bluuebunny/crossref_metadata_2025_split huggingface dataset:
RACTERISTICS OF HUMAN MEDULLOBLASTOMA CELL LINE TE‐671 UNDER DIFFERENT GROWTH CONDITIONS IN VITRO: A MORPHOLOGICAL AND IMMUNOHISTOCHEMICAL STUDY
Authors: MØRK S. J. , MAY E. E. , PAPASOZOMENOS S. CH. , VINORES S. A. 
Published: May 2008

Characteristics of human medulloblastoma cell line TE‐671 under different growth conditions in vitro: a morphological and immunohistochemical studyThe human medulloblastoma cell line, TE‐671, was studied in vitro both in monolayer culture and in a three‐dimensional culture system using gelfoam as the supporting matrix. Flow cytometry studies of cells grown in monolayer culture revealed a unimodal, tetraploid DNA content. Most cells in both in vitro systems contained neuron‐specific enolase (NSE), actin, and tubulin, while only occasional cells or cell clusters contained the 68 000 molecular weight subunit of neurofilaments (NF mol. wt 68 000) or microtubule‐associated protein 2 (MAP‐2). In monolayer culture, long cellular processes containing NSE, NF mol. wt 68 000 and MAP‐2, which were present at 2 days, were nearly absent by 7 days. All antigens were present at 4 days in the organ culture system; by 72 days, cells still stained positively for NF mol. wt 68000 and MAP‐2, but staining for NSE, actin, and β‐tubulin was diminished as compared to 4 days. Retinoic acid (RA) in the 13‐cis isomer form at 10‐6 M was applied to monolayer cultures at day 1 for 6 days and to gelfoam cultures at day 1 for 28 days. RA did not significantly alter cell proliferation up to 7 days in vitro and did not appreciably affect cellular expression of NSE, NF mol. wt 68000, MAP‐2, β‐tubulin, or actin in either system. By electron microscopy, most cells grown under different culture conditions with or without RA treatment appeared to be undifferentiated and polygonal, with occasional cytoplasmic annulate lamellae.The immunohistochemical and ultrastructural features reported indicate that the TE‐671 medulloblastoma line is composed primarily of primitive neuroepithelial cells with a limited potential for neuronal differentiation. This differentiation was not promoted by RA or by an in vitro system known to favour differentiation in a number of human and animal nervous system tumours. The findings suggest that the cells of the TE‐671 line lack either receptors for retinoic acid or the capacity to respond to bound retinoic acid.
A QUANTITATIVE STUDY OF THE ULTRASTRUCTURE OF PYRAMIDAL NEURONS OF THE CEREBRAL CORTEX IN ALZHEIMER'S DISEASE IN RELATIONSHIP TO THE DEGREE OF DEMENTIA
Authors: SUMPTER P. Q. , MANN D. M. A. , DAVIES C. A. , NEARY D. , SNOWDEN J. S. , YATES P. O. 
Published: May 2008

A quantitative study of the ultrastructure of pyramidal neurons of the cerebral cortex in Alzheimer's disease in relationship to the degree of dementiaQuantitative morphometric (stereological) methods have been used to measure the number or amount of organelles in pyramidal nerve cells, unaffected by neurofibrillary degeneration, in biopsy specimens of temporal cortex from 11 patients with Alzheimer's disease, and to relate these to the degree of dementia, as measured by psychometric testing. Only areal proportion (AA) and surface area (SA) of rough endoplasmic reticulum were significantly reduced in line with the severity of the degree of dementia. It is suggested that these changes reflect a progressively diminishing requirement for packaging and transport of replacement proteins, particularly in relation to neurotransmitter metabolism in nerve terminals following the loss of synapses which we have shown to occur in these patients.
CYTOFLUOROMETRIC QUANTIFICATION OF SOMATOPETAL AXONAL TRANSPORT: EFFECTS OF A CONDITIONING LESION AND 2,5‐HEXANEDIONE
Authors: NENNESMO INGER , KRISTENSSON KRISTER 
Published: May 2008

Cytofluorometric quantification of somatopetal axonal transport: effects of a conditioning lesion and 2,5‐hexanedioneCytofluorometric quantification of axonally transported fluorescein isothiocyanate (FITC)‐labelled wheat germ agglutinin (WGA) from the injection site in the snout area was performed in the facial nucleus at various times during regeneration of one of the facial nerves. Measurements were made on single neurons on both operated and non‐operated sides in three different groups of mice 8, 12 and 16 days after a nerve crush, Group 1: (control group) animals with a nerve crush, Group 2: animals with a conditioning lesion (nerve injury) made 3 days before the nerve crush, and Group 3: animals exposed daily to 2,5‐hexanedione from 2 weeks before nerve crush until killing. A conditioning lesion caused a more rapid return of transport in regenerating nerves but there was no evidence for an increase in the total amount of transported FITC‐WGA. For mice exposed to 2,5‐hexanedione a transient increase of tracer transport in regenerating nerves could be demonstrated on day 12 after nerve crush. On day 16, however, a reduction of transport was seen in both operated and non‐operated nerves. This study shows that it is possible experimentally to manipulate the influx of macromolecules to the nerve cell body from the periphery during nerve regeneration, and the present method offers the opportunity to study quantitatively the effects of various treatments on reinnervation of a muscle.
THE PATHOLOGICAL EFFECT ON THE CENTRAL NERVOUS SYSTEM OF MICE FOLLOWING SINGLE AND REPEATED INFECTIONS OF THE DEMYELINATING A7(74) STRAIN OF SEMLIKI FOREST VIRUS
Authors: ILLAVIA S. J. , WEBB H. E. 
Published: May 2008

The pathological effect on the central nervous system of mice following single and repeated infections of the demyelinating A7(74) strain of Semliki Forest virusThe avirulent strain A7(74) of Semliki Forest virus was inoculated intraperitoneally into mice at weekly intervals for 7 weeks. Pathological, virological and serological studies were carried out twice weekly, after each infecting dose. Similar studies were performed on mice that had been given repeated inoculations at 2, 3 or 4 weekly intervals as were a group of control mice given a single dose of SFV.Results showed grossly enhanced central nervous system lesions, in particular the perivascular cuffing and demyelination, after the 2nd and 3rd weekly inoculation. With further injections there was no increase in severity of the lesions and by the eighth inoculation the pathological changes in the brain appeared to have recovered. The maximum and most persistent damage to the brain was seen after the 2nd and 3rd weekly inoculations. As the interval between two SFV inoculations was increased, the lesions in the central nervous system were reduced and protection increased. Virus in the blood was only detectable after the first inoculation and brain virus after the first and second inoculations. Peak IgG antibody levels were seen on day 46 after a single inoculation and day 35 in the multiple inoculations.It was concluded that repeated inoculations of SFV do not produce a relapsing demyelinating disease, but the 7th and 14th day inoculations do enhance the lesions which are seen to persist after the inoculation on the 21st day. In spite of the gross pathological changes inflicted, the brain damage appears to recover.
THE EFFECTS OF THIOCTIC ACID ON MOTOR NERVE TERMINALS IN ACRYLAMIDE–POISONED RATS
Authors: KEMPLAY S. , MARTIN P. , WILSON S. 
Published: May 2008

The effects of thioctic acid on motor nerve terminals in acrylamide–poisoned ratsAcrylamide causes a distal neuropathy by combining with and depleting glutathione and other sulphydryl–containing compounds in axons and nerve terminals. This results in damage to the axon membrane and impaired efficiency of synaptic vesicle recycling. The changes may be assessed by staining nerve terminals in muscle with zinc iodide and osmium, a technique which depends upon the presence of sulphydryl compounds for the development of the stain. The present experiments were designed to test whether thioctic acid, itself a sulphydryl–containing compound, could protect against acrylamide–induced damage of motor nerve terminals. In vitro and in vivo experiments on acrylamide–poisoned rats showed that thioctic acid was able to maintain the integrity of the nerve terminal membrane, as shown by the ability of the terminals to develop ‘spontaneous’ sprouts and to stain with the zinc iodide osmium technique. Thioctic acid treatment also enhanced recovery after partial denervation of muscles in both normal and acrylamide–poisoned animals. The results suggest that thioctic acid is itself able to react with the acrylamide before the latter has a chance to bind and deplete axonal and nerve terminal glutathione.
THE EFFECTS OF ALUMINIUM ON BRAIN GANGLIOSIDES IN URAEMIC RATS TREATED WITH 24R, 25–DIHYDROXYVITAMIN D3
Authors: VUKIčEVIć S. , KRAčUN I. , STAVLJENIć A. , KELOVIć Z. , KREMPIEN B. , RÖSNER H. 
Published: May 2008

The effects of aluminium on brain gangliosides in uraemic rats treated with 24R, 25‐dihydroxyvitamin D3The administration of aluminium to uraemic rats leads to aluminium accumulation in different brain regions. Aluminium intoxication significantly alters brain gangliosides, the content of which is increased in uraemic animals. This phenomenon can be prevented by administration of 24R, 25‐dihydroxyvitamin D3 (24, 25(OH)2D3).Our results could possibly find an application in the prevention of aluminium‐induced encephalopathy in patients on haemodialysis.
The response of neurons and microglia to blast injury in the rat brain
Authors: Kaur C. , Singh J. , Lim M. K. , Ng B. L. , Yap E. P. H. , Ling E. A. 
Published: May 2008

Rats subjected to a single non‐penetrative blast were examined for possible neuronal damage and glial reaction by immunohistochemistry and electron microscopy. The most dramatic feature in rats killed between 1 and 14 days after the blast was the widespread response of microglial cells in various parts of the brain in which the cells were hypertrophied and their surface antigens, like complement type three receptors (CR3), were upregulated. The blast wave also induced the vigorous expression of major histocompatibility complex (MHC) class I and II (Ia) antigens. In rats killed 21 days after the blast, the elevated immunoreactivity of microglia had subsided and at 28 days both the microglial external morphology and immunoreactivity were comparable to those of normal animals. In rats killed 4–7 days after the blast, the neurons in the cerebral and cerebellar cortex appeared normal except for the occurrence of some ‘darkened dendrites’. The incidence of ‘darkened’ den‐drites was most common in rats killed at day 14 but they were absent at 21 and 28 days. Microglial cells were closely associated with some of the ‘darkened’ dendrites.Results in this study show that a non‐penetrative blast in rats provokes a widespread microglial activation suggesting increased endocytosis and immunological responses. However, it remains uncertain whether such a drastic response was a direct activation of the cells by the blast wave or elicited indirectly by some chemical factors released from the damaged brain tissues.
IL‐27‐Mediated Activation of Natural Killer Cells and Inflammation Produced Antitumour Effects for Human Oesophageal Carcinoma Cells
Authors: Liu L. , Wang S. , Shan B. , Shao L. , Sato A. , Kawamura K. , Li Q. , Ma G. , Tagawa M. 
Published: May 2008

AbstractInterleukin (IL)‐27, composed of p28 and EBV‐induced gene 3 subunits, has diverse functions in enhancing cell‐mediated immunity and silencing the immunity. We examined whether forced expression of the p28‐linked EBI3 gene in human oesophageal carcinoma cells (Eca109) produced antitumour effects in a T cell‐defective condition. Tumour growth of Eca109 cells expressing IL‐27 (Eca109/IL‐27) was retarded in nude mice compared with parental and vector DNA‐transduced tumours and survival of the mice inoculated with Eca109/IL‐27 cells was prolonged. Expression of the tumour necrosis factor‐α, IL‐1β and IL‐6 genes was up‐regulated in Eca109/IL‐27 tumour specimens while the tumours remained small in size but the increased transcription was subsequently down‐regulated in enlarged tumours. Spleen cells from mice‐bearing Eca109/IL‐27 tumours produced interferon‐γ and showed YAC‐1‐targeted cytotoxic activities greater than those of mice inoculated with parental or vector DNA‐transducer tumours. Numbers of DX5+CD69+ natural killer cells in spleen of mice‐bearing Eca109/IL‐27 tumours and those of CD31+ cells within Eca109/IL‐27 tumours remained the same as found in mice‐bearing parental or vector DNA‐transduced tumours. These data collectively suggest that the IL‐27‐mediated antitumour effects produced in a mature T cell‐defective condition were attributable to enhanced interferon‐γ production and natural killer activities.
High‐value oils from plants
Authors: Dyer John M. , Stymne Sten , Green Allan G. , Carlsson Anders S. 
Published: May 2008

SummaryThe seed oils of domesticated oilseed crops are major agricultural commodities that are used primarily for nutritional applications, but in recent years there has been increasing use of these oils for production of biofuels and chemical feedstocks. This is being driven in part by the rapidly rising costs of petroleum, increased concern about the environmental impact of using fossil oil, and the need to develop renewable domestic sources of fuel and industrial raw materials. There is also a need to develop sustainable sources of nutritionally important fatty acids such as those that are typically derived from fish oil. Plant oils can provide renewable sources of high‐value fatty acids for both the chemical and health‐related industries. The value and application of an oil are determined largely by its fatty acid composition, and while most vegetable oils contain just five basic fatty acid structures, there is a rich diversity of fatty acids present in nature, many of which have potential usage in industry. In this review, we describe several areas where plant oils can have a significant impact on the emerging bioeconomy and the types of fatty acids that are required in these various applications. We also outline the current understanding of the underlying biochemical and molecular mechanisms of seed oil production, and the challenges and potential in translating this knowledge into the rational design and engineering of crop plants to produce high‐value oils in plant seeds.
Production of renewable polymers from crop plants
Authors: Van Beilen Jan B. , Poirier Yves 
Published: May 2008

SummaryPlants produce a range of biopolymers for purposes such as maintenance of structural integrity, carbon storage, and defense against pathogens and desiccation. Several of these natural polymers are used by humans as food and materials, and increasingly as an energy carrier. In this review, we focus on plant biopolymers that are used as materials in bulk applications, such as plastics and elastomers, in the context of depleting resources and climate change, and consider technical and scientific bottlenecks in the production of novel or improved materials in transgenic or alternative crop plants. The biopolymers discussed are natural rubber and several polymers that are not naturally produced in plants, such as polyhydroxyalkanoates, fibrous proteins and poly‐amino acids. In addition, monomers or precursors for the chemical synthesis of biopolymers, such as 4‐hydroxybenzoate, itaconic acid, fructose and sorbitol, are discussed briefly.
Harnessing plant trichome biochemistry for the production of useful compounds
Authors: Schilmiller Anthony L. , Last Robert L. , Pichersky Eran 
Published: May 2008

SummaryPlant trichomes come in a variety of shapes, sizes and cellular composition. Some types, commonly called glandular trichomes, produce large amounts of specialized (secondary) metabolites of diverse classes. Trichomes are implicated in a variety of adaptive processes, including defense against herbivores and micro‐organisms as well as in ion homeostasis. Because trichomes protrude from the epidermis and can often be easily separated from it and harvested, the mRNAs, proteins and small molecules that they contain are unusually accessible to analysis. This property makes them excellent experimental systems for identification of the enzymes and pathways responsible for the synthesis of the specialized metabolites found in these structures and sometimes elsewhere in the plant. We review the literature on the biochemistry of trichomes and consider the attributes that might make them highly useful targets for plant metabolic engineering.
Biosynthesis of plant‐derived flavor compounds
Authors: Schwab Wilfried , Davidovich‐Rikanati Rachel , Lewinsohn Efraim 
Published: May 2008

SummaryPlants have the capacity to synthesize, accumulate and emit volatiles that may act as aroma and flavor molecules due to interactions with human receptors. These low‐molecular‐weight substances derived from the fatty acid, amino acid and carbohydrate pools constitute a heterogenous group of molecules with saturated and unsaturated, straight‐chain, branched‐chain and cyclic structures bearing various functional groups (e.g. alcohols, aldehydes, ketones, esters and ethers) and also nitrogen and sulfur. They are commercially important for the food, pharmaceutical, agricultural and chemical industries as flavorants, drugs, pesticides and industrial feedstocks. Due to the low abundance of the volatiles in their plant sources, many of the natural products had been replaced by their synthetic analogues by the end of the last century. However, the foreseeable shortage of the crude oil that is the source for many of the artifical flavors and fragrances has prompted recent interest in understanding the formation of these compounds and engineering their biosynthesis. Although many of the volatile constituents of flavors and aromas have been identified, many of the enzymes and genes involved in their biosynthesis are still not known. However, modification of flavor by genetic engineering is dependent on the knowledge and availability of genes that encode enzymes of key reactions that influence or divert the biosynthetic pathways of plant‐derived volatiles. Major progress has resulted from the use of molecular and biochemical techniques, and a large number of genes encoding enzymes of volatile biosynthesis have recently been reported.
Terpenoid biomaterials
Authors: Bohlmann Jörg , Keeling Christopher I. 
Published: May 2008

SummaryTerpenoids (isoprenoids) encompass more than 40 000 structures and form the largest class of all known plant metabolites. Some terpenoids have well‐characterized physiological functions that are common to most plant species. In addition, many of the structurally diverse plant terpenoids may function in taxonomically more discrete, specialized interactions with other organisms. Historically, specialized terpenoids, together with alkaloids and many of the phenolics, have been referred to as secondary metabolites. More recently, these compounds have become widely recognized, conceptually and/or empirically, for their essential ecological functions in plant biology. Owing to their diverse biological activities and their diverse physical and chemical properties, terpenoid plant chemicals have been exploited by humans as traditional biomaterials in the form of complex mixtures or in the form of more or less pure compounds since ancient times. Plant terpenoids are widely used as industrially relevant chemicals, including many pharmaceuticals, flavours, fragrances, pesticides and disinfectants, and as large‐volume feedstocks for chemical industries. Recently, there has been a renaissance of awareness of plant terpenoids as a valuable biological resource for societies that will have to become less reliant on petrochemicals. Harnessing the powers of plant and microbial systems for production of economically valuable plant terpenoids requires interdisciplinary and often expensive research into their chemistry, biosynthesis and genomics, as well as metabolic and biochemical engineering. This paper provides an overview of the formation of hemi‐, mono‐, sesqui‐ and diterpenoids in plants, and highlights some well‐established examples for these classes of terpenoids in the context of biomaterials and biofuels.
Improvement of biomass through lignin modification
Authors: Li Xu , Weng Jing‐Ke , Chapple Clint 
Published: May 2008

SummaryLignin, a major component of the cell wall of vascular plants, has long been recognized for its negative impact on forage quality, paper manufacturing, and, more recently, cellulosic biofuel production. Over the last two decades, genetic and biochemical analyses of brown midrib mutants of maize, sorghum and related grasses have advanced our understanding of the relationship between lignification and forage digestibility. This work has also inspired genetic engineering efforts aimed at generating crops with altered lignin, with the expectation that these strategies would enhance forage digestibility and/or pulping efficiency. The knowledge gained from these bioengineering efforts has greatly improved our understanding of the optimal lignin characteristics required for various applications of lignocellulosic materials while also contributing to our understanding of the lignin biosynthetic pathway. The recent upswing of interest in cellulosic biofuel production has become the new focus of lignin engineering. Populus trichocarpa and Brachypodium distachyon are emerging as model systems for energy crops. Lignin research on these systems, as well as on a variety of proposed energy crop species, is expected to shed new light on lignin biosynthesis and its regulation in energy crops, and lead to rational genetic engineering approaches to modify lignin for improved biofuel production.
Deciphering gene regulatory networks that control seed development and maturation in Arabidopsis
Authors: Santos‐Mendoza Monica , Dubreucq Bertrand , Baud Sébastien , Parcy François , Caboche Michel , Lepiniec Loïc 
Published: May 2008

SummarySeeds represent the main source of nutrients for animals and humans, and knowledge of their biology provides tools for improving agricultural practices and managing genetic resources. There is also tremendous interest in using seeds as a sustainable alternative to fossil reserves for green chemistry. Seeds accumulate large amounts of storage compounds such as carbohydrates, proteins and oils. It would be useful for agro‐industrial purposes to produce seeds that accumulate these storage compounds more specifically and at higher levels. The main metabolic pathways necessary for oil, starch or protein accumulation are well characterized. However, the overall regulation of partitioning between the various pathways remains unclear. Such knowledge could provide new molecular tools for improving the qualities of crop seeds (Focks and Benning, 1998,Plant Physiol.118, 91). Studies to improve understanding of the genetic controls of seed development and metabolism therefore remain a key area of research.In the model plant Arabidopsis, genetic analyses have demonstrated thatLEAFY COTYLEDONgenes, namelyLEC1,LEC2andFUSCA3(FUS3), are key transcriptional regulators of seed maturation, together withABSCISIC ACID INSENSITIVE 3(ABI3). Interestingly, LEC2, FUS3 and ABI3 are related proteins that all contain a ‘B3’ DNA‐binding domain. In recent years, genetic and molecular studies have shed new light on the intricate regulatory network involving these regulators and their interactions with other factors such as LEC1, PICKLE, ABI5 or WRI1, as well as with sugar and hormonal signaling. Here, we summarize the most recent advances in our understanding of this complex regulatory network and its role in the control of seed maturation.