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71.
The Childhood Trauma Questionnaire (CTQ) is internationally accepted as a key tool for the assessment of childhood abuse and neglect experiences. However, there are relative few psychometric studies available and some authors have proposed two different factor solutions. We examined the dimensional structure and internal consistency of the Brazilian version of the CTQ. A total of 1,925 participants from eight different clinical and non-clinical samples including adolescents, adults and elders were considered in this study. First, we performed Confirmatory Factor Analysis to investigate the goodness of fit of the two proposed competitive factor structure models for the CTQ. We also investigated the internal consistency of all factors. Second, multi-group analyses were used to investigate measurement invariance and population heterogeneity across age groups and sex. Our findings revealed that the alternative factor structure as opposed to the original factor structure was the most appropriate model within adolescents and adults Brazilian samples. We provide further evidence for the validity and reliability of the CTQ within the Brazilian samples and report that the alternative model showed an improvement in fit indexes and may be a better alternative over the original model.  相似文献   
72.

Introduction

Activating calcium sensing receptor (CaSR) mutations cause autosomal dominant hypocalcemia (ADH) characterized by low serum calcium, inappropriately low PTH and relative hypercalciuria. Four activating CaSR mutations cause additional renal wasting of sodium, chloride and other salts, a condition called Bartter syndrome (BS) type 5. Until today there is no specific medical treatment for BS type 5 and ADH. We investigated the effects of different allosteric CaSR antagonists (calcilytics) on activating CaSR mutants.

Methods

All 4 known mutations causing BS type 5 and five ADH mutations were expressed in HEK 293T cells and receptor signalling was studied by measurement of intracellular free calcium in response to extracellular calcium ([Ca2+]o). To investigate the effect of calcilytics, cells were stimulated with 3 mM [Ca2+]o in the presence or absence of NPS-2143, ATF936 or AXT914.

Results

All BS type 5 and ADH mutants showed enhanced signalling activity to [Ca2+]o with left shifted dose response curves. In contrast to the amino alcohol NPS-2143, which was only partially effective, the quinazolinone calcilytics ATF936 and AXT914 significantly mitigated excessive cytosolic calcium signalling of all BS type 5 and ADH mutants studied. When these mutants were co-expressed with wild-type CaSR to approximate heterozygosity in patients, ATF936 and AXT914 were also effective on all mutants.

Conclusion

The calcilytics ATF936 and AXT914 are capable of attenuating enhanced cytosolic calcium signalling activity of CaSR mutations causing BS type 5 and ADH. Quinazolinone calcilytics might therefore offer a novel treatment option for patients with activating CaSR mutations.  相似文献   
73.
Fish and zooplankton populations of nine Ethiopian freshwater lakes were quantitatively sampled along a North–South gradient. Differences in altitude and latitude resulted in a temperature gradient from North to South. We tested three hypotheses: (1) the degree of zooplanktivory decreases with water temperature, i.e. from North to South; (2) the degree of zooplanktivory increases with the abundance of large-bodied zooplankton; and (3) the pattern of zooplanktivory in eutrophic Ethiopian water bodies differs from other tropical and temperate water bodies. Proportions of zooplanktivory in the fish communities did not show a geographical trend, but mainly depended on fish species, zooplankton density and the availability of large-bodied cladocerans. The degree of zooplanktivory in eutrophic Ethiopian water bodies differs from other eutrophic water bodies, both temperate and tropical. In Ethiopia, the degree of zooplanktivory can be both low and high, in contrast with other tropical water bodies where zooplanktivory is generally low and with temperate eutrophic water bodies where it is generally high. As a result, predation pressure on zooplankton by fish varies dramatically amongst Ethiopian water bodies.  相似文献   
74.

Background

The gene YCL047C, which has been renamed promoter of filamentation gene (POF1), has recently been described as a cell component involved in yeast filamentous growth. The objective of this work is to understand the molecular and biological function of this gene.

Results

Here, we report that the protein encoded by the POF1 gene, Pof1p, is an ATPase that may be part of the Saccharomyces cerevisiae protein quality control pathway. According to the results, Δpof1 cells showed increased sensitivity to hydrogen peroxide, tert-butyl hydroperoxide, heat shock and protein unfolding agents, such as dithiothreitol and tunicamycin. Besides, the overexpression of POF1 suppressed the sensitivity of Δpct1, a strain that lacks a gene that encodes a phosphocholine cytidylyltransferase, to heat shock. In vitro analysis showed, however, that the purified Pof1p enzyme had no cytidylyltransferase activity but does have ATPase activity, with catalytic efficiency comparable to other ATPases involved in endoplasmic reticulum-associated degradation of proteins (ERAD). Supporting these findings, co-immunoprecipitation experiments showed a physical interaction between Pof1p and Ubc7p (an ubiquitin conjugating enzyme) in vivo.

Conclusions

Taken together, the results strongly suggest that the biological function of Pof1p is related to the regulation of protein degradation.
  相似文献   
75.
Flies have been buzzing around on earth for over 300 million years. During this time they have radiated into more than 125,000 different species (Yeates and Wiegmann 1999), so that, by now, roughly every tenth described species is a fly. They thus represent one of the most successful animal groups on our planet. This evolutionary success might, at least in part, be a result of their acrobatic maneuverability, which enables them, for example, to chase mates at turning velocities of more than 3000 degrees s(-1) with delay times of less than 30 ms (Land and Collett 1974; Wagner 1986). It is this fantastic behavior, which has initiated much research during the last decades, both on its sensory control and the biophysical and aerodynamic principles of the flight output (Dickinson et al. 1999, 2000). Here, we review the current state of knowledge about the neural processing of visual motion, which represents one sensory component intimately involved in flight control. Other reviews on this topic have been published with a similar (Hausen 1981, 1984; Hausen and Egelhaaf 1989; Borst 1996) or different emphasis (Frye and Dickinson 2001; Borst and Dickinson 2002). Because of space limitations, we do not review the extensive work that has been done on fly motion-sensitive neurons to advance our understanding of neural coding (Bialek et al. 1991; Rieke et al. 1997; de Ruyter et al. 1997, 2000; Haag and Borst 1997, 1998; Borst and Haag 2001). Unless stated otherwise, all data presented in the following were obtained on the blowfly Calliphora vicina which we will often casually refer to as 'the fly'.  相似文献   
76.
H Decker  S Haag 《Journal of bacteriology》1995,177(21):6126-6136
A DNA fragment was cloned as cosmid purd8, which encodes a polyketide synthase involved in the production of the angucycline antibiotic urdamycin from Streptomyces fradiae Tü2717. Deletion of the polyketide synthase genes from the chromosome abolished urdamycin production. In addition, purd8 conferred urdamycin resistance on introduction into Streptomyces lividans TK24. Sequence analysis of 5.7 kb of purd8 revealed six open reading frames transcribed in the same direction. The deduced amino acid sequences of the six open reading frames strongly resemble proteins from known type II polyketide synthase gene clusters: a ketoacyl synthase, a chain length factor, an acyl carrier protein, a ketoreductase, a cyclase, and an oxygenase. Heterologous expression of the urdamycin genes encoding a ketoacyl synthase and a chain length factor in Streptomyces glaucescens tetracenomycin C-nonproducing mutants impaired in either the TcmK ketoacyl synthase or TcmL chain length factor resulted in the production of tetracenomycin C. Heterologous expression of a putative oxygenase gene from the urdamycin gene cluster in S. glaucescens GLA.O caused production of the hybrid antibiotic 6-hydroxy tetracenomycin C.  相似文献   
77.
The zebrafish genome contains at least five msx homeobox genes, msxA, msxB, msxC, msxD, and the newly isolated msxE. Although these genes share structural features common to all Msx genes, phylogenetic analyses of protein sequences indicate that the msx genes from zebrafish are not orthologous to the Msx1 and Msx2 genes of mammals, birds, and amphibians. The zebrafish msxB and msxC are more closely related to each other and to the mouse Msx3. Similarly, although the combinatorial expression of the zebrafish msx genes in the embryonic dorsal neuroectoderm, visceral arches, fins, and sensory organs suggests functional similarities with the Msx genes of other vertebrates, differences in the expression patterns preclude precise assignment of orthological relationships. Distinct duplication events may have given rise to the msx genes of modern fish and other vertebrate lineages whereas many aspects of msx gene functions during embryonic development have been preserved.   相似文献   
78.
The rennin–angiotensin–aldosterone system (RAAS) is a critical pathway in regulating blood pressure and salt/water homeostasis, possessing an intimate relationship with the development of systemic artery hypertension (SAH). Once hypertension is considered a risk factor for coronary artery disease (CAD), the RAAS is also related to this pathology. This investigation aimed to analyse if the frequencies of AGT M235T (rs699) and ACE I/D (rs4646994) polymorphisms are associated with CAD and SAH in African-Brazilians and Caucasian-Brazilians. In this study we analysed 714 subjects who underwent coronary angiography to detect obstructive lesions and CAD, as well as blood pressure measurement and SAH, grouped according to ethnicity: 266 African-Brazilians and 448 Caucasian-Brazilians. Among CAD and SAH cases and controls, the genotype and allele frequencies of ACE I/D polymorphism were similar in both ethnic groups. The AGT 235TT genotype and 235T allele frequencies were higher in SAH cases (32%, 54.7%) versus controls in Caucasian-Brazilians (19.8%, 46.4%; P= 0.038, P= 0.031, respectively). The AGT 235TT (OR = 1.8; P= 0.028) demonstrated to be an independent factor risk in a multivariate logistic regression increasing SAH risk in Caucasians but not in African-Brazilians. In summary, AGT M235T polymorphism was associated with SAH risk in Caucasian-Brazilians, and no association was detected with CAD. No association was also observed in ACE I/D polymorphism either in CAD or SAH in African-Brazilians and Caucasian-Brazilians.  相似文献   
79.
Feral Pigeons Columba livia are highly adapted to urban environments and are thus often abundant in cities. This can lead to various problems, including fouling of building facades and pavements, transmission of allergens and pathogenic micro‐organisms, and infestations of ectoparasites derived from breeding sites. To develop effective, long‐lasting and humane control strategies, it is necessary to understand the demography of Feral Pigeons. Although food shortage is a major source of reproductive failure in Feral Pigeons, it is still unclear at which phase of the reproductive cycle this reduces overall reproductive success. Here, we assess the effect of a sudden reduction in the food base on the reproduction of a well‐studied Feral Pigeon breeding colony. The findings of this study suggest that the number of broods per pair decreases significantly during food scarcity, and that although hatching success remains constant, a significantly greater number of nestlings die during the rearing phase. This suggests that the high energy demand of Feral Pigeon nestlings could not be met under conditions of food scarcity, which reduced the total number of fledged young by more than half and led to a reduction in the colony size. These results have important implications for selecting suitable, durable and humane control strategies for the management of large Feral Pigeon populations in urban environments.  相似文献   
80.
Industrialized nations face a critical problem in replacing the sources of liquid fuels that traditionally have been supplied by petroleum. One solution that has gained increasing support in this country is the use of ethanol produced by fermentation of renewable biomass as an extender in, or supplement to, gasoline for transportation fuel. Distillation, the present method of separating ethanol from the fermentation broth, is an energy-intensive one and frequently uses more energy than is available from the ethanol recovered. There are many investigations under way to find alternative, less energy-intensive techniques for the ethanol-water separation. The separations method described in this article involves the use of solid materials to preferentially remove ethanol from fermentation broths. Subsequent stripping of the ethanol from the sorbent with a dry gas reduces dramatically the energy required for the separation. Three solid sorbents have been investigated experimentally. Their sorption/desorption characteristics are described, and their incorporation in an ethanol recovery process is evaluated. Three sorbents were investigated: two commercially available divinylbenzene crosslinked polystyrene resins in bead form (one with a nominal surface area of 300 m(2)/g, the other with 750 m(2)/g) and an experimental proprietary molecular sieve with hydrophobic properties. Equilibrium adsorption isotherms for two of the sorbents were obtained at ambient temperature (21 degrees C) for ethanol-water solutions containing up to 12 wt. % ethanol. In addition, 40 degrees C isotherms were obtained for the polystyrene sorbents. Although different, the equilibrium isotherms for the sorbents indicated that ethanol could be preferentially sorbed from a dilute solution. Column breakthrough curves indicated very favorable kinetics. Desorption of the ethanol was readily effected with warm (60-80 degrees C), dry nitrogen.  相似文献   
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