bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of attached data‐loggers on the activity budgets of captive Humboldt penguins
Authors: Simeone Alejandro , Wilson Rory P. , Knauf Gabriele , Knauf Werner , Schützendübe Jeannine
Published: October 2002

Although they can provide valuable information on at‐sea ecology, data‐loggers may adversely affect energetics, diving performance, and breeding success of equipped birds. With the aim of determining the effects of leg‐attached data‐loggers on the activity budgets of Humboldt penguins (Spheniscus humboldti) while on land, we equipped birds kept at the Landau Zoo, Landau, Germany, with such devices. We followed them during sample periods and recorded the occurrence and length of behaviors. Birds quickly habituated to the devices within 1 day of deployment, and mean rates of device‐pecking were low (0.7–1.7 pecks/hr), with device‐induced behaviors accounting for <1% of the mean daily activity budget. The method of device attachment appears behaviorally less stressful than the traditional tape‐based system in which devices are normally attached to the penguin's back. By facilitating the testing of newly developed data‐loggers on captive birds, or the development of methods for device attachment, zoos and aquaria may strengthen their role in animal conservation by helping research on free‐ranging animals. Zoo Biol 21:365–373, 2002. © 2002 Wiley‐Liss, Inc.
Regional collection planning for speciose taxonomic groups
Authors: Smith Brandie , Hutchins Michael , Allard Ruth , Warmolts Doug
Published: October 2002

Regional collection planning and implementation are essential if professional zoological parks and aquariums are to achieve their collective conservation and animal management goals. Several regional associations currently have taxon advisory groups (TAGs) in place whose primary role is to develop taxon‐specific collection plans. During their planning process, TAGs review all known taxa of interest and evaluate them based on relevant criteria. TAGs also evaluate the total amount of captive space available to determine the number of priority taxa that can be maintained. In addition, some TAGs heighten their impact on conservation by producing an action plan of select conservation and research projects to be supported by participating institutions. Although current guidelines for regional collection plan (RCP) development are extremely useful for some TAGs, such as those for most mammalian taxa, they do not address the needs of other more speciose TAGs, such as those for fish, invertebrates, and amphibians. These TAGs, characterized by their numerous taxa and more flexible space requirements, still need to develop plans for the species they manage. We recommend that highly speciose TAGs make development of an action plan their highest priority and use it to direct the RCP process. This will limit the number of taxa they need to consider, while ensuring that their RCPs are directly relevant to conservation. Once their action plans have been developed, speciose TAGs can then determine which species are most important to zoological collections and at what level they should be managed. This strategy represents a departure from the current processes used to develop RCPs for many mammalian and avian species and, as such, has not yet been addressed. An action plan‐driven approach will result in more practical and relevant planning for speciose TAGs. Zoo Biol 21:313–320, 2002. © 2002 Wiley‐Liss, Inc.
Enzyme‐immunoassay for the measurement of luteinizing hormone in the serum of African elephants (Loxodonta africana)
Authors: Graham Laura H. , Bolling Jeff , Miller Gary , Pratt‐Hawkes Nancy , Joseph Sharon
Published: October 2002

Circulating patterns of progesterone and luteinizing hormone (LH) in the elephant have been well characterized, and routine monitoring of these hormones is now viewed as a valuable tool for making informed decisions about the reproductive management of elephants in captivity. Currently, LH monitoring in elephants is done with radio‐immunoassays (RIAs); unfortunately, the use of radioactive materials in RIAs limits their application to institutions with laboratory facilities equipped for the storage and disposal of radioactive waste. Enzyme‐immunoassays (EIAs) offer an inexpensive and more zoo‐friendly alternative to RIA. This work reports on an EIA capable of quantifying circulating LH in African elephants. The EIA employs a biotin label and microtiter plates coated with goat anti‐mouse gamma globulin. LH surges in African elephants (n=3) increased fivefold over baseline concentrations (1.00±0.1 ng/ml vs. 0.2±0.1 ng/ml) and occurred 19.3±0.2 days apart. Ovulatory LH surges were associated with an increase in serum progestogens from 4.8±0.4 ng/ml to 11.7±0.4 ng/ml. The ability to quantify reproductive hormones in elephants via EIA is an important step in the process of making endocrine monitoring more accessible to zoos housing these species. Zoo Biol 21:403–408, 2002. © 2002 Wiley‐Liss, Inc.
Partial activation of surf clam oocytes by hypertonic treatment.
Authors: Coutu Louise , Larochelle Stéphane , Dubé François
Published: October 2002

In prophase I‐arrested surf clam oocytes, fertilization is the normal trigger for resumption of meiosis, first evidenced by germinal vesicle breakdown (GVBD). Various artificial agents are able to induce GVBD and most of them require the presence of external Ca2+ to be efficient. One exception to this rule is the reported possibility of inducing GVBD by an hypertonic treatment, using high concentrations of glycerol, in the complete absence of external Ca2+. We have investigated the processes underling glycerol‐induced activation and found that, under this condition, GVBD shows very slow kinetics and is not followed by any normal subsequent steps of meiosis, such as formation of metaphase chromosomes or polar body extrusion. Glycerol‐activated oocytes do not show the normal response in protein synthesis but they undergo increased protein phosphorylation which is inhibited by 6‐dimethylaminopurine (6‐DMAP), which also inhibits GVBD. We conclude that the hypertonic treatment by glycerol, in the complete absence of external Ca2+, induces a partial program of activation through increased protein phosphorylation but that the normal full response requires an increased Ca2+ influx as triggered by other well‐known artificial activating agents.
Modulation of glycolysis induction in primary cultures of rabbit kidney proximal tubule cells: the role of shaking, glucose and insulin.
Authors: Monteil Christelle , Leclere Caroline , Dantzer Françoise , Elkaz Veronika , Fillastre Jean‐Paul , Morin Jean‐Paul
Published: October 2002

We have assessed the impact of increasing oxygen availability on cellular phenotype expression of rabbit proximal tubule cells in primary culture developed with variable glucose and/or insulin contents. To mitigate hypoxia at the cell/medium interface, cells were shaken for the whole culture duration and their expressed phenotype was compared with those expressed by static cultures. O2 and CO2 tensions were kept constant in the incubator atmosphere. Glycolysis and gluconeogenesis pathways, detoxication system, and mitochondrial, apical and basolateral membrane marker enzyme activities were assessed. This study showed that the induction of glycolysis which appear in primary cultures of proximal tubule cells may be partially prevented by continuously shaking the cultures. This effect was more marked in the presence of glucose, suggesting better substrate oxidation in shaken cultures.
Immunodetection of spectrin antigens in plant cells
Authors: De Ruijter Norbert , Emons AnneMie
Published: October 2002

The occurrence of spectrin in plant cells was studied by immunoblotting of extracts, and its localization by immunolabelling of cells, using two polyclonal antibodies raised against spectrin from human and chicken erythrocytes. A variety of plant cells were studied. The two antibodies gave the same results on blots as well as on cells. Western blots of extracts showed weak immunolabelling at 220 kD, where spectrin can be expected, but bands at 85 kD stained more heavily. Because the latter bands were also seen on blots with commercially purified spectrin, we conclude that they were breakdown products of spectrin. Native plant extracts on blots from IEF gels showed a band at pI 4.8, where the purified animal spectrin is also found. Immunolocalizations done on whole cells, PEG‐, BMM‐, or cryo‐sections gave similar data. In most cells the labelling was localized predominantly at the plasma membrane, especially of thin‐walled cells. Labelling was also seen in the periphery of a particular class of organelles, probably plastids. This labelling was tissue specific in maize somatic embryos. During carrot somatic embryogenesis cytoplasmic labelling was observed depending on the developmental stage. Many cells with cytoplasmic labelling also had stained nuclei. Labelled nuclei had more condensed chromatin than non‐labelled nuclei.
The distribution of secretory products in plant cells is affected by brefeldin A
Authors: Satiat‐Jeunemaitre Béatrice , Hawes Chris
Published: October 2002

The patterns of redistribution of two classes of Golgi derived cell surface antigens recognised by monoclonal antibodies JIM1 and JIM7, after the treatment of roots with Brefeldin A (BFA) are described. The results for these secretory products are compared with those previously reported for Golgi membrane epitopes recognised by JIM 84. The preliminary results described here demonstrate that the combination of immunocytochemical techniques with drug induced perturbation of secretory pathways will be invaluable in enhancing our understanding of the pathways of intracellular trafficking in plants.
Spatial and temporal patterns of B hordein synthesis in developing barley (Hordeum vulgare L.) caryopses
Authors: Davies J. T. , Shewry P. R. , Harris N.
Published: October 2002

mRNA species encoding B hordeins and B hordein protein have been localised in developing barley caryopses using in situ hybridisation and immunocytochemistry. B hordeins are first detected immunocytochemically in sections from 5 dpa (days post anthesis) barley caryopses. At this stage the endosperm is well differentiated and hordein levels are relatively constant across the starchy endosperm though notably absent from the aleurone layer. Analysis of serial transverse sections through later stages of caryopsis development (7‐10 dpa) show a distinct differential accumulation of B hordeins. Hordeins accumulate at the periphery of the starchy endosperm, towards the apex and along the endosperm/scutellum boundary. Using in situ hybridisation B hordein mRNA was detected in equivalent patterns to the protein indicating that there is regulation of gene product accumulation at a transcriptional level. 3‐D reconstruction of hordein in developing barley caryopses have been made using data from multiple serial sections in conjunction with a commercial computer‐aided design package.
Outer membrane protein gene expression traced by immunogold labelling in Rhizobium Leguminosarum bv. viciae strain 248 in Vicia sativa ssp. nigra.
Authors: Goosen‐de Roo Leentje , De Maagd Ruud A. , Lugtenberg Ben J. J.
Published: October 2002

During differentiation from bacterium into nitrogen fixing bacteroid, the outer membrane protein RopA decreases in density. Comparison between size increase of the rhizobia and density decrease of a RopA protein epitope after immuno‐gold labelling, indicates that although ropA gene expression stops at the onset of nitrogen fixation, the amount of RopA protein probably remains the same.
Cytoskeleton‐bound polysomes in plants. III. Polysome‐cytoskeleton‐membrane interactions in corn endosperm.
Authors: Davies E. , Comer E. C. , Lionberger J. M. , Stankovic B. , Abe S.
Published: October 2002

Over 80% of the polysomes in corn endosperm sediment along with protein bodies at 30 xg from seeds ground in cytoskeleton‐stabilizing buffer. The cytoskeleton‐disrupting agents, Tris‐HCl, K+, heparin, and sodium deoxycholate cause polysome release, while protease K and the non‐ionic detergent, PTE, are effective only in the presence of these agents, and RNase is almost without effect. We suggest that many of the polysomes in corn endosperm are associated via their ribosomes, but not mRNA or nascent polypeptides with the actin component of the cytoskeleton and only indirectly with membranes. Corn endosperm homogenates examined under the fluorescence microscope show polysomes coating individual protein bodies and co‐localizing with actin, but not with ER.
Phagocytic activity of Dictyostelium amoebae treated with an organochlorine pesticide.
Authors: Gayatri R. , Chatterjee S.
Published: October 2002

The effect of an organochlorine pesticide benzene hexachloride (containing α, β, γ and δ isomers) on the phagocytic activity of the vegetative cells of Dictyostelium discoideum was investigated. Benzene hexachloride (BHC) at concentrations of 60 ppm and above inhibited the phagocytic activity as revealed by 3H‐labelled E. coli uptake. The BHC treated cells also showed smaller and delayed plaque formation. Interactions of lipophilic pesticide with the hydrophobic cell surface presumably alters the receptor mediated phagocytosis of Dictyostelium amoebae.
The effect of differentiation inducers on the integrin expression of K562 erythroleukemia cells.
Authors: Järvinen Maarit , Ylänne Jari , Virtanen Ismo
Published: October 2002

We studied the effects of differentiation‐inducers on the integrin profile and adhesive properties of K562 leukemia cells. The fibronectin (Fn) receptor integrin, α5β1, was the only integrin expressed in suspension cultured K562 cells. When the cells were exposed to 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) immunoreactivity for the β1 integrin subunit was slightly enhanced. TPA exposure also induced the appearance of the α2, α3, αv and β3 integrin subunits, but the platelet integrin subunit αIIb was not detected. On the other hand, hemin chloride‐induced erythroid differentiation of K562 cells diminished the expression of the α5β1 integrin on the surface of the cells. Adhesion experiments with TPA‐exposed K562 cells indicated that although the adherence to the extracellular matrix (ECM) proteins as a rule was low a few cells spread on these proteins. The present results specify the effects of differentiation inducers on the integrin profile of K562 cells and excludes the comprehension that TPA would induce expression of the platelet integrin αIIb on their surface. Our results also show, that an increased expression of a certain integrin does not necessarily lead to a comparable adhesion ability on its ligand in vitro.
Suppression of DNA synthesis and induction of apoptosis in rat prostrate by human seminal plasma inhibin (HSPI).
Authors: Mundle Suneel D. , Sheth Nandini A.
Published: October 2002

In vivo administration of HSPI (10.7 kDa FSH suppressing peptide of prostate) to intact adult male rats was found to suppress the basal levels of incorporation of 3H‐thymidine into DNA of ventral and dorsolateral lobes of the prostate, in a dose‐dependent manner. Interestingly, microscopic examination of the prostate histology of HSPI treated rats revealed a significantly increased incidence of apoptotic bodies which are indicative of cell death. In another experiment, HSPI was also found to suppress the active DNA synthesis in testosterone‐induced regrowth of prostate in castrated rats. Thus HSPI can suppress the basal and stimulated DNA synthesis and also induce apoptotic cell death in rat prostate.
Synergistic effect of interferon‐γ and phorbol myristate acetate on superoxide production by human monocytes.
Authors: Wolfson Marina , Nathan Ilana , Aharon Miriam , Dvilansky Alexander , Aboud Mordechai
Published: October 2002

This study demonstrates a synergistic effect of IFNγ and PMA on superoxide generation by human monocytes. A strict correlation was observed between the induction of superoxide production and PK‐C activation by PMA alone. No such correlation was evident for IFNγ. However, exposure of the cells to IFNγ for 10 to 15 hr prior to PMA treatment enhanced both superoxide production and PK‐C activation. Using protein kinase inhibitors, we noticed that while PMA exerted its effect by activating PK‐C, IFNγ operated via activation of calcium/calmodulin‐dependent or some other calcium‐dependent protein kinases. These kinases appeared to be involved in the effect of IFNγ on superoxide production, as well as in its potentiation of PMA activity.
In patients with common variable immunodeficiency, interleukin‐6 and expression of its receptor on B‐cells are normal
Authors: Junker U. , Heyden‐Rynsch B. v. d. , Dieher C. , Vogelsang H. , Jäger L.
Published: October 2002

In a group of patients suffering from common variable immunodeficiency (CVID), levels of interleukin‐6 (IL6) were measured and found to be in the normal range or even increased, for single patients. IL6 production of peripheral blood mononuclear cells was shown to be in the normal range when corrected for monocyte number. To exclude the possibility that the Interleukin‐6 receptor (IL6R) on B‐cells is missing, its expression was measured by assessing the binding of a Phycoerythrin‐derivative of IL6 by flow cytometry and correlated with various markers for B‐cells and T‐cells. As compared with normal controls, no statistically significant deviation of the group as a whole nor for individual patients could be shown. It was concluded that lack of B cell differentiation in the presence of normal to high IL6 as shown for these patients is not due to inability of the B cells to detect IL6 in the serum.
Role of stress fibers in the association of intermediate filaments with microtubules in fibroblast cells.
Authors: Roy Sujata Guha
Published: October 2002

The association between intermediate filaments (IF) and microtubules (MT) has been demonstrated by several experiments using MT inhibitors and by microinjecting specific antibodies. The actin cytoskeleton has recently been assigned a role in this process of drug induced IF collapse. However, this was not found to be true in large cells with irregular morphology. For instance, in early passage diploid fibroblasts of human origin and in armadillo cell lines, where the cells are large, irregular in shape and exhibit prominent stress fibers (SF), depolymerization of MT with nocodazole did not lead to collapse of IF. Instead, the IF formed bundles of coils that seemed to associate with the SF. Disintegration of the SF with cytochalasin B led to the collapse of the IF. It appears that the actin organization in such large cells with extensive SF, is not as contractile as in typical spindle shaped fibroblasts which have relatively less stable actin organization. The stable SF may actually prevent IF collapse.
Elemental mapping of fluorine using electron spectroscopic imaging for the intracellular localisation of an anthracycline drug (ME2303) in human ovarian cancer cells.
Authors: Huxham I. M. , Barlow A. L. , Mairs R. , Gaze M. N. , Workman P.
Published: October 2002

A major limitation to the clinical usefulness of cancer chemotherapy is the onset of acquired drug resistance, in which the effectiveness of a drug such as Doxorubicin (DOX), used in a wide variety of neoplasms, diminishes following repeated administration. Resistance is associated with drug exclusion from tumour cell nuclei. New analogues of DOX have been synthesised to reduce patient cardiotoxicity and to increase anti‐tumour activity. More recently, a 2‐fluoroglycoside of DOX (ME2303) has been shown to be more resistant to glycolysis and has marked anti‐proliferative effects on DOX‐resistant tumours. The aim of the current study was therefore to determine the intracellular localisation of ME2303 in drug sensitive and resistant human ovarian cancer cell aggregates by mapping fluorine, as a means of understanding the complex mechanisms of drug resistance. Cell aggregates of the human ovarian cell line A2780 and its DOX‐resistant subline 2780AD were cultured for 1hr in 5μM of the drug ME2303, then chemically fixed and embedded in Lowicryl K4M using alcohol dehydration at −20°C. Ultrathin sections (40‐50nm) were examined on a Zeiss TEM 902 energy filtering electron microscope using 80Kv at a magnification of 12,000x. Fluorine maps were generated using the two window method by collecting two integrated images above and two integrated images below the K ionisation edge for fluorine (685eV) with a 15eV window. Image sequences were collected within 20sec to minimise the effects of mass loss from the specimen via a Dage SIT 66 video camera connected to a DT 2861 video interface board (512x512 pixels with 256 grey levels) within a 486 PC. In the A2780 cell line, fluorine was found to be distributed diffusely within the cytoplasm and at discrete sites within the nucleus. In contrast, fluorine in the 2780AD subline (co‐cultured with 1.4μM DOX to maintain resistance) was found to be largely associated with the peri‐nuclear Golgi region and with mitochondria, but was also found within cell nuclei, along the inner nuclear envelope and in the nucleolus. The intra‐nuclear localisation of fluorine suggests that even in the presence of DOX, ME2303 can mediate anti‐proliferative activity in DOX resistant human ovarian cancer cells by effective nuclear translocation.
Active ribosomal cistrons in plant nucleolus
Authors: Ghosh S. , Chakrabarti A. , Chaudhuri S. K.
Published: October 2002

In onion root‐tip cell nucleoli some tapered cylindrical structures appear in the dense fibrillar component (DFC) after cycloheximide treatment. These structures resemble the "Christmas‐tree" like configurations which have been noted in spread preparations from the nucleoli. The similarities in their general appearance are strengthened by observations after RNase and pepsin digestions. The presence of such structures in the DFC of prophase nucleoli has also been demonstrated. These observations indicate the presence of active ribosomal cistrons in DFC of the nucleolus. It is proposed that nucleolar transcription becomes initiated in the DFC around the FC (fibrillar centres) and then these transcripts along with their axis move to the granular component (GC) for their processing. As such some of these structures were observed to penetrate into the GC.
Changes in prometaphase chromosome motion are dependent on experimentally induced changes in kinetochore structure.
Authors: Geck David C. , Snyder Judith A.
Published: October 2002

Prometaphase PtK1 cells are treated with low concentrations of sucrose in order to analyze its effects on kinetochore structure, microtubule (MT) associations with the developing kinetochore and chromosome congression. Prometaphase cells treated with 0.15M sucrose slows chromosome congression, yet chromosomes form a metaphase configuration. However, 0.2M sucrose treatment prevents chromosome congression and affects some of the kinetochore MT linkages with the kinetochore, resulting in loss of chromosome congression. We use time lapse video microscopy and ultrastructural analysis to correlate changes in the linkages in the kinetochore MTs and the kinetochore to explain these findings. It appears hyperosmotic shock treatment can produce non‐functional linkages between kinetochore MTs and kinetochores such that chromosome congression is affected. When non‐functional linkages are formed, the presence of both a corona and matrix‐like material is also present, proximal to the kinetochore. The role of this material and its organization at the klnetochore is discussed in its relation to generating mitotic forces.
The effect of in vitro heating on the distribution of nuclear matrix polypeptides in HeLa cells
Authors: Martelli A. M. , Bareggi R. , Riederer B. M. , Marugg R. A. , Narducci P.
Published: October 2002

The in situ nuclear matrix was obtained from HeLa cells. After permeabilization with nonionic detergent, the resulting structures were incubated for 1h at 37°C to determine whether or not such an incubation might result in the redistribution of nuclear polypetides which resisted extraction with buffers of high‐ionic strength (1.6 M NaCl or 0.25 M (NH4)2SO4 as well as DNase I digestion. Using indirect immunofluorescence experiments and monoclonal antibodies we show that heating to 37° C changes the distribution of a 160 kDa protein previously shown to be a component of the inner matrix network. On the other hand, a 125 kDa polypeptide was not affected at all by the incubation. Our results clearly indicate that the inclusion of a 37°C incubation (for example during digestion with DNase I) in the protocol to obtain the in situ nuclear matrix can result in the formation of in vitro artifacts.
Video enhanced laser scanning microscopic analysis of DNA comet formation.
Authors: Fairbairn Daryl W. , Rowe Kevin C. , O'Neill Kim L.
Published: October 2002

Laser Scanning Microscopy is a sensitive tool that provides a unique method of analyzing biological systems. Coupled with the Single Cell Gel assay, it allows for accurate and reproducible detection of DNA strand breaks. An understanding of the theory of DNA comet formation is lacking. Using dexamethasone induced apoptosis in murine thymocytes as a model for double strand breaks, we used video enhanced laser scanning microscopy to evaluate the leading edge of DNA migration in the single cell gel assay. In this system, comet length increases significantly within the first thirty seconds of electrophoresis, the greatest increase in length is completed within the first minute, and the first two minutes are important in significant increases in DNA migration during DNA comet formation.
ENDOCYTOSIS DURING POSTNATAL DIFFERENTIATION IN SUPERFICIAL CELLS OF THE MOUSE URINARY BLADDER EPITHELIUM
Authors: Romih Rok , Jezernik Kristijan
Published: October 2002

This electron microscopical study was performed in order to follow the endocytic pathway of horseradish peroxidase and colloidal gold tracers and to determine the involvement of endocytosis in postnatal differentiation in superficial cells of the mouse urinary bladder epithelium. Morphometric analyses of late endosomes/multivesicular bodies from day of birth to day 25 were performed. The internalisation and intracellular transport of luminal plasmalemma to multivesicular bodies via endocytic vesicles, early endosomes and pleomorphic compartments was established. Dynamic changes in endocytic activity took place within the first few days of postnatal differentiation. During this period the number of multivesicular bodies changed in an inverse ratio to their size. After the third day endocytic activity gradually approached the low rate of adult urothelium.
EVALUATION OF FREQUENCY OF MICRONUCLEI IN EXFOLIATED CELLS FROM BLADDER OF MICE TREATED WITH BENZO(A)PYRENE, 2‐ACETYLAMINOFLUORENE AND CYCLOPHOSPHAMIDE
Authors: Konopacka Maria
Published: October 2002

The micronucleus test (MNT) was applied in the epithelial cells from the bladder of mice treated with benzo(a)pyrene (BaP), 2‐acetylaminofluorene (2‐AAF) and cyclophosphamide (CP). Micronuclei (MN) were scored at different time on Feulgen and fast green stained smear preparations of exfoliated cells. These cells were obtained by scraping the internal surface of the bladder. The tested compounds gave the maximal response at 7‐10 days after treatment. The number of MN in epithelial cells was dose dependent. These results suggest that exfoliated bladder cells from mice can be used as indicators for genotoxic damage in proliferating cell populations.
Water channels in membranes
Authors: Benga Gheorghe
Published: October 2002

A systematic programme of comparative nuclear magnetic resonance measurements of the membrane permeability for water (Pd) and of activation energy (Ea,d) of this process in red blood cells of various wild, laboratory and domestic animals was carried out here. The RBC from humans, cow, sheep and kangaroos had Pd values around 5·10−3 cm/s at 25 °C, 7 · 10−3 cm/s at 37 °C with Ea,d values around 25 kJ/mol. For RBC from other ten marsupial species and from mouse, rat and rabbit, the Pd values were more than twice as high as for human RBC. For mosr RBC a high value of Pd was associated with a low value of Ea,d (range from 15 to 21 kJ/mol), pointing to specialized channels for water diffusion incorporated in membrane proteins. Recently a channel‐forming integral protein of 28 kDa (CHIP 28) was identified as a major water channel protein in the RBC membrane. A procedure for quantitating the purified CHIP 28 by densitometry of silver‐stained polyacrylmide gel electrophoreograms was developed. The analysis of a purified fraction of CHIP 28 showed that the 28 kDa component represents approximately two‐thirds of the sample with the remainder comprising the glycosylated high‐molecular‐weight component. A correlation between the content in CHIP 28 and the relative water permeability among RBC from different vertebrate species was attempted.
Synthesis and secretion of an estrus stage‐specific protein by rat uterus.
Authors: Yang L. S. , Marshall A. , Dao B. , Koide S. S.
Published: October 2002

A specific protein with an estimated molecular weight of 260 kDa was found to be synthesized and secreted into the incubation medium by rat uterus only during the estrus stage of the cycle. This secreted uterine protein was designated as estrus stage‐specific protein (ESP). ESP was not produced by pregnant, lactating or immature pup rat uteri. Estradiol administered to ovariectomized rats induced production of ESP which was blocked by the antiestrogen, ICI 182, 780. The present results show that the synthesis and secretion of ESP is regulated by estradiol and this protein maybe involved in blastocyst implantation.
Batten disease fibroblasts in culture accumulate mitochondrial ATP synthase subunit 9.
Authors: Tanner Allison , Dice J. Fred
Published: October 2002

Batten Disease is a lysosomal storage disease in which the major component that accumulates is subunit 9 of mitochondrial ATP synthase. Whether or not fibroblasts in culture exhibit this phenotype is controversial. We show that fibroblasts from a human Batten Disease patient and from a mouse model of this disease exhibit autofluorescent inclusion bodies. We also demonstrate that levels of ATP synthase subunit 9 are elevated in these diseased fibroblasts when compared to control cells. However, the exact growth state of the human fibroblasts was critical, and this factor probably accounts for discrepencies in the literature.
Digital image analysis of chromatin fibre phenotype after "in situ" digestion with restriction endonucleases
Authors: Gosálvez Jaime , López‐Fernández Carmen , Fernández José L. , Goyanes Vicente J. , Buño Ismael
Published: October 2002

Restriction Endonucleases (REs) may recognize, cleave and remove DNA from fixed chromatin producing specific chromosome banding patterns. However, the modifications produced in the chromatin fibre are not easy to evaluate and compare. The aim of the present investigation was to visualize differences resulting in the texture of the chromatin fibre from metaphase chromosomes after each digestion using digital image analysis (DIA) facilities. To this purpose, metaphase chromosomes derived from a L‐929 mouse cell line were digested with different REs (AluI, HpaII and HaeIII).

Since light microscopy does not permit the observation of the chromatin fibre, DIA was performed on digitalized images of metaphase chromosomes under electron microscopy. The application of a LUT (Look Up Table) within the DIA software assigns a colour to each grey level of a digital image. The results obtained using a particular LUT, which permits the discrimination of specific chromatin fibre phenotypes resulting from each digestion, are reported and compared with those obtained under the light microscope.
A comparative study of the desquamation of urothelial cells during gestation and in adults mice following moderate stress or endotoxin treatment
Authors: Jezernik K. , Medalia O. , Aronson M.
Published: October 2002

The present paper deals with the comparative EM study of the detachment of mouse urinary bladder epithelial cells under various physiological conditions, namely, during gestation and in adult mice following induction by endotoxin or by exposure to moderate stress. It has been shown that desquamation during gestation involves two distinct modes, shedding of single cells and formation of apoptotic bodies. Moderate stress in adult female mice induced by constant illumination for 72 or 96 hours, results in desquamation of superficial and intermediate cells. Application of LPS is followed by desquamation of single cells and whole sheets of cells.

Cell detachment involves interruption of tight junctions between neighbouring cells and formation of numerous cup shaped vesicles, multivesicular bodies and vacuoles at the base of desquamating cells. LPS induces desquamation entails delivery of lysosomal enzymes extracellulary into the intercellular space. In the areas of sloughing the bladder epithelium lack permeability barrier. Desquamated cells in the bladder lumen are mostly alive. These results clearly demonstrate the existence of specific adhesion mechanisms of detachment and desquamation of uroepithelial cells.
Genome size and chromosomes in marine sponges [Suberites domuncula, Geodia cydonium]
Authors: Imsiecke Georg , Custodio Marcio , Borojevic Radovan , Steffen Renate , Moustafa Mohamed A. , Müller Werner E. G.
Published: October 2002

The genome size of the marine sponges Suberites domuncula and Geodia cydonium has been determined by flow cytofluorometric analysis using diamidino‐phenylindole [DAPI]. Using human lymphocytes as reference the amount of DNA in cells from S. domuncula has been determined to be 3.7 pg and that of G. cydonium 3.3 pg. While no chromosomes could be identified in G. cydonium, the karyotype of the Suberites domuncula is 32 chromsomes in the diploid state. The size of the chromosomes was between 0.25 and 1.0 μm. No pronounced banding pattern was visible.
Modulation of human Caco‐2 intestinal epithelial cell phenotype by protein kinase C inhibitors
Authors: Basson Marc D. , Hong Fu
Published: October 2002

Protein kinase C (PKC) isoforms are altered in colon tumors and upon exposure of intestinal mucosa to nutrients. We evaluated the effects of the PKC inhibitors staurosporine and calphostin C on human Caco‐2 intestinal epithelial proliferation, motility, and differentiation. Motility was quantitated by monolayer expansion and the brush border enzymes dipeptidyl dipeptidase (DPDD) and alkaline phosphatase (AP) by synthetic substrate digestion. Staurosporine (0.03‐1.0 ng/ml) and calphostin C (10−12M‐10−4 M) dose‐dependently inhibited monolayer expansion and AP but stimulated DPDD. Proliferation was also inhibited but the effects of each inhibitor on motility, AP, and DPDD were preserved after mitomycin C proliferative blockade, suggesting that these effects were proliferation‐independent. PKC inhibitors independently inhibit motility, AP and proliferation in human intestinal Caco‐2 epithelial cells, but selectively stimulate the small intestinal differentiation marker DPDD. PKC may regulate small intestinal epithelial differentiation.
Proliferation of chick primordial germ cells cultured on stroma cells from the germinal ridge.
Authors: Chang Il‐Kuk , Tajima Atsushi , Chikamune Tateki , Ohno Tadao
Published: October 2002

Fluorescent reagent‐labelled PGCs isolated from the blood of 2‐day‐old chick embryos were cultured on stroma cells derived from 5‐day‐old germinal ridge in Medium 199 supplemented with 10% FBS, human IGF‐1, bovine FGF‐b, and murine LIF. In 7 experiments, the number of MCs increased by an average of 4.8 fold in 4 days. Intrinsic PGCs in the 5‐day embryonic germinal ridge were observed loosely attached to the stroma cells, and they also increased 3.8 fold during culture for 4 days. These results indicate the possibility of applying this culture method to the production of transgenic chickens.
Inducible expression of Mad accelerates growth arrest of serum deprived human glioblastoma cells
Authors: Roy Baishali , Reisman David
Published: October 2002

Mad is a basic‐helix‐loop‐helix leucine zipper protein that heterodimerizes with Max. Mad: Max heterodimers recognize the same DNA binding sites as Myc: Max heterodimers. However, Myc and Mad are thought to influence transcription and cell proliferation in opposite ways through interaction with Max. While Myc activates transcription and cell proliferation Mad represses these activities (Ayer et. al., Cell 72, 211‐222, 1993). We have constructed an expression vector containing the mad cDNA cloned downstream of an inducible viral promoter. Cell lines carrying the construct were derived by transfection into human glioblastoma cells and the effect of Mad induction on their growth rate was studied. When the cells were cultured in low serum concentrations (0.1%) Mad induction resulted in accelerated growth arrest. These findings are consistent with the proposed growth repression function of the Mad protein.
NGF: not just for neurons.
Authors: Scully Jackie Leach , Otten Uwe
Published: October 2002

Nerve growth factor (NFF) is the prototypic member of a family of related neurotrophins (Nts). Although originally defined by its actions in the peripheral and central nervous systems, recent data indicate the presence of extensive interactions between NGF and the endocrine and immune systems steroid hormones are able to modulate the neurosomal expression of NGF, while functional NGF receptors have been detected on cells of the immune system, and increased levels of NGF protein are found during the acute phase of diseases with a significant inflammatory component. These wider functions are likely to be of concern in any attempted therapeutic use of NGF.
Production of human immunodeficiency virus by chronically infected cells grown in protein‐free medium.
Authors: Pintér Claudia , Siccardi Antonio G. , Clivio Alberto
Published: October 2002

A human T cell line chronically infected with Human Immunodeficiency Virus (HIV) has been adapted to grow in a chemically defined, protein‐free medium. Virus particles are produced at rates comparable to those of serum‐supplemented cultures; virus preparations free of undesirable proteins can be produced in preparative amounts by simple ultrafiltration procedures and cell culture supernatants can be used as such for the preparation of ELISA solid phases. This material has been used very conveniently for studies concerning characterization of antibodies against HlV‐specific proteins, interaction of HIV with complement components and inclusion of human cell‐derived proteins into virions; we propose its use as a powerful tool for the structural as well as functional analysis of the virus particle itself.
A γ‐tubulin that associates specifically with centrioles in HeLa cells and the basal body complex in Chlamydomonas
Authors: Dibbayawan Teresa P. , Harper John D. I. , Elliott Janet E. , Gunning Brian E. S. , Marc Jan
Published: October 2002

γ‐Tubulin is a putative component of microtubule initiating material. To further explore its subcellular distribution in plant and animal cells, we have raised a polyclonal antibody, Rb27, directed towards a conserved region (EEFATEGTDRKDVFFY) of the γ‐tubulin molecule. Immunoblotting of cell protein extracts with Rb27 reveals a polypeptide band of Mr 49 kD in HeLa and a 58 kD band in Chlamydomonas. Although these polypeptides are comparable in size to forms of γ‐tubulin detected previously in mammalian and plant protein extracts by other antibodies to γ‐tubulin, by immunofluorescence microscopy Rb27 gives localization patterns not previously seen. It localizes specifically with the centrioles in HeLa cells and with the basal body complex in Chlamydomonas. Other γ‐tubulin antibodies label pericentriolar material. Because of the similarities in the size of the polypeptides recognized by our and other γ‐tubulin antibodies, and a restricted co‐localization with known microtubule‐organizing centres in evolutionarily distant organisms, we propose that Rb27 recognizes a novel conserved γ‐tubulin isotype.
Effect of microtubule‐specific drugs upon spatial organization of extracellular matrix in fibroblastic cultures.
Authors: Domnina L. V. , Ivanova O. Y. , Vasiliev J. M.
Published: October 2002

The aim of this investigation was to study the effects of microtubule‐specific drugs, taxol and colcemid, on the distribution of cell‐associated extracellular matrix in dense cultures of fibroblasts. Immunomorphological examination of human seven‐day cultures revealed a dense network of fibronectin and tenascin matrix filaments preferentially oriented in parallel with the long axes of cell bodies. Depolymerization of the microtubular system by colcemid and its disorganization by taxol led to rapid and drastic changes in the organization of matrix network: fibronectin and tenascin filaments became disordered and, in particular, lost any orientation. These data show that the microtubular system controls the morphological organization, not only of intracellular cytoskeletal systems, but also of extracellular matrix structures.
A NOVEL METHOD FOR PRODUCTION OF MONOCLONAL ANTIBODIES. EVALUATION AND EXPECTATION OF THE RAT LYMPH NODE METHOD IN CELL AND MOLECULAR BIOLOGY
Authors: SADO YOSHIKAZU , OKIGAKI TOHRU
Published: October 2002

A newly developed method using rat lymph nodes provided us with substantial amounts of high quality monoclonal antibodies. The method has characteristic features, a single injection of an emulsified antigen via the rat's hind footpads is sufficient for immunization. Enlarged medial iliac lymph nodes can be used for cell fusion to produce hybridomas 2 weeks and later after the antigen injection. The production frequency of target hybridomas is about 10 times higher than that of a conventional spleen method. Our current knowledge about the production of monoclonal antipeptide antibodies and monoclonal nephritogenic autoantibodies by the method is described.
MOLECULAR MECHANISMS IN DEVELOPMENTAL BIOLOGY
Authors: GIUDICE GIOVANNI
Published: October 2002

Some general molecular mechanisms underlying development are described. Namely: those involved in the differentiation of the R7 receptor inDrosophilaembryonic retina; those involved in the determination of embryonic axes and in polar cell differentiation, inDrosophila; those involved in the determination of the AB and P cell lineage and in vulva differentiation inCaenorhabditisembryos.
TRANSCRIPTIONAL CONTROL OF CELL CYCLE PROGRESSION: THE HISTONE GENE IS A PARADIGM FOR THE G1/S PHASE AND PROLIFERATION/DIFFERENTIATION TRANSITIONS
Authors: STEIN GARY S. , STEIN JANET L. , van WIJNEN ANDRÉ J. , LIAN JANE B.
Published: October 2002

The histone gene is a paradigm for transcriptional control at the G1/S phase transition point in the cell cycle. The histone gene promoter provides a blueprint for integration of regulatory signals which mediate responsiveness to factors controlling competency for cell cycle progression at the initiation of DNA replication. The downregulation of proliferation at the onset of differentiation is accompanied by and functionally linked to modifications in protein—DNA and protein—protein interactions at histone gene promoter regulatory elements. Chromatin structure, nucleosome organization and gene‐nuclear matrix interactions facilitate crosstalk between regulatory sequences and targeting of transcription factors to cognate binding domains.
X‐RAY MICROANALYSIS IN CELL BIOLOGY AND CELL PATHOLOGY
Authors: ROOMANS GODFRIED M. , VON EULER ANNE
Published: October 2002

Electron probe X‐ray microanalysis has been used for the last 25 years by biologists to obtain information about the distribution of elements at the cell and tissue level. During this period, progress has mainly been made through the development of more adequate techniques for specimen preparation (mainly low temperature techniques) and quantitative analysis, so that accurate analysis of the physiologically important cellular ions can be carried out. Use ofin vitrosystems and cell cultures may further increase the number of problems to which X‐ray microanalysis can be applied. Among the numerous applications of X‐ray microanalysis in cell biology and cell pathology, applications in the areas of epithelial ion transport, the role of calcium in secretory and contractile cells, and the role of ions in cell proliferation and cancer are discussed in more detail.
MAINTENANCE OF IONS, PROTEINS AND WATER IN LENS FIBER CELLS BEFORE AND AFTER TREATMENT WITH NON‐IONIC DETERGENTS
Authors: CAMERON IVAN L. , HARDMAN W. , FULLERTON GARY D. , MISETA ATTILA , KOSZEGI TAMAS , LUDANY ANDREA , KELLERMAYER MIKLOS
Published: October 2002

If the plasma membrane and its associated transport proteins are solely responsible for maintenance of the asymmetric solute distribution then disruption of the plasma membrane would quickly lead to the symmetric distribution of all unattached inorganic ions between the cell and the extracellular environment. To test this hypothesis fresh pig lenses were incubated in Hanks ’ balanced salt solution in either absence or presence of non‐ionic detergents (0.2 % Triton X‐100 or 0.2 % Brij 58). Both detergents caused permeabilization of every lens fiber cell as shown by electron microscopy. The flux kinetics of K+, Mg2 +, Na+, Ca2 +, water and protein out of and into the permeabilized lens fiber cells was measured. Triton X‐100 caused a faster flux rate of all solutes than did Brij 58. The Triton X‐100 induced flux of solutes and water was associated with a decrease in lens ATP. Incubation of untreated lenses in solutions of different osmotic pressures at 0 °C demonstrated that the major fraction of lens water was osmotically unresponsive. Thus the asymmetric distribution of solutes in lens fiber cells is dependent on an intact plasma membrane and on a co‐operative ATP‐dependent association between K+, Mg2 +, water and cytomatrix proteins.
CANNABINOID ENANTIOMER ACTION ON THE CYTOARCHITECTURE
Authors: WILSON RONALD G. , TAHIR STEPHEN K. , MECHOULAM RAPHAEL , ZIMMERMAN SELMA , ZIMMERMAN ARTHUR M.
Published: October 2002

The negative and positive enantiomers of 7‐hydroxy‐ Δ6‐tetrahydrocannabinol‐dimethylheptyl (designated HU‐210 and HU‐211 respectively) differentially affect undifferentiated and differentiating cultured pheochromocytoma cells (PC‐12 cells). In general, cell viability and cell proliferation were suppressed to a much greater extent with HU‐210 than with HU‐211 in differentiating cells. The effects of these synthetic cannabinoids on the cytoskeleton of PC‐12 cells were examined by epifluorescence and confocal microscopy. In both undifferentiated and differentiating PC‐12 cells, HU‐211 has little effect on the cytoarchitecture whereas HU‐210 disrupts the distribution of microtubules and microfilaments. Vacuoles (2–4 μm) were evident in the cytoplasm of HU‐210‐treated cells but not in the cytoplasm of HU‐211‐treated cells or in vehicle controls. Tubulin and actin mRNA levels were reduced to 5 and 40 %, respectively (relative to untreated controls) in 10 μmHU‐210‐treated cells whereas the same concentration of HU‐211 reduced tubulin and actin mRNA levels to 90 and 95 %, respectively. A comparison of the effects of the paired enantiomers and Δ1‐THC on the cellular parameters studied reveals that in differentiating cells the action of Δ1‐THC is intermediate between that of HU‐210 and HU‐211. This study demonstrates that compared to HU‐210 and Δ1‐THC the positive enantiomer HU‐211 has little cellular activity.
ONTOGENY OF ANGIOTENSIN II RECEPTORS
Authors: SHANMUGAM SADOUTOUNNISSA , SANDBERG KATHRYN
Published: October 2002

Aside from the well known role of angiotensin II (Ang II) in blood pressure regulation and fluid homeostasis, accumulating evidence suggests that the octapeptide hormone also plays a role in growth and development. There are two major classes of Ang II receptors (AT1and AT2) which mediate Ang II action. Both classes are members of the large superfamily of seven transmembrane domain spanning receptors. Fetal tissue express high levels of AT receptors. Throughout fetal and postpartum life, the AT1and AT2tissue distribution changes dramatically. The evolution of each receptor type is distinct and varies according to the organ. Thus, the different patterns of temporal expression of each receptor class could be related to various roles that Ang II may play during development.