bluuebunny/crossref_metadata_2025 huggingface dataset:
Synergistic Effect of Natural Human Tumor Necrosis Factors α and β in the Clonogenic Assay
Authors: Miyake Mikio , Fuchimoto Sadanori , Orita Kunzo
Published: October 2008

We tested the antiproliferative effect induced by the natural human tumor necrosis factors α and β (nHuTNF-α, -β) or a combination of these in the clonogenic assay. The antiproliferative effects were evaluated by examining the inhibition of clonogenic growth of RPMI-4788 cells, which had been established from a human colon cancer. TNF-α and -β were natural human types produced by a B cell leukemia line (BALL-1 cells) and were both over 99% pure. The antiproliferative effect in combination of nHuTNF-α and -β was analysed by using the median effect plot and the combination index. The results indicate a synergism between two factors.
Cell Surface Changes during Electromagnetic Field Exposure
Authors: Hamada Spencer H. , Witkus Ruth , Griffith, Jr. Ronald
Published: October 2008

Fibroblasts from 5½-day-old chick embryos go through a sequential series of changes when exposed to a constant electromagnetic field (EMF) of 10 V/cm. These changes include rounding up, becoming bipolar in shape, assuming a cylindrical profile, elongating perpendicular to the EMF, and migrating to the cathode. These morphological changes are associated with changes of the cell surface, which include the formation of filopodia and extensive sheet-like contacts on the cathodic cell surface, the retraction of processes and the formation of focal contacts on the anodic cell surface.
Partial Purification of Human Urinary Megakaryocyte Colony-Stimulating Factor
Authors: Ogata Kiyoyuki , Kuriya Shin-ichiro , Dan Kazuo , Nomura Takeo
Published: October 2008

Urinary extracts from patients with aplastic anemia are known to promote murine megakaryocytopoiesis. In this report, we show a simple method for the partial purification of megakaryocyte colony-stimulating factor from human urine. A four-step purification procedure, which included ethanol precipitation, CM Affi-Gel Blue chromatography, wheat germ agglutinin-Sepharose chromatography and high-resolution hydroxyapatite chromatography, resulted in an about 430- to 630-fold increase of specific activity. The final fractions were still contaminated with erythropoietin, but the contaminated content of erythropoietin was not enough to stimulate mouse megakaryocytopoiesis in our culture system. We also demonstrate that human urinary extracts stimulated human megakaryocyte colony formation.
Further Characterization of the Biological Properties of Human Hematopoietic Survival and Growth Factor
Authors: Hiraoka Atsunobu , Ohkubo Tadashi , Fukuda Minoru
Published: October 2008

Human hematopoietic survival and stem cell growth factor (SCGF), derived from the KPB-M15 myeloid cells, is a heat- and pH-stable protein. Chemical modification with various denaturing agents and proteolytic enzymes abrogated SCGF activity. The granulocyte-macrophage colony-potentiating and erythroid burst-promoting activities of SCGF were proportional to the density of the bone marrow (BM) cells cultured, the optimal BM cell density for △ granulocyte- and △ burst-promoting activities being 5 to 10 × 105/ml. These data could be important in enabling the use of SCGF to induce proliferation of human hematopoietic stem cells in vitro.
Electrically Regulated Cellular Morphological and Cytoskeletal Changes on an Optically Transparent Electrode
Authors: Yaoita M. , Aizawa M. , Ikariyama° Y.
Published: October 2008

Electrically regulated morphological and cytoskeletal changes of HeLa cells were studied on an optically transparent electrode (OTE), on which potential-applied surface cellular behavior and morphogenesis were easily observed. Upon application of a potential, HeLa cells in an OTE exhibited remarkable morphological changes above +0.5 V (vs. Ag/AgCl) and below 0 V. At each potential in this potential range, change in F-actin distribution was observed using a fluorescent probe (rhodamine phalloidin). These results suggest that an electrical field induces a subcellular cytoskeletal change. Electrostimulation of cells with OTE can be a valuable strategy for the manipulation of cultured human cells.
Differential Adhesion of Metastatic Rat Mammary Carcinoma Cells to Organ-Derived Microvessel Endothelial Cells and Subendothelial Matrix
Authors: Lichtner Rosemarie B. , Belloni Paula N. , Nicolson Garth L.
Published: October 2008

The in vitro adhesion rates of rat 13762NF mammary adenocarcinoma cell clones of different spontaneous metastatic potentials to cloned microvessel endothelial cell monolayers and their subendothelial extracellular matrix were investigated. In this system, high rates of adhesion of the cloned tumor cell lines to syngeneic target (lung) organ-derived subendothelial matrix correlated with spontaneous metastatic potential, whereas adhesion to the lung microvessel endothelial cell apical surfaces occurred at lower rates and was not highly significantly different among the tumor cell lines. Adhesion rates to bovine aortic large vessel, and human brain and human meningeal microvessel endothelial cell monolayers were, in general, lower than those found with syngeneic lung microvessel endothelial cells, and did not correlate with spontaneous metastatic potential. Growth of endothelial cells in fetal bovine serum or platelet-poor horse serum did not affect the results, suggesting that in this system metastasis-associated organ-adhesive specificity is determined at the level of the subendothelial matrix.
Expression of Lewis Antigenic Determinants in Colorectal Adenocarcinomas
Authors: Blasco Eduardo , Torrado Julio , Cosme Angel , Alvarez Elvira , Zugasti Amaia , Gutierrez-Hoyos Ariel , Arenas Juan Ignacio
Published: October 2008

Expression of type 1 and type 2 chain Lewis antigens was studied in 32 rectal adenocarcinoma specimens; the results were correlated with the patients’ Lewis phenotype and secretor status. In addition, the pattern of expression of these antigens was analyzed in adjacent and distant normal mucosa. We used an indirect immunofluorescence technique with p-phenylenediamine counterstaining (Oriol technique) and a panel of monoclonal antibodies directed against the different antigenic specificities. Normal distal colonic mucosa only expresses monofucosylated structures (Lea and X) arising from activity of the α1–3,4-fucosyltransferase coded by the Le gene. Rectal adenocarcinomas also show Lea and X, but also reexpress blood group antigens ABH and exhibit difucosylated determinants (Leb and Y). The accumulation of mono- and difucosylated type 2 chain in neoplastic processes, independently of the Le and Se genes, could be due to the enzymes coded by reactivation of the H and X genes. Blood group antigens form a complex signal code, genetically regulated, which intervenes in differentiation, growth and cellular recognition processes, and which may undergo important modifications during malignant transformation. These alterations could be useful in the diagnosis and prognosis of some types of carcinoma.
Membrane Fluidity and Cancer Metastasis
Authors: Sherbet G.V.
Published: October 2008

The membrane fluidity of murine B16 melanoma and L5178 lymphoma variants is examined in relation to their metastatic potential. A higher lateral mobility of membrane proteins in metastasis is indicated by lectin receptor-mediated agglutination studies, but these do not constitute incontrovertible evidence that higher fluidity might be relevant in the metastatic process. The membranes of tumour cells with higher metastatic potential have a lower cholesterol/phospholipid ratio but greater unsaturated phospholipid content. This is partly supported by partition characteristics of metastatic variants in aqueous two-polymer phases. Steady-state fluorescence polarisation, which measures lipid order and the degree of rotational motion of lipids, does not suggest marked differences in bulk ‘fluidity’ of metastatic variants. Transbilayer fluidity differences have been described and these may be of some significance in the control of activity of membrane-associated enzymes and other membrane properties. The plasma membrane is a mosaic of domains possessing different degrees of microviscosity and this mosaicism may be relevant in the context of metastatic dissemination of tumours.
In vitro Interaction of Heterologous Platelets with Isolated Neoplastic Cells from a Murine Mammary Gland Tumor
Authors: Eynard A.R. , Falo C. , Quiroga P. , Pasqualini M.E.
Published: October 2008

The purpose of the present work was to study the in vitro effects of challenging human whole-blood and platelet-rich plasma (PRP) with neoplastic cells (NC) isolated from a murine mammary gland adenocarcinoma. Viable, but not formalinized, isolated tumoral cells induced platelet aggregation in citrated whole blood. NC did not induce aggregation of PRP samples whereas the NC added to PRP induced aggregation in 33% of volunteers if samples were previously stimulated with a subaggregatory strength of collagen. The results suggest a role for other blood cells since the proaggregatory effect was less evident on PRP. Adenocarcinoma M3 seems to be a suitable model to study in vitro platelet-cell tumor interactions.
Age-Related Changes in Fibronectin in Annulus fibrosus of the Sand Rat (Psammomys obesus)
Authors: Silberberg R. , Meier-Ruge W. , Odermatt B.
Published: October 2008

Fibronectin stains were carried out and evaluated by microspectrophotometric techniques in annuli fibrosi of vertebral discs of sand rats (Psammomys obesus) of both sexes and two age groups, 13–18 months and over 2 years of age. The distribution of fibronectin in the annulus shows a centripetal gradient from the outer to the inner laminae. Fibronectin was significantly more abundant in the annuli of old than of young animals of corresponding sex. Sex differences were not significant. The dorsal segment contained more fibronectin than the ventral, but the difference was statistically significant only in the aged females. The outer laminae of the annuli appeared consistently higher in fibronectin content than the inner laminae.
Nodular Organization and Differential Intrametastatic Distribution of the Fluorescent Dye Hoechst 33342 in B16 Melanoma Liver Metastasis
Authors: Aliño Salvador F. , Hilario Enrique
Published: October 2008

The development of B16F10 liver metastases as related to its vascular organization was studied by morphological and functional methods, using the DNA-binding fluorochrome, Hoechst 33342. Experimental metastases were produced by intrasplenic injection of B16F10 melanoma cells, and the animals were sacrificed 3–7 days after tumor cell injection. The results show that early metastases are made up of avascular nodules of tumor cells, which subsequently developed lacunae which are not lined by endothelial cells and usually contain blood cells. A more developed metastasis seems to be made up of several nodules with or without lacunae. Between the nodules, vessels connected to blood circulation were usallly observed. A functional study with a fluorescent dye showed that early metastases stained negatively, while more developed metastases showed a reticular fluorescent pattern, coincident with the intrametastatic vascular network and displaying a nodular image. In this case, the fluorescence displayed a gradient of intensity decreasing from the vessels towards the lacunae, where the tumor cells showed no fluorescence. In summary, our results suggest that B16 liver metastases have a nodular growth pattern, which is characterized by the formation, during their development, of lacunae not connected to the general circulation and that tumor cells have poor access to small molecules delivered from the blood.
Studies on Thymocyte Subpopulations in Guinea Pigs
Authors: Kölare Susanne , Sandberg G.
Published: October 2008

Thymocytes spontaneously proliferating in vitro were labelled with 3H-thymidine, and the distribution of label among rosette-forming cells (RFC+) and nonrosetting cells (RFC-), as well as in populations differing in buoyant density, was measured by liquid scintillation counting and autoradiography before and after incubation for 24 h. Initially most labelled cells (88%) belonged to the low-density (la) subpopulation, the majority being RFC+. After incubation for 24 h, low-density nonrosetting thymocytes (1 a, RFC-) contained the highest amount of label. A decreased rosette formation occurred not only in labelled cells but also in the population as a whole, and in separately incubated high-density cells. The decreased rosette formation was mainly caused by a change in rosette-forming ability of viable high-density cells, however in part also by decreased viability. A shift from low to high density occurred among labelled cells during incubation and was shown to occur in both RFC+ and RFC-. The decreased rosette formation of labelled cells during in vitro culture contrasts with the increase earlier observed in vivo and may therefore represent affinity alterations or a down-regulation of the rosette receptor in vitro. We conclude that the observed changes in density, but not in rosette-forming ability, may reflect normal differentiation.
Generalized Cutaneous Hyperpigmentation in Hairless Mice Induced by Topical Dimethylbenzanthracene
Authors: Tsambaos D. , Sampalis F. , Berger H.
Published: October 2008

The skin of hairless (Ng/Bln) mice topically treated with dimethylbenzanthracene (DMBA) was investigated by light microscopy, histochemistry, electron microscopy and autoradiography in order to gain some insight into the mechanisms by which the DMBA-induced cutaneous hyperpigmentation is mediated. The results of the present study indicate that this phenomenon is due to the DMBA-induced stimulation of both the tyrosinase system and the mitotic activity of dopa-inactive dormant melanocytes.
Interaction between Endothelial Cells and Basement Membrane Components
Authors: Rixen Helma , Kirkpatrick Charles James , Schmitz Ursula , Ruchatz Dagmar , Mittermayer Christian
Published: October 2008

Understanding the mechanisms involved in maintaining the integrity of the vascular endothelium is fundamental to studies on atherosclerosis, thrombosis, inflammation and tumor invasion. One of the essential aspects is the relationship between the endothelial cell (EC) layer and the underlying components of the basement membrane (BM). The importance of the biological role of the individual components of the BM in the promotion of EC adhesion is investigated. In this study suspensions of bovine corneal ECs (BCECs; 5 × 104/ml) were used to investigate the adhesion of EC to collagen type IV and a mixture of fragments of the tetrameric molecule (IV-F, consisting of 75, 120 and 140 kD fragments), as well as collagen types I and III, coated at a 10-µg/ml concentration onto glass coverslips in vitro. Adhesion was quantified after 2 h of interaction by direct counting in the light microscope following fixation of the adherent cells. Collagens type IV and IV-F markedly promoted BCEC adhesion both in the presence or absence of 10 or 50% fetal calf serum, indicating that the integrity of the tetrameric molecule is not required for EC adhesion to collagen type IV, but can be replaced by high molecular weight fragments. Collagens type I and HI increased EC adhesion in the absence of serum, although not in the presence of serum. Indirect evidence for a possible role of fibronectin in EC adhesion to type-IV collagen is given by the ability of the tetrapeptide (Arg-Gly-Asp-Ser (10 µg/ml) to temporarily block (15–30 min) the adhesion-promoting effect of type-IV collagen. The nature of the adhesion sequences on the fragments of type-IV collagen remains to be elucidated.
Alkaline Phosphatase Expression in Human Cell Lines Derived from Primary Hepatomas
Authors: Tokiwa Takayoshi , Endo Akira , Sato Jiro
Published: October 2008

Isozyme patterns of alkaline phosphatase (ALP) were electrophoretically examined in human cell lines derived from one hepatoblastoma, five hepatocellular carcinomas (HCCs) and two cholangiocellular carcinomas. Most of the cell lines tested had a liver-type ALP isozyme. In addition, an abnormal ALP isozyme, which was similar to variant ALP, was detected in one hepatoblastoma and two HCC cell lines. One HCC cell line of these variantlike ALP-positive cell lines was α-fetoprotein (AFP)-negative. These findings suggest that variant-like ALP may be useful for the identification of human hepatoma cell lines, especially in AFP or albumin-negative cell lines.
In vitro Proliferation of Murine Spleen Cells: Inhibition by Monoclonal Antibodies to L3T4 and Lyt-2 T Cell Markers or Intracellular Cyclic Adenosine Monophosphate
Authors: Zhou P. , Gorzynski T. , Dowjat W.K. , Rabin R. , Zaleski M.B.
Published: October 2008

Proliferation of normal (not immunized intentionally) murine spleen cells was elicited with concanavalin A, supernatant fluid from cultures of EL-4 cells, human recombinant interleukin 2 (IL-2), or a mixture of phorbol ester and calcium ionophore A23187. IL-2-induced proliferation was inhibited by membrane-permeable dibutyryl cyclic adenosine monophosphate (cAMP) or by the adenylate cyclase activator forskolin. Consistent with these observations was the finding that stimulation with IL-2 decreased and forskolin increased the intracellular content of cAMP. IL-2-induced proliferation, as well as that induced by concanavalin A or phorbol-ionophore mixture, was inhibited by monoclonal antibodies specific for L3T4 or Lyt-2 cell surface markers. This inhibition was observed even when antibodies were added several hours after exposure of cells to IL-2. Notably, antibodies did not alter the intracellular content of cAMP. Thus, the experimental data failed to establish a functional linkage between the inhibitory effect of antibodies and the regulatory effect of the adenylate cyclase system. However, our results provide a rational basis for the postulation that antibodies, upon binding to their corresponding ligands, generate a negative signal that interferes with IL-2-induced proliferation. Therefore, L3T4 and Lyt-2 molecules appear to play an important role in the regulation of lymphocyte proliferation.
Growth Kinetics of Human Lung Tumours in Nude Mice
Authors: Mattern J. , Haag D. , Wayss K. , Volm M.
Published: October 2008

In order to investigate the growth characteristics of xenografts of human tumours in nude mice, we heterotransplanted 22 human tumours of the lung into nude mice. We noted growth in 11 of these tumours (50%). The histological appearance of most of the tumours growing in the first passage in nude mice was comparable with that of the donor tumours. In further passages, however, a progressive dedifferentiation was noted in many tumours, depending on their growth rate. With the aid of growth curves and cell cycle kinetics (FMF analysis) it is shown that the growth kinetics of these tumours is affected by the transplantation and that the growth rate of such xenografts in nude mice is different from that of the original tumour in the patient.
Biochemical Studies of Bone from Diabetic Rats and Rats Bearing Transplanted Pancreatic Islets
Authors: Silberberg Ruth , Scharp David W. , Lesker Peggy A.
Published: October 2008

A comparison of lysozymal enzymes involved in glycosaminoglycan metabolism in cortical bone found significantly increased activity in the presence of streptozotocin-induced diabetes. The presence of transplanted pancreatic islets and restitution of the normal systemic insulin and glucose values did not alter these changes. The enzyme activity of cancellous bone appeared to be even less responsive to diabetic pathology with changes developing only with advancing age.
The Suppression of Tumorigenicity in Human X Mouse Cell Hybrids
Authors: Chopan Michael , Kopelovich Levy
Published: October 2008

The nature of genetic determinants associated with the regulation of malignancy was investigated in interspecies (human × mouse) cell hybrids. An apparently transformed diploid human cell strain (ME) was fused with a malignant, HGPRT-deficient, mouse cell line (A9). A primary hybrid with an unusual stellate appearance that contained the isozymic forms of lactate dehydrogenase from both parent cells was selected. Through further cloning, four tertiary hybrid cell clones were obtained in which malignancy was substantially inhibited and in which the human chromosome content was reduced or completely absent. Two of the hybrid clones whose malignant phenotype was stably suppressed contained no apparent human chromosomes, whereas the other two, whose phenotype was unstable, contained a part of a human chromosome. Our results are consistent with the view that suppression of malignancy occurs in interspecies hybrids consisting of a malignant mouse and a transformed human parent cell. At present, however, any assignment of a specific human chromosome, or specific fragments thereof, that may suppress the expression of malignancy in these hybrids, is a matter of conjecture.
Intracranial Growth of Pulmonary Small Cell Carcinoma Cells in Nude Athymic Mice
Authors: Chambers W.F. , Pettengill O.S. , Sorenson G.D.
Published: October 2008

Pulmonary small cell carcinoma of the lung cells were inoculated intracranially and subdermally in nude athymic mice (Balb/c strain). There was a 100% intracranial tumor incidence in response to 1/10th the cell dose required to produce subdermal tumors in immunosuppressed nude mice. Tumors did not grow in the brains of Balb/c normal (haired) mice.
Nuclear and Mitotic Abnormalities Produced by Cycloheximide in the Newt Egg during Cleavage and Their Relationship to the Cell Cycle
Authors: Sentein Paul
Published: October 2008

In cleaving newt eggs short-lasting treatments with millimolar quantities of cycloheximide (½, 1/3 , 1/6 cycle) produce, after 6 h recovery, nuclear and mitotic abnormalities which are less drastic, but similar to those produced by treatments lasting 6 h. Special disturbances of the spindle and asters are different from those produced by spindle inhibitors (reduction in size of the asters and of the number of poles by nucleus, usual suppression of the spindle, failure of cytokinesis, separation of asters from nuclei). But the structure of nuclei is different according to the time when the treatment started (telophasic when it begun at anaphase or telophase, prophasic when begun at prophase). The difference in percentage of these two types of nuclei is highly significant and independent of the time passed after the beginning of the treatment. Each nucleus has to complete the whole cycle before the effect can be stopped.
In vitro Human Lymphocyte PHA Response – the Heterogeneous Effect of Methylazoxymethanol Acetate
Authors: Jenkins Edmund C. , Evans Lemuel A.
Published: October 2008

In earlier studies on the effect of methylazoxymethanol acetate (MAM AC), a mutagen, teratogen and carcinogen, upon sister chromatid exchange, the concentrations tested in short-term lymphocyte cultures from 9 individuals were not identical for each person. (The concentrations were derived from dose-effect curves for each individual, involving the quantity of MAM AC [5...50...80 µg/ml] versus blast transformation using PHA.) The differences obtained between the curves were investigated further by repeating the dose-effect curves in cell cultures derived from 10 normal male individuals, except that Ficoll-Hypaque-purified mononuclear cells were cultured at a concentration of 3 × 105 viable cells/ml. Five identical microwell cultures (150 µl) were tested for each variable within an individual experiment. Controls with and without PHA (PHA+, PHA-) were included. The results show that not all individuals’ cultures exhibited the same PHA response for each concentration of MAM AC. In the 10 cases studied: (1) dose-effect curves were not uniform for all experiments; (2) the percentages of 3H-incorporation at 5 µg/ml of MAM AC compared to that of PHA+ controls were not the same across experiments; depending on the experiment, 5 µg/ml significantly increased, reduced or had no effect on PHA when 3H-uptake was compared to PHA+ control levels; (3) when mean log values of the above percentages were plotted with their confidence intervals, striking differences were exhibited between individuals or groups of individuals; (4) the TD50 values, referred to as the concentration of MAM AC at which half as much label was incorporated as compared to PHA+ control cultures, were different, and (5) the lowest MAM AC concentrations effective in reducing 3H-uptake levels to those of PHA-controls were not the same. Familial and/or laboratory animal studies will demonstrate whether these differences are genetically determined.
Multicellular Tumor Spheroids of Human Colon Carcinoma Origin
Authors: Lees Rosemary K. , Sordat Bernard , MacDonald Robson
Published: October 2008

The relationship between destruction and concomitant host cell infiltration of human tumor xenografts has been quantitatively investigated by using the multicellular tumor spheroid model. Multicellular tumor spheroids of HT-29 human colon carcinoma cells were grown in vitro and subsequently implanted in the peritoneal cavity of BALB/c mice. At various times thereafter, spheroids were recovered and dissociated and their viability was quantitatively assessed by using a clonogenic assay. Little damage to spheroids was observed during the initial 4 days after implantation, but essentially complete destruction ( >99% reduction in clonogenic tumor cells) occurred between days 4 and 7. In parallel studies, host cell infiltration was assessed by light and electron microscopy both in situ on sections and on dissociated suspensions of spheroid cells. The data demonstrate the value of utilizing a model system in which both functional and morphological techniques can be combined in a quantitative assessment of the relationship between host cell infiltration and graft destruction in situ.
Correlation between in vitro DNA Synthesis, DNA Strand Separation and in vivo Multiplication of Cancer Cells
Authors: Beljanski Mirko , Bourgarel Pierre , Beljanski Monique
Published: October 2008

The chemicals 9,10-dimethylbenzanthracene (DMBA), ethionine, daunorubicin, actinomycin D, l-(2-chloroethyl-1)-nitrosourea (CCNU), steroids, croton oil and dimethylsulfoxide (DMSO) were used in order to correlate their effect on the in vitro synthesis of normal and cancer DNA, on DNA strand separation and on accelerated in vivo multiplication of cancer cells. All of the compounds tested strongly stimulate the synthesis of cancer DNA in vitro catalyzed by DNA-dependent DNA polymerase I and measured as an acid-precipitable labeled product. Under the same conditions, the synthesis of DNA originating from healthy tissues is only slightly enhanced, except in the case of croton oil and DMSO. These substances are almost equally active on cancer and normal DNA. Although both cancer and normal DNA contain a large amount of double-stranded regions, the extent of DNA strand separation measured by the increase in UV absorbance (hyperchromicity) in the presence of each compound tested is much higher for all cancer DNA than for corresponding normal DNA. In contrast, DMSO and croton oil do not appear to distinguish cancer DNA from normal DNA. Additive and differential effects of various compounds on cancer DNA strand separation can be observed. Small doses of DMBA and CCNU stimulate the multiplication of Ehrlich ascites tumor cells in vivo in mice. There is thus a possible correlation between DNA strand separation, DNA synthesis, multiplication and differentiation of cancer cells in the presence of the above compunds, which is different from the response of normal cells to these compounds.
Sarcomere Formation in Dystrophic Skeletal Muscle
Authors: Murphy B.J. , Allen E.R.
Published: October 2008

Early aspects of in vivo sarcomere organization were studied using normal and dystrophic New Hampshire chick embryos. Brachial somites 17-22 were removed from stages 16 through 28 embryos, processed for electron microscopy, and analyzed. Comparisons of normal and dystrophic material disclosed that thick filaments appeared later in dystrophic myotomal cells. This was correlated with a similar delay in the appearance of long polyribosomes. By stage 28, normal myotomal cells contained well-defined sarcomeres, whereas dystrophic sarcomeres were frequently unorganized, with myofilaments in poor longitudinal alignment. Periodic tubules were poorly developed or lacking.
Studies on the Toxicity and Binding Kinetics of Abrin in Normal and Epstein Barr Virus-Transformed Lymphocyte Culture-I: Experimental Results – 1
Authors: Witten Matthew , Bennett Carol E. , Glassman Armand
Published: October 2008

The effects of treatment with varying doses of abrin, a D-galactose binding lectin, on DNA and protein synthesis of normal and Epstein Barr virus-transformed lymphocytes have been investigated. Activation, stimulation and relative toxicity factor indices are studied as well as possible relationships between the DNA and protein synthesis rates, as measured by simultaneous 3H-TdR and 14C-leucine uptake.
Studies on the Toxicity and Binding Kinetics of Abrin in Normal and Epstein Barr Virus-Transformed Lymphocyte Culture-I: Experimental Results – 2
Authors: Bennett Carol E. , Glassman Armand , Witten Matthew
Published: October 2008

The effects of treatment with varying doses of abrin, a D-galactose binding lectin, on DNA and protein synthesis of normal and Epstein Barr virus-transformed lymphocytes have been investigated. Studies of activation and stimulation indices, as well as two new indices; the metabolic self and cross-coupling indices, lead to the prediction that there are three morphologically distinct subpopulations of EBV-transformed lymphocytes with different abrin binding site numbers. This conclusion is supported by SEM morphological differences.
Effect of a Hemodiafiltration Session with On-Line Regeneration of the Ultrafiltrate on Oxidative Stress
Authors: González-Diez B. , Cavia M. , Torres G. , Abaigar P. , Muñiz P.
Published: October 2008

Background: The influence of a dialysis session using hemodiafiltration with on-line regeneration of the ultrafiltrate (HFR) is compared with that of a conventional hemodialysis session with polysulfone (HD-PS) and with a group of healthy individuals. Methods: Total antioxidant capacity (TAC), antioxidants, i.e., superoxide dismutase (SOD) glutathione peroxidase (GPX), reduced glutathione (GSH) and catalase, and biomarkers of oxidative stress were evaluated in plasma, whole blood and lymphocytes. Results: The study showed decreased plasma TAC, decreased activities of antioxidant enzymes and decreased GSH levels along with increased thiobarbituric-acid-reactive substances and 8–hydroxy-2-deoxyguanosine (8-OHdG) levels in lymphocytes. The antioxidants and biomarkers of lipid and protein damage after dialysis sessions with HFR were similar or better than following HD-PS. Thus, the blood GPX activity was comparable to that of healthy controls and significantly better than following HD-PS. An increase in 8-OHdG levels was observed in the HD-PS group after dialysis but not in the HFR group. Conclusions: These results show that HFR induces less oxidative stress than HD-PS.
Frontotemporal Dementia: Change of Familial Caregiver Burden and Partner Relation in a Dutch Cohort of 63 Patients
Authors: Riedijk Samantha , Duivenvoorden Hugo , Rosso Sonia , Van Swieten John , Niermeijer Martinus , Tibben Aad
Published: October 2008

Background/Aims: The current study examined the change of caregiver burden and the development of the quality of the partner relation in frontotemporal dementia (FTD). Methods: During a 2-year period, deterioration, behavioural problems, caregiver burden, general psychopathology, quality of life, social support, coping strategies and relationship quality were inspected in 63 FTD caregiver-care recipient dyads. Results: After 2 years patients reached maximum dementia severity with stable Neuropsychiatric Inventory levels. Contrary to expectations, caregiver burden decreased and psychological well-being remained stable. Coping style and social support changed unfavourably. Relationship closeness and getting along were preserved, whereas communication and sharing viewpoint on life were dramatically reduced. Conclusions: FTD caregivers need support in coping with the increasingly hopeless situation of their patients. Future research methods into caregiver burden should address response shift as a means for psychological adjustment.
Stereoselective Glucuronidation of Propranolol in Human and Cynomolgus Monkey Liver Microsomes: Role of Human Hepatic UDP-Glucuronosyltransferase Isoforms, UGT1A9, UGT2B4 and UGT2B7
Authors: Hanioka Nobumitsu , Hayashi Keiko , Shimizudani Takeshi , Nagaoka Kenjiro , Koeda Akiko , Naito Shinsaku , Narimatsu Shizuo
Published: October 2008

The stereoselective glucuronidation of propranolol (PL) in human and cynomolgus monkey liver microsomes, and the roles of human hepatic UDP-glucuronosyltransferase (UGT) isofoms involved in the enantiomeric glucuronidation of PL using recombinant UGT enzymes were investigated. In Michaelis-Menten plots, R- and S-PL glucuronidation by human liver microsomes showed sigmoidal kinetics whereas the kinetics of enantiomeric PL glucuronidation by cynomolgus monkey liver microsomes was monophasic. The Km, Vmax and CLint values of cynomolgus monkey liver microsomes were generally higher than the S50, Vmax and CLmax values of human liver microsomes in R- and S-PL glucuronidation. The glucuronidation of R- and S-PL was catalyzed by at least 3 UGT isoforms: UGT1A9, UGT2B4 and UGT2B7. Michaelis-Menten plots for R- and S-PL glucuronidation by UGT1A9 were monophasic, whereas the kinetics of UGT2B7 showed sigmoidal curves. Enantiomeric R-PL glucuronidation by UGT2B4 showed sigmoidal kinetics, whereas S-PL glucuronidation displayed monophasic kinetics. UGT1A9 showed remarkable stereoselectivity in Vmax and CLint values of R-PL < S-PL. These findings demonstrate that the profiles of enantiomeric PL glucuronidation in human and cynomolgus monkey liver microsomes are largely different and suggest that the human hepatic UGT isofoms UGT1A9, UGT2B4 and UGT2B7 play distinctive roles in enantiomeric PL glucuronidation.
Relationships among Lightning, Precipitation, and Hydrometeor Characteristics over the North Pacific Ocean*
Authors: Pessi Antti T. , Businger Steven
Published: October 2008

Lightning data from the Pacific Lightning Detection Network (PacNet) and Lightning Imaging Sensor (LIS) on the Tropical Rainfall Measuring Mission (TRMM) satellite were compared with TRMM precipitation radar products and latent heating and hydrometeor data. Three years of data over the central North Pacific Ocean were analyzed. The data were divided into winter (October–April) and summer (June–September) seasons. During the winter, the thunderstorms were typically embedded in cold fronts associated with eastward-propagating extratropical cyclones. Summer thunderstorms were triggered by cold upper-level lows associated with the tropical upper-tropospheric trough (TUTT). Concurrent lightning and satellite data associated with the storms were averaged over 0.5° × 0.5° grid cells and a detection efficiency correction model was applied to quantify the lightning rates. The results of the data analysis show a consistent logarithmic increase in convective rainfall rate with increasing lightning rates. Moreover, other storm characteristics such as radar reflectivity, storm height, ice water path, and latent heat show a similar logarithmic increase. Specifically, the reflectivity in the mixed-phase region increased significantly with lightning rate and the lapse rate of Z decreased; both of these features are well-known indicators of the robustness of the cloud electrification process. In addition, the height of the echo tops showed a strong logarithmic correlation with lightning rate. These results have application over data-sparse ocean regions by allowing lightning-rate data to be used as a proxy for related storm properties, which can be assimilated into NWP models.
An Interpretation of Baroclinic Initial Value Problems: Results for Simple Basic States with Nonzero Interior PV Gradients
Authors: de Vries Hylke , Methven John , Frame Thomas H. A. , Hoskins Brian J.
Published: October 2008

In the Eady model, where the meridional potential vorticity (PV) gradient is zero, perturbation energy growth can be partitioned cleanly into three mechanisms: (i) shear instability, (ii) resonance, and (iii) the Orr mechanism. Shear instability involves two-way interaction between Rossby edge waves on the ground and lid, resonance occurs as interior PV anomalies excite the edge waves, and the Orr mechanism involves only interior PV anomalies. These mechanisms have distinct implications for the structural and temporal linear evolution of perturbations.

Here, a new framework is developed in which the same mechanisms can be distinguished for growth on basic states with nonzero interior PV gradients. It is further shown that the evolution from quite general initial conditions can be accurately described (peak error in perturbation total energy typically less than 10%) by a reduced system that involves only three Rossby wave components. Two of these are counterpropagating Rossby waves—that is, generalizations of the Rossby edge waves when the interior PV gradient is nonzero—whereas the other component depends on the structure of the initial condition and its PV is advected passively with the shear flow. In the cases considered, the three-component model outperforms approximate solutions based on truncating a modal or singular vector basis.
Investigation of Droplet Size Distributions and Drizzle Formation Using A New Trajectory Ensemble Model. Part II: Lucky Parcels
Authors: Magaritz L. , Pinsky M. , Krasnov O. , Khain A.
Published: October 2008

A novel trajectory ensemble model of the cloud-topped boundary layer containing 1340 Lagrangian parcels moving with a turbulent-like flow with the observed statistical properties was applied to investigate the formation of the microphysical structure of stratocumulus clouds (Sc) in a nonmixing limit (when turbulent mixing between the parcels is not taken into account). The Sc observed in two research flights during the Second Dynamics and Chemistry of the Marine Stratocumulus field study (DYCOMS II)—RF01 (no drizzle) and RF07 (weak drizzle)—are simulated. The mechanisms leading to a high variability of droplet size distributions (DSDs) with different spectrum width and dispersion are discussed. Drizzle formation was investigated using the radar reflectivity–LWC and LWC–effective drop radius diagrams simulated by the model in the nondrizzle and drizzle cases. It is shown that in the RF07 case large cloud droplets that trigger drop collisions and drizzle formation form only in a small fraction (about 1%) of the parcels (which will be referred to as lucky parcels) in which LWC exceeds ∼1.5 g m−3. This value exceeds the horizontally averaged LWC maximum value of 0.9 g m−3 by two to three standard deviations, indicating a small amount of lucky parcels. In a nondrizzling cloud simulation this threshold is exceeded extremely rarely. The dependence of the threshold value of LWC on aerosol concentration is discussed. The lucky parcels (at least in the nonmixing limit) start their updraft in the vicinity of the surface, where the water vapor mixing ratio is maximum, and ascend to the highest levels close to the cloud top. It is shown that the lucky parcel tracks are related to the large eddies in the boundary layer, which indicates the substantial role of large eddies in drizzle formation.
Aerosol Radiative Forcing and Forcing Efficiency in the UVB for Regions Affected by Saharan and Asian Mineral Dust
Authors: García O. E. , Díaz A. M. , Expósito F. J. , Díaz J. P. , Redondas A. , Sasaki T.
Published: October 2008

The influence of mineral dust on ultraviolet energy transfer is studied for two different mineralogical origins. The aerosol radiative forcing ΔF and the forcing efficiency at the surface ΔFeff in the range 290–325 nm were estimated in ground-based stations affected by the Saharan and Asian deserts during the dusty seasons. UVB solar measurements were taken from the World Ozone and Ultraviolet Data Center (WOUDC) for four Asian stations (2000–04) and from the Santa Cruz Observatory, Canary Islands (2002–03), under Gobi and Sahara Desert influences, respectively. The Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth at 550 nm was used to characterize the aerosol load τ, whereas the aerosol index provided by the Total Ozone Mapping Spectrometer (TOMS) sensor was employed to identify the mineral dust events. The ΔF is strongly affected by the aerosol load, the values found being comparable in both regions during the dusty seasons. Under those conditions, ΔF values as large as −1.29 ± 0.53 W m−2 (τ550 = 0.48 ± 0.24) and −1.43 ± 0.38 W m−2 (τ550 = 0.54 ± 0.26) were reached under Saharan and Asian dust conditions, respectively. Nevertheless, significant differences have been observed in the aerosol radiative forcing per unit of aerosol optical depth in the slant path, τS. The maximum ΔFeff values associated with dust influences were −1.55 ± 0.20 W m−2 τS550−1 for the Saharan region and −0.95 ± 0.11 W m−2 τS550−1 in the Asian area. These results may be used as a benchmark database for establishing aerosol corrections in UV satellite products or in global climate model estimations.
The Mesoscale Kinetic Energy Spectrum of a Baroclinic Life Cycle
Authors: Waite Michael L. , Snyder Chris
Published: October 2008

The atmospheric mesoscale kinetic energy spectrum is investigated through numerical simulations of an idealized baroclinic wave life cycle, from linear instability to mature nonlinear evolution and with high horizontal and vertical resolution (Δx ≈ 10 km and Δz ≈ 60 m). The spontaneous excitation of inertia–gravity waves yields a shallowing of the mesoscale spectrum with respect to the large scales, in qualitative agreement with observations. However, this shallowing is restricted to the lower stratosphere and does not occur in the upper troposphere. At both levels, the mesoscale divergent kinetic energy spectrum—a proxy for the inertia–gravity wave energy spectrum—resembles a −5/3 power law in the mature stage. Divergent kinetic energy dominates the lower stratospheric mesoscale spectrum, accounting for its shallowing. Rotational kinetic energy, by contrast, dominates the upper tropospheric spectrum and no shallowing of the full spectrum is observed. By analyzing the tendency equation for the kinetic energy spectrum, it is shown that the lower stratospheric spectrum is not governed solely by a downscale energy cascade; rather, it is influenced by the vertical pressure flux divergence associated with vertically propagating inertia–gravity waves.
Equilibration of Baroclinic Turbulence in Primitive Equations and Quasigeostrophic Models
Authors: Zurita-Gotor Pablo , Vallis Geoffrey K.
Published: October 2008

This paper investigates the equilibration of baroclinic turbulence in an idealized, primitive equation, two-level model, focusing on the relation with the phenomenology of quasigeostrophic turbulence theory. Simulations with a comparable two-layer quasigeostrophic model are presented for comparison, with the deformation radius in the quasigeostrophic model being set using the stratification from the primitive equation model. Over a fairly broad parameter range, the primitive equation and quasigeostrophic results are in qualitative and, to some degree, quantitative agreement and are consistent with the phenomenology of geostrophic turbulence.

The scale, amplitude, and baroclinicity of the eddies and the degree of baroclinic instability of the mean flow all vary fairly smoothly with the imposed parameters; both models are able, in some parameter ranges, to produce supercritical flows. The criticality in the primitive equation model, which does not have any convective parameterization scheme, is fairly sensitive to the external parameters, most notably the planet size (i.e., the f /β ratio), the forcing time scale, and the factors influencing the stratification. In some parameter settings of the models, although not those that are most realistic for the earth’s atmosphere, it is possible to produce eddies that are considerably larger than the deformation scales and an inverse cascade in the barotropic flow with a −5/3 spectrum. The vertical flux of heat is found to be related to the isentropic slope.
Regimes of Dry Convection above Wildfires: Idealized Numerical Simulations and Dimensional Analysis*
Authors: Kiefer Michael T. , Parker Matthew D. , Charney Joseph J.
Published: October 2008

Wildfires are capable of inducing atmospheric circulations that result predominantly from large temperature anomalies produced by the fire. The fundamental dynamics through which a forest fire and the atmosphere interact to yield different convective regimes is still not well understood. This study uses the Advanced Regional Prediction System (ARPS) model to investigate the impact of the environmental (i.e., far upstream, undisturbed by fire) wind profile on dry convection above a prescribed heat source of an intensity and spatial scale comparable to a wildfire. Dimensional analysis of the fire–atmosphere problem provides two relevant parameters: a surface buoyancy parameter that addresses the amount of heat a parcel of air receives in transiting above the fire and an advection parameter that addresses the degree to which the environmental wind advects updrafts away from the fire. Two-dimensional simulations are performed in which the upstream surface wind speed and mixed layer mean wind speed are varied independently to better understand the fundamental processes governing the organizational mode and updraft strength.

The result of these experiments is the identification of two primary classes of dry convection: plume and multicell. Simulated plume cases exhibit weak advection by the mean wind and are subdivided into intense plume and hybrid classes based on the degree of steadiness within the convection column. Hybrid cases contain columns of largely discrete updrafts versus the more continuous updraft column associated with the intense plume mode. Multicell cases develop with strong mixed layer advection and are subdivided into strong and weak classes based on the depth of convection. Intense plume and strong multicell (hybrid and weak multicell) cases occur when the surface buoyancy is large (small). Parcel analyses are performed to more closely examine the forcing of convection within different areas of the parameter space. The multicell (strong and weak) and intense plume modes are forced by a combination of buoyancy and dynamic pressure gradient forcing associated with the perturbation wind field, whereas the hybrid mode is forced by a combination of buoyancy and dynamic pressure gradient forcing associated with the strong background shear.

The paper concludes with a discussion of the degree of nonlinearity that is likely to exist at the fire front for each of the convective modes; nonlinear fire behavior is most likely for the hybrid mode and least likely for the weak multicell mode. Knowledge of the sensitivity of the convective mode to upstream conditions can provide information about the degree of nonlinear or erratic fire behavior expected for a given wind profile upstream of the fire.