Bibliographies: 'Factor H family' – Grafiati (2024)

Abstract:

At present, the human Factor H protein family represents seven multidomain, multifunctional serum proteins. This group includes the complement and immune regulators Factor H, the Factor H-like protein 1 (FHL-1) and five Factor H-related proteins proteins (FHR-1, -2, -3, -4 and -5). Each is exclusively composed of individually folded protein domains, termed short consensus repeats (SCRs) or complement control modules. Structure-function analyses allowed the localization of the complement regulatory domain of Factor H and FHL-1 in the N-terminal region within SCRs 1–4. In addition, multiple binding sites for C3b, heparin and microbial surface proteins were localized in the N-terminus, within the middle region and also in the C-terminus of Factor H and FHL-1. Recent results show a central role for the C-terminus of Factor H, i.e. SCRs 19–20. These particular domains are conserved in all FHRs identified so far, include contact points for C3b, heparin and microbial surface proteins and represent a ‘hot-spot’ for gene mutations in patients that suffer from the Factor H-associated form of haemolytic uraemic syndrome.

Abstract:

We report a case of an 18-month-old boy with H factor deficiency with atypical presentation: recurrent acute otitis media and several maternal family members with autoimmune disorders (vitiligo, thyroiditis and immune trombocytopenia). Blood tests revealed low C3 and AH50, as well as low properdin and H factor. I factor was normal. CFH gene molecular test confirmed the H factor deficiency diagnosis. This child had none of the typical manifestations of this disorder, namely Neisseria meningitidis infection or renal disease (glomerulonephritis and atypical haemolytic uremic syndrome). Autoimmune family history and correct interpretation of blood tests’ results were crucial for this diagnosis.

Abstract:

This study describes levels of asset development and involvement in at-risk behaviors among 4-H youth. To collect the data, 202 4-H teens participating in the 1996 Utah State 4-H Contests completed surveys. Results reveal numerous differences between males and females. Females scored significantly higher on 18 of 29 assets. Males reported significantly higher levels of involvement on 8 of 10 at-risk behaviors. Significant differences existed between types of 4-H clubs on 4 of 29 assets and 1 of I 0 at-risk behaviors. No significant differences were found based on grade in school, years in 4-H, number of 4-H project areas, and number of 4-H events. The study revealed that these 4-H members have developed personal assets related to family, education, individual skills, and involvement in positive activities. The majority have never participated in at-risk activities (drugs- 90%; sexual intercourse- 85%; criminal activities- 80%; and alcohol or shoplifting- 77%). These 4-H youth are laying solid foundations for their futures.

Abstract:

The purpose of the current study was to examine personal cognitive variables (adolescents&rsquo
beliefs supporting aggression, adolescents&rsquo
self-efficacy for alternatives to aggression, and adolescents&rsquo
personal value on achievement) as potential mediators of the relationship between perceived family factors (parental support for aggression, family conflict, and parental monitoring) and adolescents physical aggression among Turkish adolescents living in Ankara. Volunteered students (2443 sixth, seventh, and eighth graders) from randomly selected schools (36 primary school) participated in the study. Physical Aggression Scale, Beliefs Supporting Aggression Scale, Self- efficacy for Alternatives to Aggression Scale, Personal Value on Achievement Scale, Parent Adolescent Relationship-Monitoring Scale, Parental Support for Aggression Scale, and Family Conflict Scale were used in the data collection. Results of the SEM analyses showed that the models adequately described the data for the sample of male and female adolescents and the fit indices were all within the acceptable thresholds. When considering the explained variance in physical aggression
the latent model accounted for 48% of the variance in physical aggression among girls and 40% of the variance in physical aggression among boys. In general, the results suggested that the influence of perceived family factors on physical aggression can be mediated by personal cognitive factors. Moreover, the patterns of interactions and the strength of the relationships differed in boys and girls model. The results revealed that the proposed model of physical aggression, which was based on integration of problem behavior theory (Jessor, 1987) and social information processing model (Huesmann, 1998) was supported by the data.

Abstract:

The purpose of the present study was to find out variables that make first year university students vulnerable to eating disorders. Pathological eating attitudes&rsquo
association with height and weight, family meal patterns, perceived social support, family values and socio-demographic variables were assessed. 299 first year university students from the Department of Basic English at Middle East Technical University participated in the study. Five assessment devices- Demographic data form, the Eating Attitude Test (EAT&ndash
40), Family Eating Attitude and Behavior Subscales, the Multidimensional Scale of Perceived Social Support, and the Traditional Family Values Questionnaire were administered. ANOVAs were conducted to assess differences on eating attitudes between participants in terms of gender, with whom they lived, perceived family type, socio economic status, body mass index and weight satisfaction. Stepwise multiple regressions were conducted to appraise to what extent perceived social support, family meal patterns, traditional family values and demographic variables predicted eating attitudes of first year students. The participants who perceived their family as traditional reported more pathological eating attitudes in dieting, preoccupation with food, social pressure on weight factor. Regression analyses for female participants revealed that dieting, parents occupation, body mass index (current / desired) perceived social support- family, relationships with family and kin, and perceived family income were associated with pathological eating attitudes. Regression analyses for males revealed that dieting, father occupation, desired body mass index and relationships with family and kin were associated with pathological eating attitudes. These findings were discussed with reference to relevant literature. Future research topics were suggested and therapeutic implications of the study were discussed.

Abstract:

Tese de mestrado em Microbiologia Aplicada, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, em 2018
Candida glabrata é um fungo patogénico que emergiu nas últimas décadas como a segunda causa mais comum de candidíase em todo o mundo. O género Candida compreende quase duzentas espécies, a maioria das quais são omnipresentes em numerosos habitats naturais e artificiais. As espécies patogénicas de Candida são encontradas como comensais no trato oral, gastrointestinal e genital de hospedeiros saudáveis e têm a propensão de se tornar patogénicas quando o hospedeiro se torna imunodeprimido. As infeções causadas por esta levedura são caracterizadas por uma elevada mortalidade e morbilidade. Entre outros fatores de virulência, as espécies do género Candida exibem, em comparação com espécies não patogénicas, uma expansão de famílias de transportadores de enzimas extracelulares e transmembranares, bem como um enriquecimento em transportadores de superfície celular com o potencial de conferirem resistência aos fármacos por funcionarem como bombas de efluxo de drogas, prejudicando a eficácia das terapias antifúngicas. C. glabrata é filogeneticamente mais próxima da levedura modelo - Saccharomyces cerevisiae do que das outras espécies do género Candida. No entanto, é frequentemente a segunda ou terceira causa mais comum de infeções fúngicas, sendo que em populações como diabéticos e idosos chega a ser o fungo patogénico dominante. Em comparação com outras espécies, C. glabrata fornece um modelo promissor para o estudo da base genética da resistência a múltiplos antifúngicos. A resistência a múltiplos fármacos é definida como a aquisição simultânea de resistência a um grande espectro de substâncias químicas citotóxicas estrutural e funcionalmente não relacionadas, às quais o organismo nunca tinha sido exposto. Este fenómeno está a tornar-se um problema clínico crescente, uma vez que compromete a eficácia da terapêutica antimicrobiana. Para diminuir com sucesso o número de agentes patogénicos resistentes a múltiplos fármacos, é fundamental adquirir um conhecimento extenso dos mecanismos moleculares subjacentes à resistência aos fármacos antimicrobianos. Esta resistência a fármacos pode ser adquirida através de vários mecanismos: (I) alteração dos níveis de expressão e atividade de proteínas da membrana plasmática ou canais e transportadores de membrana; (II) degradação enzimática ou inativação dos fármacos; (III) ativação de sistemas de replicação e reparação de DNA; (IV) impedimento da entrada do fármaco na célula e/ou extrusão ativa do mesmo catalisada por transportadores transmembranares; (V) sequestro do fármaco em vesículas intracelulares; (VI) alteração ou modificação do alvo do fármaco. A ação de transportadores de membrana, incluindo bombas de efluxo da superfamília ATP-Binding Cassette (ABC) e transportadores da família Drug:H+ Antiporter (DHA), é fundamental para a resistência a múltiplos fármacos. Os transportadores ABC obtêm energia por hidrólise de ATP, enquanto que os transportadores DHA utilizam o gradiente de protões através da membrana plasmática para exportar compostos para fora da célula. O genoma de C. glabrata codifica 18 transportadores ABC, seis meios transportadores e 12 transportadores completos, dos quais seis pertencem à subfamília PDR (Pleiotropic Drug Resistance) e apenas alguns foram estudados para resistência a fármacos ou atividades de transporte; codifica ainda 15 transportadores DHA1 que codificam para proteínas DHA com 12 segmentos transmembranares. Desde a década de 1950 várias classes de drogas antifúngicas foram desenvolvidas, no entanto, apenas quatro deles são atualmente usados na prática clínica para tratar infeções por Candida: análogos de pirimidina, polienos, azóis e equinocandinas. A extensão da resistência aos fármacos antifúngicos varia para as diferentes classes de fármacos. Em espécies de Candida há resistência bastante limitada aos polienos e equinocandinas, enquanto que a resistência ao análogo de pirimidina 5-flucitosina e a azóis é mais comum. Neste trabalho foi estudado o efeito da exposição de células de C. glabrata ao fármaco antifúngico 5-flucitosina, ao nível do proteoma de membrana. Hoje em dia, novas abordagens quantitativas que utilizam a Espectrometria de Massa (MS) e a química estável de rotulagem de isótopos oferecem uma alternativa às técnicas tradicionais que empregam a eletroforese bidimensional comparativa para estudos de proteómica de expressão. A MS é uma ferramenta particularmente relevante no caso de proteínas de membrana, que não são detetáveis em géis bidimensionais, porque são em grande parte insolúveis em tampões de focagem isoelétrica. Neste trabalho, realizou-se análise proteómica de membrana baseada em iTRAQ-MS (isobaric Tags for Relative and Absolute Quantification) para identificar e quantificar as proteínas associadas à membrana em células de C. glabrata cuja concentração se altera após exposição à 5-flucitosina (5-FC). Um total de 32 proteínas apresentaram diferenças de expressão na membrana depois de expostas a 5-FC, quando comparadas com células em condições controlo. Estas proteínas estão envolvidas nos seguintes processos biológicos: remodelação da parede celular, metabolismo lipídico, metabolismo de aminoácidos/nucleotídeos, componentes ribossomais e maquinaria de tradução, função mitocondrial, metabolismo da glicose e transportadores de membrana. Por comparação com as alterações que se verificam nas mesmas condições ambientais no mutante Δpdr1, com o gene PDR1 eliminado, observou-se que 50 % das proteínas cuja expressão se altera após exposição a 5-FC estão sob influência do fator de transcrição CgPdr1, que se verificou ser determinante na resistência à 5-FC por C. glabrata. Este resultado surpreendente é muito interessante, uma vez que o fator de transcrição CgPdr1 é o principal determinante de resistência a azóis em C. glabrata. A observação de que também poderá estar envolvido na aquisição de resistência a 5-FC sugere a existência de um mecanismo comum à resistência a duas famílias de antifúngicos, o que é preocupante na perspetiva da aquisição de resistência a agentes antifúngicos, sem necessidade de exposição prévia aos mesmos. Entre as proteínas encontradas com expressão aumentada encontra-se o transportador da família DHA - CgFlr1, que foi eleito para estudos posteriores. Foi estudado o papel do CgFlr1, e do seu homólogo CgFlr2, na resistência à 5-flucitosina. Os resultados obtidos demonstram que ambas as proteínas conferem resistência a 5-flucitosina. Adicionalmente, e apesar do seu elevado grau de hom*ologia, CgFlr1 parece conferir resistência especificamente ao fungicida mancozeb, enquanto CgFlr2 parece conferir resistência a azóis e a anfotericina B. Verificou-se que a proteína CgFlr1 se localiza na membrana plasmática, quando expresso em C. glabrata, mas também quando expresso em S. cerevisiae, complementando o fenótipo de suscetibilidade a 5-FC exibido pelo mutante Δflr1. Verificou-se que a eliminação dos genes CgFLR1 e CgFLR2 leva a uma acumulação intracelular de 5-FC maior do que a registada em células da estirpe selvagem, o que sugere que estes transportadores desempenham um papel direto na resistência à 5-FC por expulsão desta droga antifúngica para o meio extracelular. No global, os resultados descritos neste estudo salientam a importância dos transportadores de múltiplos fármacos da família DHA no fenótipo de resistência a antifúngicos, em particular no que diz respeito a 5-FC. A caracterização dos transportadores CgFlr1 e CgFlr2 como estando envolvidos na resistência a 5-FC reforça a noção de que é necessário estudar os restantes membros desta família em C. glabrata, dado o seu provável impacto clínico. Adicionalmente, este estudo realça a importância do recurso a abordagens à escala do genoma, em particular ao nível do proteoma, na identificação e compreensão dos mecanismos de resposta e resistência a antifúngicos. Os processos biológicos e os seus efetores identificados no presente estudo representam alvos promissores para o desenvolvimento de novos sensitizadores da resistência à flucitosina, que poderão permitir a utilização terapêutica de 5-FC em mais baixas concentrações e sem riscos tão elevados de falência da terapêutica, limitando o desenvolvimento de resistência a 5-FC em C. glabrata que habitualmente acontece com elevada rapidez.
Candida glabrata is pathogenic fungi that emerged in the last decades as the second most common cause of candidiasis worldwide. The infections caused by this yeast are characterized for a high mortality and morbidity, and the action of drug efflux pumps is impairing treatment effectiveness. Multidrug resistance has emerged in most organisms and poses a severe clinical problem for the treatment because the extensive use of antifungal drugs had led to a huge increase in the number of intrinsically resistant infections with fungal pathogens. Since resistance often relies on the action of membrane transporters, including drug efflux pumps from ATP-Binding Cassette (ABC) family or from the Drug:H+ Antiporter (DHA) family, an iTRAQ-based (isobaric Tags for Relative and Absolute Quantification) membrane proteomics analysis was performed to identify all the membrane-associated proteins whose abundance changes in C. glabrata cells exposed to the Fluoropyrimidine drug 5-Flucytosine (5-FC). A total of 32 proteins were found to display significant expression changes in the membrane fraction of cells exposed to 5-FC, when compared to cells in the unstressed control conditions, 50 % of which under the influence of the transcription factor CgPdr1, found to be a determinant of C. glabrata resistance to 5-FC. These proteins cluster into functional groups associated to cell wall assembly, lipid metabolism, amino acid/nucleotide metabolism, ribosome components and translation machinery, mitochondrial function, glucose metabolism and multidrug resistance transport. Among the proteins whose concentration was found increased in 5-FC stressed cells, CgFlr1 was elected for further studies. The role of CgFlr1, and of its close hom*olog CgFlr2, in 5-FC resistance was assessed. Results obtained demonstrate that both proteins confer 5-FC resistance. Despite their high degree of hom*ology, CgFlr1 seems to specifically confer resistance to the fungicide mancozeb, while CgFlr2 appears to confer resistance to azole antifungal drugs and amphotericin B. CgFlr1 was found to be localized in the plasma membrane in C. glabrata and when heterologously expressed in Saccharomyces cerevisiae, complementing the 5-FC susceptibility phenotype exhibited by the S. cerevisiae Δflr1 mutant. Additionally, the deletion of CgFLR1 and CgFLR2 was found to lead to increased intracellular accumulation of 5-FC, suggesting that these transporters play a direct role in the resistance to 5-FC by extruding this antifungal drug to the extracellular medium.

Abstract:

Abnormal regulation of complement is intimately associated with C3 glomerulopathy and atypical haemolytic uraemic syndrome. Atypical haemolytic uraemic syndrome is characterized by renal thrombotic microangiopathy due to an inability to regulate complement activation along the renal endothelium. The development of thrombosis is critically dependent on the ability to activate C5. Eculizumab, a monoclonal anti-C5 antibody, is an effective therapy for this condition. C3 glomerulopathy refers to glomerular lesions characterized by accumulation of C3 in the absence of immunoglobulin. The prototypic example is dense deposit disease. This condition is associated with impaired regulation of the alternative pathway in plasma. In other subtypes of C3 glomerulopathy, familial studies have identified mutations within the complement factor H-related protein family. Polymorphic variation within this protein family also influences susceptibility to IgA nephropathy. The mechanism underlying these associations remains unknown and is the subject of ongoing research efforts.

Abstract:

The non-Hodgkin lymphomas (NHL) are a heterogeneous group of over forty lymphoid neoplasms that have undergone a major redefinition over the last twenty-five years, in part due to advances in immunology and genetics as well as implementation of the WHO classification system. NHLs are considered clonal tumors of B-cells, T-cells, or natural killer (NK) cells arrested at various stages of differentiation, regardless of whether they present in the blood (lymphoid leukemia) or lymphoid tissues (lymphoma). In the United States, the age-standardized NHL incidence rate (per 100,000) doubled from 1973 (10.2) to 2004 (21.4) and then stabilized, while five-year relative survival rates improved from 42% in 1973 to 70% in 2004. Established risk factors for NHL or specific NHL subtypes include infectious agents (HTLV-1, HIV, EBV, HHV8, HCV, H. pylori), immune dysregulation (primary immunodeficiency, transplantation, autoimmunity, and immunosuppressive drugs), family history of lymphoma, and common genetic variants identified by genome-wide association studies.

Abstract:

Yielding from an overall quantitative study of the residential sector of Bosnia and Herzegovina (B&H), this chapter concentrates on the ratio between single-family and collective housing, as well as on the urban-rural ratio of the single-family housing. Based on the data from the existing building stock (buildings built by 2014) and the statistical estimates, 23% of the buildings belong to the urban areas and 77% belong to the rural areas. The main goal was to study the correlation between the characteristics of the building envelope, the shape factor (A/V ratio) and the energy savings potential for the application of conventional measures of refurbishment of the building envelope of the single-family houses (type of buildings, which dominate in rural and urban areas). The chapter wraps up with recommendations for the adequate level of the energy performance indicator (energy need for heating) for the approved energy class for single-family houses located in the climate zone of the northern B&H.

Abstract:

Molecular complexes grouped under the names of tight, adherent or gap junction regulate the flow of water, ions and macromolecules through epithelium paracellular spaces. The main constituents of tight junctions are claudins, a family of 26 different proteins whose expression and distribution are tissue specific but varies in tumors. A change in claudin 1, 3, 4, 5, 6, 7, 9 and 18 expression, that contributes to lose epithelial cohesion, has been associated to enhanced cell proliferation, migration, and invasiveness in gastric neoplastic tissue. Chronic inflammation process induced by H. pylori infection, a major risk factor for gastric cancer development, disrupts tight junctions via CagA gene, Cag pathogenicity island, and VacA, but the effect upon the epithelial barrier of H. pylori lipopolysaccharides or H. pylori-induced up-regulation of mTOR and ERK signaling pathways by microRNA-100 establishes new concepts of proof.

Abstract:

Age-related macular degeneration (AMD) is a multifactorial disease that results from a complex and unknown interplay among environmental, genetic, and epidemiologic factors. Risk factors include aging, family history, obesity, hypercholesterolemia, and hypertension, along with cigarette smoking, which is the most influential modifiable risk factor. Single nucleotide polymorphisms (SNPs) in numerous genes such as complement factor H (CFH) pose some of the known genetic risks. The pathophysiology in AMD is incompletely understood, but is known to involve oxidative stress, inflammation, dysregulated antioxidants, lipid metabolism, and angiogenesis. Animal models have been integral in expanding our knowledge of AMD pathology. AMD is classified as non-exudative or exudative. Because there is no perfect animal model that recapitulates all aspects of the human disease, rodents, rabbits, and non-human primates offer different advantages and disadvantages to serve as models for various aspects of the disease. Scientific advances have also allowed for the creation of polygenic pre-clinical models that may better represent the complexity of AMD, which will likely expand our knowledge of disease mechanisms and serve as platforms for testing new therapeutics. There have been, and there continues to be, many drugs in the pipeline to treat both exudative and non-exudative AMD. However, Food and Drug Administration (FDA)-approved therapies for exudative AMD that mainly target angiogenic growth factors are the only therapeutics currently being used in the clinics. There remains no FDA-approved therapy for the non-exudative form of this disease. This chapter contains a basic overview and classification of AMD and multiple animal models of AMD are highlighted. We include an overview of both current FDA-approved treatments and those in development. Lastly, we conclude with a summary of the important role of pre-clinical studies in the development of therapeutics for this highly prevalent disease.

Abstract:

As Lee (1987) pointed out, vital rates of the human population are often determined by forces such as culture, institutions, technology, and individual rationality, forces that have little to do with density pressure or prior growth. Perhaps most people also expect “rational” human practice to weaken the biological responses of both fertility and mortality to density pressure, while strengthening the nonbiological response through institutional regulations. But can human institutional designs and rational responses really reduce the impact of natural checks? As we study the pattern of population dynamics in ancient China, we can provide some viewpoints different from the general opinion. The long-term relationship between human institutional designs and natural checks is discussed in chapter 14. The books by Ho (1959) and Chao and Hsieh (1988; hereinafter C&H) contain the most thorough research on the history of Chinese population. The data summarized in C&H have presented us with a time-population diagram, shown in figure 9.1. From this figure, as well as other related literature, the following “stylized facts” of population dynamics in Chinese history can be summarized: 1. Population declines often coincided with dynasty changes (C&H; Ho, 1959). 2. Population declines were often drastic in a rather short period of time. 3. Natural checks such as famine and epidemics did not independently reduce the population surplus (Ho, 1959); rather, population declines were often the direct and indirect results of internecine wars. 4. There are obvious peaks and troughs in the population data, but no regular cyclical patterns (C&H). The fact that no serious population decline appears to have been independently due to famines and epidemics seems to suggest a weak pattern of density-dependency for ancient Chinese populations, a pattern consistent with the observation of Lee mentioned in the beginning of this chapter. However, as noted by many historians (see, e.g., Ho, 1959, and C&H 1988), the frequent clashes between soldiers and rebellious peasants in Chinese history were often initiated by famine or density pressure. As such, the originally weak natural checks on population were often magnified by war, and such magnified “institutional checks” caused very drastic population changes.

Abstract:

Between 1847 and 1852, John built four separate aqueducts for the Delaware and Hudson Canal; moved his home, family, and wire rope factory from western Pennsylvania to Trenton, New Jersey; secured the contract to build a huge railroad bridge over the Kentucky River; and continued to mount substantial campaigns to win contracts to span the Ohio at Wheeling and the Niagara Gorge. The four D&H spans were mini masterpieces of engineering and planning. Each structure was very different; each required new solutions to site-specific problems. One of the spans, the Delaware Aqueduct, exists to this day, the oldest suspension bridge in the United States and one of the oldest “modern” suspension bridges in the world. On the larger projects, John again lost out to his old rival Ellet on both the Wheeling and the Niagara spans.

Abstract:

Acyl group transfer processes are plentiful in enzymatic reactions. Examples may be found in ATP-dependent ligation in chapter 11, carbon-carbon bond formation in chapter 14, and fatty acid biosynthesis in chapter 18. In this chapter, we begin by presenting the basic chemistry of acyl group transfer. We then consider four major classes of proteases that catalyze acyl group transfer in the hydrolysis of peptide bonds. Acyl group transfer is so common in organic and biochemistry that the chemistry by which it occurs is often taken for granted. Early studies provided evidence for a mechanism initiated by nucleophilic addition of the acyl group acceptor to the carbonyl group to form a tetrahedral intermediate, analogous to the reversible addition of a nucleophilic molecule to the carbonyl group of an aldehyde or ketone. A mechanism of this type is shown in scheme 6-1 for acyl group transfer from a group :X to a nucleophile :G catalyzed by a general base. This mechanism is drawn from a larger family of possible mechanisms involving specific acid-base, general acid, general base, or concerted general acid-base catalysis of nucleophilic addition to an acyl carbonyl group to form a tetrahedral intermediate, followed by the elimination of :X–H to produce the new acyl compound. In enzymatic reactions the nucleophilic atom G in scheme 6-1 is normally nitrogen, oxygen, sulfur, or a carbanionic species. An acyl carbonyl group is less polar and correspondingly less reactive toward nucleophilic addition than an aldehyde or ketone. The reason is the effect on the heteroatom of nonbonding electrons, which reside in p orbitals that overlap the π orbital of the carbonyl group. The consequent delocalization of electrons stabilizes the carbonyl group and attenuates its reactivity with nucleophiles. Other factors being equal, the order of reactivity is thioester > ester > amide, which is the inverse of the degree of delocalization. Delocalization is least in thioesters because of the high energy of the sulfur p orbitals, which reside in the next higher principal quantum number relative to oxygen in the acyl carbonyl group.

Abstract:

Abstract Research efforts aimed at optimizing the computational efficiency of the p-method are described. These include (i) a novel quadrature scheme for hierarchical shell elements, (ii) a family of assumed strain hierarchical shell elements, (iii) selective polynomial order escalation for assumed strain elements, and (iv) accelerated multi-grid-like solution procedures. Numerical experiments indicate that with these enhancements it is possible to speed up the overall computational time of p-method for analysis of shells by a factor greater than three for relatively small problems (less than 10,000 degrees of freedom), while computational savings for larger problems are even more significant. It has been found that the performance of the enhanced variant of the p-method for shells is comparable to that of the h-method for low accuracy requirements, and better if higher accuracies are desired.

Abstract:

Previous studies have indicated that the majority of haemophilia B patients who produce anti-factor IX inhibitors (antibodies) have some kind of deletion of the factor IX gene. We have analysed DNA from nine haemophilia B inhibitor patients using the Southern blotting method and hybridisation with (i) factor IX cDNA and intragenomic probes (ii) probes originating from flanking sequences up to 60kb 5' and 170kb 3' to the factor IX gene that have been isolated by gene walking experiments (D.S.Anson and G.G.Brownlee, unpublished observations).Two patients who are brothers (haemophilia B (Chicago I)) were shown to have a presumably identical complex rearrangement of the factor IX gene involving two separate deletions. The first deletion is approx. 5.0kb and removes exon e. The second deletion is between 9 and 29kb and removes exons g and h but leaves exon f intact. An abnormal TaqI fragment at one end of the deletions junctions acted as a marker for the inheritance of haemophilia B in the patients' family. Furthermore, an abnormal llkb Bglll fragment (detected with an intragenomic probe containing exon f) in DNA from both patients and their mother acted as a marker for the presence of both deletions. Since the patients' grandmother only showed the normal 12kb Bgl II fragment then both deletions appear to have arisen at the same time. We believe that haemophilia B (Chicago 1) is the first observation of a natural gene rearrangement involving two separate deletions within the same gene.Patient haemophilia B (Jersey 1) was revealed to have a deletion of at least 170kb including the entire factor IX gene and > 60kb of 5' flanking sequence. The 3' breakpoint of this deletion was mapped to between 80 and 140kb 3' to the factor IX gene. One further patient, haemophilia B (Boston I) was shown to have a deletion of > 230kb including the factor IX gene, > 60kb of 5' flanking sequence and >140kb of 3' flanking sequence. Five other inhibitor patients had a structurally intact gene as detected by this method.Although all nine haemophilia B inhibitor patients studied did not have a detectable plasma factor IX only in four of them is this absence due to a large deletion of the factor IX gene.

Abstract:

Limulus clotting factor, factor C, is a lipopolysaccharide (LPS)-sensitive serine-protease zymogen present in the hemocytes. It is a two-chain glycoprotein (M.W. = 123,000) composed of a heavy chain (M.W. = 80,000) and a light chain (M.W. = 43,000) T. Nakamura et al. (1986) Eur. J. Biochem. 154, 511-521 .On further studies of this zymogen, a single-chain factor C (M.W. = 123,000) was identified by Western blotting technique. The heavy chain had an NH2-terminal sequence of Ser-Gly-Val-Asp-, which was consistent with the NH2-terminal sequence of the single-chain factor C, indicating that the heavy chain is located in the NH2-terminal part of the zymogen. The light chain had an NH22-terminal sequence of Ser-Ser-Gln-Pro-. Incubation of the two-chain zymogen with LPS resulted in the cleavage of a Phe-Ile bond between residues 72 and 73 of the light chain. Concomitant with this cleavage, the A (72.amino acids) and B chains derived from the light chain was formed. The complete amino acid sequence of the A chain was determined by automated Edman degradation. The A chain contained a typical segment which is similar structuraly to those a family of repeats in human β2 -glycoprotein I, complement factors B, Clr, Cls, H, C4b-binding protein, 02, coagulation factor XIII b subunit, haptoglobin a chain, and interleukin 2 receptor. The NH2-terminal sequence of the B chain was Ile-Trp-Asn-Gly-. This chain contained the serine-active site sequence of -ASP-Ala-Cys-Ser-Gly-Asp-SER-Gly-Gly-Pro-.These results indicate that limulus factor C exists in the hemocytes in a single-chain zymogen form and is converted to an active serine-protease by hydrolysis of a specific Phe-Ile peptide bond. The correlation of limulus factor C and mammalian complement proteins was also suggested.

Abstract:

Platelets are assumed to play a crucical role in stroke. Abnormal reactivity of platelets has been observed in patients suffering from stroke but it seems unclear whether or not this abnormal reactivity represents a basic factor of stroke. If abnormal platelet reactivity is more but a consequence of stroke it should be present before stroke happens.In families with stroke patients stroke is more frequent as usual. In order to obtain more information we determined platelet reactivity in healthy persons with a family history without vascular events and healthy persons with a history showing stroke in the family.Platelet reactivity was measured using a modification ofa platelet test system described by WU and HOAK(1)Platelet-index-value for the 110 healthy persons without history was 0.98 + /- 0.09 and for the 72 healthy relatives of stroke patients 1.18 + /- 0.28 The difference was significant (p<0.01).The results support the hypothesis that increased platelet reactivity may not only be regarded as a consequence of stroke. It may be possible that this increased platelet function may represent a pathogenetic co-factor in ischemic events and in atherosclerosis also.1) Grotemeyer K.-H. et al., DMW (1985) 110, 256

Abstract:

A new analytical method was established, allowing the characterization of von Willebrand Factor (vWF) degradation fragments from minute amounts of plasma without the need for immunopurification of vWF. Ten ul of citrated plasma in 20 ul of 0.1 M Tris-HCl, pH 7.8, 0.1 M NaCl, 10 mM EDTA buffer were treated with S. aureus V-8 protease for 15 min to 3 h at 22°C. Following addition of 1 mM DFP, the cleaved fragments were separated by SDS-polyacrylamide or SDS-agarose gel electrophoresis and identified by 125 I-labeled polyclonal or monoclonal antibodies (MAbs) to vWF andautoradiography. Quantification of each fragmentwas estimated by counting radioactivity in slices of the dry gel. In normal plasma, S. aureus V-8 protease produced two dimeric fragments of vWF, with identical electrophoretic and antigeniccharacteristics to those produced from highly purified vWF, ie a C-terminal fragment of 220 kd (Spll) and a series of N-terminal fragments (Spill) with a major species of Mr 320 kd (SpIIIa) and two minor ones of 265 kd (SpIIIb) and 215 kd (SpIIIc). The method was applied to further characterize the molecular abnormalities of vWF in 15 patient plasmas with variant (type II) von Willebrand disease (vWD). In all cases with type IIA, IIB, IIC and IID tested, fragment Spll had the same mobility as in normal plasma. In 7 patients with type IIA, the amount and distribution ofthe three Spill species were clearly abnormal, with a marked decrease or absence of SpIIIa and an increase of SpIIIb and SpIIIc. Results slightly varied between patients but were consistent within one family. In 4 patients with type IIC, the band SpIIIb was lacking. In 2 patients with type IIB and 2 patients with type IID, there was no significant modification of Spill. In all cases the pattern of Spill was similar whether using polyclonal antibodies to vWF or MAbs to Spill.The pattern of normal or abnormal Spill remainedthe same in fresh or frozen plasma and was not modified by the presence of 5 mM EDTA at the timeof blood collection. Furthermore, the abnormaldistribution of Spill in type IIA or IIC vWD wasalready present after the shortest digestion time(15 min) indicating that the fragment Spill was produced from an abnormal vWF during the primary digestion with S. aureus V-8 protease. In conclusion, the molecular abnormality of vWF in type IIA and IIC vWD appears to reside in Spill, the N-terminal portion of the subunit (residues 1 to 1,365).

Abstract:

Interaction between cells and between cells and extracellular matrices are critical for a number of biological processes, including organ development, cell differenciation, cell motility, and the inimune' response. These interactions are mediated by a family of adhesion receptors that recognize short sequences such as Arg-Gly-Asp (RGD). These receptors share similar structural properties. They are heterodimers composed of a and B subunits and sometime express common epitopes. This suggests that the structural and functional relationship of these receptors may result from the transcription of related genes or may arise from cell specific post-transcriptional events. Thus, analysis of the biosynthesis and processing of these receptors would provide valuable insights into the molecular mechanism which control their expression at the surface,of different cells. Platelet membrane glycoprotein (GP) IIb-IIIa is a member of this receptor family. This protein is a non covalent heterodimer composed of two distinct polypeptides, Glib which consists of two subunits Ilba and IlbB (Mr = 116 kD, Mr = 25 kD) and GPIIIa (Mr = 100 kD, reduced). GPIIb-IIIa functions at site of platelet aggregation and serves as receptor for RGD containing factors including fibrinogen, fibronectin and von Willebrand factor. We report here on the investigation of the biosynthetic pathways of this RGD receptor in human megakaryocytes. High number of megakaryocytic cells from the megakaryoblastic stage to the polyploid mature megakaryocyte were obtained from liquid culture of cryopreserved leukocyte stem cell concentrates from patients with chronic myelogenous leukemia (CML). After sorting, using a FACS IV and indirect immunofluores-cent labeling with monoclonal antibodies anti-GPIIb-IIIa, 95 % of the cells in culture were of the megakaryocytic lineage. These megakarocytes represented an excellent tool to delineate at the molecular level events associated with the biosynthesis of GPIIb-IIIa.Metabolic labeling and pulse-chase experiments indicated that GPIIb and GPIIIa are synthesized from separate mRNA and that the two subunits of GPIIb derive from a common precursor. This was further confirmed by cell-free translation of megakaryocyte mRNA and the identification of separate cDNA containing sequences coding for the pro-GPIIb and for GPIIIa. These cDNA were isolated from a Xgt11 expression library constructed with purified megakaryocyte RNA, and were used to size the messengers coding for the two polypeptides. A single mRNA species of 3.9 kB was found to encode the pro-GPIIb, whereas two different mRNA species of 2.9 kB and 4. 1 kB were identified with the GPIIIa cDNA.The newly synthesized GPIIIa associates early with the pro-GPIIb in the rough endoplasmic reticulum. Examination of the glycosylation pathways with endoglycosidase H, tunicamycin and monensin indicated that high mannose oligosaccharides are added to the GPIIIa and pro-GPIIb polypeptide backbone. The pro-GPIIb is then processed with conversion of high mannose to the complex type carbohydrate, whereas GPIIIa remains endoH sensitive. Glycosylation of pro-GPIIb-IIIa and processing of oligosaccharides are prerequisite for proteolytic maturation of pro-GPIIb and the expression of the mature complex at the surface of the cell. Thus post-translational processing of GPIIb-IIIa requires an early assembly of the complex. This may have important implications in the maturation of megakaryocyte granules and in the molecular mechanism underlying the Glanzmann thrombastenic disease.

Abstract:

Plasminogen activation provides an important source of localized proteolytic activity not only during fibrinolysis, but also during ovulation, cell migration, epithelial cell differentiation, tumor invasion and a variety of other physiological processes. Precise regulation of plasminogen activator (PA) activity thus constitutes a critical feature of many biological processes. This control is achieved in large part through the action of specific PA inhibitors (PAIs). Although 4 distinct PAIs have been detected,1the endothelial cellTderived inhibitor (PAI-1) is the only one that efficiently inhibits both urokinase (Kd=2.3×10−13M; Kassoc =1.6×108 M−1s−1) and single-chaintissue-type PA (tPA; Kd=1.3×lO−15 M Kd=3.9×lO7M−1s−1). It also inhibits trypsin (Kassoc=6.8×106M−1 s−1 ) ancl Plasmin (Kassoc=7.6×l05 M−1 s5 Analysis of the effect of PAI-1 on the rate of plasminogen activation revealed a competitive type of inhibition when urokinase was employed but a linear mixed type of inhibition when single chain tPA was employed. These results suggest that the interaction of PAI-1 with tPA, in contrast to its interaction with urokinase, may involve 2 sites on the tPA molecule.PAI-1 has been purified from medium conditioned by cultured bovine aortic endothelial cells and partially characterized. It is a major biosynthetic product of these cells, accounting for as much as 12% of the total protein released by the cells in 24 h. It has an M of 50,000, an isoelectric point of 4.5-5.0, and is immunologically and biochemically related to the rapidly acting inhibitor present in human platelets and in the plasma of some patients at risk to develop thrombotic problems. Although it is relatively stable to conditions which inactivate most protease inhibitors (acid pH, SDS), it is extremely sensitive to oxidants. The molecular cloning of the PAI-1 gene revealed that the mature human protein is 379 amino acids long, contains an NH2-terminal valine, lacks cysteines and has a methionine at the Pi position of it's reactive center. The conversion of this methionine to methionine sulfoxide may be responsible for the rapid inactivation of PAI-1 by oxidants. Human PAI-1 has extensive (30%) hom*ology with α1-antitrypsin and antithrombin III and is thus a member of the serine proteinase inhibitor (serpin) family; a group of related molecules that control the major protease cascades of the blood. The PAI-1 gene is approximately 12.2 kilobase pairs in length and is organized into nine exons and eight introns.The production of PAI-1 by endothelial cells is stimulated by endotoxin, interleukin-1, tumor necrosis factor, and transforming growth factor β(TGFβ). The cells are extremely sensitive to TGFβwith maximal effects (100-fold stimulation) observed with 1-2 ng/ml. These changes were relatively specific for PAI-1, and could be detected at both the protein and the RNA level. Interestingly, TGFgalso stimulated the amount of PAI-1 present in the extracellular matrix (ECM) of BAEs. PAI-1 was one of the primary ECM components of these cells, constituting 10-20% of the ECM proteins detected after SDS-PAGE.One of the most unusual properties of PAI-1 is that it exists in blood and in various cellular samples in both an active and an inactive (latent) form, the ratio depending on the source. The latent form can be converted into the active one by treatment with denaturants like SDS or guanidine-HCl. Although the majority of the cell-associated PAI-1 is active, it rapidly decays (t1/2=3 h) into the latent form once it is released from the cells. In contrast, the half-life of ECM associated PAI-1 was greater than 24 h. These data suggest that PAI-1 is produced by BAEs in an active form, and is then either released into the medium where it is rapidly inactivated, or released into the subendothelium where it binds to ECM. The specific binding of PAI-1 to ECM protects it from this inactivation.

Abstract:

The MS6001C gas turbine combines the proven reliability of the General Electric gas turbine family with the advanced technology developed for the FA, FB and H machine designs. The engine configuration is a single shaft bolted rotor, driving a 50 or 60 Hz. generator though a cold end mounted load gear. Rated at 42.3 MW, with a thermal efficiency of 36.3%, the MS6001C will provide greater than a four percent increase in efficiency over the MS6001B. This paper is focused on the design and development of the MS6001C gas turbine, highlighting the commonality between this and other General Electric Power Systems (GEPS) and General Electric Aircraft Engines (GEAE) designs, as well as introducing some new and innovative features. The new high efficiency, 12 stage, axial flow compressor, features a 19:1 pressure ratio with three stages of variable guide vanes. The can annular, six chamber, Dry Low NOx (DLN-2.5H) combustion system is scaled from field proven, low emission technology. The turbine incorporates three stages, two cooled blade rows, and operates at a 1327°C firing temperature. After a thorough factory full speed no load test has been conducted, the first MS6001C engine will be shipped to a customer site in Kemalpasalzmir Turkey, where an instrumented full load test will be conducted to validate the design.