bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal deformation analysis of BGA package by digital image correlation technique
Authors: Zhang J. , Li M. , Xiong C.Y. , Fang J. , Yi S.
Published: January 2005

Purpose

The mismatch of the thermal expansion coefficients of the materials in multiplayer structure may induce serious stress concentrations in electronic packaging. Experimental evaluation of the thermal stresses and strains in those electronic composites is becoming significantly important for optimizing design and failure prediction of the electronic devices.

Design/methodology/approach

Digital image correlation (DIC) technique was utilized to obtain thermal deformation filed of a BGA package. With the help of white light to illuminate the cross section of the BGA package, the gray images were taken from the rough surface of the specimen, that offer a kid of carrier pattern for the DIC processing with statistical resemblance in gray distributions. By using the algorithm of correlation computation, the DIC searched the matching spots in a pair of those images in which the spot displacements were involved in between, to obtain the deformation fields of the package specimen caused by temperature changes.

Findings

The results show interesting strain distributions in the assembly. Both the horizontal displacement component and its normal derivative are strongly related to the arrangement of the solder joints in the bonding medium between the die and the ceramic substrate. The strain components in the middle region of the package are larger than those in the side regions where the strain relaxation may exist near the stress‐free boundaries. The shear strain components show special bands of parallel lines with identical amount over the chip‐package to sustain the shearing of the packed structure under thermal loading.

Originality/value

The DIC technique shows to be a useful tool for the thermal strain analysis of the electronic packaging devices. Not only provides it the whole field deformation of the assembly, but also maintains the surface pictures of the package without covering any fringes, which is important to compare the deformation field with the specimen surface to reveal the stain distribution related to the failure prediction of the materials.
Environmental management in Swedish higher education
Authors: Sammalisto Kaisu , Arvidsson Karin
Published: January 2005

Purpose

This study of environment management systems implementation in Swedish universities contributes to the dialogue about the role of management systems as tools in developing sustainability in higher education.

Design/methodology/approach

The empirical study is based on Government directives that make environmental management systems implementation compulsory for all public organisations in Sweden, annual environmental reports of Swedish universities for the years 1997‐2002, their internet home pages, and a survey.

Findings

Many universities focus only on direct environmental aspects like paper use and waste handling, even though the main tasks of the universities, namely education, research and co‐operation with the surrounding society, that is the indirect aspects, are likely to have a considerable environmental impact. The organisation of the environmental work and the placement of the environmental coordinator also vary. Two main patterns appear; the coordinator has a function in the service department or an administrative function in the president's office. The goal of certification increases the likelihood of the environmental coordinator being placed in the president's office.

Originality/value

The aim is to increase the understanding of why and how a concept that was first introduced in industry is applied to institutions of higher education.
Intangibles in commercialisation: the case of air navigation services in the South Pacific
Authors: Warn James
Published: January 2005

Purpose

To demonstrate that different approaches to commercialisation can determine the nature of intangible resources that managers can develop.

Design/methodology/approach

A framework linking political strategy, financial capitalisation and business strategy is developed to analyse the management of intellectual capital in the commercialisation of air navigation services in New Zealand and Fiji. Case study evidence is organised as an intellectual capital portfolio and links are drawn to subsequent business outcomes for each organisation.

Findings

Explains how key decisions about financial capitalisation and business strategy at the time of commercialisation influence the subsequent management and development of intangible resources in the organisation. Identifies how political assumptions about commercialisation can constrain or enhance subsequent management success in developing intellectual capital to pursue business growth.

Research limitations/implications

The interpretations offered, although plausible in the context of the case studies, may not generalise to other situations.

Practical implications

Key decision makers need to design commercialisation arrangements that will resource the desired intellectual capital portfolio of the commercialised organisation.

Originality/value

The paper provides a framework for establishing a linkage between strategic management decisions and the development of an intellectual capital portfolio in the context of commercialisation. The paper develops the theoretical extent of intellectual capital concepts and provides practical analysis to decision makers contemplating commercialisation issues.
Situation of intangible assets in Spanish firms: an empirical analysis
Authors: Gallego Isabel , Rodríguez Luis
Published: January 2005

Purpose

The purpose of this work is to analyze, both from a theoretical and an empirical point of view, the significance of intangible assets in Spanish firms.

Design/methodology/approach

To perform this study Spanish firms listed in the Spanish Securities and Exchange Commission (CNMV) were examined, in which intangible assets play a significant role in their business models. Using a questionnaire of 25 items, the final sample consisted of 39 firms (response rate =15.2 per cent) that could be used for the analyses. From the information thus gathered, a statistical treatment was implemented using the SPSS computer program and the answers to each of the 25 items were analysed. An analysis of principal components in the question was also established, in order to summarize all 12 reasons proposed into just a few factors.

Findings

Among others, certain relevant conclusions about intangible assets indicated that: Spanish firms have moved from an industrial economy toward a knowledge‐based economy; the disclosure of information about intangible assets in Spanish firms is still limited; some of the most relevant intangible assets are customer relationships, employee experience, information technologies, brand image, procedures and systems; and the number of indicators used by Spanish firms is about 20.

Research limitations/implications

To select the sample for the questionnaire the database of the CNMV was used. The final sample thus comprised 257 firms, but the authors finally received answers from 39 firms.

Practical implications

The paper is a very useful source of information for the Spanish firms and for investigators in this subject.

Originality/value

This paper is pioneering in the analysis of the situation of intangible assets in Spanish firms, as well as in determining some of the most relevant intangible assets used by those firms.
Organisational self‐assessment and the adoption of managerial innovations
Authors: Burgess T.F. , Shaw N.E. , de Mattos C.
Published: January 2005

Purpose

This paper investigates manager's use of self‐assessment in diagnostic routines to assist organisations embarking on major organisational change involving the adoption of a managerial innovation.

Design/methodology/approach

The illustrative case focuses on the comparative adoption of two assessment tools set within a methodology developed via action research to improve the performance of new process development in the specialty chemical industry.

Findings

Features of the case context, such as prior commitment to the methodology, contribute to explaining managerial preferences for the non‐financial diagnostic tool over the financial one.

Practical implications

For practitioners the case illustrates how prior commitment can obscure rational considerations when faced with planning and implementing major change, particularly so when introducing managerial innovations. For academics the case study highlights the potential for fruitful research into the design and use of self‐assessment routines that precede or coincide with the adoption and implementation of such managerial innovations.

Originality/value

The paper focuses on self‐assessment routines constructed to aid chemical firms contemplating the adoption of a major managerial innovation; a methodology that entails a radical approach to designing and developing new manufacturing processes for chemical production.
An analytical model for the optimisation of maintenance profitability
Authors: Oke S.A.
Published: January 2005

Purpose

The paper presents a mathematical model that measures the profitability of the maintenance system based on the traditional accounting definition of profitability. There is currently a dire need for an article presenting a scientific‐based framework for practitioners in maintenance to make optimal instead of sub‐optimal decisions on profitability. Design/methodology/approach – A case study is presented to reflect the actual application of the proposed model. Different situations were considered in modelling to obtain optimal results. Simulation experiments were conducted to demonstrate that maintenance profitability is a reality through the use of differential calculus. Findings – It was observed that the approach presented is a holistic viewpoint of maintenance profitability measurement. Research limitations/implications – An adequate understanding of the maintenance system is needed to properly implement the model. Practical implications – The practical application of the model is that the maintenance system will now be viewed as a value‐adding activity instead of “a necessary evil” or “a bottomless pit for expenses”. Originality/value – This paper fulfils an identified need and offers practical help to managers in taking guided decisions that are optimal.
Secretion of prostatic specific antigen, proliferative activity and androgen response in epithelial–stromal co‐cultures from human prostate carcinoma
Authors: CASTELLÓN ENRIQUE , VENEGAS KARINA , SÁENZ LEONARDO , CONTRERAS HÉCTOR , HUIDOBRO CHRISTIAN
Published: January 2005

We investigate the proliferative activity, prostatic specific antigen (PSA) secretion, morphology and androgen response of human prostate tumour epithelial cells co‐cultured with stromal cells in a bicameral system. Stromal and epithelial cells were isolated from prostate adenocarcinoma by enzyme digestion and cultured in defined media. Immunocytochemistry for prostate carcinoma tumour antigen (PCTA‐1) was performed for culture purity evaluation. Also, the morphology of the epithelial cells in co‐culture was evaluated by electron microscopy. PSA was determined by microparticle enzyme immunoassay (MEIA) automatized protocol and the proliferation was evaluated by a commercial spectrophotometric kit, based on formazan salt formation. Both cell cultures showed more than 90% of purity. The epithelial cell co‐cultures showed marked membrane processes and cell interdigitations. The proliferative activity of the epithelial cells was increased in presence of stromal cells. Also, PSA secretion was significantly increased and maintained for at least 14 days, whereas the androgen response for PSA secretion was evidenced only in co‐culture condition. Primary co‐cultures of epithelial and stromal cells from human prostate carcinoma are able to maintain, for a prolonged time, proliferative and secretory properties as well hormone response, and represent a valuable tool for cellular and molecular studies on prostate cancer.
Comparison of the outcome of intracytoplasmic sperm injection in obstructive and non‐obstructive azoospermia in the first cycle: a report of case series and meta‐analysis
Authors: GHANEM MOHAMED , BAKR NAGWA I. , ELGAYAAR MAHA A. , EL MONGY SHYMAA , FATHY HANAN , IBRAHIM ABDEL‐HAMID A.
Published: January 2005

To investigate the outcome of intracytoplasmic sperm injection with fresh and cryopreserved‐thawed testicular spermatozoa in the first cycle in patients with obstructive azoospermia (OA) and non‐obstructive azoospermia (NOA), a total of 90 cases, 48 OA and 42 NOA were studied. All patients underwent sperm retrieval by testicular sperm extraction (TESE) while their wives received conventional ovarian hyperstimulation. The hormone levels, testicular histology, the rates of sperm retrieval, fertilization, implantation and pregnancy were analysed and evaluated. This study and other four similar studies were subjected to meta‐analysis. Sperm retrieval was successful in 100% OA and 61% NOA. Fresh spermatozoa were used in 87.5% and 92.4% of OA and NOA cases respectively; while cryopreserved‐thawed spermatozoa were used in 12.5% and 7.6% of OA and NOA, respectively. The fertilization, implantation and clinical pregnancy rates were 65.5%, 15% and 25% respectively in OA group, and 54.2%, 5% and 23.1% respectively in NOA group. Sperm status (fresh or thawed), male partner's age, female age and male serum follicle‐stimulating hormone had no significant effect upon fertilization rate, implantation rate, or pregnancy rate per embryo transfer. The results of meta‐analysis indicate that there is no statistically significant difference in clinical pregnancy rates between the two groups. There was a significantly higher fertilization rate among OA patients in all analysed studies (95% CI = 14.29–15.71, d.f. 832, T = 1.96). In conclusion, although the fertilization rate was significantly higher in the OA group in our study and from the given meta‐analysis, there were some differences as regards pregnancy rates. Although the overall effect was more or less similar pregnancy rates in both subtypes of azoospermia, this may not be true if non‐male infertility variables were controlled for in all studies.
Venlafaxine extended release for the treatment of patients with premature ejaculation: a pilot, single‐blind, placebo‐controlled, fixed‐dose crossover study on short‐term administration of an antidepressant drug
Authors: KILIÇ S. , ERGIN H. , BAYDINÇ Y. C.
Published: January 2005

In this study, we aimed at evaluating the efficacy and safety of venlafaxine extended release 75 mg, a serotonin and noradrenaline reuptake inhibitor, in the treatment of patients with premature ejaculation. Thirty‐one patients with intravaginal ejaculation latency of less than 2 min received venlafaxine XR (75 mg/day) or placebo during a 2‐week period for each agent with a washout period of 1 week between agents. Efficacy was assessed for each agent with changes in ejaculation latency measured with a stopwatch and sexual satisfaction scores of patients and partners. Side‐effects, pre‐ and post‐treatment levels of biochemical and spermiogram parameters, follicle‐stimulating hormone (FSH), luteinizing hormone (LH), prolactin and total testosterone were recorded for each agent. Statistical analysis was performed on 21 patients. After 2 weeks of treatment with placebo and venlafaxine, ejaculation latency time was significantly increased from 60.1 ± 39.1 to 126.9 ± 98.3 sec and to 178.1 ± 122.8 sec, respectively (p < 0.0001 for each one). However, the difference between the two agents was insignificant (p = 0.144). Venlafaxine and placebo increased sexual satisfaction scores of both patients and partners similarly, no statistically significant difference was found between them in this respect. The incidence of side‐effects with venlafaxine was indifferent than that of placebo (p > 0.1) except nausea (p = 0.035). Both agents did not change the blood and spermiogram parameters significantly, except FSH increases.

Short‐term use of venlafaxine XR 75 mg has only a placebo effect on ejaculation latency and sexual satisfaction scores, therefore, is not appropriate for the patients with premature ejaculation. Further dose‐time studies are required to draw final conclusions on the inefficacy of this drug in premature ejaculation.
Gonadal Steroid Replacement Reverses Gonadectomy‐Induced Changes in the Corticosterone Pulse Profile and Stress‐Induced Hypothalamic‐Pituitary‐Adrenal Axis Activity of Male and Female Rats
Authors: Seale J. V. , Wood S. A. , Atkinson H. C. , Harbuz M. S. , Lightman S. L.
Published: January 2005

We investigated the effects of gonadal hormone replacement on the pulsatile parameters underlying basal circadian corticosterone secretion in castrated male and ovariectomized female rats using an automated sampling system. Blood was collected from freely moving, unanaesthetized rats every 10 min over a 24‐h period and sampling was continued during a noise stress and after lipopolysaccharide (LPS) administration. Castrated male rats had markedly higher corticosterone levels than intact controls. This was reflected by increased number and frequency of pulses in addition to an increase in the pulse height and amplitude under both basal circadian and stress conditions. Hormone replacement with either testosterone or dihydrotestosterone returned these corticosterone levels and circadian profile to those found in intact males, confirming an androgen‐mediated effect. Ovariectomized females had significantly lower basal and stress‐induced corticosterone levels with lower frequency and amplitude of corticosterone pulses than intact females. 17β‐oestradiol replacement returned basal levels, pulsatile measurements and stress‐induced corticosterone levels to those found in intact females. Three hours post‐LPS administration, castrated males demonstrated significantly higher values of parvocellular paraventricular nucleus (PVN) arginine vasopressin and corticotrophin‐releasing factor and anterior pituitary pro‐opiomelanocortin mRNA while ovariectomized females showed significantly lower levels of all three transcripts compared to intact controls. PVN glucocorticoid receptor mRNA levels 3 h post‐LPS administration were significantly decreased in castrated males and significantly increased in ovariectomized female rats. Replacement of gonadal steroids resulted in a return to the levels found in intact controls after LPS. Gonadal steroid replacement is sufficient to reverse changes in the pulsatile characteristics of corticosterone release after gonadectomy. In addition, gonadal steroid replacement reverses stress‐induced alterations in hypothalamic‐pituitary‐adrenal (HPA) activity. These data demonstrate a major contribution of gonadal steroids to the regulation of HPA axis activity and to the pulsatile characteristics of corticosterone release.
Gonadotrophin Inhibitory Hormone Depresses Gonadotrophin α and Follicle‐Stimulating Hormone β Subunit Expression in the Pituitary of the Domestic Chicken
Authors: Ciccone N. A. , Dunn I. C. , Boswell T. , Tsutsui K. , Ubuka T. , Ukena K. , Sharp P. J.
Published: January 2005

Studies performed in vitro suggest that a novel 12 amino acid RF amide peptide, isolated from the quail hypothalamus, is a gonadotrophin inhibitory hormone (GnIH). The aim of the present study was to investigate this hypothesis in the domestic chicken. Injections of GnIH into nest‐deprived incubating hens failed to depress the concentration of plasma luteinizing hormone (LH). Addition of GnIH to short‐term (120 min) cultures of diced pituitary glands from adult cockerels depressed follicle‐stimulating hormone (FSH) and LH release and depressed common α and FSHβ gonadotrophin subunit mRNAs, with no effect on LHβ subunit mRNA. Hypothalamic GnIH mRNA was higher in incubating (out‐of‐lay) than in laying hens, but there was no significant difference in the amount of hypothalamic GnIH mRNA in out‐of‐lay and laying broiler breeder hens at the end of a laying year. It is concluded that avian GnIH may play a role in controlling gonadotrophin synthesis and associated constitutive release in the domestic chicken.
Sex Differences in the Distribution and Abundance of Androgen Receptor mRNA‐Containing Cells in the Preoptic Area and Hypothalamus of the Ram and Ewe
Authors: Scott C. J. , Clarke I. J. , Rao A. , Tilbrook A. J.
Published: January 2005

Rams and ewes show a negative‐feedback response to peripheral treatment with testosterone, with both sexes having a similar degree of suppression in luteinizing hormone (LH) secretion during the breeding season. At least part of the action of testosterone to suppress gonadotropin‐releasing hormone/LH secretion is exerted via interaction with an androgen receptor. The distribution of androgen receptor‐containing cells in the hypothalamus has been described for the ram, but similar studies have not been performed in the ewe. In the present study, we tested the hypothesis that levels of androgen receptor mRNA expression in the preoptic area and hypothalamus would be similar in rams and ewes. Perfusion‐fixed brain tissue was obtained from adult Romney Marsh ewes (luteal phase) and rams during the breeding season (n = 4/sex). Androgen receptor mRNA expression was quantified in hypothalamic sections by in situ hybridization using an 35S‐labelled riboprobe and image analysis. Hybridizing cells were found in the medial preoptic area, bed nucleus of the stria terminalis, anterior hypothalamic area, ventromedial nucleus, arcuate nucleus and premamillary nucleus. The level of androgen receptor mRNA expression was higher in rams than ewes in the rostral preoptic area, caudal preoptic area and rostral portion of the bed nucleus of the stria terminalis, with no sex difference in other regions. The preoptic area and bed nucleus of the stria terminalis are important for reproductive behaviour and the sex differences in androgen receptor mRNA expression at these levels may relate to this. The high level of androgen receptor mRNA expression in the basal hypothalamus, with no sex difference, is consistent with the role of this region in the regulation of gonadotropin secretion.
THE TEMPORAL SCHEDULE OF DNA SYNTHESIS AND CELL DIFFERENTIATION
Authors: FUJITA SETSUYA
Published: January 2005

The temporal schedule of DNA synthesis in cells of developing and adult mice is analysed by means of Feulgen cytofluorometry combined with tritiated thymidine autoradiography. The results obtained with cells taken from liver, esophageal epithelium and mucosae of gastrointestinal tracts seemed to conform to the hypothesis that a cell at a particular state of cytodifferentiation possesses specifically inactivated sets of late replicating genes showing a specific pattern of the temporal schedule of DNA synthesis.
STUDIES ON THE GASTRULATION OF AMPHIBIAN EMBRYOS: NUMERICAL CRITERIA FOR STAGE DETERMINATION DURING BLASTULATION AND GASTRULATION OF XENOPUS LAEVIS
Authors: NAKATSUJI NORIO
Published: January 2005

The changing external features of Xenopus laevis embryos were examined from the first cleavage through the late gastrula as a means to develop quantitative criteria for the determination of stages for this period. During blastulation, the cell number along arcs centered on the animal or vegetal pole and representing one‐sixth of a meridian ‐ called the MCNo. ‐ can be used as such a criterion. During gastrulation, the width of the blastopore divided by the diameter of the whole embryo can be used as such a criterion.
SITE OF 1‐METHYLADENINE RECEPTORS IN THE MATURATION OF STARFISH OOCYTES
Authors: SHIDA HISATO , HIRAI SETSURO
Published: January 2005

Maturation of vitelline coat‐free (VCF) oocytes of the starfish, Asterina pectinifera, was studied. When the oocytes, the vitelline coats of which were elevated by adding the ionophorc A‐23187, were forced through two sheets of copper mesh, the vitelline coats were completely removed from the oocytes. Although some of the VCF oocytes underwent germinal vesicle breakdown following this mechanical treatment, most of them retained the normal germinal vesicles. These VCF immature oocytes underwent breakdown of germinal vesicles after addition of 1‐methyladenine (1‐MA). Dose‐response curves of VCF oocytes to 1‐MA were similar to those of normal oocytes. These results indicate that 1‐MA reacts with the plasma membrane and that the presence of the vitelline coat is not prerequisite for inducing oocyte maturation.
PRODUCTION OF TRIPLOID AND GYNOGENETIC DIPLOID XENOPUS BY COLD TREATMENT
Authors: KAWAHARA HIROMICHI
Published: January 2005

Methods are described for producing triploids and gynogenetic diploids of Xenopus laevis. A high frequency of triploids was obtained when the eggs were refrigerated at 2‐3 C for 15 min, starting 10–16 min after insemination. By this procedure, the suppression of second polar body emission was cytologically evident. The occurrence of triploidy was confirmed by chromosome and nucleolar counts, as well as microspectrophotomctric determination of nuclear DNA contents. Thus, more than 60% of the feeding tadpoles were triploids. Using the refrigeration method for inducing triploids, gynogenetic diploids were produced by inseminating eggs by sperm previously irradiated with ultraviolet light. Triploids and gynogenelic diploids thus obtained developed normally beyond metamorphosis, and have been growing well for more than 1.5 years.
SPERMIOGENESIS IN THE PULMONATE SNAIL, EUHADRA HICKONIS II. STRUCTURAL CHANGES OF THE NUCLEUS
Authors: TAKAICHI S.
Published: January 2005

In accordance with the characteristic shape of the nucleus and degree of condensation of the nuclear substance, spermiogenesis in Euhadra hickonis can be roughly divided into four stages. The chromatin in the highly polymorphic nucleus of the first stage, early spermatid, forms relatively thick (ca. 50 nm) fibrils which associate here and there into irregular clumps. In the next stage, the spermatid nucleus becomes conspicuously spherical, its contents appear more finely homogeneous and the irregular clumps of chromatin are few. In the third stage, the nucleus gradually takes on an ellipsoidal shape as the antero‐posterior axis shortens. The anterior part of its envelope becomes structurally modified in preparation for the adherence to it of the developing acrosome, and an implantation fossa forms posteriorly at the center of a second area where the nuclear envelope has been modified. The diameter of the chromatin fibrils again increases and those near the implantation fossa become oriented perpendicular to the nuclear envelope.

As the nucleus elongates in the fourth stage, a concentric sheath of microtubules closely surrounds it. These appear to depolymerize as the nuclear elongation proceeds, so that they are no longer present in the head region of the mature spermatozoon. The diameter of the chromatin fibrils increases to about 10 nm and they become oriented parallel to the long axis of the cell. With the decrease in the nuclear volume the fibrils unite laterally to form longitudinal sheets, and these finally merge in the mature spermatozoon into a mass of very dense chromatin without perceptible internal structure.
MECHANICAL PROPERTIES OF THE CELL SURFACE IN STARFISH EGGS
Authors: NAKAMURA SOICHI , HIRAMOTO Y.
Published: January 2005

The mechanical properties of the cell surface of the starfish egg at various stages of maturation have been investigated using the cell elastimeter. When constant negative pressure was applied to a part of the cell with a micropipette closely in contact with it, it bulged out, and the bulge rapidly increased at first and then gradually reached a steady value within one min. The relation between the deformation of the cell surface (i.e. degree of bulging) and applied negative pressure was almost linear in both oocytes at the germinal vesicle stage and mature eggs. The surface force and the elasticity value: i.e., the product of the elastic modulus of the surface membrane (layer) and its thickness, were determined from the relation between the deformation and the negative pressure. The elasticity value was about 5 times the surface force in both oocytes at the germinal vesicle stage and mature eggs. When maturation of the oocyte was induced by 1‐methyladenine, the stiffness of the cell surface decreased shortly before the breakdown of the germinal vesicle. The stiffness transiently increased at the time of formation of the first and second polar‐bodies.
SPECIES‐SPECIFIC ADHESION OF SPERMATOZOA TO THE SURFACE OF FIXED EGGS IN SEA URCHINS
Authors: KATO KOICHI H. , SUGIYAMA MASAO
Published: January 2005

When the spermatozoa of sea urchins are added to eggs which have been fixed with glutaraldehyde and washed thoroughly, the spermatozoa swarm around the eggs and adhere to the egg surface. The mode of sperm adhesion to the fixed egg is assumed, on the evidence of electron‐microscopical studies, to be the same as that of adhesion to the intact egg at the initial stage of normal fertilization. The spermatozoa and fixed eggs of five species of sea urchins were combined and heterologous crosses were studied. Species‐specific adhesion of sperm to fixed eggs was clearly demonstrated. There is a direct relationship between the cross‐fertilization of living gametes and the binding capacity of spermatozoa and fixed eggs in so far as the employed five species are concerned.
BINDING OF CONCANAVALIN A TO THE SURFACE OF STARFISH FOLLICLE CELLS AND PRODUCTION OF 1‐METHYLADENINE
Authors: KUBOTA JUNKO , KANATANI HARUO
Published: January 2005

Starfish follicle cells, treated with concanavalin A (Con A), continued to produce 1‐methyl‐adenine (1‐MeAde), an inducer of starfish oocyte maturation, after rinsing with artificial seawater (ASW). On the other hand, they ceased to produce the substance if treated with methyl α‐Dmannoside (αMM). These cells produced again 1‐MeAde when re‐stimulated with Con A after removal of αMM. An optical study with fluorescein revealed that Con A bound to the cells was not dissociated by rinsing with ASW, but was removed if the cells were treated with αMM. These results suggest that continuous binding of Con A to the surface of the follicle cells is essential for the production of 1‐MeAde.
CHANGES IN NUCLEOLI AT MATURATION OF NEWT OOCYTE
Authors: IMOH HIROSHI
Published: January 2005

Changes in the nucleoli of maturing oocytes and the eggs of Cynops pyrrhogaster were studied with light and electron microscopy. Extrachromosomal nucleoli moved toward the center of the germinal vesicle in response to the maturation stimulus, released presumed ribosomal ribonucleoprotein, and further moved toward the center of the nucleus to form an aggregate with chromosomes which behaved in a similar manner. A few. ball‐shaped nucleolar masses were formed from this aggregate, leaving the chromosomes and probably the extrachromosomal nucleolar organizer. The chromosomes then proceeded to the first meiotic metaphase. The nucleolar masses were surrounded by a layer of mitochondria and became smaller with formation of pinched‐off fragments, which were also surrounded by mitochondria, during the time the egg was moving down the oviduct. Only fragments were observed in the subcortical area of the animal hemisphere of the egg after reaching the lowest part of the oviduct.
CYCLIC SURFACE CHANGES IN THE NON‐NUCLEATE EGG FRAGMENT OF XENOPUS LAEVIS
Authors: SAKAI MASAO , KUBOTA HIROSHI Y.
Published: January 2005

Fertilized uncleaved eggs of Xenopus laevis were divided into nucleate and non‐nucleate egg fragments. Both fragments, together with the whole egg of the same batch, were observed by time‐lapse cinematography.

Two kinds of cyclic surface changes, (1) rounding‐up and relaxing movements and (2) surface contraction waves, accompanying each cleavage in the whole eggs and the nucleate fragments, were also observed even in the non‐nucleate fragments although they do not cleave.

Cleavage intervals of the whole egg and the nucleate fragment were nearly equal, but the rounding‐up intervals of the non‐nucleate fragment were slightly but definitely longer than the cleavage intervals of the nucleate fragment and the whole egg.
ANDROGENIC GLAND HORMONE AND DEVELOPMENT OF OVIDUCTS IN THE ISOPOD CRUSTACEAN, ARMADILLIDIUM VULGARE
Authors: HASEGAWA YURIKO , KATAKURA YASUTOSHI
Published: January 2005

When androgenic glands from mature males were implanted into females of Armadillidium vulgare during the 3rd, 4th and 5th instars, oviducts developed in 14.3, 37.9 and 85.2% of the masculinized females, respectively. These results show that development of the rudimentary oviducts is inhibited by the androgenic gland hormone in very young females. Development of the oviduct seems to be determined at a critical period in about the 4th instar and after this, the hormone has little inhibitory effect.
ESTABLISHMENT AND SOME CHARACTERISTICS OF A CONTINUOUS CELL LINE DERIVED FROM FAT BODYS OF THE CABBAGE ARMYWORM (LEPIDOPTERA, NOCTUIDAE)
Authors: MITSUHASHI JUN
Published: January 2005

Fat bodies from fully grown larvae of the cabbage armyworm, Mamestra brassicae, were cultivated in a synthetic medium, MGM–431. Small free cells migrated out and multiplied rapidly. The first cell passage was done after culture for 26 days, and 100 passages were performed in the following 9 months. The established cell line was designated as NIAS–MaBr–85. The cell population is morphologically heterogeneous, but most of the cells are hexaploid with 180 microchromosomes. The cells could be stored for 3 months at 5°C, or for longer when frozen at ‐80°C in medium containing 10% glycerol. Qualitatively the cell line requires few amino acids: only cystine, histidine, isoleucine, methionine and threonine are essential as determined by omission of individual amino acids. The cells are susceptible to Chilo iridescent virus and Autographa californica nuclear polyhedrosis virus. This cell line can grow in serum‐free M‐M medium.
Biochemical Studies on the Acrosome Reaction of the Starfish, Asterias Amurensis I. Factors Participating in the Acrosome Reaction
Authors: IKADAI HIROYUKI , HOSHI MOTONORI
Published: January 2005

In contrast with the case in sea urchin sperm, in starfish the acrosome reaction is not spontaneously induced by simply increasing the extracellular Ca2+ concentration or pH. At higher pHs, starfish sperm undergo morphological changes accompanied by exocytosis of the acrosomal vacuole, but they do not form acrosomal filaments. Nomarski‐microscopic observation confirmed that spermatozoa undergo the acrosome reaction within the jelly coat. Acrosome reaction‐inducing substance, a glycoprotein from the egg jelly, required a diffusible cofactor(s) present in the egg jelly for full activity. Several lines of evidence showed that this diffusible factor(s) is not merely Ca2+.
Cyclic Changes in Shape of A Non‐Nucleate Egg Fragment of Tubifex (Annelida, Oligochaeta)
Authors: SHIMIZU TAKASHI
Published: January 2005

A non‐nucleate fragment separated from the fertilized Tubifex egg at metaphase of the second meiosis showed temporary surface deformation at 3–3.5 hr intervals, i.e., synchronously with the onset of formation of the second polar body and early cleavages in control eggs. From the two‐cell stage on, the periodicity of the surface activity in the non‐nucleate fragment was found to be synchronous with the cleavage cycles of the CD‐cell and its descendants, but not with those of the AB‐cell. This surface deformation was completely inhibited by cytochalasin B (50 μg/ml). Electron microscopy shows that microfilaments are present exclusively in the cortical layer of the deforming fragments. Cycloheximide‐treated egg fragments commenced surface deformation after a delay of 1–2 hrs; pulse‐treatment indicated that the surface deformation requires proteins synthesized specifically during the period of the previous surface deformation. These results are discussed in relation to the nucleus‐independent cytoplasmic rhythm and asynchronous cleavage of Tubifex eggs.
Concanavalin A‐Induced Morphological Changes and Its Binding Sites in Starfish Follicle Cells as Revealed by Electron Microscopy
Authors: KAWAI NORIO , SANO KIYOSHI , NAGAHAMA YOSHITAKA , KANATANI HARUO , HIRANO HIROSHI
Published: January 2005

Concanavalin A (Con A) stimulates the production in starfish follicle cells of 1‐methyladenine, a hormone which induces oocyte maturation. We have therefore investigated Con A‐induced morphological changes and Con A‐binding sites in the follicle cell using native Con A and horseradish peroxidase‐ or ferritin‐labeled Con A (HRP‐Con A, Fer‐Con A). After isolated follicle cells were incubated with Con A (1 mg/ml), vacuoles, the Golgi complex and multivesicular body‐like organelles (MVBs) became prominent in most of the cells. After follicle cells were prefixed and then incubated with Fer‐Con A for 60 min, tagged ferritin was diffusely and randomly distributed as single or small clustered particles on the cell surface. The incubation of isolated follicle cells with Fer‐Con A for 10 min before fixation resulted in numerous ferritin particles localized along the internalized membrane, and also in vacuoles, MVBs and small lysosome‐like structures. After 60 min incubation with Fer‐Con A, ferritin was further located in large lysosome‐like structures and in vesicles near and in the Golgi area as well as in the organelles described above. HRP‐Con A binding sites were also observed in vacuoles and MVBs of the intact cells.

These results suggest that Con A binds at first to the cell surface and causes rapid internalization and that membrane‐bound Con A is easily endocytosed into vacuoles, MVBs and lysosome‐like structures, and is later incorporated in some vesicles in the Golgi area.
Effects of Oestradiol‐17 β on the Ovaries of the Starfish Asterias rubens
Authors: SCHOENMAKERS H. J. N. , VAN BOHEMEN CH. G. , DIELEMAN S. J.
Published: January 2005

Oocyte diameters and their frequency distribution, and various other data determined for the oestradiol‐17 β treated female specimens of Asterias rubens proved to be significantly different from those for the control animals. The maturation index of the treated animals is 2.4, that of the control animals 1.4. Since the treated animals show a greater heterogeneity in development than the control animals, and because the diameter of the smallest oocytes is the same for both treated and control animals, a threshold size of the oocytes may be required before oocyte growth can be stimulated by oestradiol‐17β, and before substances originating in the pyloric caeca are incorporated into the oocytes. Oestradiol‐17β treatment caused a tenfold increase of the oestrone level in the ovaries, whereas a non‐significant increase was observed in the pyloric caeca. This may indicate that in vivo oestradiol‐17β is converted into oestrone in the ovaries but not in the pyloric caeca.
Vegetalization of Sea Urchin Larvae Induced with Cycloheximide
Authors: YOSHIMI TAKAHITO , YASUMASU IKUO
Published: January 2005

The embryos, kept at 20°C for 3 hr–6 hr from the time of fertilization (at the morula stage), were cultured in sea water containing cycloheximide (10–16 mM) for successive 3 hr and then transferred to normal sea water. The embryos, thus treated, became vegetalized larvae. With the same treatment performed at a developmental stage prior to 3 hr of fertilization, most of embryos developed to small blastulae filled with mesenchyme‐like cells. The treatment at a stage after 6 hr of fertilization yielded normal plutei. From the embryos exposed to both 14C‐leucine and 3H‐thymidine during the treatment, labelled chromatin was isolated. Only in the presumptive vegetalized embryos obtained by the cycloheximide treatment of morulae, ratio of 14C‐radioactivity found in proteins of chromatin to 3H‐radioactivity in DNA was markedly lower than that observed in chromatin from control embryos. The rate of 3H‐radioactivity‐decrease by DNase I treatment was higher in chromatin isolated from the presumptive regetalized embryos than that observed in chromatin isolated from control ones. Probable failure of chromatin structure formation, due to cycloheximide‐inhibition of chromatin protein synthesis, seems to disturb the determination in the embryos at the morula stage, resulting in an induction of vegetalized embryos.
Intercellular Contacts Between the Embryonic or Extraembryonic Ectoderm and the Primitive Endoderm in Rat Egg Cylinders Prior to the Formation of Primitive Streak
Authors: TAKEUCHI IKUO K. , TAKEUCHI YOSHIKO K.
Published: January 2005

In pre‐primitive streak‐stage rat egg cylinders, both the embryonic and extraembryonic ectodermal cells projected cytoplasmic protrusions through gaps in the basal lamina and formed intimate cell‐to‐cell contact with the primitive endodermal cells. The 70 Å microfilaments were considered to participate in the production of these cytoplasmic protrusions. However, direct cell contact mediated by adherent junctions was occasionally found between the embryonic or extraembryonic ectodermal cells and the primitive endodermal cells. It has been proposed that these cell‐to‐cell contacts may play a role either in the supporting effect of primitive endodermal cells in the maintenance of cellular organization of the ectodermal cells, or in the facilitation of transport of nutritive materials from the primitive endodermal cells to both types of ectodermal cells.
Periodic Rotation of Chromosomes During the Mitotic Divisions in Secondary Spermatogonia of Newt, Cynops Pyrrhogaster
Authors: ABE SHIN‐ICHI , NISHIKAWA AKIO
Published: January 2005

Mitosis was frequently observed in the secondary spermatogonia of newt in in vitro cultures. From prometaphase to mid‐anaphase, the whole set of the chromosomes rotated alternately clockwise and counterclockwise generally in the same plane as the bottom of a plastic dish. The axis of rotation was almost always perpendicular to the bottom of a dish, passing through the central part of the cell. This rotation of chromosomes was so fast that we could discern it directly by a phase contrast microscope. It was a rhythmic and regular motion with almost the constant frequency and magnitude. The average period of each cycle during metaphase varied from cell to cell and between 70 to 20 seconds (0.9–3.0 rotations/min) and the average angle traversed during each motion also varied and between 10 to 90 degrees at 25°C. By marking the cell surface with iron particles, it was demonstrated that the inner part of the cell actively rotated and not the cell as a whole. Colcemid at the concentration of 1.0 μg/ml reversibly arrested the chromosomal rotation and karyokinesis. Cytochalasin B (4.0 μg/ml) also reversibly disturbed the rotation though the karyokinesis continued. These results suggest that the rotation of chromosomes as a set may be mediated by filamentous organelles such as microtubules in the mitotic spindle and cytoplasmic microfilaments.
Activation and Suppression of Melanogenesis in Mouse Melanoma Cells by Hybridization with Chick Embryonic Cells
Authors: ISHIGURO SEI‐ICHI , TAKEUCHI TAKUJI
Published: January 2005

Sendai virus‐induced fusion of 6‐thioguanine‐resistant mouse melanoma cells (TG14) with various types of chick embryonic tissue cells resulted in the formation of hybrid cells. Isolated hybrid clones possessed almost complete sets of the cell chromosomes of the parent mouse and several dot‐like chromosomes of the chick. Each type of hybrid clone showed characteristic tyrosinase activity that resulted in melanin production. An enhanced production of melanin was observed in the hybrids between not highly pigmented TG14 cells and retinal pigment cells. Electrophoretic analyses showed that banding patterns of tyrosinase were not of chick type but of mouse melanoma type. Numerous stage 111 and IV melanosomes of the mouse melanoma type were observed in pigmented hybrid clones. On the other hand, hybrid cells between mouse melanoma cells and chick embryonic liver cells exhibited lower tyrosinase activity.
Transdifferentiation of Adult Frog Iris in Retina or Lens by Exogeneous Influences
Authors: HOPERSKAYA OLGA A. , ZVIADADZEZ KETEVAN G.
Published: January 2005

The mechanisms of transdifferentiation of iris epithelial cells of Rana temporaria (Anura) in culture depending on influences from different sources were studied. In terminally differentiated iris cells, the process of transdifferentiation is initiated by dedifferentiation. Melanosomes are shed from iris cells due to cell surface activity. After depigmentation, iris epithelial cells become capable of proliferating and competent to react to the influences of various exogenous factors. Under the influence of retinal factors secreted by lentectomized tadpole eyes, both dorsal and ventral irises are converted to neural retina. Under the influence of factors from eye vesicles, the irises are converted to neural retina as well. Similar results were obtained in transfilter experiments, in which a 3‐day period of transfilter interaction between the irises and eye vesicles ensured depigmentation of the iris followed by transdifferentiation into complete NR with visual receptor. Lentoid formation occurred under the influence of adult frog lens epithelium. Immunofluorescent analysis confirmed the lens nature of the lentoids. In control experiments under the conditions of the tadpole eye orbit, in which programming influences were absent, iris epithelial cells remained unaffected.

The problem of true cell‐reprogramming to new differentiation in contrast to expression of inherent properties of the iris epithelial cells is discussed.
Persistence of Disorganized Pathways and Tortuous Trajectories of Regenerating Retinal Fibers in the Adult Newt Cynops pyrrhogaster
Authors: FUJISAWA HAJIME
Published: January 2005

The anatomical pathways and trajectories of regenerating retinal fibers within the optic tract and tectum of adult newts were examined, 7 months after transection of the optic nerve. In spite of restoration of retinotopic ordered central connection within the tectum, the pathways of individual regenerating retinal fibers within the optic tract were greatly disorganized; the misrouted retinal fibers exhibited tortuous trajectories on the tectal surface in approach to their sites of normal innervation. These results suggest that the regenerating retinal fibers with abnormal pathways and tortuous trajectories can be maintained provided they are in contact with appropriate targets.
Muscle Differentiation in Cultured Pineal Body Cells of Neonatal Rats
Authors: WATANABE K. , AOYAMA H. , NOJYO Y. , MATSUURA T. , OKADA T. S.
Published: January 2005

Dissociated cells of pineal bodies of new‐born rats were cultured to see what cell types would be differentiated during culture in vitro for about 4 weeks. In early stages of culture, about 10 days after inoculation, flattened cells with piliform processes, small round cells and small bubbling cells were distinguishable in the cultures. After about 2 weeks, neuronal cells with axon‐like processes and multinuclear muscle‐like cells were differentiated. On further culture, the latter cells differentiated into mature striated myotubes. The developmental origin of myotube formed in cell cultures of pineal body is discussed.