103 research outputs found
Protein disulphide isomerase-mediated grafting of cysteine-containing peptides onto over-bleached hair
The ability of Protein disulphide isomerase (PDI) to promote the grafting of two cysteine-containing peptides onto hair was investigated in order to develop an alternative treatment for over-bleached hair. The studied peptides were designed based on human keratin and human lung surfactant proteins and were linked to a fluorescent dye to facilitate visualisation of the grafting process and to assess hair penetration. The ability of the peptides to restore mechanical and thermal properties lost by repeated bleaching treatments was also studied. After eight bleaching treatments, hair samples displayed 42% less mechanical resistance, coupled with a decrease in α-helix denaturation enthalpies and temperatures. Hair surface damage following bleaching was visualized by scanning electron microscopy. Addition of PDI to the treatment formulations promoted peptide attachment to the hair via disulphide bonds, facilitating their penetration into the hair cortex, as observed by fluorescence microscopy. The proposed peptide treatment resulted in an increase in α-helix denaturation enthalpy in over-bleached hair, as well as an increase in both Young's modulus and tensile strength. Thus, mechanical and thermal properties were improved after the peptide treatment in the presence of PDI; suggesting that the formulations presented in this work are promising candidates for hair-care applications
Health for sale: the medicinal plant markets in Trujillo and Chiclayo, Northern Peru
Traditional methods of healing have been beneficial in many countries with or without access to conventional allopathic medicine. In the United States, these traditional practices are increasingly being sought after for illnesses that cannot be easily treated by allopathic medicine. More and more people are becoming interested in the knowledge maintained by traditional healers and in the diversity of medicinal plants that flourish in areas like Northern Peru. While scientific studies of medicinal plants are underway, concern has arisen over the preservation of both the large diversity of medicinal plants and the traditional knowledge of healing methods that accompanies them. To promote further conservation work, this study attempted to document the sources of the most popular and rarest medicinal plants sold in the markets of Trujillo (Mayorista and Hermelinda) and Chiclayo (Modelo and Moshoqueque), as well as to create an inventory of the plants sold in these markets, which will serve as a basis for comparison with future inventories. Individual markets and market stalls were subjected to cluster analysis based on the diversity of the medicinal plants they carry. The results show that markets were grouped based on the presence of: (1) common exotic medicinal plants; (2) plants used by laypeople for self-medication related to common ailments ("everyday remedies"); (3) specialized medicinal plants used by curanderos or traditional healers; and (4) highly "specialized" plants used for magical purposes. The plant trade in the study areas seems to correspond well with the specific health care demands from clientele in those areas. The specific market patterns of plant diversity observed in the present study represent a foundation for comparative market research in Peru and elsewhere
Shadows of the colonial past – diverging plant use in Northern Peru and Southern Ecuador
This paper examines the traditional use of medicinal plants in Northern Peru and Southern Ecuador, with special focus on the Departments of Piura, Lambayeque, La Libertad, Cajamarca, and San Martin, and in Loja province, with special focus on the development since the early colonial period. Northern Peru represents the locus of the old Central Andean "Health Axis." The roots of traditional healing practices in this region go as far back as the Cupisnique culture early in the first millennium BC
Recovery of hormone sensitivity after salvage brachytherapy for hormone refractory localized prostate cancer
Radiological progression of cerebral metastases after radiosurgery: assessment of perfusion MRI for differentiating between necrosis and recurrence
To assess the capability of perfusion MRI to differentiate between necrosis and tumor recurrence in patients showing radiological progression of cerebral metastases treated with stereotactic radiosurgery (SRS). From 2004 to 2006 dynamic susceptibility-weighted contrast-enhanced perfusion MRI scans were performed on patients with cerebral metastasis showing radiological progression after SRS during follow-up. Several perfusion MRI characteristics were examined: a subjective visual score of the relative cerebral blood volume (rCBV) map and quantitative rCBV measurements of the contrast-enhanced areas of maximal perfusion. For a total of 34 lesions in 31 patients a perfusion MRI was performed. Diagnoses were based on histology, definite radiological decrease or a combination of radiological and clinical follow-up. The diagnosis of tumor recurrence was obtained in 20 of 34 lesions, and tumor necrosis in 14 of 34. Regression analyses for all measures proved statistically significant (χ2 = 11.6–21.6, P < 0.001–0.0001). Visual inspection of the rCBV map yielded a sensitivity and specificity of 70.0 respectively 92.9%. The optimal cutoff point for maximal tumor rCBV relative to white matter was 2.00 (improving the sensibility to 85.0%) and 1.85 relative to grey matter (GM), improving the specificity to 100%, with a corresponding sensitivity of 70.0%. Perfusion MRI seems to be a useful tool in the differentiation of necrosis and tumor recurrence after SRS. For the patients displaying a rCBV-GM greater than 1.85, the diagnosis of necrosis was excluded. Salvage treatment can be initiated for these patients in an attempt to prolong survival
Traditional medicinal plant use in Northern Peru: tracking two thousand years of healing culture
This paper examines the traditional use of medicinal plants in Northern Peru, with special focus on the Departments of Piura, Lambayeque, La Libertad, Cajamarca, and San Martin. Northern Peru represents the center of the old Central Andean "Health Axis," stretching from Ecuador to Bolivia. The roots of traditional healing practices in this region go at least as far back as the Moche period (AC 100–800). Although about 50% of the plants in use reported in the colonial period have disappeared from the popular pharmacopoeia, the plant knowledge of the population is much more extensive than in other parts of the Andean region. 510 plant species used for medicinal purposes were collected, identified and their vernacular names, traditional uses and applications recorded. The families best represented were Asteraceae with 69 species, Fabaceae (35), Lamiaceae (25), and Solanaceae (21). Euphorbiaceae had twelve species, and Apiaceae and Poaceae 11 species. The highest number of species was used for the treatment of "magical/ritual" ailments (207 species), followed by respiratory disorders (95), problems of the urinary tract (85), infections of female organs (66), liver ailments (61), inflammations (59), stomach problems (51) and rheumatism (45). Most of the plants used (83%) were native to Peru. Fresh plants, often collected wild, were used in two thirds of all cases, and the most common applications included the ingestion of herb decoctions or the application of plant material as poultices
Spirals of Spirituality: A Qualitative Study Exploring Dynamic Patterns of Spirituality in Turkish Organizations
This paper explores organizational spirituality, uncovers it as spiralling dynamics of both positive and negative potentialities, and proposes how leaders can shape these dynamics to improve the human conditions at the workplace. Based on case study of five Turkish organizations and drawing on the emerging discourse on spirituality in organizations literature, this study provides a deeper understanding of how dynamic patterns of spirituality operate in organizations. Insights from participant observation, organizational data, and semi-structured interviews yield three key themes of organizational spirituality: reflexivity, connectivity, and responsibility. Each of these themes has been found to be connected to upward spirals (inspiration, engagement, and calling) and downward spirals (incivility, silence, and fatigue). The study provides a detailed and holistic account of the individual and organizational processes through which spirituality is enacted both positively and negatively, exploring its dynamic and dualistic nature, as embodied in the fabric of everyday life and culture
The Transmembrane Domain of CEACAM1-4S Is a Determinant of Anchorage Independent Growth and Tumorigenicity
CEACAM1 is a multifunctional Ig-like cell adhesion molecule expressed by epithelial cells in many organs. CEACAM1-4L and CEACAM1-4S, two isoforms produced by differential splicing, are predominant in rat liver. Previous work has shown that downregulation of both isoforms occurs in rat hepatocellular carcinomas. Here, we have isolated an anchorage dependent clone, designated 253T-NT that does not express detectable levels of CEACAM1. Stable transfection of 253-NT cells with a wild type CEACAM1-4S expression vector induced an anchorage independent growth in vitro and a tumorigenic phenotype in vivo. These phenotypes were used as quantifiable end points to examine the functionality of the CEACAM1-4S transmembrane domain. Examination of the CEACAM1 transmembrane domain showed N-terminal GXXXG dimerization sequences and C-terminal tyrosine residues shown in related studies to stabilize transmembrane domain helix-helix interactions. To examine the effects of transmembrane domain mutations, 253-NT cells were transfected with transmembrane domain mutants carrying glycine to leucine or tyrosine to valine substitutions. Results showed that mutation of transmembrane tyrosine residues greatly enhanced growth in vitro and in vivo. Mutation of transmembrane dimerization motifs, in contrast, significantly reduced anchorage independent growth and tumorigenicity. 253-NT cells expressing CEACAM1-4S with both glycine to leucine and tyrosine to valine mutations displayed the growth-enhanced phenotype of tyrosine mutants. The dramatic effect of transmembrane domain mutations constitutes strong evidence that the transmembrane domain is an important determinant of CEACAM1-4S functionality and most likely by other proteins with transmembrane domains containing dimerization sequences and/or C-terminal tyrosine residues
Protein disulphide isomerase-assisted functionalization of proteinaceous substrates
Protein disulphide isomerase (PDI) is an enzyme that catalyzes thiol-disulphide exchange reactions among a broad spectrum of substrates, including proteins and low-molecular thiols and disulphides. As the first protein-folding catalyst reported, the study of PDI has mainly involved the correct folding of several cysteine-containing proteins. Its application on the functionalization of protein-based materials has not been extensively reported. Herein, we review the applications of PDI on the modification of proteinaceous substrates and discuss its future potential. The mechanism involved in PDI functionalization of fibrous protein substrates is discussed in detail. These approaches allow innovative applications in textile dyeing and finishing, medical textiles, controlled drug delivery systems and hair or skin care products.We thank to FCT 'Fundacao para a Ciencia e Tecnologia' (scholarship SFRH/BD/38363/2007) for providing Margarida Fernandes the grant for PhD studies
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