Hepatocytes.

Among all classes of nanomaterials, silver nanoparticles (AgNPs) have potentially an important ecotoxicological impact, especially in freshwater environments. Fish are particularly susceptible to the toxic effects of silver ions and, with knowledge gaps regarding the contribution of dissolution and unique particle effects to AgNP toxicity, they represent a group of vulnerable organisms. Using cell lines (RTL-W1, RTH-149, RTG-2) and primary hepatocytes of rainbow trout (Oncorhynchus mykiss) as in vitro test systems, we assessed the cytotoxicity of the representative AgNP, NM-300K, and AgNO3 as an Ag+ ion source. Lack of AgNP interference with the cytotoxicity assays (AlamarBlue, CFDA-AM, NRU assay) and their simultaneous application point to the compatibility and usefulness of such a battery of assays. The RTH-149 and RTL-W1 liver cell lines exhibited similar sensitivity as primary hepatocytes towards AgNP toxicity. Leibovitz's L-15 culture medium composition (high amino acid content) had an important influence on the behaviour and toxicity of AgNPs towards the RTL-W1 cell line. The obtained results demonstrate that, with careful consideration, such an in vitro approach can provide valuable toxicological data to be used in an integrated testing strategy for NM-300K risk assessment.

A combined measure for quantifying and qualifying the topology preservation of growing self-organizing maps

The Self-OrganizingMap (SOM) is a neural network model that performs an ordered projection of a high dimensional input space in a low-dimensional topological structure. The process in which such mapping is formed is defined by the SOM algorithm, which is a competitive, unsupervised and nonparametric method, since it does not make any assumption about the input data distribution. The feature maps provided by this algorithm have been successfully applied for vector quantization, clustering and high dimensional data visualization processes. However, the initialization of the network topology and the selection of the SOM training parameters are two difficult tasks caused by the unknown distribution of the input signals. A misconfiguration of these parameters can generate a feature map of low-quality, so it is necessary to have some measure of the degree of adaptation of the SOM network to the input data model. The topologypreservation is the most common concept used to implement this measure. Several qualitative and quantitative methods have been proposed for measuring the degree of SOM topologypreservation, particularly using Kohonen's model. In this work, two methods for measuring the topologypreservation of the Growing Cell Structures (GCSs) model are proposed: the topographic function and the topology preserving map

Telomerase expression and activity are coupled with myocyte proliferation and preservation of telomeric length in the failing heart

The role and even the existence of myocyte proliferation in the adult heart remain controversial. Documentation of cell cycle regulators, DNA synthesis, and mitotic images has not modified the view that myocardial growth can only occur from hypertrophy of an irreplaceable population of differentiated myocytes. To improve understanding the biology of the heart and obtain supportive evidence of myocyte replication, three indices of cell proliferation were analyzed in dogs affected by a progressive deterioration of cardiac performance and dilated cardiomyopathy. The magnitude of cycling myocytes was evaluated by the expression of Ki67 in nuclei. Ki67 labeling of left ventricular myocytes increased 5-fold, 12-fold, and 17-fold with the onset of moderate and severe ventricular dysfunction and overt failure, respectively. Telomerase activity in vivo is present only in multiplying cells; this enzyme increased 2.4-fold and 3.1-fold in the decompensated heart, preserving telomeric length in myocytes. The contribution of cycling myocytes to telomerase activity was determined by the colocalization of Ki67 and telomerase in myocyte nuclei. More than 50% of Ki67-positive cells expressed telomerase in the overloaded myocardium, suggesting that these myocytes were the morphological counterpart of the biochemical assay of enzyme activity. Moreover, we report that 20–30% of canine myocytes were telomerase competent, and this value was not changed by cardiac failure. In conclusion, the enhanced expression of Ki67 and telomerase activity, in combination with Ki67-telomerase labeling of myocyte nuclei, support the notion that myocyte proliferation contributes to cardiac hypertrophy of the diseased heart.

Planktonic foraminiferal preservation in Plio/Pleistocene sediments from the western equatorial Atlantic and Caribbean

Records of mean sortable silt and planktonic foraminiferal preservation from the Ceará Rise (western equatorial Atlantic) and from the Caribbean are presented to analyze the Pliocene (3.5-2.2 Ma) to Pleistocene (1.6-0.3 Ma) evolution of near-bottom current strength and the carbonate corrosiveness of deep water. During the mid-Pleistocene climate transition (~1 Ma) a drastic decrease in glacial bottom current strength and an increase in carbonate corrosiveness is registered, demonstrating a substantial decrease in the glacial contribution of the Lower North Atlantic Deep Water (LNADW) to the Atlantic Ocean. Also, an increased sensitivity to eccentricity orbital forcing is registered after the MPT. By contrast, carbonate preservation increases considerably in the deep Caribbean in response to a strong and persistent stable contribution of Upper North Atlantic Deep Water (UNADW). We found evidence for the strongest and most stable circulation within the LNADW cell during the Northern Hemisphere cooling period between ~3.2 and 2.75 Ma. This is in agreement with the 'superconveyor model' which postulates that the highest NADW production took place prior to ~2.7 Ma. A considerable decrease in bottom current strength and planktonic foraminiferal preservation is observed synchronous with the first occurrence of large-scale continental ice sheets in the Northern Hemisphere. This documents the final termination of the 'superconveyor' at ca. 2.75 Ma. However, our data do not support a 'superconveyor' in the interval between 3.5 and 3.2 Ma when high-amplitude fluctuations in bottom current flow and preservation in planktonic foraminifera are observed. Because of the great sensitivity of NADW production to changes in surface water salinity, we assume that the high-amplitude fluctuations of LNADW circulation prior to ~3.2 Ma are linked to changes in the Atlantic salinity budget. After 2.75 Ma they are primarily controlled by ice-sheet forcing. In contrast to the stepwise deterioration of planktonic foraminiferal preservation in the western deep Atlantic, a trend toward better preservation from the Pliocene to Pleistocene is observed in the deep Caribbean. This indicates a long-term increase in the contribution of UNADW to the Atlantic Ocean.

Exercise and the endothelial cell

Regular exercise is known to be effective in the prevention and treatment of cardiovascular disease. Among the cardioprotectant mechanisms influenced by exercise, the endothelium is becoming recognised as a major target. Preservation of endothelial cell structure is vital for frictionless blood flow, prevention of macrophage and lipid infiltration and, ultimately, optimal vascular function. Exercise causes various kinds of mechanical, chemical and thermal stresses, and repeated exposure to these stresses may precondition the endothelial cell to future stresses through a number of different mechanisms. This review discusses stress-induced changes in endothelial cell morphology, biochemistry and components of platelet activation and cell adhesion that impact on endothelial cell structure. An enhanced understanding of the effects of exercise on the endothelial cell will assist in directing future research into the prevention of cardiovascular disease. (c) 2004 Elsevier Ireland Ltd. All rights reserved.

Total pharyngolaryngectomy for squamous cell carcinoma of the hypopharynx: A review

Objectives. To evaluate our experience with total pharyngolaryngectomy in the treatment of hypopharyngeal squamous cell carcinoma. Study Design: Retrospective analysis of consecutively treated patients in an academic otolaryngology, head and neck department. Methods. One hundred eighty patients who had total pharyngolaryngectomy performed for hypopharyngeal carcinoma were included in this study. Patients with a history of previous head and neck cancer were excluded. Clinicopathologic parameters were recorded and survival calculated using the Kaplan-Meier method. Results. One hundred sixty-two (90%) of the patients were male, and the patients had a mean age of 62 years. The majority (91%) of patients had advanced overall clinical stage disease (stage 3,4). Thirty-one (17.8%) and 43 (24%) patients developed locoregional and metastatic disease recurrence, respectively. The 2- and 5-year disease-specific survival rates were 72% and 52%, respectively. Advanced nodal stage, perineural invasion, lymphovascular invasion, and positive margins were predictors of poor survival on univariate analysis, and lymphovascular invasion was an independent prognostic factor on multivariate analysis. Conclusion: Surgery and postoperative radiotherapy remains the treatment against which other modalities should be compared for advanced stage hypopharyngeal squamous cell carcinoma.

Preservation of nitric oxide availability as nitrite and nitrosothiols

Nitric Oxide (NO) has been known for long to regulate vessel tone. However, the close proximity of the site of NO production to "sinks" of NO such as hemoglobin (Hb) in blood suggest that blood will scavenge most of the NO produced. Therefore, it is unclear how NO is able to play its physiological roles. The current study deals with means by which this could be understood. Towards studying the role of nitrosothiols and nitrite in preserving NO availability, a study of the kinetics of glutathione (GSH) nitrosation by NO donors in aerated buffered solutions was undertaken first. Results suggest an increase in the rate of the corresponding nitrosothiol (GSNO) formation with an increase in GSH with a half-maximum constant EC50 that depends on NO concentration, thus indicating a significant contribution of NO2 mediated nitrosation in the production of GSNO. Next, the ability of nitrite to be reduced to NO in the smooth muscle cells was evaluated. The NO formed was inhibited by sGC inhibitors and accelerated by activators and was independent of O2 concentration. Nitrite transport mechanisms and effects of exogenous nitrate on transport and reduction of nitrite were examined. The results showed that sGC can mediate nitrite reduction to NO and nitrite is transported across the smooth muscle cell membrane via anion channels, both of which can be attenuated by nitrate. Finally, a 2-D axisymmetric diffusion model was constructed to test the accumulation of NO in the smooth muscle layer from reduction of nitrite. It was observed that at the end of the simulation period with physiological concentrations of nitrite in the smooth muscle cells (SMC), a low sustained NO generated from nitrite reduction could maintain significant sGC activity and might affect vessel tone. The major nitrosating mechanism in the circulation at reduced O2 levels was found to be anaerobic and a Cu+ dependent GSNO reduction activity was found to deliver minor amounts of NO from physiological GSNO levels in the tissue.