bluuebunny/crossref_metadata_2025 huggingface dataset:
Problems and solutions in myoblast transfer therapy
Authors: Smythe Gayle M. , Hodgetts Stuart I. , Grounds Miranda D.
Published: May 2007

Duchenne muscular dystrophy is a severe X‐linked neuromuscular disease that affects approximately 1/3500 live male births in every human population, and is caused by a mutation in the gene that encodes the muscle protein dystrophin. The characterization and cloning of the dystrophin gene in 1987 was a major breakthrough and it was considered that simple replacement of the dystrophin gene would ameliorate the severe and progressive skeletal muscle wasting characteristic of Duchenne muscular dystrophy. After 20 years, attempts at replacing the dystrophin gene either experimentally or clinically have met with little success, but there have been many significant advances in understanding the factors that limit the delivery of a normal dystrophin gene into dystrophic host muscle. This review addresses the host immune response and donor myoblast changes underlying some of the major problems associated with myoblast‐mediated dystrophin replacement, presents potential solutions, and outlines other novel therapeutic approaches.
Abnormalities of platelet aggregation in chronic myeloproliferative disorders
Authors: Avram Simona , Lupu Anca , Angelescu Silvana , Olteanu Nicoleta , Mut‐Popescu Delia
Published: May 2007

A large variety of platelet dysfunctions has been described in chronic myeloproliferative disorders. These abnormalities may be due to deficiency of platelet granules, arahidonic acid metabolism defects or platelet membrane glycoproteins abnormalities. In this study we intend to detect the incidence of platelet function defects in 76 patients with various types of chronic myeloproliferative disorders. The platelet activity was studied in vitro by measuring platelet aggregation in response to ADP, epinephrine, collagen, arachidonic acid and ristocetin. These results were subsequently correlated with bleeding time and clinical aspects (bleeding or thrombosis). We found complex changes in platelet response with all agonists, in varied proportions. These abnormalities include absent, decreased or abnormal platelet aggregation response. In a few cases we found a markedly decreased, almost absent platelet response to all agonists while in some patients a normal platelet aggregation was noted. The correlation between these results and template bleeding time, thrombotic or hemorrhagic events and the type of diseases was difficult to establish and sometimes conflictual. Despite this fact, we consider that investigating platelet aggregation may be useful not only for the assesment of the hemostatic balance in chronic myeloproliferative disorders but also for a better insight into cell abnormalities occuring in these pathologic conditions.
Fibroblast growth factors in myocardial ischemia / reperfusion injury and ischemic preconditioning
Authors: Cuevas P. , Carceller F. , Giménez‐Gallego G.
Published: May 2007

Angiogenic growth factors such as fibroblast growth factors (FGFs) are currently in clinical trials for accelerating blood vessel formation in myocardial and limb ischemic conditions. However, recent experimental evidence suggests that FGFs can also participate as endogenous cardioprotective agents. In this report, the current knowledge for FGFs implication in myocardial ischemic tolerance will be summarized. Pharmacologic preconditioning with drugs as FGFs that mimic the beneficial effects of ischemic preconditioning could lead to novel therapeutic approaches for the treatment of ischemic disorders including myocardial infarction and stroke.
Cardiac apoptosis: from organ failure to allograft rejection
Authors: Hinescu M. E.
Published: May 2007

Cardiac myocyte apoptosis has been extensively studied in the last few years. Increased interest in the field stems from the hope that pharmacological manipulation of apoptosis may become a valuable tool for preventing excessive cell death observed in different pathological conditions. This paper is not intended as a comprehensive overview of current research about life and death in the cardiovascular system, but rather as a concise update on new developments in areas that were highlighted in a recent series of excellent reviews. A short inventory of unsolved issues concerning the significance of cardiac myocyte loss through apoptosis in both physiological and pathological circumstances is addressed.
Can a mixed damage interfere with DNA‐prottein cross‐links repair?
Authors: Marzano Christine , Severin Emilia , Bordin Franco
Published: May 2007

Some photochemical and photobiological properties of 4,5′,8‐trimethylpsoralen (TMP) have been studied in comparison with 1,4,6,8‐tetramethyl‐2H‐furo[2,3‐h]quinolin‐2 one (FQ) and 8‐methoxypsoralen (8‐MOP). TMP and FQ can photobind to mammalian cell DNA in vivo, by UVA irradiation, forming DNA‐protein cross‐links (DPC), but only TMP shows a strong capacity of inducing interstrand cross‐links (ISC). The mechanism of DPC formation was studied using the double irradiation method in Chinese hamster ovary (CHO) cells, and DPC were detected by alkaline elution. Both TMP and FQ induce covalent diadducts linking together DNA and proteins. Studying the formation of double strand breaks (DSB) in CHO cells we observed that TMP induced a low amount of DSB, similar to 8‐MOP. TMP and 8‐MOP induced chromosomal aberrations in CHO cells to the same extent, while FQ appeared to be more active. Our data suggest that the ISC induced by TMP could trap enzymes involved in DPC repair.
Effects of synovial fluid on the respiratory burst of granulocytes in rheumatoid arthritis
Authors: Bostan M. , Brasoveanu L. I. , Livescu A. , Manda G. , Neagu M. , Iordachescu D.
Published: May 2007

Neutrophil infiltration in the synovia is an important feature of the local inflammatory process associated with rheumatoid arthritis. The present study is focused on the effects exerted in vitro by the synovial fluid versus serum on the respiratory burst of granulocytes isolated either from blood or synovial fluid of rheumatoid arthritis patients. The respiratory burst was evaluated as superoxide anion release, by lucigenin‐amplified chemiluminescence. Our data show that the respiratory burst of granulocytes isolated from rheumatoid arthritis patients might trigger a significant oxidative stress both in periphery and the inflamed joint. These cells show no pathological pattern when activated in vitro by the chemotactic peptide fMLP, heterologous synovial fluid or serum. Acellular synovial fluid amplifies the superoxide anion release induced by fMLP more than the corresponding serum, indicating that a bacterian infection in the joint might enhance the oxidative damage in the inflamed synovium.
Apolipoprotein E: a major piece in the Alzheimer's disease puzzle
Authors: Cedazo‐Mínguez A. , Cowburn R. F.
Published: May 2007

Alzheimer's disease (AD) is a complex neurodegenerative disorder with multiple etiologies. The presence of the E4 isoform of apolipoprotein E (apoE) has been shown to increase the risk and to decrease the age of onset for AD and is the major susceptibility factor known for the disease. ApoE4 has been shown to intensify all the biochemical distrubances characteristic of AD, including beta amyloid (Aβ) deposition, tangle formation, neuronal cell death, oxidative stress, synaptic plasticity and dysfunctions of lipid homeostasis and cholinergic signalling. In contrast, other apoE isoforms are protective. Here we review and discuss these major hypotheses of the apoE4‐AD association.
The total peroxyl radical trapping potential in serum ‐ an assay to define the stage of atherosclerosis
Authors: Niculescu L. , Stancu Camelia , Sima Anca , Toporan Daniela , Simionescu Maya
Published: May 2007

Lipid peroxides were identified among the factors that contribute to the atherosclerotic plaque formation in the arterial wall. We hypothesised that a correlation may exist between the content of antioxidant constituents in the serum and the gravity of atherosclerosis. To this purpose, we have determined the serum total peroxyl radical‐ trapping potential (TRAP), which is the combined capacity of all antioxidants to neutralize free radicals in serum and followed its variation in hyperlipemic animals in correlation with the stage of atherosclerosis. In addition, we compared TRAP values in the sera of coronary heart disease (CHD) patients, with or without type II diabetes mellitus. Results showed that after 18 weeks of hyperlipemic diet, the mean TRAP values measured in sera isolated from hyperlipemic hamsters exhibited an about 44% decrease, in good agreement with the increase of serum cholesterol and triglycerides. In the 3 groups of CHD patients, TRAP values decreased with about 10% in sera of stable angina patients, 20% in unstable patients, as compared with normal subjects. The lowest TRAP values were detected in the sera of patients with acute myocardial infarction. The results obtained for different experimental animals and for CHD patients sera indicate that the TRAP method, as adapted in our laboratory, is a reliable and reproducible assay, fit to be used in clinical studies as an ex vivo measurable parameter that correlates with the stage of the atherosclerosis.
Cell viability of retinal photoreceptor evaluated by polar distribution of Ca2+ and electrical charge
Authors: Kovács Eugenia , Pilarczyk G. , Monajembashi Shamci , Moraru Roxana Pologea , Greulich K. O.
Published: May 2007

The polar organisation is characteristic to the living cell and disappears with the cell functional decay. Here we report experimental evidence that frog retinal photoreceptor rod cell shows a polar distribution of the electrical charge and of free cytosolic Ca2+ along its length. Retinal rod cells were loaded with Calcium sensitive dye (Green 1) and examined under fluorescence microscopy coupled with an image analysis system. In addition, suspension of rod cells was placed in direct current electric field for electrical polarity assessment. Both polar Ca2+ and electrical charge distribution can be objectively measured and quantified providing thus a fine test for cell viability. Such a test is required in checking the functional integrity of photoreceptors used in rentinal transplant.
Maintenance of size and function of influenza virus hemagglutinin specific transgenic T‐cell clone during life
Authors: Radu D. L. , Weksler M. E. , Bona C. A.
Published: May 2007

Immunization induces less protective immunity against infectious diseases in old compared to young subjects. We have studied the effect of age on the in vitro and in vivo function of murine transgenic T cells expressing a receptor for influenza hemagglutinin 110‐120 peptide. During aging the transgenic T cells undergo the age‐associated shift from naive to memory phenotype but maintain, despite thymic involution, their number as well as their cytokine production and proliferative responses induced by the hemagglutinin 110‐120 peptide in vitro. The maintenance of the size and functions of transgenic T cells during the aging may be related to low expression of CTLA‐4 molecules known to exhibit a negative regulatory effect subsequent to interaction with costimulatory molecules as well as of stimulation of T cells by unknown cross reactive endogenous factors but not by nominal antigen since innate immunity prevents natural infection with influenza virus of murine species. This suggests that the impaired immunity induced by immunization in old subjects reflects defects in the development and maintenance of T cell memory and not in the expression of effector activity.
Apoptosis in human embryo development: 3. Fas‐induced apoptosis in brian primary cultures
Authors: Nat Roxana , Radu E. , Regalia T. , Popescu L. M.
Published: May 2007

Fas (APO‐1/CD95) is an important apoptotic mediator for both immune and nervous systems. In the present study, we have investigated the expression and function of Fas in human embryonic/fetal brain primary cultures from 12 human embryos and fetuses with gestational ages between 5 to 22 weeks. Anti‐Fas fluorescent antibody was used for labeling of Fas positive cells and for quantitation of Fas expression in brain cultures. To demonstrate that Fas receptor is functional in human embryonic/fetal brain cells, anti‐Human‐Fas monoclonal antibody (0.5 μg/ml) was used to induce apoptosis in brain primary cultures. Apoptosis was investigated by flow‐cytometry and fluorescent microscopy using TUNEL and annexin V labeling. Fas was found to be expressed in the embryonic/fetal human primary brain cultures, on neuronal and glial cells or their precursors, varying with gestational ages. Cross‐linking of Fas induced apoptosis in brain cultures indicating that Fas receptor functions as a death receptor. We also showed that cell death triggered through Fas receptor was caspase dependent, hence it was blocked by a selective caspase‐8 inhibitor (IETD‐fmk).These results suggest that Fas is involved in neuronal apoptosis in the developing human brain.
Classification of thymic epithelial neoplasms: a controversial issue coming to an end?
Authors: Kuo Tseng‐Tong
Published: May 2007

The classification of thymic epithelial neoplasms has been one of the most controversial issues in tumor pathology. There are two opposing schools of pathologists holding different views regarding the classification of thymic epithelial neoplasms. One school of pathologists believe that histological classification of thymomas is not possible or useful. Another school of pathologists believe that thymomas can be histologically subclassified despite their complex histomorphology and that these histological subtypes correlate with their aggressiveness and clinical behavior. A compromised histological classification has been established by World Health Organization (WHO) to designate thymic epithelial neoplasms with letters and numbers. This classification should be adopted internationally to facilitate the communication among concerned pathologists and oncologists. A simple histological classification of thymomas based on cytomorphology and supported by cytokeratin expressions is proposed and compared to the WHO and Müller‐Hermelink's histogenetic classifications.
Cytochromes P450 and experimental models of drug metabolism
Authors: Zuber R. , Anzenbacherová Eva , Anzenbacher P.
Published: May 2007

For the development of new drugs, evaluation of drug‐drug interactions with already known compounds, as well as for better understanding of metabolism pathways of various toxicants and pollutants, we studied the drug metabolism mediated by cytochromes P450. The experimental approach is based on animal drug‐metabolising systems. From the ethical as well as rational reasons, the selection of an appropriate system is crucial. Here, it is necessary to decide on the basis of expected CYP system involved. For CYP1A‐mediated pathways, all the commonly used experimental models are appropriate except probably the dog. On the contrary, the dog seems to be suitable for modelling of processes depending on the CYP2D. With CYP2C, which is possibly the most large and complicated subfamily, the systems based on monkey (Maccacus rhesus) may be a good representative. The CYP3A seems to be well modelled by pig or minipig CYP3A29. Detailed studies on activities with individual isolated CYP forms are needed to understand in full all aspects of inter‐species differences and variations.
APOE polymorphism and clinical duration determine regional neuropathology in Swedish APP670, 671 mutation carriers: implications for late‐onset Alzheimer's disease
Authors: Bogdanovic N. , Corder Elizabeth , Lannfelt L. , Winblad B.
Published: May 2007

Neurofibrillary changes throughout the brain were investigated for three relatives who carried the Swedish APP670,671 mutation which causes overproduction of Aβ40 and Aβ42. They differed in terms of APOE genotype, age at the onset of dementia, and disease duration (P1: ɛ2/3, age 57, 11 years; P2: ɛ2/3, age 61, 5 years; P3: ɛ4/4, age 44, 12 years). For each subject, paraffin‐embedded sections from diverse anatomically and cytoarchitectonically well‐preserved regions were stained using the modified Bielschowsky method. Neurofibrillary tangles (NFT) and neuritic plaques (NP) were counted, and the area occupied by plaque estimated (%NP). In addition, sections from the medial frontal gyrus were stained with monoclonal antibodies to APOE. The regional patterns of neurofibrillary changes were consistent with those for late‐onset AD. Longer disease duration was associated with further accumulations in earlier‐affected areas, with superficial cortical layers consistently containing higher %NP than deep layers. APOE ɛ4/4 was associated with deeper limbic and frontal NFT, with an excess of NP (especially in the outer parietal cortex) which stained heavily for APOE ‐ as well as with very early onset. APP670,671 mutation carriers demonstrate regional brain neurofibrillary changes characteristic of late‐onset Alzheimer's disease with evidence for more Aβ deposition for ɛ4/4 than ɛ2/3. This raises the possibility that early Braak Stage I‐II lesions might also follow this pattern of promotion.
Apoptosis in the immune system: 1. Fas‐induced apoptosis in monocytes‐derived human dendritic cells
Authors: Nat Roxana , Radu E. , Regalia T. , Popescu L. M.
Published: May 2007

Dendritic cells (DC) are cells of the hematopoietic system specialized in capturing antigens and initiating T cell‐mediated immune responses. We show here that human DC generated from adherent peripheral blood mononuclear cells (PBMC) after in vitro stimulation with granulocyte macrophage colony stimulating factor (GM‐CSF) and interleukin‐4 (IL‐4) express Fas antigen (APO‐1, CD95) and can undergo apoptosis upon triggering of Fas by monoclonal antibodies. Immature monocytes‐derived dendritic cells (MDDC) upregulate CD86 and HLA‐DR expression and develop dendrites and veiled processes. Flow cytometry analysis revealed CD95 expression in approx. 40% of these MDDC and incubation with anti‐CD95 mAb (0.5μg/ml) induced apoptosis when compared to untreated controls. The extent of apoptosis induced by the agonist anti‐Fas antibody strongly related to the percentage of cells expressing CD 95. Upon tumor necrosis factor α (TNF‐α) additional stimulation, MDDC assumed a characteristic mature dendritic cells morphology showing prolonged veils, CD83 expression, and high levels of HLA‐DR. These cells have downregulated their Fas receptors (to approx. 20%) and undergo apoptosis to a lesser extent when treated with anti‐CD 95, as demonstrated by the hardly noticeable effect of this antibody on the viability of cultured cells as compared to controls. Thus, upon TNF‐α induced maturation, MDDC became resistant to Fas‐induced apoptosis. The apoptotic episodes surrounding the earlier stage of DC differentiation appeared to be mediated by Fas. In contrast, a Fas independent pathway is probably responsible for the apoptotic events associated with terminally differentiated DC.
The adenylosuccinate synthetase‐1 gene is activated in the hypertrophied heart
Authors: Wen H. Y. , Xia Y. , Young M. E. , Taegtmeyer H. , Kellems R. E.
Published: May 2007

Adenylosuccinate synthetase 1 (ADSS1) functions as an important component in adenine nucleotide biosynthesis and is abundant in the heart. Here we report that the Adssl gene is up‐regulated in two in vivo rodent models of surgically induced cardiac hypertrophy. In addition, we examined an in vitro hypertrophy system of rat neonatal cardiomyocytes treated with angiotensin II to study Adssl gene regulation. We show that this stimulus triggers a signaling cascade that results in the activation of the Adssl gene. The induction of Adssl gene expression was blocked by cyclosporin A in vitro, suggesting that calcineurin, a calmodulin activated phosphatase, is involved in this signaling pathway. Consistent with this view we provide evidence that the induction of Adss1 by angiotension II requires the presence of an NFAT binding site located 556 base pairs upstream of the Adssl transcription start site. We propose that ADSS1 plays a role in the development of cardiac hypertrophy through its function in adenine nucleotide biosynthesis.
Comparative study of some energetic and steric parameters of the wild type and mutants HIV‐1 protease: a way to explain the viral resistance
Authors: Avram Speranta , Movileanu L. , Mihailescu D. , Flonta Maria‐Luiza
Published: May 2007

Because, in vivo, the HIV‐1 PR (HIV‐1 protease) present a high mutation rate we performed a comparative study of the energetic behaviors of the wild type HIV‐1 PR and four type of mutants: Val82/Asn; Val82/Asp; Gln7/Lys, Leu33/Ile, Leu63/Ile; Ala71/Thr, Val82/Ala. We suggest that the energetic fluctuation (electrostatic, van der Waals and torsion energy) of the mutants and the solvent accessible surface (SAS) values can be useful to explain the viral resistance process developed by HIV‐1 PR. The number and localization of enzyme mutations induce important modifications of the van der Waals and torsional energy, while the electrostatic energy has an insignificant fluctuation. We showed that the viral resistance can be explored if the solvent accessible surfaces of the active site for the mutant structures are calculated. In this paper we have obtained the solvent accessible surface for a group of 15 mutants (11 mutants obtained by Protein Data Bank (PDB) file, 4 mutants modeled by CHARMM software) and for the wild type HIV‐1 PR). Our study try to show that the number and localization of the mutations are factors which induce the HIV‐1 PR viral resistance. The larger solvent accessible surface could be recorded for the point mutant Val 82/Phe.
Potentiation of angiogenic response by ischemic and hypoxic reconditioning of the heart
Authors: Maulik Nilanjana , Das D. K.
Published: May 2007

This review is intended to discuss the newly discovered role of preconditioning which should make it an attractive therapeutic stimulus for repairing the injured myocardium. We recently found that apart from rendering the myocardium tolerant to ischemic reperfusion injury, preconditioning also potentiates angiogenesis. Our study demonstrated for the first time that both ischemic and hypoxic preconditioning triggered myocardial angiogenesis at the capillary and arteriolar levels which nicely corroborated with the improved myocardial contractile function.Hypoxic preconditioning resulted in the stimulation of VEGF, the most potent angiogenic factor known to date. In concert, endothelial cell specific tyrosine kinase receptors, Tie 1, Tie 2 and Flt‐1 and Flk‐1 were also significantly enhanced in the preconditioned myocardium. The redox‐regulated transcription factor NFkB was found to play an essential role in the preconditioning regulation of angiogenesis
Regulation of apoptosis by the ubiquitin and proteasome pathway
Authors: Wójcik Cezary
Published: May 2007

Regulated proteolysis plays important roles in cell physiology as well as in pathological conditions. In most of the cases, regulated proteolysis is carried out by the ubiquitin‐ and proteasome‐dependent proteolytic system, which is also in charge of the bulk of cytoplasmic proteolysis. However, apoptosis or the process of programmed cell death is regulated by a different proteolytic system, i.e. by caspases, a family of specialized cysteine proteases. Nevertheless, there is plenty of evidence of a crosstalk between the apoptotic pathways and the ubiquitin and proteasome system, whose function in apoptosis appears to be very complex. Proteasome inhibitors induce apoptosis in multiple cell types, while in other they are relatively harmless or even prevent apoptosis induced by other stimuli. Proteasomes degrade specific proteins during apoptosis, but on the other hand some components of the proteasome system are degraded by caspases. The knowledge about the involvement of the ubiquitin‐ and proteasome‐dependent system in apoptosis is already clinically exploited, since proteasome inhibitors are being tested as experimental drugs in the treatment of cancer and other pathological conditions, where manipulation of apoptosis is desirable.
The study of CTLA‐4 and vitamin D receptor polymorphisms in the Romanian type 1 diabetes population
Authors: Guja C. , Marshall S. , Welsh K. , Merriman M. , Smith A. , Todd J. A. , Ionescu‐Tîrgoviste C.
Published: May 2007

Several studies suggested that part of the genetic susceptibility for Type 1 diabetes (TIDM) is encoded by some polymorphisms of CTLA‐4 gene (2q33) and of Vitamin D Receptor gene (VDR; 12q12‐14). Our aim was to assess their contribution to TIDM genetic susceptibility in the Romanian population. We typed CTLA‐4 49 A/G and VDR FokI (F/f), ApaI (A/a) and TaqI (T/t) polymorphisms by Sequence Specific Primer PCR (SSP‐PCR) in 204 Romanian diabetic families (756 individuals: 212 TIDM probands and 544 unaffected parents and siblings). We studied alleles transmission using the Transmission Disequilibrium Test (TDT). We found an increased transmission of CTLA‐4 49G allele to diabetics (54.8%, p=0.11). The transmission of F (56.1%, p=0.063), a (55.7%, p=0.061) and T (51.8%, p=0.37) alleles of VDR gene to diabetics was increased but did not reach statistical significance. In conclusion we found the same increased transmission of CTLA‐4 49 G allele to diabetics as previously reported. VDR FoqI F allele seems to be predisposing while TaqI T allele seems to be protective.
Image processing, diagnostic information extraction and quantitative assessment in pathology
Authors: Santinelli Alfredo , Mazzucchelli Roberta , Colanzi Paola , Tinca Antonela , Montironi Rodolfo
Published: May 2007

As we enter the information age we hold strong beliefs in the benefits of digital technology applied to pathology: numerical representation offers objectivity. Digital knowledge may indeed lead to significant information discovery, and, processing systems might be designed to allow a true evolution of capabilities. Questions arise whether the methodology underlying quantitative analysis provides the information that we need and whether it is appropriate for some of the problems encountered in diagnostic and prognostic histopathology. While one certainly would not dispute the value of statistical procedures, the clinical needs call for individual patient targeted prognosis.
Megamitochondria formation ‐ physiology and pathology
Authors: Wakabayashi T.
Published: May 2007

Mitochondria undergo structural changes simultaneously with their functional changes in both physiological and pathological conditions. These structural changes of mitochondria are classified into two categories: simple swelling and the formation of megamitochondria (MG). Data have been accumulated to indicate that free radicals play a crucial role in the mechanism of the MG formation induced by various experimental conditions which are apparently various. These include ethanol‐, chloramphenicol‐ and hydrazine‐induced MG formation. Involvement of free radicals in the mechanism of MG formation is showed by the fact that MG formation is successfully suppressed by free radical scavengers such as α‐tocopherol, coenzyme Q10, and 4‐OH‐TEMPO. Detailed mechanisms and pathophysiological meanings of MG formation still remain to be investigated. However, a body of evidence strongly suggests that enormous changes in physicochemical and biochemical properties of the mitochondrial membranes during MG formation take place and these changes are favorable for membrane fusion. A recent report showed that continous exposure of cells with MG to free radicals induces apoptosis, finding which suggests that MG formation is an adaptative process to unfavorable environments at the level of intracellular organelles. Mitochondria try to decrease intracellular reactive oxygen species (ROS) levels by decreasing the consume of oxygen via MG formation. If mitochondria succeed to suppress intracellular ROS levels, MG return to normal both structurally and functionally, and they restore the ability to actively synthesize ATP. If cells are additionally exposed to excess amounts of free radicals, MG become swollen, membrane potential of mitochondria (ΔΨm) decreases, cytochrome c is released from mitochondria, leading to activation of caspases and apoptosis is induced.
Activated c‐Met signals through PI3K with dramatic effects on cytoskeletal functions in small cell lung cancer
Authors: Maulik G. , Madhiwala P. , Brooks S. , Ma P. C. , Kijima T. , Tibaldi E. V. , Schaefer E. , Parmar K. , Salgia R.
Published: May 2007

Small cell lung cancer (SCLC) is an aggressive illness with early metastases. There are several receptor tyrosine kinases (RTKs) overexpressed in SCLC, including c‐Met. c‐Met contains an external semaphorin‐like domain, a cytoplasmic juxtamembrane domain, tyrosine kinase domain and multiple tyrosines that bind to adapter molecules. We have previously reported that c‐Met is abundantly expressed in the NCI‐H69 SCLC cell line and now have determined the downstream effects of stimulating c‐Met via its ligand hepatocyte growth factor (HGF). Utilizing unique phospho‐specific antibodies generated against various tyrosines of c‐Met, we show that Y1003 (binding site for c‐Cb1 and a negative regulatory site), Y1313 (binding site for PI3K), Y1230/Y1234/Y1235 (autophosphorylation site), Y1349 (binding site for Grb2), Y1365 (important in cell morphogenesis) are phosphorylated in response to HGF (40 ng/ml, 7.5 min) in H69 cells. Since multiple biological and biochemical effects are transduced through the PI3K pathway, we determine the role of PI3K in the c‐Met/HGF stimulation pathway. We initially determined that by inhibiting PI3K with LY294002 (50μM over 72 hours), there was at least a 55% decrease in viability of H69 cells. Since H69 SCLC cells form clusters in cell culture, we determined the effects of HGF and LY294002 on cell motility of the clusters by time‐lapse video microscopy. In response to HGF, SCLC moved much faster and formed more clusters, and this was inhibited by LY294002. Finally, we determined the downstream signal transduction of HGF stimulation of c‐Met with and without inhibition of c‐Met (with geldanamycin, an anisamycin antibiotic that inhibits c‐Met in SCLC) or PI3K (with LY294002). We show that association of c‐Met with PI3K and GAB2 is diminished by inhibiting c‐Met. In summary, activation of the c‐Met pathway targets the PI3K pathway in SCLC and this may be an important therapeutic target.
Dantrolene protects neurons against kainic acid induced apoptosis in vitro and in vivo
Authors: Popescu B. O. , Oprica M. , Sajin Maria , Stanciu Cristina L. , Bajenaru O. , Predescu Andreea , Vidulescu Cristina , Popescu L. M.
Published: May 2007

Apoptotic cell death induced by kainic acid (KA) in cultures of rat cerebellar granule cells (CGC) and in different brain regions of Wistar rat pups on postnatal day 21 (P21) was studied. In vitro, KA (100–500 μM) induced a concentration‐dependent loss of cell viability in MTT assay and cell death had apoptotic morphology as studied by chromatin staining with propidium iodide (PI). In vivo, twenty‐four hours after induction of status epilepticus (SE) by an intraperitoneal KA injection (5 mg/kg) we quantified apoptotic cells in hippocampus (CA1 and CA3), parietal cortex and cerebellum using PI staining and terminal deoxynucleotidyl transferase‐mediated dUTP nick end labeling (TUNEL) technique. We report that dantrolene, a specific ryanodine receptor antagonist, was able to significantly reduce the apoptotic cell death in CGC cultures and in hyppocampal CA1 and parietal cortex regions. Our finding can be valuable for neuroprotective therapy strategies in patients with repeated generalized seizures or status epilepticus.
Ex vivo differentiation of umbilical cord blood progenitor cells in the presence of placental conditioned medium
Authors: Chivu Mihaela , Diaconu Carmen C. , Brasoveanu Lorelei , Alexiu Irina , Bleotu Coralia , Banceanu G. , Miscalencu D. , Cernescu C.
Published: May 2007

Hematopoetic stem cells (HSC) are the progenitors for the lympho‐hematopoietic system, with long lifespan and high proliferation potential. Transplantation of HSC from bone marrow or peripheral blood represents a standard therapy in severe hematological conditions. A possible alternative source of HSC is the umbilical cord blood, prepared by various separation procedures followed by expansion in cultures supplemented with hematopoietic growth factors. In order to check the effects of placental conditioned medium (PCM) from placental cells culture upon viability of HSC, we added plasma, PCM, dimetil sulfoxyde or hemin in HSC cultures. Flow cytometry or direct scoring of solid cultures using CD45+, CD34+, CD71+ and CD14+ fluorescent‐labeled monoclonal antibodies evaluated the effects upon cell proliferation and colony forming ability of HSC cultures, versus controls. PCM produced the highest proliferation, followed by plasma, DMSO and hemin. PCM improved the survival time and maintained a higher proportion of immature cells. PCM stimulates the differentiation towards myeloid lineage progenitor cells (>90% being CD45+), increasing the percentage of CD14+, granulocites /monocytes precursors. It is highly suggestive that PCM contains growth factors or cytokines, which regulate the development of HSC. Characterization of these factors is in progress.
Significance of platelet‐activating factor acetylhydrolase in patients with non‐insulin‐dependent (type 2) diabetes mellitus
Authors: Serban M. , Tanaseanu Cristina , Kosaka T. , Vidulescu Cristina , Stoian Irina , Marta Daciana S. , Tanaseanu S. , Moldoveanu Elena
Published: May 2007

Background: Non‐insulin dependent diabetes mellitus (NIDDM) represents an independent risk factor for cardiovascular diseases (CVD), being characterized by a continnous low‐grade inflammation and endothelial activation state. Plasma platelet ‐ activating factor ‐ acetylhydrolases (PAF‐AHs) are a subgroup of Ca2+ ‐independent phospholipase A2 family (also known as lipoprotein‐associated phospholipases A2) that hydrolyze and inactivate the lipid mediator platelet‐activating factor (PAF) and/or oxidized phospholipids. This enzyme is considered to play an important role in inflammatory diseases and atherosclerosis. The present study aims to investigate the relations between the levels of PAF‐AH activity and LDL‐cholesterol/HDL‐cholesterol (LDL‐ch/HDL‐ch) ratio in NIDDM patients as compared to controls. Methods: serum PAF‐AH activity was measured in 50 patients with dyslipidemia, in 50 NIDDM patients and in 50 controls (normal lipid and glucose levels). Total cholesterol, LDL‐ch, HDL‐ch, triglyceride and blood glucose were determined in all subjects. Results: All NIDDM patients display hiperlipidemia, with increased LDL‐ch and triglyceride levels. There is a significant correlation between LDL‐ch levels (especially LDL‐ch / HDL‐ch ratio) and PAF‐AH activity in dyslipidemic and NIDDM patients. Conclusion: Diabetic and dyslipidemic patients have an increased plasma PAF‐AH activity correlated with their LDL‐ch levels and mainly with LDL‐ch / HDL‐ch ratio. Plasma PAF‐AH high levels appear to be important as a risk marker for endothelial dysfunction in patients with NIDDM.
Multiorgan dysfunction syndrome: how water might contribute to its progression
Authors: Lange H.
Published: May 2007

Mulitorgan dysfunction syndrome (MODS) is one of the most frequent conditions encountered in intensive‐care medicine. MODS is defined as total r partial loss oftwo or more organs with vital functions. The development of acute renal failure (ARF) in MODS leads to an additional aggravation with considerably higher hospital mortality than in other ICU patients with MODS. Whereas dissolved substances involved in the regulation of regional blood flow, endothelial cell injury, microvascular permeability, oxygnation, and nutrition of cells are at the focus of interest in MODS, hardly any scientific attention is paid to their main solvent water. An impaired renal water excretion and an icreased metabolic water volunme requiring exceetion interfere with diffusive and convective oxygen transport through the different fluid compartments. It will be shown first that the ratio of Uosm/Posm appears to be a reliable tools to assess overhydration in ARF. Secondly, the limits of urinary output in response to water intake will be considered. Furthermore, the metabolic water formation by an enhanced degradation of endogenous protein and fat will be discussed. Finally, the daily caloric intake is questioned with respect to energy expenditure and metabolic water formation.
Protein folding in the post‐genomic era
Authors: Yon Jeannine M.
Published: May 2007

Protein folding is a topic of fundamental interest since it concerns the mechanisms by which the genetic message is translated into the three‐dimensional and functional structure of proteins. In these post‐genomic times, the knowledge of the fundamental principles are required in the exploitation of the information contained in the increasing number of sequenced genomes. Protein folding also has practical applications in the understanding of different pathologies and the development of novel therapeutics to prevent diseases associated with protein misfolding and aggregation. Significant advances have been made ranging from the Anfinsen postulate to the “new view” which describes the folding process in terms of an energy landscape. These new insights arise from both theoretical and experimental studies. The problem of folding in the cellular environment is briefly discussed. The modern view of misfolding and aggregation processes that are involved in several pathologies such as prion and Alzheimer diseases. Several approaches of structure prediction, which is a very active field of research, are described.
Biomedical applications of protein chips
Authors: Ng Jocelyn H. , Ilag Leodevico L.
Published: May 2007

The development of microchips involving proteins has accelerated within the past few years. Although DNA chip technologies formed the precedent, many different strategies and technologies have been used because proteins are inherently a more complex type of molecule. This review covers the various biomedical applications of protein chips in diagnostics, drug screening and testing, disease monitoring, drug discovery (proteomics), and medical research. The proteomics and drug discovery section is further subdivided to cover drug discovery tools (on‐chip separations, expression profiling, and antibody arrays), molecular interactions and signaling pathways, the identification of protein function, and the identification of novel therapeutic compounds. Although largely focused on protein chips, this review includes chips involving cells and tissues as a logical extension of the type of data that can be generated from these microchips.
Targeting apoptosis in neurological disease using the herpes simplex virus
Authors: Perkins Dana
Published: May 2007

Herpes Simplex Viruses type 1 (HSV‐1) and 2 (HSV‐2) cause central nervous system (CNS) disease ranging from benign aseptic meningitis to fatal encephalitis. In adults, CNS infection with HSV‐2 is most often associated with aseptic meningitis while HSV‐1 frequently produces severe, focal encephalitis associated with high mortality and morbidity. Recent studies suggested that the distinct neurological outcome of CNS infection with the two viruses may be due to their distinct modulation of apoptotic cell death: HSV‐1 triggers neuronal apoptosis, while HSV‐2 is neuroprotective. Apoptosis also occurs in the etiology of neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and Down's syndrome, and determines the loss of specific neuronal populations and the decline in cognitive functions. Notwithstanding, the therapy of these disorders may rely on the use of replication‐defective HSV‐1 vectors to deliver anti‐apoptotic transgenes to the CNS. However, the recent discovery of a neuroprotective activity innate to the HSV‐2 genome (the ICP10 PK gene) suggests that: i) ICP10 PK may constitute a novel therapeutic approach by targeting both the apoptotic cell death and the cognitive decline, and ii) HSV‐2 may be more suitable than HSV‐1 as a vector for targeting neuronal disease.
Effects of oral supplement of L‐glutamine on diverted colon wall
Authors: Paulo F. L.
Published: May 2007

Diverted colorectal segments can present trophic and inflammatory changes. These alterations are of special importance in the patients whose colostomy becomes permanent, as well as in the differential diagnosis with other inflammatory diseases. This study was accomplished to quantify these alterations and to determine if oral supplement of L‐glutamine would avoid them. Twenty‐six adult male Wistar rats were distributed in three groups: control, colostomized and colostomized+L‐glutamine. The colostomized group received a loop colostomy. The colostomized+L‐glutamine group received a colostomy similar to the previous group and oral supplement of L‐glutamine. Partial volumes of all layers of the colonic wall were measured by image analysis stereology. The diversion caused a decrease of partial volumes of the mucosa and the epithelium as well, and also of the height of the intestinal crypts (p<0.05). There was an increase of partial volumes of the lamina propria, of the submucosa and of the muscularis mucosae vs controls (p<0.05). The partial volume of the muscularis propria didn't show significant alteration. The supplementation of L‐glutamine was effective in preventing the atrophy of mucosa and epithelium (p<0.05), also avoiding the increase of partial volumes of the submucosa and lamina propria (p<0.05). This supplement didn't change significantly the muscular layers. In conclusion, colostomy causes the atrophy of the colon wall, mainly due to the atrophy of the epithelium. The supplementation of L‐glutamine is able to avoid these changes.
Relationship between chromosomal changes complexity and disease aggressiveness in myeloid and lymphoid disorders
Authors: Lungeanu Agripina , Arghir Aurora , Lupu Anca , Popescu Delia Mut , Berbec Nicoleta
Published: May 2007

In this paper are presented four cases, with unusual chromosomal abnormalities, identified at the first presentation, among over 100 patients with myeloid and lymphoid acute and chronic leukemias cytogenetically investigated. The complexity and nature of cytogenetic abnormalities was in direct relationship with the disease evolution. The first case, a 22 years old man with acute lymphoblastic leukemia type L3, exhibited many structural changes in bone marrow cells with diploid number of chromosomes: del(3)(q26); del (5)(p13); t(8;14) (q24;q32); del(9)(p11q11);inv(15)(p12qter). The second case, a 62 years old woman, diagnosed as poorly differentiated acute leukemia, refractory to treatment, showed hiperdiploidy (48–54 chromosomes) and 3–4 markers derived from chromosomes 5 and 12. The third case, a young man of 27 years old, diagnosed as acute myeloid leukemia, apart of Philadelphia chromosome, presented trisomy 16, both in diploid and aneuploid cells. None of these three patients did respond to any medical therapy. Their rapid death was a powerful proof of the correlation between the complexity of genome changes and disease aggressiveness. In the fourth case, a constitutional translocation t(3;5)(q26.3;q21) identified in a 72 years old woman with essential thrombocythemia, appeared not to be involved in the etiology of the disease. In this case, the treatment with hydroxyurea was successful and the disease evolution was favourable. In conclusion, we appreciate that in the three cases of myeloid and lymphoid leukemias it was a direct relationship between the complexity of genomic changes and the aggressiveness of the disease.
Evaluation of the cholesterol influence in type II collagen‐induced arthritis in DBA/1J mice: an autoradiographic study
Authors: Hamer Erica R. , Apfel M.I.R. , Carvalho J.J. , Pereira M.J.S. , Levy R.A.
Published: May 2007

In order to verify the cholesterol influence in RA severity in DBA/1J mice, we quantified the cholesterol present in the knee joints of normal (N) and with collagen II induced arthritis (CIA). Forty male DBA/1J mice, were divided in normal (n=20) and CIA group (n=20). Mice in CIA group were injected with 100 μg of collagen II emulsified in Freund's complete adjuvant. Sixteen DBA/1J (8 N and 8 CIA) received an injection of 2.96 × 106 Bq of 3H‐cholesterol and were anesthetized and sacrificed. Semi‐fine sections were covered with LM‐1 emulsion, exposed for six weeks and developed. Collagen induced edema, erythema and dysfunction of knee joints in CIA group. Radioactive cholesterol was located more on the synovial membrane, where we found the greatest density of silver grains, significantly (P<0.0001) higher in group CIA vs. controls (61±2.3 × 18±0.7). We conclude that the cholesterol deposits on the synovial membrane is related to CIA severity.
Selective protection by phosphatidic acid against staurosporine‐induced neuronal apoptosis
Authors: Popescu A.T. , Vidulescu Cristina , Stanciu Cristina L. , Popescu B.O. , Popescu L.M.
Published: May 2007

Phosphatidic acid, the main product of lipid breakdown through phospholipase D activation, has been implicated in important signal transduction pathways able to influence cell fate in many ways. The purpose of this work was to determine possible effects of phosphatidic acid on neuronal cell death pathways. Here we used cerebellar granular cell cultures and cell death was triggered with either staurosporine or H2O2. Cell viability was quantified by spectrophotometry, using the 3‐ (4, 5‐dimethylthiazol‐2‐y1)‐2, 5‐diphenyl‐tetrazolium bromide (MTT) test. Staurosporine (1‐3 μM) or H2O2 (50‐800 μM) induced cell death in a dose‐dependent manner. Using fluorescent staining (propidium iodide or annexin V‐Cy3/6‐carboxyfluorescein) we showed that cell death was mostly apoptotic in staurosporine treated cells and mostly non‐apoptotic (necrotic) in H2O2 treated cells. Phosphatidic acid was able to increase cell viability in staurosporine‐, but not in H2O2 ‐ treated cells. We therefore conclude that phosphatidic acid has neuroprotective potential in neurons exposed to stimuli that trigger apoptosis.
Heart failure: a hemodynamic disorder complicated by maladaptive proliferative responses
Authors: Katz A. M.
Published: May 2007

Heart failure has traditionally been viewed as a hemodynamic syndrome characterized by fluid retention, high venous pressure, and low cardiac output. Over the past decade, however, it has become clear that because of deterioration and progressive dilatation (remodeling) of the diseased heart, this is also a rapidly fatal syndrome. The importance of prognosis came to be appreciated when clinical trials showed that therapy which initially improves such functional abnormalities, as high venous pressure and low cardiac output, often fail to improve survival, and that some drugs which improve hemodynamics worsen long‐term prognosis. The latter is true for most vasodilators which, in spite of alleviating the adverse short‐term consequences of high afterload, shorten survival. Notable exceptions are ACE inhibitors, whose vasodilator effects do not explain their ability to prolong survival; instead, these drugs slow both deterioration and remodeling of the failing heart. Inotropic agents, while providing immediate relief of symptoms, generally shorten long‐term survival, whereas β‐blockers slow deterioration and remodeling, and reduce mortality. Aldosterone antagonists exert beneficial effects on prognosis that are not easily explained by their diuretic effects, but instead can be explained by their ability to inhibit signaling pathways that stimulate maladaptive hypertrophy, remodeling, apoptosis and other deleterious responses that cause deterioration of the failing heart. These and other findings demonstrate that heart failure is more than a hemodynamic disorder; these patients suffer from maladaptive proliferative responses that cause cardiac cell death and progressive dilatation that play a key role in determining the poor progressive in this syndrome.