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121.
122.
The tumor necrosis factor-alpha converting enzyme (TACE): a unique metalloproteinase with highly defined substrate selectivity 总被引:16,自引:0,他引:16
Mohan MJ Seaton T Mitchell J Howe A Blackburn K Burkhart W Moyer M Patel I Waitt GM Becherer JD Moss ML Milla ME 《Biochemistry》2002,41(30):9462-9469
TNF alpha converting enzyme (TACE) processes precursor TNF alpha between Ala76 and Val77, yielding a correctly processed bioactive 17 kDa protein. Genetic evidence indicates that TACE may also be involved in the shedding of other ectodomains. Here we show that native and recombinant forms of TACE efficiently processed a synthetic substrate corresponding to the TNF alpha cleavage site only. For all other substrates, conversion occurred only at high enzyme concentrations and prolonged reaction times. Often, cleavage under those conditions was accompanied by nonspecific reactions. We also compared TNF alpha cleavage by TACE to cleavage by those members of the matrix metalloproteinase (MMP) family previously implied in TNF alpha release. The specificity constants for TNF alpha cleavage by the MMPs were approximately 100-1000-fold slower relative to TACE. MMP 7 also processed precursor TNF alpha at the correct cleavage site but did so with a 30-fold lower specificity constant relative to TACE. In contrast, MMP 1 processed precursor TNF alpha between Ala74 and Gln75, in addition to between Ala76 and Val77, while MMP 9 cleaved this natural substrate solely between Ala74 and Gln75. Additionally, the MMP substrate Dnp-PChaGC(Me)HK(NMA)-NH(2) was not cleaved at all by TACE, while collagenase (MMP 1), gelatinase (MMP 9), stromelysin 1 (MMP 3), and matrilysin (MMP 7) all processed this substrate efficiently. All of these results indicate that TACE is unique in terms of its specificity requirements for substrate cleavage. 相似文献
123.
Cueto M 《History and philosophy of the life sciences》2003,25(3):319-335
During the turn of the 20th century medical geography in Peru concentrated in the study of a native disease (bartonellosis, also known as Carrión's disease and Verruga Peruana) and reinforced the relationship between the country's 'natural' regions (coast, highlands and Amazon) and different patterns of disease. Expert knowledge on these themes was portrayed as important not only for the practice of medicine but also for the development of the country. This knowledge was instrumental for an emergent local medical tradition and for legitimizing the authority, power and prestige of Lima's medical elite. The city was the capital of a country whose population was mainly Indian and rural, and lived in the highlands. This article studies the development of medical geography in Peru emphasizing the role played by Ernesto Odriozola, an influential clinician from Lima trained in Paris. 相似文献
124.
This paper presents a list of 131 Mallophaga type specimens deposited in the Werneck Collection of Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil. It includes 69 holotypes, 62 allotypes, 683 paratypes, 1 syntype and 2 neoparatypes, distributed among 6 families and 35 genera. The types are listed with their respective data and literature. 相似文献
125.
Bezerra FS Nogueira-Machado JA Martins-Souza RL Chaves MM Correa RF Coelho PM 《Memórias do Instituto Oswaldo Cruz》2003,98(1):73-75
High doses of gamma radiation (10 Krad) in Biomphalaria tenagophila snails (Taim strain), which have been found to be resistant to Schistosoma mansoni, were not sufficient to impair their resistance to the parasite. The number of hemocytes, as well as their phagocytic activity, were not affected by irradiation, thus showing resemblance with mammal macrophages, which are resistant to gamma irradiation also. 相似文献
126.
Brandalise M Maia IG Borecký J Vercesi AE Arruda P 《Journal of bioenergetics and biomembranes》2003,35(3):203-209
An Arabidopsis thaliana cDNA clone encoding a plant uncoupling mitochondrial protein (AtPUMP1) was overexpressed in transgenic tobacco plants. Analysis of the AtPUMP1 mRNA content in the transgenic lines, determined by Northernblot, revealed variable levels of transgene expression. Antibody probing ofWestern blots of mitochondrial proteins from three independent transgenic lines showed significant accumulation of AtPUMP1 in this organelle. Overproduction of AtPUMP1 in transgenic tobacco plants led to a significantincrease in tolerance to oxidative stress promoted by exogenous hydrogen peroxide as compared to wild-type control plants. These results provide thefirst biological evidence for a role of PUMP in protection of plant cells against oxidative stress damage. 相似文献
127.
Ortiga-Carvalho TM Oliveira Kde J Morales MM Martins VP Pazos-Moura CC 《Experimental biology and medicine (Maywood, N.J.)》2003,228(9):1083-1088
Neuromedin B (NB), a bombesin-like peptide, highly concentrated in rat pituitary gland, has been shown to act as an autocrine/paracrine inhibitor of thyrotropin (TSH) release. Here it is shown that a single injection of thyrotropin-releasing hormone (TRH, 1.5 microg/animal, ip), the most important stimulator of thyrotropin secretion, induced approximately 35%-45% decrease in pituitary NB content in rats, as well as an important decrease in NB mRNA at 15 and 30 min (P < 0.05). Acute cold exposure, which induced higher serum TSH with a peak at 30 min, was associated with progressive decrease in pituitary NB, starting at 15 min although only reaching statistical significance after 2 hr (P < 0.05). Although not involved in the early peak, the decrease in NB may be contributing to maintenance of higher serum TSH in cold-exposed animals compared with those at room temperature. Fed rats, 2 hr after being subcutaneously injected with mouse recombinant leptin (8 microg /100 g body wt), showed a x2 increase in serum TSH and 38% reduction in pituitary NB (P < 0.05). In conclusion, TRH and leptin rapidly decreased pituitary NB and it is first proposed that the reduction of the inhibitory tonus of NB on TSH release will ultimately contribute to the amplification of TSH secretion elicited by TSH secretagogues. 相似文献
128.
De Donato M Gallagher DS Lehn C Gill C Taylor JF 《Genetics and molecular research : GMR》2003,2(3):260-270
Seven genes were assigned by molecular cytogenetic methods to bovine chromosome 5. To accomplish this, specific primers were either publicly available or were designed from highly conserved regions of the publicly available mammalian gene sequences. The identity of the amplified segments was verified by sequencing and alignment with the published sequences. The optimized primers that amplified the desired bovine genes were used for screening a bovine bacterial artificial chromosome library. The positive clones were localized to a specific band of bovine chromosome 5 by fluorescence in situ hybridization. The genes HOXC4, SP1 and IGFBP6 were localized to band q21, COL2A1 was localized to bands q21-q23, IGF1 was localized to band q26, MB to band q31 and the gene CYP2D6 was localized to band q35. The cytogenetic assignment of SP1, IGFBP6, COL2A1, IGF1, MB and CYP2D6 is first reported here and the assignment of HOXC4 refines the previous assignment of this gene. The identification and localization of these genes further support the development of the human to bovine comparative map through characterizing the homologous segments conserved in the evolution of these species. This information will be useful for the future localization of genes that affect economically important traits in bovines. 相似文献
129.
The arachnids of the order Opiliones (harvestmen) have a pair of scent glands opening at the sides of the body, the substances of which are used in defense. Several types of behavioral, morphological and chemical defensive mechanisms have been assigned to the order as a whole, although some of these tactics were restricted to particular groups. Only around 25 species have been studied from this perspective so far. In the present paper, we analyzed 33 species (mostly from the largest harvestmen family, the Gonyleptidae) aiming at recognizing the usefulness of the defensive characters in taxonomy and evolutionary biology. We observed the morphology of the gland opening (ozopore) area and the defensive behavior, and their relationship, and mapped these traits on an available phylogenetic hypothesis of relationship within Gonyleptidae. As outgroups, we analyzed Cosmetidae and Stygnidae. Combining the observed behavioral characters of the emission of defensive secretion (near the ozopore, with liquid displacement through an integumentary groove, or in form of a jet) with the morphological types of the gland opening (direction of the integumentary dome that surrounds the gland opening, presence of two openings and the relationship between their sizes, and presence of a V-shaped cut at the anterior opening), we recognized eight patterns. In addition, we could examine the evolution of such traits within Gonyleptidae. 相似文献
130.