The Teenek (or Huastec) Indians in Mexico's Northeast maintain an ambivalent relationship with their dogs. On the one hand, these dogs, famished and mangy, are constantly targeted for blows and other forms of torment. On the other hand, according to indigenous cosmology, a person should treat his or her dog well, since after death it is the dog that will guide the dead to the afterworld. A contradiction seems to exist between these two opposite positions. However, an examination of the names given by the Teenek to their dogs and the language used to address them could provide a solution to this apparent riddle. Furthermore, the analysis may well reveal a classification system of Self and Other, uncovering a subtle indigenous process for the preservation of the memory of an autochthonous tradition. 相似文献
Chronic obstructive pulmonary disease and emphysema are common destructive inflammatory diseases that are leading causes of death worldwide. Here we show that emphysema is an autoimmune disease characterized by the presence of antielastin antibody and T-helper type 1 (T(H)1) responses, which correlate with emphysema severity. These findings link emphysema to adaptive immunity against a specific lung antigen and suggest the potential for autoimmune pathology of other elastin-rich tissues such as the arteries and skin of smokers. 相似文献
Stress fracture is a common musculoskeletal problem affecting athletes and soldiers. Repetitive high bone strains and strain rates are considered to be its etiology. The strain level necessary to cause fatigue failure of bone ex vivo is higher than the strains recorded in humans during vigorous physical activity. We hypothesized that during fatiguing exercises, bone strains may increase and reach levels exceeding those measured in the non-fatigued state. To test this hypothesis, we measured in vivo tibial strains, the maximum gastrocnemius isokinetic torque and ground reaction forces in four subjects before and after two fatiguing levels of exercise: a 2km run and a 30km desert march. Strains were measured using strain-gauged staples inserted percutaneously in the medial aspect of their mid-tibial diaphysis. There was a decrease in the peak gastrocnemius isokinetic torque of all four subjects' post-march as compared to pre-run (p=0.0001), indicating the presence of gastrocnemius muscle fatigue. Tension strains increased 26% post-run (p=0.002, 95 % confidence interval (CI) and 29% post-march (p=0.0002, 95% CI) as compared to the pre-run phase. Tension strain rates increased 13% post-run (p=0.001, 95% CI) and 11% post-march (p=0.009, 95% CI) and the compression strain rates increased 9% post-run (p=0.0004, 95% CI) and 17% post-march (p=0.0001, 95% CI). The fatigue state increases bone strains well above those recorded in rested individuals and may be a major factor in the stress fracture etiology. 相似文献
S-adenosylmethionine (SAM) is the substrate used in the methylation of homogalacturonan (HGA) in the Golgi apparatus. SAM is synthesized in the cytosol, but it is not currently known how it is then transported into the Golgi. In this study, we find that HGA methyltransferase is present in Golgi-enriched fractions and that its catalytic domain faces the lumen of this organelle. This suggests that SAM must be imported into the Golgi. We performed uptake experiments using [methyl-(14)C]SAM and found that SAM is incorporated into the Golgi vesicles, resulting in the methylation of polymers that are sensitive to pectinase and pectin methylesterase but not to proteases. To avoid detecting the transfer reaction, we also used [carboxyl-(14)C]SAM, the uptake of which into Golgi vesicles was found to be sensitive to temperature, detergents, and osmotic changes, and to be saturable with a K(m) of 33 microm. Double-label uptake experiments using [methyl-(3)H]SAM and [carboxyl-(14)C]SAM also revealed a time-dependent increase in the (3)H to (14)C ratio, suggesting that upon transfer of the methyl group, the resulting S-adenosylhomocysteine is not accumulated in the Golgi. SAM incorporation was also found to be inhibited by S-adenosylhomocysteine, whereas UDP-GalA, UDP-GlcA, and acetyl-CoA had no effect. DIDS, a compound that inhibits nucleotide sugar transporters, also had little effect upon SAM incorporation. Interestingly, the combination of UDP-GalA + acetyl-CoA or UDP-GlcA + acetyl-CoA produced a slight increase in the uptake of SAM. These results support the idea that a SAM transporter is required for HGA biosynthesis. 相似文献
Although they have distinct functions, the signaling of dopamine-D(2) receptor short and long isoforms (D(2)S and D(2)L) is virtually identical. We compared inhibitory regulation of extracellular signal-regulated kinases (ERK1/2) in GH4 pituitary cells separately transfected with these isoforms. Activation of rat or human dopamine-D(2)S, muscarinic or somatostatin receptors inhibited thyrotropin-releasing hormone-induced ERK1/2 phosphorylation, while the D(2)L receptor failed to inhibit this response. In order to address the structural basis for the differential signaling of D(2)S and D(2)L receptors, we examined the D(2)L-SS mutant, in which a protein kinase C (PKC) pseudosubstrate site that is present in the D(2)L but not D(2)S receptor was converted to a consensus PKC site. In transfected GH4 cells, the D(2)L-SS mutant inhibited thyrotropin-releasing hormone-induced ERK1/2 phosphorylation almost as strongly as the D(2)S receptor. A D(2)S-triple mutant that eliminates PKC sites involved in D(2)S receptor desensitization also inhibited ERK1/2 activation. Similarly, in striatal cultures, the D(2)-selective agonist quinpirole inhibited potassium-stimulated ERK1/2 phosphorylation, indicating the presence of this pathway in neurons. In conclusion, the D(2)S and D(2)L receptors differ in inhibitory signaling to ERK1/2 due to specific residues in the D(2)L receptor alternatively spliced domain, which may account for differences in their function in vivo. 相似文献
The words ‘infection’ and ‘inflammation’ lack specific definitions. Here, such words are not defined. Instead, the ability to visualize host-microbial interactions was explored.
Methods
Leukocyte differential counts and four bacterial species (Staphylococcus aureus, Streptococcus dysgalactiae, Staphylococcus chromogenes, and Escherichia coli) were determined or isolated in a cross-sectional and randomized study conducted with 611 bovine milk samples. Two paradigms were evaluated: (i) the classic one, which measures non-structured (count or percent) data; and (ii) a method that, using complex data structures, detects and differentiates three-dimensional (3D) interactions among lymphocytes (L), macrophages (M), and neutrophils (N).
Results
Classic analyses failed to differentiate bacterial-positive (B+) from –negative (B−) observations: B− and B+ data overlapped, even when statistical significance was achieved. In contrast, the alternative approach showed distinct patterns, such as perpendicular data inflections, which discriminated microbial-negative/mononuclear cell-predominating (MCP) from microbial-positive/phagocyte-predominating (PP) subsets. Two PP subcategories were distinguished, as well as PP/culture-negative (false-negative) and MCP/culture-positive (false-positive) observations. In 3D space, MCP and PP subsets were perpendicular to one another, displaying ≥91% specificity or sensitivity. Findings supported five inferences: (i) disease is not always ruled out by negative bacterial tests; (ii) low total cell counts can coexist with high phagocyte percents; (iii) neither positive bacterial isolation nor high cell counts always coincide with PP profiles; (iv) statistical significance is not synonymous with discrimination; and (v) hidden relationships cannot be detected when simple (non-structured) data formats are used and statistical analyses are performed before data subsets are identified, but can be uncovered when complexity is investigated.
Conclusions
Pattern recognition-based assessments can detect host-microbial interactions usually unobserved. Such cutoff-free, confidence interval-free, gold standard-free approaches provide interpretable information on complex entities, such as ‘infection’ and ‘inflammation’, even without definitions. To investigate disease dynamics, combinations of observational and experimental longitudinal studies, on human and non-human infections, are recommended. 相似文献
Biojas® is a fermented broth of Lasiodiplodia theobromae, a jasmonic acid–producing fungus characterized as a plant growth regulator and as biological control of phytopathogenic microorganisms and pests. The present work describes the use of Biojas® in in vitro culture of pineapple. On the other hand, plant scientists usually record multiple indicators in their experiments. The common statistical data evaluations involve univariate analyses such as t test, Mann-Whitney, and analysis of variance (ANOVA) followed by Tukey’s HSD. Such analyses do not evaluate integrally the effects of the experimental treatments because each indicator is analyzed independently. For this reason, we explored in this study the Euclidean distance combined with the data of the Biojas® treatment (0–2 mg l−1) on pineapple in vitro plantlets as an integrating indicator. Plant height; number of leaves; D leaf length, width, and area; diameter of the plant base; fresh and dry weights of the plant; levels of chlorophylls; transpiration rate; CO2 assimilation; and water use efficiency were recorded. Several statistically significant differences among Biojas® treatments were recorded. However, the most significant effects of Biojas® treatments were only noted in the plant height, length and area of D leaf, and water use efficiency. Variables mentioned above increased until 1.0 mg l−1 Biojas® and decreased with high levels of Biojas®. Calculation of the Euclidean distance from each Biojas® level to the ideal physiological status of the pineapple plantlets revealed that 1.0 mg l−1 Biojas® produced the pineapple plantlets with the best physiological status.