Morphology and Longevity of Cells Cultured from Primate, Carnivore and Rodent Tissues

Most workers agree that cells derived from avian and from human sources, and propagated rapidly in monolayer culture, usually come to be dominated by diploid cells of fibroblastic morphology, and are usually also limited in their ability to divide in vitro. The experiments reported here, as well as those reported in some other laboratories, suggest that this phenomenon may occur in primates generally. It does not seem to apply, however, to the cells of some other forms, such as some amphibian groups, the rat, and the ferret: cells from these sources can sometimes be propagated in euploid form for much longer than expected on the basis of experience with primate and avian cells. In addition, such long-term euploid lines are sometimes epithelioid in morphology. This is a feature of special interest in the context of much observation which is consistent with the proposal that fibroblastic (i.e. stroma) cells could indeed be limited in in vivo division potential, and with the observation that epithelial (i.e. most organ parenchymal) cells in many cases cannot be so limited, or must have limits on division potential at very high levels in vivo. Much recent work in other laboratories suggests, however, that many differences between these groups may be explained or circumvented with appropriate medium composition.     

Fermentation process development for the production of medium-chain-length poly-3-hyroxyalkanoates

This paper presents a review of the existing fermentation processes for the production of medium-chain-length poly-3-hydroxyalkanoates (MCL-PHAs). These biodegradable polymers are usually produced most efficiently from structurally related carbon sources such as alkanes and alkanoic acids. Unlike alkanoic acids, alkanes exhibit little toxicity but their low aqueous solubility limits their use in high density culture. Alkanoic acids pose little mass transfer difficulty, but their toxicity requires that their concentration be well controlled. Using presently available technology, large-scale production of MCL-PHA from octane has been reported to cost from US $5 to 10 per kilogram, with expenditures almost evenly divided between carbon source, fermentation process, and the separation process. However, MCL-PHAs, even some with functional groups in their subunits, can also be produced from cheaper unrelated carbon sources, such as glucose. Metabolic engineering and other approaches should also allow increased PHA cellular content to be achieved. These approaches, as well as a better understanding of fermentation kinetics, will likely result in increased productivity and lower production costs.     

Novel conserved segments are associated with differential expression patterns for Pinaceae dehydrins

Dehydrins are thought to play an essential role in the response, acclimation and tolerance to different abiotic stresses, such as cold and drought. These proteins have been classified into five groups according to the presence of conserved and repeated motifs in their amino acid sequence. Due to their putative functions in the response to stress, dehydrins have been often used as candidate genes in studies on population variability and local adaptation to environmental conditions. However, little is still known regarding the differential role played by such groups or the mechanism underlying their function. Based on the sequences corresponding to dehydrins available in public databases we have isolated eight different dehydrins from cDNA of Pinus pinaster. We have obtained also their genomic sequences and identified their intron/exon structure. Quantitative RT-PCR analysis of their expression pattern in needles, stems and roots during a severe and prolonged drought stress, similar to the ones trees must face in nature, is also reported. Additionally, we have identified two amino acid motifs highly conserved and repeated in Pinaceae dehydrins and absent in angiosperms, presumably related to the divergent expression profiles observed.     

HIV/AIDS in rural India: context and health care needs

Primary research on HIV/AIDS in India has predominantly focused on known risk groups such as sex workers, STI clinic attendees and long-distance truck drivers, and has largely been undertaken in urban areas. There is evidence of HIV spreading to rural areas but very little is known about the context of the infection or about issues relating to health and social impact on people living with HIV/AIDS. In-depth interviews with nineteen men and women infected with HIV who live in rural areas were used to collect experiences of testing and treatment, the social impacts of living with HIV and differential impacts on women and men. Eight focus group discussions with groups drawn from the general population in the four villages were used to provide an analysis of community level views about HIV/AIDS. While men reported contracting HIV from sex workers in the cities, women considered their husbands to be the source of their infection. Correct knowledge about HIV transmission co-existed with misconceptions. Men and women tested for HIV reported inadequate counselling and sought treatment from traditional healers as well as professionals. Owing to the general pattern of husbands being the first to contract HIV women faced a substantial burden, with few resources remaining for their own or their children's care after meeting the needs of sick husbands. Stigma and social isolation following widowhood were common, with an enforced return to the natal home. Implications for potential educational and service interventions are discussed within the context of gender and social relations.     

Alkaliphilic bacteria: applications in industrial biotechnology

Alkaliphiles are interesting groups of extremophilic organisms that thrive at pH of 9.0 and above. Many of their products, in particular enzymes, have found widespread applications in industry, primarily in the detergent and laundry industries. While the enzymes have been a runaway success from the industrial point of view, many more products have been reported from alkaliphiles such as antibiotics and carotenoids. Less known are their potential for degradation of xenobiotics. They also play a key role in biogeocycling of important inorganic compounds. This review provides an insight into the huge diversity of alkaliphilic bacteria, the varied products obtained from them, and the need for further investigations on these interesting bacteria.     

Intercultural consultations: investigation of factors that deter non-English speaking women from attending their general practitioners for cervical screening.

OBJECTIVES--To determine the factors that deter ethnic minority women living in east London from attending their general practitioner for cervical cytology screening. DESIGN--Qualitative study by means of focus group discussions between October 1993 and March 1994. SETTING--East London. SUBJECTS--Non-health specific established community groups and specially convened groups of Bengali, Kurdish, Turkish, Urdu and Punjabi, and Chinese speaking women. MAIN OUTCOME MEASURES--The spontaneous views of non-English speaking women resident in east London on cervical screening, focusing on attitudes to screening, their experiences of the cervical cytology screening services as currently provided, and their knowledge and beliefs about cervical screening. RESULTS--Some reported attitudinal barriers to cervical cytology screening such as fear of cancer were not deterrents. Administrative and language barriers were more important, as were inadequate surgery premises and concerns about sterility. CONCLUSION--Contrary to popular belief among general practitioners in east London, women from ethnic minorities are enthusiastic about cervical cytology screening once they understand the purpose of the test and the call and recall procedures. It is possible to consult with community groups in their own language through focus group discussions, working with bilingual health advocates who have had a short practical training in facilitating small group discussions. This form of user consultation could be carried out focusing on other aspects of health promotion.     

Children Love Their Pets: Do Relationships between Children and Pets Co-vary with Taxonomic Order,Gender, and Age?

Generally, children love their pets. However, a deeper insight into the beneficial effects of pets on the physical, psychological, and social wellbeing and development of children is needed. This study investigated whether children have more intense relationships with animals which are behaviorally similar to humans (according to the scala naturae), and whether the relationship patterns between 11- to 14-year-old children (n = 72) and their pets differ from those in prepubescent children, between 6 and 10 years of age (n = 84). We also investigated whether pet-relationship quality is associated with children’s age, gender, and number of siblings. Data about individual bonding type and attachment quality between the children and their pet were collected using a questionnaire. The results indicate that the younger children’s relationships clearly co-varied with taxonomic order of the pet. In contrast, 11- to 14-year-old children reported similarly high scores of attachment with their mouse or iguana as with their dog or cat, and the relationship patterns did not co-vary with taxonomic order. Gender effects on relationship quality were found in both age groups; especially girls reported intense relationships with their pets. In addition to gender, children without siblings had stronger attachment to their pet than children who had siblings. Our data suggest that young children develop high-quality relationships with pets, particularly those which are taxonomically closely related, such as dogs and cats, and less so with other pet species, such as birds or fish. Older children were also able to strongly attach to other pet species. We argue that mental relationship representations change during puberty and that older (11- to 14-year-old) children may no longer make attachments to pets based on them being behaviorally similar to people.     

The aging signature: a hallmark of induced pluripotent stem cells?

The discovery that somatic cells can be induced into a pluripotent state by the expression of reprogramming factors has enormous potential for therapeutics and human disease modeling. With regard to aging and rejuvenation, the reprogramming process resets an aged, somatic cell to a more youthful state, elongating telomeres, rearranging the mitochondrial network, reducing oxidative stress, restoring pluripotency, and making numerous other alterations. The extent to which induced pluripotent stem cell (iPSC)s mime embryonic stem cells is controversial, however, as iPSCs have been shown to harbor an epigenetic memory characteristic of their tissue of origin which may impact their differentiation potential. Furthermore, there are contentious data regarding the extent to which telomeres are elongated, telomerase activity is reconstituted, and mitochondria are reorganized in iPSCs. Although several groups have reported that reprogramming efficiency declines with age and is inhibited by genes upregulated with age, others have successfully generated iPSCs from senescent and centenarian cells. Mixed findings have also been published regarding whether somatic cells generated from iPSCs are subject to premature senescence. Defects such as these would hinder the clinical application of iPSCs, and as such, more comprehensive testing of iPSCs and their potential aging signature should be conducted.     

Chromosomes form into seven groups in hexaploid and tetraploid wheat as a prelude to meiosis

Hexaploid wheat possesses 42 chromosomes derived from its three ancestral genomes. The 21 pairs of chromosomes can be further divided into seven groups of six chromosomes (one chromosome pair being derived from each of the three ancestral genomes), based on the similarity of their gene order. Previous studies have revealed that, during anther development, the chromosomes associate in 21 pairs via their centromeres. The present study reveals that, as a prelude to meiosis, these 21 chromosome pairs in hexaploid (and tetraploid) wheat associate via the centromeres into seven groups as the telomeres begin to cluster. This results in the association of multiple chromosomes, which then need to be resolved as meiosis progresses. The formation of the seven chromosome clusters now explains the occasional occurrence of remnants of multiple associations, which have been reported at later stages of meiosis in hexaploid (and tetraploid) wheat. Importantly, the chromosomes have the opportunity to be resorted via these multiple interactions. As meiosis progresses, such interactions are resolved through the action of loci such as Ph1, leaving chromosomes as homologous pairs.     

Methylation of the guanidino group of arginine residues prevents citrullination by peptidylarginine deiminase IV

Peptidylarginine deiminase IV (PAD IV) catalyzes the citrullination of Arg residues of proteins, such as histones. Suzuki et al. recently reported that haplotypes of the PAD IV gene are associated with susceptibility to rheumatoid arthritis. To investigate the mechanism of substrate specificity and inhibitors of PAD IV, a series of the Arg derivatives were synthesized and their reactivity to PAD IV examined. The results suggest that both imino and carboxyl groups are important in the molecular recognition of PAD IV and that methylation of the guanidino group prevents citrullination. In addition, the findings herein show that Bz-N(G)-monomethyl-Arg and Bz-N(G),N(G)-dimethyl-Arg specifically inhibit citrullination.     

Biophysical aspects and biological implications of the interaction of benzophenanthridine alkaloids with DNA

Benzophenanthridine alkaloids represent a very interesting and significant group of natural products that exhibit a broad range of biological and pharmacological properties. Among this group of alkaloids, sanguinarine, nitidine, fagaronine, and chelerythrine have the potential to form molecular complexes with DNA structures and have attracted recent attention for their possible clinical and pharmacological utility. This review focuses on the interaction of these alkaloids with polymorphic DNA structures (B-form, Z-form, H^L-form, and triple helical form) reported by several research groups employing various physical techniques such as spectrophotometry, spectrofluorimetry, circular dichroism, NMR spectroscopy, thermal melting, viscometry as well as thermodynamic analysis by isothermal titration calorimetry and differential scanning calorimetry to elucidate the mode and mechanism of action at the molecular level to determine the structure-activity relationship. DNA binding properties of these alkaloids are interpreted in relation to their biological activity.     

Human Pannexin 1 channel: Insight in structure–function mechanism and its potential physiological roles

Pannexins, large non-gap junction super family exists in vertebrates, play multiple roles in different cellular functions through their ATP release. Panx1-mediated adenosine 5′-triphosphate (ATP) release plays a vital role in physiological and pathophysiological conditions and is known major extracellular molecule in purinergic signaling. To modulate their function in vivo, a proper regulation of channel is necessary. Post-translational modifications are considered to be some regulating mechanisms for PANX1, while PANX2, PANX3 have been uncharacterized to date. Through their significant evidences, PANXs exclude from gap junction and conduits ATP release and other cellular molecules from cells by various mechanisms. PANX1 is most extensive characterized and implicated in ATP signaling and inflammatory processes. Despite the constant advances, much significance of PANX1 in physiological processes remains elusive. Recently, various research groups along with our group have reported the Cryo-EM structure of Panx1 channel and uncovered the hidden functions in structure–function mechanism as well as to provide the clear understanding in physiological and pathophysiological roles. These research groups reported the novel heptameric structure with contains 4 transmembrane helices (TM), two extracellular loops and one intracellular loop with N and C terminus located at the intracellular side. In addition, the structure contains a large pore of which an inhibitor CBX act as a plug that blocking the passage of substrate. In this context, this review will present current mechanistic understanding in structure and function together with significant physiological roles particularly ATP release in health and disease. As such, this review emphasizes on recent functional properties associated with novel heptameric channel and demystifies channel-mediated ATP release function.

     

Spiders do not escape reproductive manipulations by Wolbachia

Background  

Maternally inherited bacteria that reside obligatorily or facultatively in arthropods can increase their prevalence in the population by altering their hosts' reproduction. Such reproductive manipulations have been reported from the major arthropod groups such as insects (in particular hymenopterans, butterflies, dipterans and beetles), crustaceans (isopods) and mites. Despite the observation that endosymbiont bacteria are frequently encountered in spiders and that the sex ratio of particular spider species is strongly female biased, a direct relationship between bacterial infection and sex ratio variation has not yet been demonstrated for this arthropod order.     

柞蚕蛹虫草代谢物组分分析及对高尿酸血症的作用

采用定量检测和代谢组学方法对柞蚕蛹虫草的成分和参与的代谢途径及通路进行了分析,并开展了其对嘌呤代谢障碍引起的高尿酸血症作用研究.结果表明,柞蚕蛹虫草共含有代谢产物233种,其中不仅含有定量检测已经报道的虫草素、虫草酸等成分,还含有皮质固醇、肾上腺素及谷胱甘肽等多种特殊代谢成分,这些成分主要隶属于羧酸及衍生物、有机氧化合...     

Relationships in six groups of rhesus monkeys I. Networks

Monkey groups are characterized in terms of their networks of relationships. Six groups, each consisting of one adult male, several adult females and immatures, were studied over the same time period. This provided data on interaction patterns within groups and the ways in which individuals' kinship, backgrounds, idiosyncrasies, age and sex affected their interactions. Consistencies and changes in group networks in the course of time and in the face of events such as births, deaths, separations, and introductions are given special attention. Principles of networks are discussed with reference to problems of social structure such as cohesion, permeability, communication, stability and competition.     

Molecular diversity of alveolates associated with neritic north atlantic radiolarians

Seven species of polycystine radiolarians and one phaeodarian species were investigated in order to determine the diversity of their associate organisms and their species specificity. Twelve partial 18S ribosomal DNA (rDNA) sequences were obtained showing a high diversity of associates, both within spumellarian and nassellarian radiolarians and among species. Two of the sequences obtained are highly similar to Scrippsiella, a dinoflagellate genus already reported as a symbiont of polycystine radiolarians. Nine of the new 18S rDNA sequences group with various alveolates. Some of these groups include parasites, such as the lethal endoparasite Amoebophrya, while others consist of non-annotated novel organisms found worldwide in various types of marine environments. We also obtained a sequence from a bacillariophytan highly similar to the 18S rDNA of the diatom species Diatoma tenue, which may derive from radiolarian food. Additionally, this is the first study to report on a phaeodarian associate.     

Controllable surface modification of poly(lactic-co-glycolic acid) (PLGA) by hydrolysis or aminolysis I: physical, chemical, and theoretical aspects

While biodegradable, biocompatible polyesters such as poly (lactic-co-glycolic acid) (PLGA) are popular materials for the manufacture of tissue engineering scaffolds, their surface properties are not particularly suitable for directed tissue growth. Although a number of approaches to chemically modify the PLGA surface have been reported, their applicability to soft tissue scaffolds, which combine large volumes, complex shapes, and extremely fine structures, is questionable. In this paper, we describe two wet-chemical methods, base hydrolysis and aminolysis, to introduce useful levels of carboxylic acid or primary and secondary amine groups, respectively, onto the surface of PLGA with minimal degradation. The effects of temperature, concentration, pH, and solvent type on the kinetics of these reactions are studied by following changes in the wettability of the PLGA using contact angle measurements. In addition, the treated surfaces are studied using X-ray photoelectron spectroscopy (XPS) to determine the effect on the surface chemical structure. Furthermore, we show using XPS analysis that these carboxyl and amine groups are readily activated to allow the covalent attachment of biological macromolecules.     

The current status of the small subunit rRNA phylogeny of the coccidia (Sporozoa)

There is no current comprehensive assessment of the molecular phylogeny of the coccidia, as all recently published papers either deal with subsets of the taxa or sequence data, or provide non-robust analyses. Here, we present a comprehensive and consistent phylogenetic analysis of the available data for the small-subunit ribosomal RNA gene sequence, including a number of taxa not previously studied, based on a Bayesian tree-building analysis and the covariotide model of evolution. The assumptions of the analysis have been rigorously tested, and the benefits and limitations highlighted. Our results provide support for a number of prior conclusions, including the monophyly of the families Sarcocystidae (cyst-forming coccidia) and Eimeriidae (oocyst-forming coccidia), but with bird-host Isospora species in the Eimeriidae and mammal-host species in the Sarcocystidae. However, it is clear that a number of previously reported relationships are dependent on the evolutionary model chosen, such as the placements of Goussia janae, Lankesterella minimia and Caryospora bigenetica. Our results also confirm the monophyly of the subfamilies Toxoplasmatinae and Sarcocystinae, but only some of the previously reported groups within these subfamilies are supported by our analysis. Similarly, only some of the previously reported groups within the Eimeriidae are supported by our analysis, and the genus Eimeria is clearly paraphyletic. There are unambiguous patterns of host-parasite relationship within the coccidia, as most of the well-supported groups have a consistent and restricted range of hosts, with the exception of the Toxoplasmatinae. Furthermore, the previously reported groups for which we found no support all have a diverse range of unrelated hosts, confirming that these are unlikely to be natural groups. The most interesting unaddressed questions may relate to Isospora, which has the fewest available sequences and host-parasite relationships apparently not as straightforward as elsewhere within the suborder.