Urinary oligosaccharides of fucosidosis. Evidence of the occurrence of X-antigenic determinant in serum-type sugar chains of glycoproteins.

Urine of a fucosidosis patient contained a large amount of fucosyl oligosaccharides and fucose-rich glycopeptides. Six major oligosaccharides were purified by a combination of Bio-Gel P-2 and P-4 column chromatographies and paper chromatography. Structural studies by sequential exoglycosidase digestion and by methylation analysis revealed that their structures were as follows: Fucalpha1 leads to 6GlcNAc, Fucalpha1 leads to 2Galbeta1 leads to 4(Fucalpha1 leads to 3)GlcNAcbeta1 leads to 2Manalpha1 leads to 3Manbeta1 leads to 4GlcNAc, Galbeta1 leads to 4(Fucalpha1 leads to 3)GlcNAcbeta1 leads to 4Manalpha1 leads to 4GlcNAc, Galbeta1 leads to 4(Fucalpha1 leads to3)GlcNAcbeta1 leads to 2Manalpha1 leads to 6Manbeta1 leads to 4GlcNAc, and Galbeta1 leads to 4(Fucalpha1 leads to 3)GlcNAcbeta1 leads to 4Manalpha1 leads to 6Manalpha1 leads to 6Manbeta1 leads to 4GlcNAc. In additon, the structure of a minor decasaccharide was found to be Galbeta1 leads to (Fucalpha1 leads to)GlcNAcbeta1 leads to Manalpha1 leads to [Galbeta1 leads to (Fucalpha1 leads to)GlcNAcbeta1 leads to Manalpha1 leads to]Manbeta1 leads to 4GlcNAc.     

Author index

Binding of dexamethasone · receptors with isolated nuclei, DNA-cellulose and cellulose has been compared with respect to dependence on salt concentration and resistance to KCl extraction and DNAase I digestion. A solution of cytoplasmic dexamethasone-receptor complexes was prepared by the incubation of rat thymus cells with steroid at 3°C and breaking the cells by hypotonic lysis. Activation of the complexes was accomplished by warming the solution at 25°C for 15 min. Activation significantly increased the ability of dexamethasone · receptors to bind to nuclei and DNA-cellulose but not to cellulose. Dexamethasone-receptor complexes bound to nuclei at 3°C are completely resistant to extraction with 0.1 M KCl, 76% resistant to 0.2 M KCl and 20% resistant to 0.4 M KCl. Dexamethasone · receptors bound to DNA-cellulose are 45% resistant to extraction with 0.1 M and 0.2 M KCl and 29% resistant to 0.4 M KCl extraction. Cellulose-bound dexamethasone · receptors are not resistant to any of these extractions. DNAase I treatment releases 60% of the dexamethasone · receptors bound to DNA-cellulose but only 13% of those bound to nuclei, though at least 60% of the nuclear DNA is solubilized. The presence of 0.15 M KCl decreases binding of activated dexamethasone · receptors to nuclei by 73% but to DNA-cellulose by only 17%. Pretreatment of nuclei with 0.1–0.4 M KCl reduces their capacity to bind activated dexamethasone · receptors by 90% whereas similar treatment reduces the capacity of DNA-cellulose to bind dexamethasone · receptors by only 29%. Nuclei extracted with 0.1 M KCl appear to have a limited capacity to accept dexamethasone · receptors. These studies demonstrate that binding of dexamethasone · receptors to nuclei and DNA-cellulose differs by (a) the higher resistance of nuclear complexes to KCl and DNAase I treatment; (b) the much greater sensitivity of nuclei to KCl treatment.     

Quantifying Predation Risk for Refuging Animals: A Case Study with Golden Marmots

Although a variety of behaviors expose animals to some risk of predation, there is no accepted way to compare their relative risk. For animals that retreat to refugia when alarmed by predators, the proportion of time devoted to each out-of-refuge behavior multiplied by the total time required to return to a refuge can be used to compare a behavior's relative predation risk. Total time to return to a refuge is a function of both response time - the time required to respond to an increased risk of predation — and travel time — the time required to flee to a refuge once alarmed. Quantifying these components can illustrate how animals minimize exposure to predators. Golden marmots (Marmota caudata aurea) were a refuging prey species used to examine the utility of this measure and to understand how marmots minimized their risk of exposure to predation. Golden marmots devoted different amounts of time to looking, foraging, self-grooming, and playing. To estimate the behavior-specific time required to return to refugia, the location of different activities was noted and a behavior-specific travel time was calculated. Alarm calls were played back to marmots engaged in different behaviors to determine, in a standardized manner, if there were behavior-specific response times. Marmots appeared to minimize their predation risk by performing most behaviors close to refugia. Results suggest that foraging was the riskiest behavior, largely because marmots foraged far from refugia and spent about 30% of their time foraging. While sample sizes were small, results also suggested that play, a rare adult behavior, exposed animals to predation because of a relatively long response time.     

横断山区的蝶类资源与珍稀蝴蝶的保护

横断山区的蝶类561种,隶属于12科,208属.在12科中,种类最多的是蛱蝶科148种,其次是眼蝶科117种,灰蝶科65种,凤蝶科63种,粉蝶科60种,弄蝶科60种,蚬蝶科18种,绢蝶科12种,斑蝶科9种,环蝶科6种,喙蝶科2种,珍蝶科1种.分布于横断山区的珍稀蝴蝶有44种,其中国家Ⅰ级保护的1种,Ⅱ级保护的3种.     

上下视野空间选择性注意的ERP研究

该文主要研究上、下视野空间选择性注意早期所诱发的ＥＲＰ反应,探讨注意上、下视野视觉信息处理的特征与差别。１０名被试的主要实验果为：１）对上、下视野的选择注意产生类似于注意左、右视野时Ｐ１、Ｎ１,Ｐ２的相对增强;２）偶极子定位显示,上、下视野刺激的早期注意反应（Ｐ１）以交叉方式投射到枕区,即下视野刺激的注意反应偏向枕区的背侧,而上视野刺激的注意反应偏向枕区的腹侧;３）上下视野的早期注意反应（Ｐ１）具     

Bacteria and phytoremediation: new uses for endophytic bacteria in plants

The use of plants and bacterial to clean up environmental pollutants has gained momentum in past years. A limitation to phytoremediation of solvents has been toxicity of the compounds to plants, and the uncertainty as to the fate of many of the compounds. In a recent study, engineered endophytes have been shown to increase plant tolerance to toluene, and to decrease the transpiration of toluene to the atmosphere. This type of work has the potential to increase the use of phytoremediation by decreasing toxicity and increasing degradation of toxins.     

Localization of Escherichia coli RNA polymerase binding sites on bacteriophage S13 and 0X174 DNAs by electron microscopy.

Complexes between Escherichia coli RNA polymerase and bacteriophage S13 and phage phiX174 replicative form III DNAs have been shown to form at specific locations on the phage genomes. The major locations on S13 have been mapped at 8 to 10 and 92 to 96% of the genome length, starting from the unique Pst I cleavage site. The locations correspond to the beginnings of genes D and B, respectively. Four minor locations map at 18 to 22, 28 to 32, 50 to 56, and 70 to 74% of the genome. The 70 to 74% site corresponds to the beginning of the A gene. The major locations on phiX174 are at 8 to 10, 50 to 54, and 92 to 94% of the genome. The 50 to 54% site is at the start of the H gene and has an equivalent minor site on S13, but it is not a promoter site. Three minor sites on phiX174, at 20 to 24, 26 to 32, and 68 to 74% of the genome, correspond to sites on S13. The data confirm the locations of sites identified by restriction fragment binding experiments (E. Rassart and J. H. Spencer, J. Virol. 27:677--687, 1978) and the assignment of putative promoters at the start of genes A, B and D.     

Specificity of the binding of trifluoperazine to the calcium-dependent activator of phosphodiesterase and to a series of other calcium-binding proteins

Trifluoperazine inhibits the activation of phosphodiesterase by binding to the calcium-dependent activator. To determine further the specificity by which trifluoperazine binds to activator, we compared the binding of trifluoperazine to activator prepared from several species and tissues and to a number of other calcium-binding proteins devoid of activator activity.Trifluoperazine binds to activator prepared from human, bovine, rat and rabbit brain and from chick embryo fibroblasts. In each case, the binding of trifluoperazine to activator was qualitatively similar and related quantitatively to the ability of the preparation to activate phosphodiesterase.Of the other calcium-binding proteins examined, namely, troponin-C, S-100 protein, phospholipase A, phospholipase B and myosin light chain, only troponin-C displayed any significant calcium-specific binding of trifluoperazine. The binding to troponin-C, however, appeared to be different from the binding to activator; whereas the binding of trifluoperazine to actovator showed no cooperativity, the binding to troponin-C showed positive cooperatively.These results and earlier data showing that trifluoperazine fails to bind to a variety of other proteins, indicate that the binding of trifluoperazine to the calcium-dependent activator of phosphodiesterase is selective and suggest that this binding may explain some of the biochemical and pharmacological actions of this antipsychotic agent.     

Surfactant protein D binds to Mycobacterium tuberculosis bacilli and lipoarabinomannan via carbohydrate-lectin interactions resulting in reduced phagocytosis of the bacteria by macrophages.

Surfactant protein-D (SP-D) is a collectin produced in the distal lung airspaces that is believed to play an important role in innate pulmonary immunity. Naive immunologic responses to Mycobacterium tuberculosis (M.tb) are especially important in the lung, since entry of this inhaled pathogen into the alveolar macrophage is a pivotal event in disease pathogenesis. Here we investigated SP-D binding to M.tb and the effect of this binding on the adherence of M. tb to human macrophages. These studies demonstrate specific binding of SP-D to M.tb that is saturable, calcium dependent, and carbohydrate inhibitable. In addition to purified SP-D, SP-D in bronchoalveolar lavage fluids from healthy donors and patients with alveolar proteinosis also binds to M.tb. Incubation of M.tb with SP-D results in agglutination of the bacteria. In contrast to its binding to M.tb, SP-D binds minimally to the avirulent Mycobacterium smegmatis. SP-D binds predominantly to lipoarabinomannan from the virulent Erdman strain of M.tb, but not the lipoarabinomannan from M. smegmatis. The binding of SP-D to Erdman lipoarabinomannan is mediated by the terminal mannosyl oligosaccharides of this lipoglycan. Incubation of M.tb with subagglutinating concentrations of SP-D leads to reduced adherence of the bacteria to macrophages (62.7% of control adherence +/- 3.3% SEM, n = 8), whereas incubation of bacteria with surfactant protein A leads to significantly increased adherence to monocyte-derived macrophages. These data provide evidence for specific binding of SP-D to M. tuberculosis and indicate that SP-D and surfactant protein A serve different roles in the innate host response to this pathogen in the lung.     

西双版纳热带雨林蚁科昆虫区系分析

在西双版纳热带雨林已鉴定蚊科昆虫９亚科７６属２６７种。西双版纳地区的蚂蚁区系以热带至亚热带分布的东洋界成分最为丰富。在属级水平上,与马来西亚界关系最为密切。与澳洲界关系较密切;与非洲界和马拉加西界的关系知中。与新北界,新热带界和古北界的关系最为疏远。可见西双版纳的蚂蚁区系具有典型的热带亚洲起源特征,同时与澳洲和非洲的热带区系有一定的渊源关系。     

Structure-function relationship of myotoxin a using peptide fragments.

Myotoxin a, a small basic polypeptide isolated from the venom of prairie rattlesnake (Crotalus viridis viridis), has been shown to bind to sarcoplasmic reticulum (SR) Ca(2+)-ATPase. The attachment of myotoxin a to Ca(2+)-ATPase is believed to cause uncoupling of the calcium pump. In order to further elucidate which portion of myotoxin a is important for the uncoupling action, five peptides were synthesized and two peptide fragments were obtained by chemical cleavage. These peptides correspond to discrete portions of the primary sequence of myotoxin a. The peptides are equivalent to the primary sequence of myotoxin a from 1 to 16 residues, 7 to 22 residues, 13 to 28 residues, 19 to 34 residues, and 25 to 42 residues. Chemically produced fragments are equivalent to 1 to 28 residues and 29 to 42 residues of myotoxin a. Peptides of the sequences "YKQCHKKGGHCFPKEK" and "LGKMDCRWKWKCCKKGSG" of myotoxin a inhibited 45Ca uptake into isolated SR and bound to Ca(2+)-ATPase. The same peptides caused weak skeletal muscle vacuolization similar to that caused by native myotoxin a and increased serum creatine kinase activity. The active peptides correspond to the N-terminal and C-terminal portions of myotoxin a. The inactive or less active peptides have sequences which correspond to the middle sequence of myotoxin a. From this study, both the N-terminal and the C-terminal regions of primary sequence of myotoxin a are required to express myotoxin a's biological activity.     

Transmitter-Induced Calcium Responses Differ in Astrocytes Acutely Isolated from Rat Brain and in Culture

Abstract: Glial fibrillary acid protein (GFAP)-positive astrocytes isolated from the cerebral cortices of 3–10-day-old rats frequently showed increased intracellular Ca²⁺ concentration responses to l -glutamate and glutamate analogues. However, few of the acutely isolated cells responded to ATP, and no such cells responded to serotonin [5-hydroxytryptamine (5-HT)]. The same cell that failed to respond to ATP or 5-HT often responded to glutamate. Culturing acutely isolated cells in media containing horse serum decreased Ca²⁺ responses to glutamate but increased the responses to ATP and induced responses to 5-HT. In primary cultures prepared from the cerebral cortices of 1-day-old rats and cultured in horse serum, fewer of the cells responded to glutamate, but almost all cells responded to ATP and 5-HT. The lack of, or limited response to, 5-HT or ATP in the acutely isolated cells seems unlikely to be due to selective damage to the respective receptors because acutely isolated GFAP-negative cells showed responses to ATP, several different proteases and mechanical dissociation yielded cells that also responded to glutamate but not to ATP, and exposure of primary cultures to papain did not abolish Ca²⁺ responses to several transmitters. The responses of the acutely isolated cells to glutamate but limited or lack of responses to ATP and 5-HT also correspond to what has been seen so far for astrocytes in situ. Thus, the present studies provide direct evidence that some of the receptors seen in primary astrocyte cultures may reflect a response to culture conditions and that, in the context of the relevant information so far available, acutely isolated astrocytes seem to reflect better the in vivo state.     

农田烟粉虱寄主植物调查初报

2001～2002年通过调查福州、漳州农田烟粉虱寄主范围,记录农田烟粉虱寄主植物17科62种(变种)．其中豆科7种、茄科6种、十字花科8种、葫芦科9种、菊科10种、苋科4种、藜科4种、旋花科2种、锦葵科2种、、大戟科2种、柳叶草科2种、蓼科1种、玄参科1种、番杏科1种、大麻科1种、免丝子科1种、伞形花科1种。农田烟粉虱寄主植物主要以蔬菜作物和农田阔叶杂草为主。     

Specific residues within the alpha 2 integrin subunit cytoplasmic domain regulate migration and cell cycle progression via distinct MAPK pathways.

The alpha(2) integrin subunit cytoplasmic domain is necessary for epidermal growth factor (EGF)-stimulated chemotactic migration and insulin-dependent entry into S-phase of mammary epithelial cells adherent to type I collagen. Truncation mutants revealed that the seven amino acids, KYEKMTK, in addition to the GFFKR motif were sufficient for these functions. Mutation of tyrosine 1134 to alanine inhibited the ability of the cells to phosphorylate p38 MAPK and to migrate in response to EGF but had only a modest effect on the ability of the cells to induce sustained phosphorylation of the ERK MAPK, to up-regulate cyclin E and cdk2 expression, and to enter S-phase when adherent to type I collagen. Conversely, mutation of the lysine 1136 inhibited the ability of the cells to increase cyclin E and cdk2 expression, to maintain long term phosphorylation of the ERK MAPK, and to enter S-phase but had no effect on the ability of the cells to phosphorylate the p38 MAPK or to migrate on type I collagen in response to EGF. Methionine 1137 was essential for both migration and entry into S-phase. Thus, distinctly different structural elements of the alpha(2) integrin cytoplasmic domain are required to engage the signaling pathways leading to cell migration or cell cycle progression.     

The effects of exposure to seaweed on willingness to mate, oviposition, and longevity in seaweed flies

Abstract  1. Large male seaweed flies (Diptera: Coelopidae) are more likely to mate than smaller males. This is due to sexual conflict over mating, by which females physically resist male attempts to copulate. In some species, large males are simply more efficient at overpowering female resistance.
2. Female reluctance to mate is likely to have evolved due to the costs of mating to females. In many dipterans, males manipulate female behaviour through seminal proteins that have evolved through sperm competition. This behavioural manipulation can be costly to females, for example forcing females to oviposit in sub-optimal conditions and increasing their mortality.
3. Previous work has failed to identify any ubiquitous costs of mating to female coelopids. The work reported here was designed to investigate the effects of exposure to oviposition sites ( Fucus algae) on the reproductive behaviour of four species of coelopid. Algae deposition in nature is stochastic and females mate with multiple males in and around oviposition sites. Spermatogenesis is restricted to the pupal stage and there is last-male sperm precedence. It was predicted that males would avoid wasting sperm and would be more willing to mate, and to remain paired with females for longer, when exposed to oviposition material compared with control males. Females were predicted to incur longevity costs of mating if mating increased their rate of oviposition, especially in the presence of algae.
4. The behaviour of males of all four species concurred with the predictions; however mating did not affect female receptivity, oviposition behaviour, or longevity. Exposure to algae induced oviposition and increased female mortality in all species independently of mating and egg production. The evolutionary ecology of potential costs of mating to female coelopids are discussed in the light of these findings.     

Not all the same after all? Superdiversity as a lens for the study of past migrations

Due to its claim of contemporary exceptionalism, the notion of superdiversity raises suspicion among historians. However, historians would do well to not dismiss the entire superdiversity debate as more hype that does not concern them. As a multidimensional perspective on diversity, encouraging researchers to examine the interplay of many different factors that condition people's lives and to move beyond an ethno-focal perspective, superdiversity could be of interest to historians as well. This article shows how the notion can help historians debunk some of the homogenizing categories that tend to characterize the representation of past immigrant populations. The paper uses a superdiversity lens to examine migration to the city of Ghent from 1960 to 1980. It is an open invitation to historians to accept the challenges that superdiversity poses and to provide a proper historicization of the concept, thus furthering its theoretical development.     

Systematic review of randomised controlled trials of strategies to promote adherence to tuberculosis treatment.

OBJECTIVE: To determine the effectiveness of strategies to promote adherence to treatment for tuberculosis. IDENTIFICATION: Searches in Medline (1966 to August 1996), the Cochrane trials register (up to October 1996), and LILACS (Literatura Latinoamericana y del Caribe en Ciencias de la Salud) (1982 to September 1996); screening of references in articles on compliance and adherence; contact with experts in research on tuberculosis and adherence. INCLUSION CRITERIA: Randomised or pseudorandomised controlled trials of interventions to promote adherence with curative or preventive treatment for tuberculosis, with at least one measure of adherence. MAIN OUTCOME MEASURE: Relative risks and 95% confidence intervals for estimates of effect for categorical outcomes. RESULTS: Five trials met the inclusion criteria. The relative risk for tested reminder cards sent to patients who defaulted on treatment was 1.2 (95% confidence interval 1.1 to 1.4), for help given to patients by lay health workers 1.4 (1.1 to 1.8), for monetary incentives offered to patients 1.6 (1.3 to 2.0), for health education 1.2 (1.1 to 1.4), for a combination of a patient incentive and health education 2.4 (1.5 to 3.7) or 1.1 (1.0 to 1.2), and for intensive supervision of staff in tuberculosis clinics 1.2 (1.1 to 1.3). There were no completed trials of directly observed treatment. All of the interventions tested improved adherence. On current evidence it is unclear whether health education by itself leads to better adherence to treatment. CONCLUSIONS: Reliable evidence is available to show some specific strategies improve adherence to tuberculosis treatment, and these should be adopted in health systems, depending on their appropriateness to practice circumstances. Further innovations require testing to help find specific approaches that will be useful in low income countries. Randomised controlled trials evaluating the independent effects of directly observed treatment are awaited.     

An Analysis of Hamster Afferent Taste Nerve Response Functions

Sensitivities to moderately intense stimuli representing four taste qualities to man were determined for 79 hamster chorda tympani fibers. Some fibers were very sensitive to sucrose, sodium chloride, or hydrochloric acid, but none were very sensitive to quinine. These sensitivities were not randomly distributed among fibers: the sucrose sensitivity was separated from and negatively correlated with the other sensitivities which were associated and positively correlated with each other. Moreover, there were a limited number of sensitivity patterns: (a) fibers responding best to sucrose responded second-best to salt, less to acid, not to quinine; (b) fibers responding best to salt either responded second-best to sucrose and not to acid or quinine; or second-best to acid, less to quinine, and not to sucrose; and (c) fibers responding best to acid responded second-best to salt, more to quinine, and less to sucrose than other fibers. Therefore, if four stimuli of different taste qualities are ordered from acceptable to unacceptable, neural response functions of most hamster chorda tympani taste fibers peak at one point. Sensitivities to nine other moderately intense stimuli which vary in quality to man were also determined for 46–49 of the fibers. Sensitivities to sweet stimuli were always associated with each other and separated from sensitivities to nonsweet stimuli. Sensitivities to nonsweet stimuli were all associated with each other; however, the strongest correlations were between sensitivities to stimuli of like quality, e.g., the three acids or the two sodium salts.     

Chiral separations on polysaccharide stationary phases using polar organic mobile phases

About 30% of a chemically diverse set of compounds were found to separate on four polysaccharide chiral stationary phases using polar organic mobile phases. No structural features appeared to correlate to successful separations. Titrations between normal and polar organic mobile phases suggested that separation mechanisms do not differ between these mobile phases. Attempts made to control retention met with varying degrees of success. Addition of hexane to alcohols had minor effects on retention although this was occasionally beneficial. Addition of water to alcohols increased retention. Addition of water to acetonitrile decreased retention. Addition of alcohol to acetonitrile also proved beneficial to the separation of some compounds. Loading studies performed to mimic preparative separations indicated that the benefits of polar organic mobile phases are largely due to increased solubility.