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At least 127 records · Page 7Linked to original sources
PubMed1989

Membrane topology and functional analysis of the sensory protein VirA of Agrobacterium tumefaciens.

The virA gene of Agrobacterium tumefaciens encodes an inner membrane that mediates the transcriptional activation of virulence genes in response to plant signal molecules. We report here a functional analysis of the N-terminal, C-terminal and periplasmic domains of VirA in transmembrane signalling. First, we show that VirA has a transmembrane topology by analysis of the alkaline phosphatase activities, determined by several virA-phoA gene fusions. Second, we report here the construction of several virA-tar chimeric genes, in which the 3'-coding region of virA is conserved to study transmembrane signalling, as well as the construction of a set of virA deletion mutations. Results of analyses of vir induction behaviour and tumour inducing abilities of agrobacteria carrying these mutant genes do not support existing models for the chemoreceptor function of the VirA periplasmic domain. We demonstrate that the periplasmic domain of VirA can be either replaced by a corresponding region of the E.coli chemosensory protein Tar or even totally deleted from VirA without a loss of function. Here, we present a model of VirA which involves a receptor function for the second membrane-spanning domain and an intracellular signalling function for the cytoplasmic domain of VirA. In addition, we show that VirA plays a role in determining the sensitivity for pH and temperature in acetosyringone-mediated vir induction, and we propose a role for the VirA periplasmic domain in detection of the external pH conditions.

Amino Acid Sequence↗
PubMed1982

Towards a functional analysis of anorexia nervosa and bulimia nervosa.

This paper is concerned with the description of an aetiological model of anorexia nervosa and one form of bulimia nervosa. The model has been generated within the conceptual framework of 'functional analysis' and is based on a combination of research evidence and clinical observation. The model attempts to explain the development of anorexia nervosa in terms of a set of hypothesized antecedent events/variables and its maintenance/exacerbation in terms of both positive and negative reinforcers. Specifically it is suggested that initial dieting behaviour is triggered by apparently innocuous psychosocial stimuli, in the context of major setting conditions which predispose the individual towards self- and bodily control: an that successful dieting is then powerfully reinforced by its consequences, which rapidly lead to a downward spiralling into full-blown anorexia nervosa. In this formulation anorexia nervosa is viewed as an attempted adaptive strategy (which has functional value to the individual), given the major setting conditions of the individual's current life situation. Similarly, bulimia nervosa following on from anorexia nervosa is viewed as an attempted adaptive strategy given prevailing environmental and biological pressures towards increasing food intake. The model is presented in the form of diagrammatic formulations and its theoretical and therapeutic implications discussed in relation to the relevant literature..

Adolescent↗
PubMedDate not supplied

Feasibility of ventricular function analysis by digital subtraction angiography.

Continuous or cine mode of digital subtraction angiography (DSA) following intravenous injection of contrast media was evaluated in regard to feasibility of obtaining physiologic data in cardiac abnormalities. Computer programs for cardiac function analysis including stroke volume, ejection fraction and display of left ventricular wall motion in end-diastole and end-systole have been developed with use of automatic contour plotting and densitometry for depth information. Experiments with contrast-filled balloons demonstrated good correlation between the true volumes and the calculated volumes. Clinical study also demonstrated good correlation between the values obtained from conventional left ventriculography and DSA.

Angiography↗
PubMed1993

Functional analysis of matrix proteins expressed from cloned genes of measles virus variants that cause subacute sclerosing panencephalitis reveals a common defect in nucleocapsid binding.

We have developed an in vitro nucleocapsid-binding assay for studying the function of the matrix (M) protein of measles virus (MV) (A. Hirano, A. H. Wang, A. F. Gombart, and T. C. Wong, Proc. Natl. Acad. Sci. USA, 89:8745-8749, 1992). In this communication we show that the M proteins of three MV strains that cause acute infection (Nagahata, Edmonston, and YN) bind efficiently to the viral nucleocapsids whereas the M proteins of four MV strains isolated from patients with subacute sclerosing panencephalitis (SSPE) (Biken, IP-3, Niigata, and Yamagata) fail to bind to the viral nucleocapsids. MV Biken (an SSPE-related virus) produces variant M sequences which encode two antigenically distinct forms of M protein. A serine-versus-leucine difference is responsible for the antigenic variation. MV IP-3 (an SSPE-related virus) also produces variant M sequences, some of which have been postulated to encode a functional M protein responsible for the production of an infectious revertant virus. However, the variant M proteins of Biken and IP-3 strains show no nucleocapsid-binding activity. These results demonstrate that the nucleocapsid-binding function is conserved in the M proteins of MV strains that cause acute infection and that the M proteins of MV strains that cause SSPE exhibit a common defect in this function. Analysis of chimeric M proteins indicates that mutations in the amino-terminal, carboxy-proximal, or carboxy-terminal region of the M protein all abrogate nucleocapsid binding, suggesting that the M protein conformation is important for interaction with the viral nucleocapsid.

Antigens, Viral↗
PubMed1993

A discriminant function analysis of various interferon parameters among alcoholics and heavy smokers.

A three-group design of alcoholics, heavy smokers and controls was used to investigate the status of the interferon system, including natural killer cell activity. Group differences were indicated via discriminant function analysis which correctly classified 86% of subjects. Test-retest relations were investigated for 14 subjects following a 30-day alcoholic inpatient program. Whereas significant immune suppression was indicated at the time of detoxification, recovery was evident at the 30-day follow-up. Results are discussed in terms of the significance of alcohol abuse on immune system functioning with consequences for susceptibility to viruses, bacteria and medical illnesses.

Adult↗
PubMed1992

Functional analysis of the rat insulin-like growth factor I gene and identification of an IGF-I gene promoter.

Insulin-like growth factor I (IGF-I) mediates many of the systemic growth-promoting effects of growth hormone and also functions as a locally acting growth stimulator. In mammals, IGF-I gene expression is complicated, as the gene is transcribed and processed into multiple mRNAs (ranging in length from less than 1 to nearly 7.5 kb) that encode at least two protein precursors. As a step toward understanding the regulation of IGF-I, we report the complete organization of the rat IGF-I gene, including identification of the structural determinants for all IGF-I mRNA species, and an initial functional analysis of its promoters. The gene is composed of 6 exons distributed over nearly 80 kb of chromosomal DNA and is structurally heterogeneous. Several transcription start sites were identified within IGF-I exons 1 and 2, adjacent to presumptive promoters 1 and 2, respectively, and at least three polyadenylation sites were mapped to exon 6. To test promoter function, fusion genes were constructed linking fragments of IGF-I DNA to a reporter plasmid. Chimeric genes containing at least 395 bp of DNA from the 5'-flanking region of exon 1 enhanced luciferase activity after transfection into the IGF-I-producing SK-N-MC cell line, while fusion plasmids containing up to 1,300 bp of DNA from the 5'-flanking region of exon 2 were inactive. Relative levels of IGF-I mRNAs containing exons 1 or 2 varied among different rat tissues, although in response to acute or chronic growth hormone treatment both classes of transcripts were induced coordinately in rat liver. These observations represent the first thorough characterization of a mammalian IGF-I gene, and provide a starting point for defining the mechanisms by which growth hormone and other trophic factors regulate IGF-I gene expression.

Amino Acid Sequence↗
PubMed1989

Disturbed endocrine function in the psychoses. II: Discriminant function analysis of multihormone data.

Discriminant function analyses were performed on plasma concentrations of prolactin, growth hormone, cortisol, TSH, and the neurophysins measured over 17 hours in 70 newly admitted drug-free psychiatric patients and 35 control subjects. The hormone data distinguished between patients with different classes of drug-free psychosis (26 schizophrenic, 12 with manic disorder, 10 with major depressive disorder, psychotic subtype, 9 with schizoaffective mania (SAM]. Higher plasma cortisol and lower TSH concentrations separated eight of nine SAM patients from all others.

Bipolar Disorder↗
PubMed1981

Collateral ligaments of the canine stifle joint: anatomic and functional analysis.

The anatomic features and functions of the collateral ligaments of the canine stifle joint were investigated, using cadaver specimens. The structure of the collateral ligaments was examined by dissection, with attention given to the spatial relationships existing between the collateral ligaments and their neighboring structures, such as the menisci and joint capsule. The relative tension of the ligaments was determined by identifying the points of attachment with lead markers and taking a series of radiographs of the joint throughout its range of motion. The distance between the points was measured, and the change in length was determined as a function of joint position. Measurements of internal and external rotation, varus angulation, and valgus angulation were made before and after severance of one or both ligaments. The medial collateral ligament was taut in extension, with only the caudal portion of the ligament becoming lax in flexion. The lateral collateral ligament was also taut in extension; however, its entire bulk because lax as the joint was flexed. In extension, the ligaments were primary restraints preventing varus and valgus angulation, and they functioned to limit internal and external rotation of the tibia. In flexion, the cranial portion of the medial collateral ligament remained taut and prevented external rotation of the tibia, whereas the relaxation of the lateral collateral ligament allowed the tibia to rotate internally, with further rotation limited by the cruciate ligaments.U

Animals↗
PubMed1987

A functional analysis of recidivistic arson.

Evidence from studies of pathological arson and normal fire setting as well as the authors' clinical experience with arsonists in a maximum security hospital is employed to generate a model of recidivistic arson within the conceptual framework of functional analysis. It is contended that certain psychosocial stimuli, in the context of major setting conditions, predispose the individual towards incendiarism which is initially positively and negatively reinforced. However, the longer-term consequences of arson are considered to maintain and exacerbate the antecedent problems encountered by arsonists. Specifically, arson is viewed as an attempt to exert a change in the arsonist's life conditions where alternative behaviours have proved, or are perceived to be, ineffective. The model incorporates adaptations of the displaced aggression and arousal hypotheses of arson, and examines possible developmental aspects of pathological arson from normal childhood fire play, and suggests that a transition from fire setting in the company of others to incendiarism alone constitutes a major factor in the pathological process. The social, clinical and theoretical implications of the model are discussed with reference to current management and treatment strategies as well as future research.

Arousal↗
PubMed1995

Sequence and functional analysis of the Streptomyces phaeochromogenes plasmid pJV1 reveals a modular organization of Streptomyces plasmids that replicate by rolling circle.

pJV1 is an 11 kb, high-copy-number conjugative Streptomyces phaeochromogenes plasmid that replicates by the rolling circle mechanism (RCR). Sequencing combined with functional analysis of deletion, insertion and frameshift mutations was used to characterize the genes involved in plasmid transfer and chromosome mobilization (Cma), the single-strand origin for RCR and an associated strong incompatibility (Sti) determinant. pJV1 contains two essential transfer genes whose expression is regulated by an adjacent repressor gene with similarity to the GntR family of regulators. A consensus sequence specific for the helix-turn-helix motifs of repressor proteins of Streptomyces plasmids is proposed. Unregulated expression of the transfer genes by inactivation of the repressor is lethal. Three additional genes increase intramycelial plasmid spread resulting in pock formation but, unlike the essential transfer genes, are not required for Cma. The pJV1 transfer genes and their regulatory region, but not the minimal replication region encoding the double-strand replication origin and replication protein, are similar in their sequence and arrangement to those of the Streptomyces nigrifaciens plasmid pSN22, revealing a modular organization of Streptomyces RCR plasmids.

Amino Acid Sequence↗
PubMed1978

[Intracellular regeneration and structuro-functional analysis of biological processes in normal cases and in pathology].

The author elucidates some problems in the history and the modern state in the doctrine on intracellular regenerative processes. Electron microscopic radioautography is considered as the most adequate method for studying intracellular regeneration. Certain examples are given to illustrate principally new possibilities of the structural-functional analysis of intracellular processes, normal and pathologic, studied by means of this method in view of the conception of intracellular generation. At the same time, new perspectives for further elaborating the problem of structural and functional integrity are stressed.

Animals↗
PubMed2026

Genome-wide association studies of plant traits and functional analysis of leaf development-related genes in citrus.

Labor-saving and high-light-efficiency tree architecture is a key breeding objective for woody fruit trees like citrus. However, population genetics information on these traits remains limited. In this study, tree architecture, thorn, and leaf traits were evaluated in 353 F2 progeny derived from a cross between Clementine mandarin and precocious trifoliate orange-an early-flowering variety. A random subset of 300 offspring was sequenced for a genome-wide association study (GWAS), which detected 10 216 significantly associated SNPs and defined several major quantitative trait loci (QTLs) for the target traits. Subsequent bulked segregant analysis (BSA) and GWAS on individuals with extreme compound leaf phenotypes mapped the causal gene(s) to a 0.8 Mb region (22.15-22.95 Mb) on chromosome 4. Genetic analysis across multiple hybrid combinations confirmed that the compound leaf trait in trifoliate orange is dominantly inherited and follows Mendelian segregation. Transcriptome profiling of parental leaves at different developmental stages identified a KNOX gene, CiKNAT6, as a candidate. Further validation using CAPS markers and Hi-Tom sequencing demonstrated tight linkage between an InDel polymorphism in CiKNAT6 and leaf shape across diverse citrus species and the F2 population, with co-segregation observed for the compound leaf trait. Due to alternative splicing producing seven splice variants, the CiKNAT6 DNA sequence was selected for genetic transformation experiments. Functional analysis revealed that the Clementine mandarin allele of CiKNAT6 is non-functional owing to an InDel, whereas ectopic expression of the trifoliate orange allele in tobacco and lemon induced leaf curling and reduced leaf size. CRISPR-Cas9 knockout of CiKNAT6 in trifoliate orange resulted in increased leaf area. These findings provide valuable genetic resources and insights for future studies on tree architecture and leaf morphology.

Plant Leaves↗
PubMed1995

Sequence and functional analysis of a 7.2 kb DNA fragment containing four open reading frames located between RPB5 and CDC28 on the right arm of chromosome II.

In a coordinated approach, several laboratories sequenced Saccharomyces cerevisiae chromosome II during the European BRIDGE project. Here we report on the sequence and functional analysis of a 7217 bp fragment located on the right arm of chromosome II between RPB5 and CDC28. The fragment contains four open reading frames probably encoding proteins of 79.2 kDa (corresponding gene YBR156c), 12.1 kDa (YBR157c), 62.7 kDa (YBR158w) and 38.7 kDa (YBR159w). All four open reading frames encode new proteins, as concluded from data base searches. The respective genes were destroyed by gene replacement in one allele of diploid cells. After sporulation and tetrad analysis, the resulting mutant haploid strains were investigated. No phenotype with respect to spore germination, viability, carbohydrate utilization, and growth was found for YBR157c, encoding the smallest open reading frame investigated. Gene replacement within the YBR156c gene encoding a highly basic and possibly nuclear located protein was lethal. Ybr158 revealed similarities to the Grrl (Cat80) protein with respect to the leucine-rich region. Cells harboring a mutation in the YBR158w gene showed strongly reduced growth as compared to the wild-type cells. The protein predicted from YBR159w shared 33% identical amino acid residues with the human estradiol 17-beta-hydroxysterol dehydrogenase 3. Haploid ybr159c mutants were only able to grow at reduced temperatures, but even under these conditions the mutants grew slower than wild-type strains.

Amino Acid Sequence↗
PubMed1988

Structure-function analysis of murine interferon-alpha: antiviral properties of novel hybrid interferons.

As described earlier the protein products of the murine interferon (IFN) genes MuIFN-alpha 1, -alpha 2, and -alpha 4 differ in their antiviral activity on hamster (CHO) and mouse (L929) cells. For structure-function analysis, hybrids were prepared between the three genes using common restriction enzyme sites. Natural and hybrid genes were transiently expressed in monkey COS cells. Under the conditions used IFN constituted 20-30% of the total amount of secreted proteins. Using a panel of hybrids either between alpha 1 and alpha 2 or between alpha 1, alpha 2, and alpha 4, the amino-terminal region of the protein, from amino acids 10 to 58, was found to determine its antiviral activity on hamster cells. On mouse cells, the antiviral activities of hybrids between alpha 4 and either alpha 1 or alpha 2 were compared. The high activity of alpha 4 (five to ten times that of alpha 1 or alpha 2) was not transmitted to hybrids having the amino-terminal part of alpha 4, but coincided with the presence of the alpha 4 carboxy-terminal region in all but one hybrid construct. The deletion of five amino acids (positions 103-107) located in this region of alpha 4 did not affect antiviral activity when introduced into MuIFN-alpha 2 and a MuIFN-alpha 42 hybrid by site-directed mutagenesis.

Animals↗
PubMed1985

Functional analysis of tight junction organization.

The functional basis of tight junction design has been examined from the point of view that this rate-limiting barrier to paracellular transport is a multicompartment system. Review of the osmotic sensitivity of these structures points to the need for this sort of analysis for meaningful correlation of structure and function under a range of conditions. A similar conclusion is drawn with respect to results from voltage-clamping protocols where reversal of spontaneous transmural potential difference elicits parallel changes in both structure and function in much the same way as does reversal of naturally occurring osmotic gradients. In each case, it becomes necessary to regard the junction as a functionally polarized structure to account for observations of its rectifying properties. Lastly, the details of experimentally-induced junction deformation are examined in light of current theories of its organization; arguments are presented in favor of the view that the primary components of intramembranous organization (as viewed with freeze-fracture techniques) are lipidic rather than proteinaceous.

Animals↗
PubMed1983

Psychotic and neurotic depression: discriminant function analysis and five-year outcome.

A consecutive series of 94 patients recently admitted to hospital from a defined catchment area and diagnosed as having a depressive illness were examined using standardized techniques for eliciting mental state, etc. The overlap between psychotic and neurotic diagnoses was 8.5% on discriminant function analysis of mental state items. A sub-sample of 71 patients was given a comprehensive postal and case record follow-up 5 years later. When patients developing organic and other complicating illnesses were excluded, those suffering from psychotic depression showed a significantly poorer outcome, as defined by relapse and required lengths of hospital care, than those diagnosed as suffering from neurotic depression.

Adult↗
PubMed1980

[Functional analysis of depressive states: integration of cognitive and behavioral contributions (author's transl)].

The article provides a review of the main contributions both of behaviorally--and cognitively--oriented litterature on depressive states and depressive behaviors. These various data are organised so as to form into a tool for the functional analysis of depression: symptoms--structures--releasing factors--mechanisms--maintaining and aggravating factors. Synthetic tables at the end of the article constitute a first attempt at a clinical report allowing the pratician to evaluate the contributions--as well as the limits--of a behavioral approach of the depression phenomenom.

Behavior↗