bluuebunny/crossref_metadata_2025_split huggingface dataset:
Blood volume in the hemoglobinless Antarctic teleost Chionodraco hamatus (Lönnberg)
Authors: Acierno R. , MacDonald J. A. , Agnisola C. , Tota B. 
Published: June 2005

AbstractBlood volume in the hemoglobinless Antarctic icefish Chionodraco hamatus (Channichthyidae) has been determined by the Evans blue dye dilution technique. A mean blood volume of 127.0 ± 5.0 ml kg−1 body weight was found, a value even higher than that previously found in another icefish, Chaenocephalus aceratus (mean blood volume, 89.7 ml kg−1 body weight; Hemmingsen and Douglas [1970] Comp. Biochem. Physiol., 33:733–744; Twelves [1972] Br. Antarct. Surv. Bull. 37:85–92). This extraordinary hypervolemia appears unique among teleosts and may compensate for the absence of hemoglobin in the icefish. © 1995 Wiley‐Liss, Inc.
Effects of all‐trans retinoic acid on regenerating limbs of the fiddler crab,Uca pugilator
Authors: Hopkins P. M. , Durica D. S. 
Published: June 2005

AbstractRegeneration of walking legs in the fiddler crabUca pugilatorrepresents true epimorphic growth since it involves organization of an undifferentiated blastema prior to regrowth of a new limb. Normal regeneration inUcaconsists of two major stages—basal growth and proecdysial growth. One of the earliest events in the basal growth stage of regeneration is the secretion of cuticle by epidermal cells that migrate under the scab at the site of limb loss. When crabs are maintained in a 0.05 mM emulsion of retinoic acid (RA) in sea water during the first 2 weeks following autotomy, the pattern of cuticle secretion is disrupted in many limb buds. Limb buds on RA‐treated crabs grow more slowly and are frequently malformed. © 1995 Wiley‐Liss, Inc.
Involvement of cAMP in inhibition of maturation of follicle‐enclosed oocytes by actinomycin D in Xenopus laevis and Rana temporaria
Authors: Skoblina M. N. , Matikainen T. , Huhtaniemi I. 
Published: June 2005

AbstractProduction of estradiol‐17β and cAMP was assayed during maturation of the follicle‐enclosed oocytes of Xenopus laevis and Rana temporaria stimulated by pituitary suspension or hCG, correspondingly. In some samples, the nuclear function was suppressed by pretreatment with AD. The level of estradiol‐17β in the oocytes of the both species was very low and was not affected by hormonal or AD treatment, while the level of cAMP (follicle + medium) increased. When maturation was stimulated by low concentrations of gonadotropic hormones inducing complete or near 100% maturation, the cAMP level increased 1.4‐ to 3.9‐fold. Both higher concentrations of the gonadotropic hormones and pretreatment of the follicles with AD increased the cAMP level still more. Combination of these treatments led to a greater increase of cAMP and to inhibition of oocyte maturation. We conclude that cAMP, rather than estradiol‐17β, is involved in the AD‐induced inhibition of amphibian oocyte maturation stimulated by gonadotropins. © 1995 Wiley‐Liss, Inc.
Temperature and sex chromosomes govern sex ratios of the mouthbrooding Cichlid fish Oreochromis niloticus
Authors: Baroiller Jean François , Chourrout Daniel , Fostier Alexis , Jalabert Bernard 
Published: June 2005

AbstractUp to now, temperature sex differentiation has been demonstrated in a single fish species, Menidia menidia. This study analyzes this hypothesis in Oreochromis niloticus. Treatments at 36°C, covering the hormone sensitive period, increased the proportion of males (33% to 81%). The male proportion was affected by treatments starting not later than 13 days after fertilization and lasting 10 days or more. Survival rates were not affected by treatments. Functional masculinization of genetic females was demonstrated by the sex‐ratio analysis of 10 temperature‐treated males. Sex reversal by temperature treatment was also confirmed on a genotypic female population. The response to temperature strongly depends upon the breeding pairs. High temperatures override sex chromosome influence in Oreochromis niloticus. Therefore, Oreochromis niloticus sex is determined by genetic factors, temperature level, and genotype‐temperature inter‐actions. Temperature‐dependent sex differentiation may occur more frequently in fish than previously thought, despite the presence of functional sex chromosomes. © 1995 Wiley‐Liss, Inc.
Role of pyriform cells during the growth of oocytes in the lizard Podarcis sicula
Authors: Motta C. M. , Scanderbeg M. Castriota , Filosa S. , Andreuccetti P. 
Published: June 2005

AbstractIn order to clarify the role of follicle cells during growth of previtellogenic oocytes in lizards, an ultrastructural and autoradiographic investigation was carried out in Podarcis sicula. The evidence obtained clearly indicated that both intermediate and pyriform cells are actively involved in the synthesis of RNA that is then transferred to the oocyte, via intercellular bridges, apparently together with a variety of cytoplasmic organelles. At the end of the previtellogenic phase of growth, during the regression of the epithelium, the rate of synthesis of RNA in follicle cells is reduced, in particular in the nucleolus, but the flow of materials toward the oocyte continues. Thus, the intermediate and pyriform cells should be regarded as nurse cells even though they have characteristics rather different from those of the nurse cells described in other animals, such as insects. © 1995 Wiley‐Liss, Inc.
Characterization of zebra mussel (Dreissena polymorpha) sperm morphology and their motility prior to and after spawning
Authors: Mojares J. J. , Stachecki J. J. , Kyozuka K. , Armant D. R. , Ram J. L. 
Published: June 2005

AbstractIn order to understand more about the reproductive physiology of the zebra mussel (Dreissena polymorpha), we have examined the effect of spawning on the kinematics and fertilization ability of their spermatozoa. Sperm morphology was characterized using scanning electron microscopy, differences in sperm kinematics were examined using CASA following manual collection of sperm from the gonad or spawning induced by 5‐hydroxytryptamine (5‐HT), and the fertilization ability of spawned and manually removed spermatozoa were compared. D. polymorpha sperm have a tail 50 μm long, a midpiece consisting of four spherical mitochondria‐rich regions approximately 0.6 μm in diameter, a conical nucleus 2.52 μm in length, and a cylindrical acrosome 0.72 μm in height and width. Kinematic analysis revealed that manually removed sperm exhibit significantly lower motion characteristics as compared to spawned sperm. Treatment with 5‐HT had no significant effect on the sperm kinematics of either manually removed or spawned spermatozoa. These data suggest that D. polymorpha spermatozoa have a similar morphology to other bivalve sperm, spawning results in a significant enhancement in sperm kinematics, and 5‐HT does not directly alter sperm motion. © 1995 Wiley‐Liss, Inc.
Restriction of cell fate of superficial cells in the marginal zone of the amphibian embryo Pleurodeles waltl
Authors: Delarue Michel , Sáez Francisco J. , Johnson Kurt E. , Boucaut Jean‐Claude 
Published: June 2005

AbstractThe fate of circumblastoral cells has been studied in the Pleurodeles waltl late blastula and early gastrula. Individual superficial cells were labeled in defined regions with a fluorescent cell lineage tracer. Labeled progeny were located in sectioned tail bud stage embryos. The injection of defined cells at different developmental stages allowed us to compare the fates of superficial cells in similar locations in late blastula and early gastrula stages and thus to study the restriction of developmental fate. A progressive spatial and temporal restriction of cell fate was observed when comparing clones of cells derived from an injected blastula stage cell and an injected gastrula stage cell. At the blastula stage, the dorsal and dorsolateral regions contain few cells already restricted in their developmental fate to a single mesodermal organ. In contrast, at the gastrula stage, most cells in the dorsal and dorsolateral regions give rise to a single mesodermal derivative, whereas ventrolateral and ventral cells still form mesodermal derivatives but also form ectodermal and endodermal derivatives. © 1995 Wiley‐Liss, Inc.
Antibacterial activity in the blood cells of the solitary ascidian, Ciona intestinalis, in vitro
Authors: Findlay Cameron , Smith Valerie J. 
Published: June 2005

AbstractThe antibacterial properties of the blood cells of the solitary ascidian, Ciona intestinalis, were investigated in vitro. The results show that blood cell lysate supernatants have potent antibacterial activity against a wide range of bacteria. Activity was strongest against Gram positive bacteria, where typically there was a 95‐99% reduction in bacterial viability within 1 h. By contrast, Gram negative bacteria were less susceptible to the antibacterial effects, with the viability of these bacteria generally reduced by approximately 20‐40% after 3 h. Activity against both types of bacteria was further found to be heat‐stable (even after heating to 100°C for 10 min or freezing to −20°C for up to 1 month), Ca2+‐but not Mg2+‐dependent, and active at very low titres. Comparison of the antibacterial vigour of lysate supernatants made from separated blood cell populations revealed that activity resides mainly in the morula cells with some, albeit weaker, activity also detectable in the hyaline amoebocytes. No activity was present in the plasma. Preliminary investigations into the mode of action of the active factors indicate that the response is not due to lysozyme, is not directly lytic in character, and is not attributable to agglutination. Instead, as preliminary characterization by gel filtration on Sephadex G‐75 revealed 4 main protein peaks, with antibacterial activity confined to peak 3 (molecular weight range of 8‐15 kDa), the phenomenon seems to be due to the action of one or more low molecular weight proteins. The location, action, and release of these factors appear to differ from those of the cecropins and defensins described in other animal groups. © 1995 Wiley‐Liss, Inc.
Occurrence and hormonal action of ecdysone on gametogenesis and energy utilization in the leech Nephelopsis obscura (Erpobdellidae)
Authors: Kalarani V. , Reddy D. C. , Habibi H. R. , El‐Shimy N. , Davies Ronald W. 
Published: June 2005

AbstractThe present study provides novel information on the presence of compounds with ecdysone‐like activity and its involvement in the control of gonadal development in a leech. The presence of ecdysone was demonstrated in leech (Nephelopsis obscura) extract by means of high‐performance liquid chromatography (HPLC) in combination with radioimmunoassy. Leech extract was found to bind specifically to an anti‐ecdysone antiserum in a similar manner as standard ecdysone. Further HPLC purification demonstrated the presence of an immunoreactive fraction coeluting exactly with the standard ecdysone, strongly suggesting the presence of ecdysone in N. obscura. Addition of ecdysone to the ambient medium not only advanced leech gametogenesis but also influenced energy utilization. Both low (60 μg·L−1) and high (600 m̈g·L−1 concentrations of ecdysone increased testisac number, spermatogonia, 4th stage spermatogonia, ovisac size, and 2nd stage oogonia within 14 days compared to 35 days in the controls. Ecdysone also caused significant decreases in glycogen, total lipid, and triacylglycerols correlated with the energetic demands of gametogenesis. The findings provide support for the hypothesis that endogenous ecdysone is involved in the regulation of reproduction in N. obscura. © 1995 Wiley‐Liss, Inc.
Prospects for using retroviral vectors for human gene therapy
Authors: Yee Jiing‐Kuan 
Published: June 2005

AbstractMost of the approved clinical trials of human gene therapy are based on vectors derived form retroviruses. For some retroviruses, such as murine leukemia virus, the life cylcel and means of gene regulation are well understood, and provirus sequences have been cloned. Cell lines that allow the generation of high‐titer retroviral vectors without helper virus contamination have been established. Vectors generated from such cell lines are infectious and can efficiently deliver the gene of interest into the target cells. Because virus‐specific genes are deleted from these vectors, further spread of the vectors is prevented. Retrovirus‐mediated gene transfer has been tested in human clinical trials for the treatment of the inherited deficiency of adenosine deaminase and the inherited deficiency of low‐density lipoprotein receptor. Preliminary results from both trials demonstrate the feasiblility and potential efficacy of using gene therapy to treat human diseases. © 1995 Wiley‐Liss, Inc.
Development of adenovirus vectors for gene therapy
Authors: Sharma Sanjai , Tozer J. R. 
Published: June 2005

AbstractThe development of methods for human gene therapy will require efficient and stable introduction of foreign gene into somatic cells. A number of gene transfer technologies are being developed that have the potential for therapeutic application to illnesses such as cancer, genetic diseases, and infectious diseases [Mulligan, 1993]. Viruses have been used in many early gene therapy model studies. Indeed, recombinant adenoviruses are one of the most promising gene transfer systems currently available. Adenovirus vectors are used in about 10% of all the gene therapy protocols approved by the recombinant advisory committee. This review focuses on the development of adenovirus vectors, their use in clinical settings, and current obstacles to prolonged gene expression. © 1995 Wiley‐Liss, Inc.
Transplantation of neural progenitor and stem‐like cells as a strategy for gene therapy and repair of neurodegenerative diseases
Authors: Snyder Evan Y. , Flax Jonathan D. 
Published: June 2005

AbstractPotential new approaches to central nervous system (CNS) dysfunction have been created by the convergence of neural progenitor and stem cell biology with gene therapy and repair. Neural progenitors can be maintained in a proliferative state in vitro through retroviral transduction of an immortalizing gene. The immobilized progenitors then appear to behave much like normal CNS stem cells and hence have been termed stem‐like cells. The ability to transplant clonally related neural progenitors that self‐renew in culture but, after transplantation to the brain, differentiate appropriately into neurons and gila, may not only facilitate developmental inquiries, but also circumvent the limitations of primary fetal tissue for neural grafting. These cells are homogenous, abundant, and well‐characterized. They may express therapeutic gene products intrinsically or be readily engineered ex vivo to do so their ability to integrate efficiently into germinal zones and to migrate make possible transplant techniques that ensure widespread engraftment. Exploiting the inherent properties of neural progenitors, which allow them to become integral members of normal structures throughout the host brain, may allow foreign gene products to be delivered in a sustained, direct, and perhaps regulated fashion without disturbing other neurobiological processes. Transplants of such stem‐like cells may make possible new strategies for gene therapy and repair of the CNS, including the replacement of degenerated cells, the engineering of donor cells to be resistant to toxins, the delivery of missing metabolic or other gene products, to the over‐expression of molecules, and the substitution of alternate metabolic pathways. These approaches appear to be successful in various mouse models of neurodegeneration. Such observation may also provide a paradigm for the therapeutic use of stem cells from other organ systems. © 1995 Wiley‐Liss, Inc.
Clinical trials of D1 and D2 dopamine modulating drugs and self‐injury in mental retardation and developmental disability
Authors: Schroeder Stephen R. , Hammock Ron G. , Mulick James A. , Rojahn Johannes , Walson Philip , Fernald Will , Meinhold Patricia , Saphare Geeta 
Published: June 2005

AbstractWe review the rationale for conducting clinical trials of D1 and D2 dopamine modulators for self‐injurious behavior (SIB) among people with mental retardation and developmental disabilities. We include a brief history of the relevant behavioral research on SIB, the psychopharmacology of neuroleptic drugs for SIB, pharmacotherapy for SIB based on dopamine function, treatment for SIB with neuroleptics, SIB and dopamine supersensitivity, and the D1 dopamine hypothesis and SIB. We also present controlled case studies of the use of clozapine to treat chronic, refractory SIB in three individuals with profound mental retardation. One was a dramatic responder at 225 mg per day; one was a partial responder at 300 mg per day; and one showed a decrease in stereotypy, but not SIB, at 100 mg per day. Studies from rats, monkeys, and humans support the hypothesis that the D1 dopamine receptor system in the nigrostriatal pathway of the basal ganglia plays a key role in SIB in some cases. © 1995 Wiley‐Liss, Inc.
The fragile X mutation
Authors: Imbert Georges , Mandel Jean‐Louis 
Published: June 2005

AbstractFragile X syndrome, the most common cause of inherited mental retardation, is the result of unstable expansions of a CGG repeat located in the 5′ untranslated region of the FMR1 gene. Normal alleles consist of 6‐50 CGG repeats, in general interspersed by 1–3 AGGs. Moderate expansions up to 200 repeats, called premutations, are found in phenotypically normal carrier males or females. When transmitted by a female, a premutation has a risk of up to 100% of further expansion to an abnormally methylated full mutation (230 to >1,000 CGGs), which results in shut‐down of FMR1 expression. In contrast, affected males with a full mutation carry a premutation in their sperm that is transmitted to their daughters. On maternal transmission, the timing of the transition from premutation to full mutation remains unsolved. It is generally believed, but has not been proven that this is a postzygotic event, in which case an imprinting mechanism is required to distinguish a premutation carried on a maternal or paternal X chromosome. As in other trinucleotide expansion diseases, linkage disequilibrium between the fragile X mutations and haplotypes of adjacent polymorphisms has been found in various populations, indicating founder effects. These studies have suggested that normal alleles that carry long perfect CGG repeats may constitute alleles that are predisposed to multistep expansion over many generations. The ability to detect the various types of mutations has revolutionized the diagnosis of the disease and genetic counseling, and should allow more precise estimates of the population frequency of the fragile X syndrome. It may also allow screening for carrier females in the general population. We discuss possible mechanisms of expansion in light of the unusual structural properties proposed for CGG repeats. Various other folate‐sensitive fragile sites that are also caused by unstable expansions of CGG (CCG) repeats are being cloned and characterized. In particular, methylated expansions at the FRAXE locus appear to be associated with mild mental retardation. © 1995 Wiley‐Liss, Inc.
The neurobiology of fragile X syndrome
Authors: Abrams Michael T. , Reiss Allan L. 
Published: June 2005

AbstractFragile X syndrome, the leading known cause of heritable mental retardation, is associated with mutations of the FMR1 gene on the X chromosome. Neurobiological research has characterized several gene‐brain‐function correlations in fragile X syndrome, although no complete pathogenic mechanisms have yet been elucidated. This report summarizes current knowledge of the neurobiology of fragile X syndrome. Published research findings are presented along with a discussion of the relevance of neurobiological data to the neurobehavioral phenotype and genetic mechanisms associated with the FMR1 mutation. © 1995 Wiley‐Liss, Inc.
Adaptive behavior in males with fragile X syndrome
Authors: Dykens Elisabeth M. 
Published: June 2005

AbstractAdaptive behavior has long been a key component of the definition of mental retardation. However, research on these important skills in fragile X and other genetic syndromes is just under way, having taken a back seat to studies using mixed etiologic groups. Further, adaptive behavior is complex, and measurements of these skills must have a developmental orientation, apply to multiple life settings, and reflect typical as opposed to optimal performance. After reviewing these features, this article highlights three areas of adaptive functioning in males with fragile X syndrome: profiles, trajectories, and adaptive behavior‐IQ relations. Many males with fragile X show relative strengths in domestic and personal chores of daily living, or so‐called “practical” intelligence. Whereas age‐related gains in adaptive skills are often seen in boys, particularly during the preschool years, adolescents and adults seem to have relative stable adaptive age scores and declines in adaptive standard scores. Such developmental courses may parallel the IQ trajectory often seen in males with fragile X syndrome. The need for further adaptive research is emphasized, particularly in light of the critical role these skills play in the ultimate life success of individuals with mental retardation. © 1995 Wiley‐Liss, Inc.
Further observations on the teratogenic action of the thyroid stimulating hormone
Authors: Beaudoin Allan R. 
Published: June 2005

AbstractPregnant Wistar Albino rats were injected intraperitoneally with the thyroid stimulating hormone (TSH), obtained from several different suppliers, and with the dye trypan blue. Twenty USP units of TSH were injected on days 7 to 10 of pregnancy, one quarter of the total dose each day. Trypan blue was injected as a single subteratogenic dose (0.6 mg/100 gm maternal body weight) on day 8. Autopsy was on day 20. Some TSH prepared as a pituitary extract possessed very weak teratogenic activity, possibly limited to the production of hydronephrosis and hydroureter. Other TSH samples similarly prepared had no embryotoxic or teratogenic effect. Thyrotropin prepared from bovine serum exhibited distinct teratogenic activity causing the production of various malformations in the offspring of treated mothers. A subteratogenic dose of trypan blue enhanced the teratogenic activity of the serum prepared TSH sample but had no effect on TSH prepared from pituitary glands. The results of this experiment suggest that there is something in the nature of preparation of TSH from bovine serum that causes it to possess teratogenic activity.