bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of Indentation Studies of Reduced Porous Ni-8YSZ Anode and Electrolyte Structures
Authors: Zhang Jing , Biswas Somnath , Nithyanantham Thangamani , Thangavel Saraswathi , Bandopadhyay Sukumar
Published: October 2008

We present a finite element model to simulate the indentation of NiO-8YSZ anode /8YSZ electrolyte structure for solid oxide fuel cell applications. The model focuses on the study of mechanical integrity of structure subject to mechanical load. Simulations showed that brittle cracks start to form within the anode due to high von Mises stresses. Residual stresses of the reduced NiO-8YSZ anode /8YSZ electrolyte structures were estimated. Simulated indentation data were also compared with experimental observations.
Modeling of Thermodynamic and Transport Phenomena in CVD Processes for Nano-Scale Applications
Authors: Nagarajan Ram , Gorai Prashun , Chawla Nidhi
Published: October 2008

To illustrate the concept of the inter-dependence between multi-component chemical reactions and transport phenomena, a theoretical investigation of a halogen-cycle tungsten filament incandescent lamp was undertaken based on local thermochemical equilibrium (LTCE) coupled with Fickian and thermal (Soret) transport of species. Deposition of tungsten on the bulb wall leads to 'bulb blackening', resulting in reduction in the luminous efficiency of the lamp, a problem typically combated by addition of small amounts of halogen and oxygen. Utilizing temperature-dependent Soret diffusion factors, elemental fluxes were analyzed. Zero element flux (ZEF) maps were generated based on temperature-dependent Soret diffusion factors. The element solubilities and the filament-to-wall element segregation were found to be strongly dependent on the bulb wall temperature, oxygen fill pressure and Soret diffusion factors. Transport-affected shifts in element solubilities from pure LTCE condition were studied. Implications of this study for the modelling of commercial CVD processes are highlighted.
Solubility of Oxygen in Molten Lead - Bismuth Eutectic Alloy (44.5% Pb - 55.5% Bi)
Authors: Verdaguer Ariadna , Abella Jordi
Published: October 2008

The management of the long-lived and high activity nuclear waste is one of the major concerns related with nuclear energy. Accelerator driven system (ADS) reactors have been proposed as one of the strategies to deal with this matter. In this type of reactors, lead - bismuth eutectic alloy (LBE) is suggested as a coolant. However, this alloy is highly corrosive towards structural steels. In order to avoid that, it is important to maintain a pasivation layer of Fe3O4 on the structural material., The oxygen content should be between 10-30 bar and 10-19 bar, In this direction, many studies about thermodynamic properties of oxygen in liquid LBE have been performed. In this work, a method to determine the oxygen solubility in LBE has been developed.
Electrochemical Impedance Spectroscopy for Characterization of Electrochemical Sensors and Biosensors
Authors: Brett Christopher
Published: October 2008

Electrochemical impedance spectroscopy is becoming increasingly widely used in the field of electrochemical sensors and biosensors, mainly for characterization of the sensor assemblies, but also as a diagnostic and as a quantitative detection method. The advantages of using EIS are outlined, the information that can be obtained from spectra that is useful for sensor development, and the possibilities for quantitative measurements are discussed. Illustrative examples include the characterization of the interfacial region associated with self-assembled monolayers, the use of impedance to deduce electrooxidation kinetics of nucleic acids in the presence of ultrasonic irradiation in order to avoid adsorption, cation-exchange-polymer-coated electrochemical sensors used for the analysis of trace metal ions in environmental samples and redox-mediated electrochemical enzyme biosensors.
Mechanisms of Long-Interval Selectivity in Midbrain Auditory Neurons: Roles of Excitation, Inhibition, and Plasticity
Authors: Edwards Christofer J. , Leary Christopher J. , Rose Gary J.
Published: October 2008

Stereotyped intervals between successive sound pulses characterize the acoustic signals of anurans and other organisms and provide critical information to receivers. One class of midbrain neuron responds selectively when pulses are repeated at slow rates (long intervals). To examine the mechanisms that underlie long-interval selectivity, we made whole cell recordings, in vivo, from neurons in the anuran inferior colliculus (anuran IC). In most cases, long-pass interval selectivity appeared to arise from interplay between excitation and inhibition; in ∼25% of these cases, the delayed inhibition to a pulse overlapped with the excitation to the following pulse at fast pulse repetition rates (PRRs), resulting in a phasic “onset” response. In the remaining cases, inhibition appeared to precede excitation. These neurons did not respond to fast PRRs apparently because delayed excitation to a pulse overlapped with the inhibition to the following pulse. These results suggest that the relative timing of inhibition and excitation govern differences in the response properties of these two cell types. Loading cells with cesium increased their responses to fast AM rates, supporting a role for inhibition in long-interval selectivity. Three cells showed little or no evidence of inhibition and exhibited strong depression of excitation. These findings are discussed in the context of current models for long-pass interval selectivity.
Complete Solutions to Extended Stokes′ Problems
Authors: Liu Chi-Min
Published: October 2008

The main object of the present study is to theoretically solve the viscous flow of either a finite or infinite depth, which is driven by moving plane(s). Such a viscous flow is usually named as Stokes′ first or second problems, which indicates the fluid motion driven by the impulsive or oscillating motion of the boundary, respectively. Traditional Stokes′ problems are firstly revisited, and three extended problems are subsequently examined. Using some mathematical techniques and integral transforms, complete solutions which can exactly capture the flow characteristics at any time are derived. The corresponding steady‐state and transient solutions are readily determined on the basis of complete solutions. Current results have wide applications in academic researches and are of significance for future studies taking more boundary conditions and non‐Newtonian fluids into account.
Fine‐Tuning Parameters for Emergent Environments in Games Using Artificial Intelligence
Authors: Kotrajaras Vishnu , Kumnoonsate Tanawat
Published: October 2008

This paper presents the design, development, and test results of a tool for adjusting properties of emergent environment maps automatically according to a given scenario. Adjusting properties for a scenario allows a specific scene to take place while still enables players to meddle with emergent maps. The tool uses genetic algorithm and steepest ascent hill‐climbing to learn and adjust map properties.Using the proposed tool, the need for time‐consuming and labor‐intensive parameter adjustments when setting up scenarios in emergent environment maps is greatly reduced. The tool works by converting the paths of events created by users (i.e., the spreading of fire and the flow of water) for a map to the properties of the map that plays out the scenario set by the given paths of events. Vital event points are preserved while event points outside the given scenario are minimized. Test results show that the tool preserves more than 70 percent of vital event points and reduces event points outside given scenarios to less than 3 percent.
Diagnosis of Neonatal Cholestasis
Authors: Girard Muriel , Lacaille Florence
Published: October 2008

Cholestasis is frequent in neonates (1/2,500 live births) and in young children. It includes many etiologies with sometimes poor prognosis. In case of neonatal cholestasis, the most important point is to look at the stool color and to rule out biliary atresia which needs to be surgically treated before the 45th day of life. Biliary atresia represents almost 50% of cases of neonatal cholestasis, the other causes being numerous. Some cases can be treated with success, such as tyrosinemia type I or inborn errors of bile acid synthesis. However, in the majority of cases, there is no specific treatment, and the evolution of the disease is toward cirrhosis or liver insufficiency leading to liver transplantation. Nowadays, liver transplantation has good results, but it is a difficult procedure with frequent side effects. In the future, analysis and a better understanding of the mechanisms of the different cholestatic diseases could allow the development of other treatments such as liver cell transplantation or gene therapy, bringing new perspectives for children.
Acquired Dysfibrinogenemia Secondary to Multiple Myeloma
Authors: Kotlín Roman , Sobotková Alžběta , Riedel Tomáš , Salaj Peter , Suttnar Jiří , Reicheltová Zuzana , Májek Pavel , Khaznadar Tarek , Dyr Jan E.
Published: October 2008

Abnormal coagulation properties indicative of a dysfibrinogen were found in the plasma of a 72-year-old male with multiple myeloma (IgGĸ, stage IIIA). The patient had high paraprotein concentration (85.75 g/l) and prolonged thrombin time (76.8 s), activated partial thromboplastin time (39.5 s), prothrombin time (23.5 s) and reptilase time (72.0 s). The fibrinogen level was increased. The fibrin polymerization induced by both thrombin and reptilase was impaired. Scanning electron microscopy revealed abnormal clot morphology. After six months of treatment, the paraprotein level decreased (19.48 g/l) and coagulation normalized as well as fibrin polymerization and fibrin clot morphology. It was found that the paraprotein interacts with the γ-chain of fibrinogen. Acquired dysfibrinogenemia associated with multiple myeloma was diagnosed in the 72-year-old patient.
Neural Correlates of the Clock Drawing Test Performance in Alzheimer’s Disease: A FDG-PET Study
Authors: Lee Dong Young , Seo Eun Hyun , Choo Il Han , Kim Shin Gyeom , Lee Jae Sung , Lee Dong Su , Jhoo Jin Hyeong , Kim Ki Woong , Youn Jong Choul , Woo Jong Inn
Published: October 2008

Background/Aim: This study aimed to identify the functional neuroanatomical correlates of impaired clock drawing test (CDT) performance in patients with Alzheimer’s disease (AD). Method: The CDT was administered to 71 patients with AD, and regional cerebral glucose metabolism (rCMglc) was measured by positron emission tomography (PET). Correlations between CDT scores and rCMglc were examined on a voxel-by-voxel basis. Results: Significant positive correlations were found between CDT performance and rCMglc in the right inferior parietal lobule and right posterior cingulate cortex. Conclusion: These results provide the first PET evidence that poor CDT performance in patients with AD is closely related to the functional decline in the right hemisphere, especially the right parietal cortex.
Multi-Center Comparison of Medial Temporal Atrophy in Patients with Alzheimer’s Disease – Data from the ICTUS Study
Authors: Galluzzi Samantha , Talassi Erika , Belussi Michela , Scheltens Philip , van de Pol Laura , Nobili Flavio , Rodriguez Guido , Froelich Lutz , Damian Marinella , Martinez-Lage Pablo , Gomez-Isla Teresa , Reynish Emma , Ousset Pierre Jean , Vellas Bruno , Frisoni Giovanni B.
Published: October 2008

Objective: To study multi-center variability of medial temporal lobe atrophy (MTA) in patients with Alzheimer’s disease (AD) recruited in a European observational study of AD. Methods: 117 mild to moderate AD patients from 5 European centers (Amsterdam, The Netherlands; Brescia and Genova, Italy; Mannheim, Germany; Pamplona, Spain) had magnetic resonance imaging scans performed as part of the routine diagnostic examination. MTA was assessed with the visual Scheltens scale. Results: AD patients from Brescia, Genova, Pamplona, and Mannheim had a mean 32% prevalence of no or borderline MTA vs. 62% of patients from Amsterdam (p = 0.002 for the difference between Amsterdam and all the other centers). The peculiar distribution of MTA in the Amsterdam patients may be attributable to younger age (70.7 ± 8.4 vs. 75.3 ± 6.8 years, p = 0.002), milder dementia severity (score 0.5 on the clinical dementia rating scale: 52 vs. 23%, p = 0.003), and less frequent depression (14 vs. 49%, p < 0.0005 in Amsterdam vs. all the other centers, respectively). Conclusion: Patients with probable AD recruited in different centers of Europe generally have similar MTA distribution, even if peculiar demographic and clinical findings might explain occasional differences. These results have implications for clinical trials in AD with biological markers as outcome measures.
Pulse Volume Changes Recorded by Air Plethysmography during Single Hemodialysis Sessions
Authors: Kusztal Mariusz , Kleszczyński Jacek , Weyde Wacław , Makulska Irena , Porażko Tomasz , Gołębiowski Tomasz , Krajewska Magdalena , Zwolińska Danuta , Klinger Marian
Published: October 2008

Aims: This study investigated whether fluid removal during a hemodialysis (HD) session affects the results of non-invasive pulse volume recording (PVR) on the lower extremities. Methods:The results of PVR by air plethysmography (Portable Vascular Laboratory; BioMedix, USA) were compared with bioelectrical impedance analysis (Nutriguard-M device; Data Input, Germany) of the human body before and after a single HD in 28 anuric patients (10 women; 18 men) aged 33–76 years. Results:Changes in the wave amplitude of the PVR correlated with the changes in the patient’s weight during HD. Lower stroke volume at the end of HD due to blood volume withdrawal resulted in PVR reduction at the ankle level. Significant Spearman coefficients were found between extracellular water and PVR amplitude changes (r = 0.7, p < 0.01) as well as between intracellular water and PVR (r = 0.6, p < 0.04). Conclusions: To avoid falsification connected with hypervolemia and stroke volume change, the most appropriate time for PVR in vascular diagnosing seems to be the period of a few hours after dialysis session.
Signaling Components Involved in Leptin-Induced Amplification of the Atherosclerosis-Related Properties of Human Monocytes
Authors: Konstantinidis Diamantis , Paletas Konstantinos , Koliakos George , Kaloyianni Martha
Published: October 2008

Background/Aims: Leptin, a 16-kDa cytokine that is released mainly by the adipose tissue, is known to affect a wide assortment of processes, ranging from energy homeostasis to angiogenesis and the immune response. In the present study, the effect of leptin on atherosclerosis-related properties of human monocytes was investigated. Methods: Monocytes were isolated from whole blood obtained from healthy donors who had normal body mass index values. Pharmacological inhibition of specific signaling proteins was implemented. Fluorescence spectrometry and immunofluorescence techniques, as well as ELISA methods, were utilized. Leptin dose response curves were determined for each type of experiment. Results: Leptin (160 ng/ml) was found to augment monocyte adhesion to laminin-1 and its migration through this glycoprotein, which is one of the main components of the extracellular matrix. Additionally, leptin increased CD36-receptor surface expression, as well as moderately oxidized low-density lipoprotein (oxLDL3) uptake levels. Conclusion: Leptin amplifies the pro-atheromatic properties of human monocytes through a complex signaling net which involves the Na+/H+ exchanger isoform-1, the actin cytoskeleton, phosphoinositide 3-kinase, certain conventional isoforms of protein kinase C and NADPH oxidase.
Pneumomediastinum during the Fourth Stage of Labor
Authors: Zapardiel Ignacio , Delafuente-Valero Jesus , Diaz-Miguel Virginia , Godoy-Tundidor Veronica , Bajo-Arenas Jose Manuel
Published: October 2008

Postpartum spontaneous pneumomediastinum (Hamman’s syndrome) is a very rare event with an estimated incidence of 1 in 100,000 deliveries. It occurs mainly in the second stage of labor and is potentially lethal. We report the case of a 29-year-old primiparous woman during the immediate puerperium (Leff’s fourth stage of labor) presenting with acute chest pain, dyspnea and petechiae. She was admitted to the intensive care unit with a suspected diagnosis of amniotic fluid embolism. A chest radiograph revealed a pneumomediastinum that finally resolved with oxygen therapy and supportive management in 3 days.
The Use of New Polymethylmethacrylate Adjuvants for Split Influenza Vaccines
Authors: Kreuter Jörg , Mauler Rudolf , Gruschkau Horst , Speiser Peter P.
Published: October 2008

Split influenza virus vaccines with varying antigen content were adjuvated with polymethylmethacrylate particles, produced by polymerizing monomeric methylmethacrylate in the presence of the subunits, or by addition of the subunits to previously polymerized methacrylate particles. Both adjuvants yielded higher antibody titers than aluminum hydroxide or fluid vaccines. The character of the antigen-adjuvant conjugate of both types of polymer adjuvants is discussed.
Effects of Blood Pressure Reduction on the Ultrastructure of the Adrenal Cortex of the Spontaneously Hypertensive Rat
Authors: Frink R. , Krupp P.P. , Root D.T. , Warshaw D.M.
Published: October 2008

Antihypertensive drugs were given to 25-week-old spontaneously hypertensive rats (SHR) and Wistar Kyoto rats, and the animals were sacrificed at 45–47 weeks of age. The effects of the decreased blood pressure on the adrenal zona glomerulosa and zona fasciculata were studied ultrastructurally and morphometrically. It was found that both groups of animals responded to the lower blood pressure in a similar manner, but the ability to respond is structurally compromised in the zona glomerulosa of SHR. This malfunction may be congenital in origin.
Collagenase Inhibitors Retarding Invasion of a Human Tumor in Nude Mice
Authors: DeVore D.P. , Houchens D.P. , Ovejera A.A. , Dill, Jr. G.S. , Hutson T.B.
Published: October 2008

Tumor invasion has been correlated with the ability of tumor cells to produce collagenolytic enzymes which are capable of degrading normal host tissues. However, the human small cell carcinoma implanted subcutaneously and growing progressively in athymic (nude) mice produced large quantities of collagenase but did not appear to significantly infiltrate adjacent host tissue. In comparison, subcutaneously implanted murine Lewis lung tumors produced similar quantities of collagenase and were locally invasive. The human tumors were surrounded by a compact layer of fibroblast cells in a fibrous matrix. This fibrous sheath exhibited anticollagenase activity and indicated a mechanism of host tissue resistance to invasion via the formation of inhibitors to degradative enzymes produced by tumor cells.
A Comparison of the Electrokinetic Properties of Metastasizing and Non-Metastasizing Forms of a Hamster Lymphosarcoma
Authors: Turner G.A. , Sherbet G.V. , Wildridge M.
Published: October 2008

Metastasizing (ML) and non-metastasizing (NML) forms of a hamster lymphosarcoma were investigated for possible differences in the cell surface properties using isoelectric equilibrium analysis and cytopherometry. ML cells were found to have a higher isoclectric point (pI) and therefore a lower net negative charge density on their surface than the NML cells. On the contrary, ML cells showed a greater electrophoretic mobility than NML cells. When pH mobility curves were constructed for the two tumour types, the curves crossed over at pH 4.8. The isoelectrophoretic points (pIE) extrapolated from these curves gave a pIE for ML cells which was higher than that of NML cells; thus, consistent with their true pi values. Furthermore, the isoelectric data showed that the two tumour types possessed similar negative charge densities at pH 4.8 which confirmed the crossover phenomenon noticed with the pH mobility curves. It is suggested that the contradictory observations may be due to differences in the depths of the zones of the cell surface probed by the two electrokinetic methods, and that in ML cells a greater proportion of cationic groups occur at a depth of between 30 and 60 Å from the shear plane, while in NML cells a majority of such groups are in a 30 Å zone adjacent to this plane. The isoelectric data also suggest that the cationic groups of NML cells are more basic than those of the ML cells.
Release of β2-Microglobulin by Human Tumors Grown in Nude Mice
Authors: DiPersio L. , Dingle S. , Michael J.G. , Pesce A.J.
Published: October 2008

Human tumors implanted subcutaneously into athmic mice produced human β2-microglobulin which was readily identified and quantified in mouse plasma. Implanted solid tumors of the lines Clouser, SW480, HEp-2, Capan-1, and HT-29 released amounts of β2-microglobulin directly related to tumor mass. The extractable β2-microglobulin per gram of tumor was constant for each cell line, but there was a 100-fold variation between the lines. In general, the plasma level of β2-microglobulin correlated with the amount of free β2-microglobulin extracted from each tumor. From these observations it can be concluded that the variability observed in the circulating levels of β2-microglobulin among cancer patients is related to the β2-microglobulin content of the tumor and the total tumor mass.
Correlation between Macrophages and Their Membrane Fraction Cytocidal Activities on Neoplastic Cells
Authors: Hakim Anwar A.
Published: October 2008

Compared with croton oil- and thioglycolate-induced macrophages, the PHA-induced peritoneal macrophages showed the highest cytocidal activity against human malignant melanoma, mammary carcinoma and rat R3230 adenocarcinoma (AdCa) cells. Resident (physiological saline-induced) macrophages showed the lowest cytocidal activities. Vibrio cholera neuraminidase (VCN) and galactose oxidase increased, whereas trypsin, plasmin, papain and mild sonication decreased the cytotoxic function of macrophages against the neoplastic target cells. The effect of macrophage membrane preparations on the cytocidal action of whole macrophages was also examined. VCN and galactose oxidase increased, whereas trypsin, plasmin, papain and mild sonication reduced the effects. It is concluded that the possible modulation of the cytocidal function of macrophages is due either to direct enzyme action on the macrophage surface, or to indirect enzyme action with enzymaticaüy produced membrane preparations. Macrophage membrane preparations could either enhance or inhibit the antineoplastic action of the macrophages.
An Investigation of the Presence of Smooth Endoplasmic Reticulum and GERL during Vitellogenesis in the Ovary of Drosophila melanogaster
Authors: Witkus Eleanor Ruth , Altman Lawrence G. , Taparowsky Judith A.
Published: October 2008

The presence of a type of smooth endoplasmic reticulum often associated with the Golgi-endoplasmic reticulum-lysosome complex (GERL) is demonstrated in the cortical region of the nurse cells located in the vitellarium of the Drosophila melanogaster ovary. This proliferation of smooth endoplasmic reticulum/GERL-like structures appears to be restricted to the area of the nurse cells that are actually involved in endocytosis in the region of adjacent, non-vitelline membrane-forming follicle cells. Smooth surface vesicles are also found in conjunction with rough endoplasmic reticulum in a close-fitting arrangement enclosing follicle and nurse cell lipid vesicles suggesting an association of GERL with secretory body formation and lipid metabolism. Autophagic vacuoles (type 2) are observed near the ‘trans’ aspect of the Golgi while residual bodies are noted to be more distal to this region. The relationship of observed ultrastructural similarities during the oogenesis of an insect to previously established findings of GERL in a variety of mammalian cell types is discussed.
Effect of Age and Sex on Lesions of the Esophagus in Buffalo Strain Rats Ingesting Diethylnitrosamine
Authors: Reuber Melvin D.
Published: October 2008

Inbred Buffalo male and female rats, 4, 12, 24, and 52 weeks of age, ingested 0.0114% diethylnitrosamine in a semisynthetic diet. Both age and sex were important in the development of preneoplastic and neoplastic lesions of the esophagus. The 4-week-old male rats had notably more carcinomas of the esophagus than female rats of the same age; whereas, 12-week-old male rats had only slightly more carcinomas than the females. The incidence of esophageal lesions was about the same in 24-week-old males and females. Rats 52 weeks of age were not susceptible to esophageal carcinogenesis.
Increased Capillary Permeability in Guinea Pigs and Rats by Peptidoglycan Fraction Extracted from Group A Streptococcal Cell Walls
Authors: Ohkuni Hisashi , Kimura Yoshitami
Published: October 2008

The increased capillary permeability in the skin of guinea pigs and rats was induced by peptidoglycan fraction (PG fraction) extracted from cell walls of group A streptococcus, but not by C-carbohydrate of streptococcal cell walls nor lipopolysaccharide of Escherichia coli and Salmonella abortus. The increased capillary permeability caused by PG fraction was also observed in germ-free rats. It was suggested that the increased capillary permeability by PG fraction might be due to the biological activity of PG fraction. The pattern of the reaction of increased capillary permeability consists of two phases: the leakage of the dye in the first phase appeared immediately after the intracutaneous injection of PG fraction, and the second phase seems to depend upon vasculitis. The increasing activity of capillary permeability by PG fraction may play an important role in inducing initial change of tissue injury by streptococcal cell walls.
Morphologic and Molecular Changes in Target Cells during in vitro Interaction with Macrophages
Authors: Keller R. , Bregnard A. , Gehring W.J. , Schroeder H.E.
Published: October 2008

Recent work has indicated that macrophages can affect eukaryote cells in a variety of ways. The inhibitory or enhancing effects on target cell proliferation are mediated by soluble factors released from macrophages and appear to affect every replicating cell. Macrophages have also been shown to affect target cell viability and this destructive potential was initially considered to be tumor-specific. The present work further assesses these macrophage effects on targets by morphologic and fluorimetric methods. Morphologic analysis of the interaction between activated nonimmune macrophages (AM) and tumor cells attests to close cell-to-cell contact as an important factor in the mediation of target cell damage. All evidence suggests that damaged targets progressively disintegrate, and residues of target cell cytoplasma and/or nucleus are then engulfed as a secondary event. Analysis by impulse cytophotometry of the alterations in the DNA distribution occurring during interaction with AM revealed a marked decrease in the number of nuclei with higher DNA content. This effect was virtually identical irrespective of whether target cells were derived from normal or transformed tissues. Analysis of the consequences of AM/target cell interaction by cytofluorimetry showed that a large proportion of tumor cells lyse in the course of the interaction. However, no such killing occurred in recent explants derived from normal tissues interacted with AM; the majority of these targets were arrested in G1.
Selective Inhibition of in vitro Synthesis of Cancer DNA by Alkaloids of β-Carboline Class
Authors: Beljanski Mirko , Beljanski Moniquen S.
Published: October 2008

The high template in vitro activity of native DNA from cancerous mammalian and plant tissues, compared to DNA from healthy tissues, enabled us to select substances which selectively inhibit cancer DNA synthesis. Among them, alstonine, serpentine, semper-virine and flavopereirine, all alkaloids which belong to the β -carboline class, distinguish cancer DNA from healthy tissue DNA and inhibit DNA in vitro synthesis when native DNA from different cancerous tissues or cells is used as template. They have practically no effect on DNA from healthy tissues. The inhibitory effect of alkaloids is due to their capacity to form an ‘alkaloid-cancer DNA’ complex which has been characterized by use of the Sephadex column. Evidence is presented showing that these alkaloids inhibit the initiation of DNA synthesis but not chain elongation. The stimulating action caused by carcinogens during cancer DNA in vitro synthesis may be prevented and reversed by alkaloids. Furthermore, the stimulating action of steroids during in vitro synthesis of hormone target tissue DNA might be neutralized by alkaloids. However, at relatively high doses, steroids reversibly compete with alkaloids for binding sites on breast cancer DNA. This is not observed with DNA from nonhormone target tissues.
Correlation among the Changes in the Levels of Thyroid Hormones, Thyrotropin and Thyrotropin-Releasing Hormone during the Development of Xenopus laevis
Authors: Bray T. , Sicard R.E.
Published: October 2008

The influence of thyroid hormones on neurogenesis suggested that these hormones might affect the maturation and development of neural centers which ultimately regulate thyroid function. Changes in the levels of the thyroid hormones, thyrotropin and the thyrotropin-releasing hormone in ‘brain’ and ‘thyroid’ fractions were, therefore, correlated at several developmental stages. All hormones showed increases from their initial detection through metamorphosis. The thyroid hormones were observed earliest in both fractions. These data are consistent with the notion that thyroid hormones influence the maturation of the particular neural regions whose later function is the regulation of the hypophyseal-thryoid axis.
Influence of Zinc and Copper on Lapine Articular Chondrocytes in Monolayer Culture
Authors: Kirkpatrick James , Mohr Winfried , Haferkamp Otto
Published: October 2008

The effects of zinc and copper ions on the structure, proliferative capacity and proteoglycan metabolism of lapine articular chondrocytes were studied in a monolayer culture system. Zn++ was cytotoxic at a concentration of 100µmol/l, whereas 50 µmol/l caused a stimulation of chondrocyte proliferation with simultaneous reduction (p& < 0.01) in macro-molecular binding of 35SO4. 10 µmol/l Zn++ failed to evoke any alteration in these parameters. Cu++ concentrations of 100 and 50 µmol/l significantly reduced cell proliferation (p& < 0.01) with a concomitant stimulation of 35SO4 uptake into pro teogly cans. 10 µmol/l Cu++ did not significantly alter chondrocyte multiplication nor binding of 35SO4 It is proposed that Zn++ may play a role in chondrocyte damage in joint disease. Furthermore, the possible therapeutic efficacy of copper in maintaining cartilage integrity is supported.
Strain-Dependent Growth of a Human Carcinoma in Nude Mice with Different Genetic Backgrounds
Authors: Maruo Kohji , Ueyama Yoshito , Hioki Kyoji , Saito Muneo , Nomura Tatsuji , Tamaoki Norikazu
Published: October 2008

Human gastric carcinoma showed different growth in nude mice depending on their genetic backgrounds which included BALB/cA-nu (nude mice with a BALB/cA genetic background), CBA/N-nu, NFS/N-nu, NIH(s)-nu, C3H/HeN+-nu, C57BL/6N-nu and lasat mice (BALB/cA-nu, Dh). Rapid growth of human carcinoma was observed in CBA/N-nu, NFS/N-nu and NIH(s)-nu. The human carcinoma in NIH(s)-nu showed the widest deviation in tumor weight. These data suggest that NFS/N-nu and CBA/N-nu are strains which are more recommended for anticancer agent screening systems than BALB/cA-nu, NIH(s)-nu, C3H/HeN+-nu, C57BL/6N-nu and lasat mice, although many other factors including productivity of the mice, strain differences in drug metabolism and drug toxicity must be considered.
Proteoglycan Modifications by Granulation Tissue in Culture
Authors: Quintner Mitchell I. , Kollar Edward J. , Rossomando Edward F.
Published: October 2008

To study the process of tissue remodeling that occurs during wound healing, radioactive proteoglycan ([35S]-PGS) was used to assay for enzymatic activities present in the extracellular fluid of healing tissue. Mice, wounded by removal of a 2 × 1.5 cm patch of skin from the dorsal surface, were sacrificed after 3 days of healing. Granulation tissue (1 cm2) was removed, spread onto a sterile wire mesh support and placed in the center well of an organ culture dish. To each well was added 1 ml MCDB medium supplemented with 10% fetal calf serum and antibiotics and 5–20 µl of [35S]-PGS (100,000 cpm/10 µl). Medium, removed from the well by aspiration after 24 and 48 h of culture, was boiled 5 min at 100 °C and stored frozen at -20 °C. Alterations of the PGS were assayed with a Sepharose 4B column (1 × 50 cm) which had an excluded and included volume of 17 and 46 ml, respectively. PGS, incubated without cells or with tissues from unwounded animals, eluted at 26 ml. PGS, incubated with granulation tissue and cultured for either 24 or 48 h, eluted from the Sepharose 4B at 29 ml, a 10% increase in elution volume, suggesting that the size or shape of the PGS has been altered by enzymes secreted by the cells of the granulation tissue. In contrast, PGS incubated with tissues from unwounded animals or without granulation tissue showed no changes. These data suggest that enzymatic activities secreted by cells of granulation tissue may be involved in remodeling during healing.
Development and Persistence of Receptor ‘Memory’ in a Unicellular Model System
Authors: Csaba G. , Németh G. , Vargha P.
Published: October 2008

A single exposure of Tetrahymena to diiodotyrosine stimulated replication of the unicellular organism significantly relative to the control. The stimulatory effect tended to decrease with progressing time, but was still demonstrable after as many as 500 generations. Reexposures to diiodotyrosine also enhanced cell growth, indicating the existence of a receptor ‘memory’ in respect to the initial exposure, but their effect tended to decline soon after initial stimulation, and did not, in all probability, contribute to the preservation of the ‘memory’ which itself tends to vanish gradually in due course.
Comparison between the Effect of Guanazole and Hydroxyurea on DNA Metabolism and DNA Repair of HeLa Cells
Authors: Partsch Gerald , Neumüller Josef
Published: October 2008

Guanazole, a triaminotriazole, has been found to have an action on the reduction of ribonucleotides. In this paper, guanazole was compared with hydroxyurea (HU) which also acts as an inhibitor of DNA synthesis. Guanazole is not as effective as HU on HeLa cells. DNA excision repair following UV irradiation is also influenced by guanazole. On the basis of results of gradient centrifugation, it is assumed that guanazole acts not only on the DNA pathway but also directly on the DNA molecule.
Prolonged in vitro Maintenance of Human Diploid Fibroblasts in a New Tissue Culture Medium (PRC-1)
Authors: Delinassios J.G.
Published: October 2008

A new medium, designated PRC-1, has been developed that (a) will support proliferation of cells outgrown from human tissue explants and (b) will maintain in culture for prolonged periods human diploid fibroblasts derived from normal, benign, or tumor stromal tissue specimens. Of the 51 tissue specimens used, 28 fibroblastic lines were produced which exceeded their expected life span and lived in the PRC-1 medium for longer than 7 months and up to 25 months (9–91 1:4 subcultivations), as contrasted with lines from the same specimens which were started and maintained in other media (McCoy’s 5a, Ham’s F12, MEM and Leibovitz LI 5). All lines of fibroblastic morphology retained their diploid chromosomal mode throughout their entire serial maintenance in vitro.
Changes in Nucleolar and Ribosomal RNA of the Frog Kidney after Malignant Transformation by the Lucke Tumor Herpesvirus
Authors: Tweedell Kenyon S. , Malin John H.
Published: October 2008

Malignant transformation of the frog kidney by the Lucke herpesvirus changes the nucleotide base composition of normal kidney nucleolar and ribosomal RNA. In the Lucke tumor there is a moderate decline in guanylic acid and a sharp decline in adenylic acid levels. Conversely, there is a sharp increase in cytidylic acid and uridylic acid levels in the tumor cells. However, there was an increase in the G + C content of nucleolar and ribosomal RNA over that obtained from the normal kidney cells. Nearly identical quantitative changes in the base composition of each RNA species were measured for the adult (spontaneous) mesonephric carcinoma and a Lucke-herpesvirus-induced pronephric tumor cell line; similar correspondence was obtained for the normal adult mesonephros and a normal pronephric cell line.
Change from Inhibition to Stimulation by Levan of AKR Lymphoma following Serial Transfers
Authors: Leibovici J. , Hoenig S. , Stark Y. , Kopel S. , Wolman M.
Published: October 2008

A progressive increase in malignancy following serial passages of AKR lymphoma is often accompanied by loss in sensitivity to the antitumor agent, levan. In further transfers, stimulation of tumor growth, instead of inhibition, is sometimes observed. It is proposed that the shift from inhibition to stimulation of tumor growth by the immunomodulator levan may be due to a change during tumor progression in the sensitivity of the tumor cells to the reported dual effect of macrophages, inhibitory or stimulatory, on tumor growth.
Immune Response against Vaccinia Virus in Rhesus Monkeys: No Evidence for Primary MHC-Restricted Cytolytic T Cells
Authors: Stitz Lothar , Zïnkernagel Rolf , Balch Charles M. , Bolhuis Reinier L.H. , Balner Hans
Published: October 2008

Rhesus monkeys were tested in vitro for their cellular immune response after infection with vaccinia virus, employing lymphocyte preparations from various lymphoid tissues. Although virus-infected target cells were lysed by lymphoid cells from immunized, but not from uninfected, rhesus monkeys, we could neither find evidence for MHC-restricted T cells nor for antibody-dependent cellular cytotoxicity. Kinetics of target cell lysis, the killing patterns of immune lymphocytes measured on syngeneic, allogeneic, and xenogeneic target cells, and the influence of protein A on cytotoxic activity in vitro suggest induction predominantly of natural killer cells in vivo which exhibit lytic activity on virus-infected target cells in vitro.
Blood Group Substances, T6 Antigen and Heterochromatin Pattern as Species Markers in the Nude Mouse/Human Skin Model
Authors: Græm Niels , Dabelsteen Erik , Tommerup Niels
Published: October 2008

Antibodies to blood group antigens and to human T6 antigen and the DNA-specific fluorochrome D287/170 were applied to human skin transplanted to nude mice and to the surrounding murine skin. It was found that the two epithelia maintained their characteristic, different blood group B antigen distributions and heterochromatin patterns. Furthermore, it was shown that human Langerhans’ cells persisted in the grafted epidermis. During an observation period of until 48 weeks after transplantation only one of 32 grafts showed signs of invasion by murine epidermis.
A Nonimmunomodulatory Effect of Chronic Cadmium Exposure on Lymphocyte Transformation Response in Rhesus Monkeys (Macaca mulatta)
Authors: Chopra R.K. , Sharma M. , Nath R.
Published: October 2008

The immunomodulatory effects of cadmium, an environmental pollutant, were assessed in male rhesus monkeys orally exposed to 5 mg cadium/kg body weight for a period of 4 months. A lymphocyte transformation test was carried out in peripheral blood lymphocytes using different concentrations of phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM). Cadmium exposure of monkeys resulted in a statistically nonsignificant increase in [3H]thymidine incorporation in PHA- and Con-A-stimulated lymphocytes. However, there was a nonsignificant decrease in [3H]thymidine incorporation in PWM-stimulated lymphocytes. These results suggest that cadmium may not have immunosuppressive effects in primates which are phylogenetically close to man.
Selective Control of Human Glioma Cell Proliferation by Specific Cell Interaction
Authors: MacDonald C.M. , Freshney R.I. , Hart E. , Graham D.I.
Published: October 2008

Cells cultured from anaplastic astrocytoma (Kernohan and Sayre, grades III and IV) will proliferate on confluent monolayers of normal glia, while cells cultured from normal brain will not. The growth of a cell line containing a high proportion of well-differentiated glioma cells (G-CCM) was partially inhibited, though not as much as normal glia, while the growth of a cell line made up of less differentiated cells (G-UVW) was enhanced by the normal glia. Although non-glial confluent monolayers also inhibited the growth of normal glia, this was less specific, as one normal glial line (N-DUT) grew on fibroblasts and intestinal epithelium, although it was unable to do so on normal glia. It is suggested that this may be a useful method for examining reduced density limitation of growth, discriminating between normal and malignant glia, and for separating glioma cells from contaminating normal cells.
Factors Influencing Phenotypic Diversity of Human Prostate Carcinoma Cells Metastasizing in Athymic Nude Mice
Authors: Ware Joy L. , Lieberman Andrew P. , Webb Karen S. , Voílmer Robin T.
Published: October 2008

Three related human prostate carcinoma cell lines, PC-3, 1-LN-PC-3-1A (1-LN), and 1-LN-PC-3–1A clone 4 (clone 4) were compared in terms of relative metastatic capacity in adult and young male nude mice. Only 1-LN produced lung metastases after intravenous injection into both 6- to 8-week-old and 4-week-old mude mice, as well as in mice injected intraperitoneally. The extent of the phenotypic diversity exhibited by these human prostate tumor lines was influenced by inherent dissemination ability, age of the host, and route of injection. These lines provide a useful system for the analysis of the biology of human tumor metastasis in nude mice.
Monoclonal Antibodies against Mouse γ-Interferon Inhibit Tumoricidal Macrophage Activation by T Lymphocytes
Authors: Landolfo Santo , Cofano Franca , Gandino Lucia , Gribaudo Giorgio , Prat Maria
Published: October 2008

A monoclonal antibody, AN-18.17.24, specific for murine interferon-gamma (IFN- γ) was produced by immunizing Wistar rats with IFN- γ secreted by a T-cell lymphoma, L12-R4, upon stimulation with phorbol myristic acetate (PMA). Antiviral activity as well as tumoricidal activation induced by PMA-stimulated L12-R4 cell supernatant or by Con A-stimulated normal spleen cells were neutralized at the same extent by AN-18 monoclonal antibody. Moreover, depletion experiments showed that inhibition of tumoricidal macrophage activation must be ascribed to the direct binding of the IFN- γ molecule by AN-18 MAb and not to the interference of the monoclonal antibody with the cell surface IFN- γ receptor. These studies conclusively demonstrate that in supematants of T lymphocytes stimulated with polyclonal activators IFN- γ was the only molecule responsible for macrophage activation in tumor cell killing.
Inhibition of Dimethyl Sulfoxide-Induced Friend Erythroleukemia Cell Differentiation in vitro by Lithium Chloride
Authors: Gallicchio Vincent S.
Published: October 2008

This report describes the ability of ultra-pure lithium chloride (LiCl) to influence the growth kinetics and differentiation of Friend erythroleukemia cells in vitro. LiCl (0.2–50 mEq/l) was effective in reducing the ability of Friend cells to grow in liquid suspension culture (p ≤ 0.001). In addition, the capacity of these erythroleukemic cells to respond to the inducing agent dimethyl sulfoxide (DMSO) was also significantly reduced (p ≤ 0.001). These results demonstrate that LiCl can influence not only the proliferation of erythroleukemia cells but also their subsequent differentiation after exposure to such chemical inducers.
Tooth Germ Epithelial-Mesenchymal Interactions in Tissue Culture
Authors: Dye Frank J.
Published: October 2008

The usefulness of the tooth germ in culture arises from the fact that it exemplifies those fundamental attributes of development, cell proliferation, cytodifferentiation, and morphogenesis, which we expect to find in the developoment of any metazoan organism. In culture, as in the organism, such development takes place in 3 dimensions. This study was undertaken to determine if it is possible to uncouple, by using 2 dimensions, cytodifferentiation from morphogenesis. Under the conditions used, cytodifferentiation in culture was not apparent (at the light microscope level). However, the following interesting observations were made: Cell populations arising from the same types of explants (enamel organ/enamel organ or dental papilla/dental papilla) readily flow together. Cell populations arising from dissimilar types of explants (enamel organ/dental papilla) form sharp boundaries at their interfaces. Additionally, cell populations arising from intact tooth germs differ from those arising from either enamel organs or dental papillae.
Changes in Activity of the Regulatory Glycolytic Enzymes and of the Pyruvate-Dehydrogenase Complex during the Development of Xenopus laevis
Authors: Raddatz Eric , Løvtrup-Rein Huguette
Published: October 2008

In this study we investigated the variations of the maximal activities of the rate-controlling glycolytic enzymes (i.e., hexokinase, HK; phosphofructokinase, PFK; pyruvate kinase, PK) and of the pyruvate-dehydrogenase complex (PDHc) during the early embryogenesis of Xenopus laevis (from cleavage through hatching). All the enzymatic assays, using different coupled reactions, were performed spectrophotometrically on cytosolic and mitochondrial fractions. The maximal HK activity increases markedly from neurulation onwards, PFK activity presents a peak around gastrulation, PK activity remains relatively constant throughout the period studied and the highest PDHc activity is observed during cleavage. The specific activities display the same temporal pattern. Furthermore, in the sequence of reactions by which glucose is degraded to form acetyl-CoA, the maximal activities of PFK and PK are not limiting while those of HK and PDHc could be rate-limiting at relatively late developmental stages (hatching).
The Endothelium of the High Endothelial Venule: A Specialized Endothelium with Unique Properties
Authors: Kraal Georg , Duijvestijn Adrian M. , Hendriks Hans H.
Published: October 2008

High endothelial venules (HEV) in lymphoid organs are specialized to facilitate the passage of lymphocytes into lymphoid parenchyma. This is accomplished by a ligand-receptor system on the endothelium and lymphocytes, which differs between lymph nodes and Peyer’s patch. Experiments discussed in this paper show that other non-HEV-derived endothelial cells can acquire the characteristics of HEV and that HEV may differentiate under influences from their local microenvironments.
Methodology for Detection of Heterogeneity of Cell Locomotory Phenotypes in Three-Dimensional Gels
Authors: Shields Edward D. , Noble Peter B.
Published: October 2008

A computer-driven, three-dimensional, optical, cell-tracking system was used to quantifiy the locomotory phenotypes of Mos-11 cells in a collagen gel. Factor analysis was used as a statistical means to make the complex variables generated by the system more tractable to analysis. Heterogeneity in locomotory behavior (two independent locomotory phenotypes) was detected among a sample of 54 cells.
Transition from Non-Muscle to Muscle Myosin Light Chains in Chick Embryo Development
Authors: Fascio U. , De Bernardi F.
Published: October 2008

In chick embryo blastoderm the electrophoretic pattern of myosin light chains changes between the 4-somite and the 19-somite stages (stages 8-13 of Hamburger and Hamilton) from that of non-muscle to muscle myosin. This transition seems to follow the differentiation of the myotomes and to be developmentally regulated.