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1.
Nervenarzt ; 89(3): 300-310, 2018 Mar.
Article in German | MEDLINE | ID: mdl-29209753

ABSTRACT

BACKGROUND: Neuroleptic malignant syndrome (NMS) is a rare but severe undesired complication of psychopharmacological treatment. The mortality has shown a significant decrease since its first description. Knowledge of NMS is important for every clinician because of the need for rapid diagnosis and treatment. OBJECTIVE: This article presents a review and critical appraisal of the current study situation for NMS. Recommendations for diagnostics, differential diagnostics and treatment are presented particularly from a clinical perspective. MATERIAL AND METHODS: A literature review with the keywords "neuroleptic malignant syndrome", "Malignes neuroleptisches Syndrom" and various psychotropic drugs was performed in PubMed. The database of the Working Group for Pharmaceutical Treatment of Psychiatric Diseases (Arbeitsgemeinschaft für Arzneimitteltherapie bei psychiatrischen Erkrankungen, AGATE) was analyzed with respect to registered cases of the undesired side effect NMS. RESULTS: In contrast to the first description, which also led to the name, there are now case reports of clinical conditions similar to NMS, which were obviously triggered by several groups of psychotropic drugs not just antipsychotic agents (German: Neuroleptika). Treatment recommendations exist whereby the effectiveness cannot always be scientifically substantiated; however, it is still undisputed that a rapid initiation of treatment is of great importance. DISCUSSION: The psychiatrist must be familiar with the symptoms of NMS, its differential diagnosis and the therapeutic options for a rapid and effective treatment. Further studies are urgently needed for scientific substantiation of the pathophysiology of NMS and to develop evidence-based guidelines for treatment.


Subject(s)
Antipsychotic Agents/adverse effects , Mental Disorders/drug therapy , Neuroleptic Malignant Syndrome/diagnosis , Psychotic Disorders/drug therapy , Psychotropic Drugs/adverse effects , Adolescent , Adult , Aged , Aged, 80 and over , Antipsychotic Agents/therapeutic use , Child , Diagnosis, Differential , Diagnostic and Statistical Manual of Mental Disorders , Dopamine Agonists/adverse effects , Dopamine Agonists/therapeutic use , Drug Therapy, Combination/adverse effects , Female , Humans , International Classification of Diseases , Male , Middle Aged , Neuroleptic Malignant Syndrome/classification , Psychotropic Drugs/therapeutic use , Risk Factors , Young Adult
2.
Nervenarzt ; 89(1): 8-17, 2018 Jan.
Article in German | MEDLINE | ID: mdl-28251242

ABSTRACT

BACKGROUND: The symptom "delusions" is a central psychopathological symptom in psychiatric diseases. Since the beginning of psychiatry various disciplines have attempted to explain and understand delusions but even now no generally accepted definition of this phenomenon exists. AIM: A comprehensive review of current psychopathological and neurobiological theories of delusions is given. MATERIAL AND METHODS: PubMed and Google scholar searches were performed using the keywords "delusion", "psychodynamic" and "neurobiology", both in English and German. Relevant German textbooks of psychiatry were also included. DISCUSSION: A differentiated perspective of the phenomenon of delusions appears to be necessary to approach this complex and fascinating symptom. A one-dimensional approach does not do justice to the complexity of delusions. The various explanatory approaches can increasingly be linked to each other and are no longer considered to be mutually exclusive.


Subject(s)
Delusions/psychology , Neurocognitive Disorders/psychology , Psychoanalytic Theory , Capgras Syndrome/diagnosis , Capgras Syndrome/psychology , Capgras Syndrome/therapy , Delusions/diagnosis , Delusions/therapy , Diagnosis, Differential , Diagnostic and Statistical Manual of Mental Disorders , Early Diagnosis , Early Medical Intervention , Gestalt Theory , Humans , International Classification of Diseases , Neurocognitive Disorders/diagnosis , Neurocognitive Disorders/therapy , Psychopathology , Psychotic Disorders/diagnosis , Psychotic Disorders/psychology , Psychotic Disorders/therapy , Schizophrenic Psychology , Social Adjustment , Theory of Mind
3.
Chemistry ; 18(24): 7506-15, 2012 Jun 11.
Article in English | MEDLINE | ID: mdl-22504878

ABSTRACT

Short-lived pivaloylmetals, (H(3)C)(3)C-COM, were established as the reactive intermediates arising through thermal heterolytic expulsion of O=CtBu(2) from the overcrowded metal alkoxides tBuC(=O)-C(-OM)tBu(2) (M = MgX, Li, K). In all three cases, this fission step is counteracted by a faster return process, as shown through the trapping of tBu-COM by O=C(tBu)-C(CD(3))(3) with formation of the deuterated starting alkoxides. If generated in the absence of trapping agents, all three tBu-COM species "dimerize" to give the enediolates MO-C(tBu)=C(tBu)-OM along with O=CtBu(2) (2 equiv). A common-component rate depression by surplus O=CtBu(2) proves the existence of some free tBu-COM (separated from O=CtBu(2)); but companion intermediates with the traits of an undissociated complex such as tBu-COM & O=CtBu(2) had to be postulated. The slow fission step generating tBu-COMgX in THF levels the overall rates of dimerization, ketone addition, and deuterium incorporation. Formed by much faster fission steps, both tBu-COLi and tBu-COK add very rapidly to ketones and dimerize somewhat slower (but still fairly fast, as shown through trapping of the emerging O=CtBu(2) by H(3)CLi or PhCH(2)K, respectively). At first sight surprisingly, the rapid fission, return, and dimerization steps combine to very slow overall decay rates of the precursor Li and K alkoxides in the absence of trapping agents: A detailed study revealed that the fast fission step, generating tBu-COLi in THF, is followed by a kinetic partitioning that is heavily biased toward return and against the product-forming dimerization. Both tBu-COLi and tBu-COK form tBu-CH=O with HN(SiMe(3))(3), but only tBu-COK is basic enough for being protonated by the precursor acyloin tBuC(=O)-C(-OH)tBu(2) .

4.
Ultraschall Med ; 32 Suppl 1: S95-101, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20414858

ABSTRACT

PURPOSE: Transcranial perfusion sonography (TPS) is an emerging noninvasive bedside method for evaluating brain perfusion. The purpose was to assess the feasibility of a low MI/almost real-time frame rate approach and to test its intra-/interobserver variability. MATERIALS AND METHODS: 10 healthy volunteers were investigated 3 times with TPS at a low MI (1.0) and a high frame rate (8.3 Hz). Investigations were performed by 2 sonographers in a cross-over design: 1.) twofold measurements each with 5 volunteers (intraobserver test), and 2.) single measurements of the other 5 volunteers (interobserver test). From 8 established regions of interest (ROI), time-intensity curves (TIC) with the following parameters were calculated: peak intensity (PI), time-to-PI (TTP), area-under-curve (AUC), and cerebral transit time (CTT). The TIC quality was described by the coefficient of determination. TIC parameters were presented descriptively. Intra- and interobserver variability was tested by Spearman's correlation. RESULTS: The overall quality of the TIC was very good (mean r(2) = 0.92, 0.87 - 0.97). TTP (25.7 - 28.1 sec; mean 26.8 sec) and CTT (8.2 - 10.7 sec; mean 9.9 sec) were the most robust parameters. The intraobserver variability was lower with the more experienced sonographer (r = 0.70 vs. r = 0.29). The interobserver reliability was r = 0.34 (p < 0.05). CONCLUSION: Low MI TPS allows for nearly real-time imaging facilitating probe control. Sound sonographer experience allows for a high reliability and makes TPS an interesting tool for the diagnosis and follow-up of perfusion changes, e. g. in stroke or anti-angiogenic brain tumor therapy.


Subject(s)
Brain/blood supply , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Ultrasonography, Doppler, Color/methods , Ultrasonography, Doppler, Transcranial/methods , Adult , Blood Flow Velocity/physiology , Contrast Media/administration & dosage , Dominance, Cerebral/physiology , Female , Humans , Linear Models , Male , Observer Variation , Phospholipids , Reference Values , Regional Blood Flow/physiology , Software , Sulfur Hexafluoride
5.
J Anim Physiol Anim Nutr (Berl) ; 90(7-8): 269-77, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16867072

ABSTRACT

We evaluated whether a probiotic supplementation in dogs with food responsive diarrhoea (FRD) has beneficial effects on intestinal cytokine patterns and on microbiota. Twenty-one client-owned dogs with FRD were presented for clinically needed duodeno- and colonoscopy and were enrolled in a prospective placebo (PL)-controlled probiotic trial. Intestinal tissue samples and faeces were collected during endoscopy. Intestinal mRNA abundance of interleukin (IL)-5, -10, -12p40 and -13, tumour necrosis factor-alpha, transforming growth factor-beta1 and interferon (IFN)-gamma were analysed and numbers of Lactobacillus spp., Bifidobacterium spp., Enterococcus spp. and Enterobacteriaceae and supplemented probiotic bacteria were determined in faeces. The Canine Inflammatory Bowel Disease Activity Index, a scoring system comprising general attitude, appetite, faecal consistency, defecation frequency, and vomitus, decreased in all dogs (p < 0.0001). Duodenal IL-10 mRNA levels decreased (p = 0.1) and colonic IFN-gamma mRNA levels increased (p = 0.08) after probiotic treatment. Numbers of Enterobacteriaceae decreased in FRD dogs receiving probiotic cocktail (FRD(PC)) and FRD dogs fed PL (FRD(PL)) during treatment (p < 0.05), numbers of Lactobacillus spp. increased in FRD(PC after) when compared with FRD(PC before) (p < 0.1). One strain of PC was detected in five of eight FRD(PC) dogs after probiotic supplementation. In conclusion, all dogs clinically improved after treatment, but cytokine patterns were not associated with the clinical features irrespective of the dietary supplementation.


Subject(s)
Colon/microbiology , Cytokines/biosynthesis , Diarrhea/veterinary , Dog Diseases/drug therapy , Duodenum/microbiology , Probiotics , Animal Feed , Animal Nutritional Physiological Phenomena , Animals , Bifidobacterium/growth & development , Colon/immunology , Colon/pathology , Diarrhea/drug therapy , Diarrhea/microbiology , Diarrhea/pathology , Dietary Supplements , Dog Diseases/microbiology , Dog Diseases/pathology , Dogs , Double-Blind Method , Duodenum/immunology , Duodenum/pathology , Enterobacteriaceae/growth & development , Enterococcus/growth & development , Feces/microbiology , Female , Food Hypersensitivity/drug therapy , Food Hypersensitivity/microbiology , Food Hypersensitivity/pathology , Food Hypersensitivity/veterinary , Lactobacillus/growth & development , Male , Prospective Studies , RNA, Messenger/metabolism , Severity of Illness Index , Treatment Outcome
6.
Dev Dyn ; 222(3): 410-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11747076

ABSTRACT

Endomucin is a recently identified sialomucin that is specifically expressed on endothelium of the adult mouse. Here, we have analysed the expression of endomucin during development of the vascular system by immunohistochemistry by using three monoclonal antibodies (mAb). We demonstrate that two of the mAb, V.5C7 and V.1A7, recognize epitopes on the nonglycosylated protein, because they recognize the antigen when it is synthesized as a bacterial fusion protein and when it is in vitro translated in a membrane-free reticulocyte lysate. During in vitro differentiation of embryonic stem cells to endothelial cells, endomucin is expressed at day 6 after onset of differentiation, 1 day later than PECAM-1. During differentiation of the mouse embryo, endomucin is first detected at E8.0 in all embryonic blood vessels detectable at this stage but is absent in blood islands of the yolk sac. Analysing the paraaortic-splanchnopleura (P-SP) region and the aorta-gonad-mesonephros (AGM) region as sites of intraembryonic hematopoiesis, we found that endothelium of the dorsal aorta is brightly positive for endomucin at E8.5-9.0 and at E11.5. At later stages and in the adult aorta, endothelial staining is strongly reduced and confined to focal areas. Cell clusters associated with the luminal surface of the endothelium of the dorsal aorta could be stained for endomucin and for CD34. At a later stage (E15.5) single leukocytes in the lumen of large venules were stained for endomucin. We conclude that endomucin is an early endothelial-specific antigen that is also expressed on putative hematopoietic progenitor cells.


Subject(s)
Aorta/embryology , Endothelium, Vascular/embryology , Hematopoietic Stem Cells/metabolism , Mucins/metabolism , Animals , Cell Aggregation , Cell Differentiation , Embryo, Mammalian/metabolism , Epitopes , Hematopoietic Stem Cells/cytology , Hematopoietic Stem Cells/physiology , Immunohistochemistry , Mice/embryology , Mucins/immunology , Sialomucins
7.
Microbiol Res ; 156(3): 267-77, 2001.
Article in English | MEDLINE | ID: mdl-11716215

ABSTRACT

In the metabolism of Lactobacillus sanfranciscensis, the acetate kinase (AK) is a key enzyme and responsible for dephosphorylation of acetyl phosphate with the concomitant production of acetate and ATP. The L. sanfranciscensis ack gene was identified by PCR methods. It encodes a 397 amino acid protein sharing 56% similarity with Bacillus subtilis AK. Whereas cotranscription of ack and pta (phosphotransacetylase) is reported in previously characterised organisms, the L. sanfranciscensis ack gene is not located in direct neighbourhood to the encoding gene. AK was heterologously expressed in E. coli and characterised by its v(max) and Km values and by the dependence of enzyme activity on temperature and pH. Based on this data the in vivo role of the enzyme is discussed.


Subject(s)
Acetate Kinase/genetics , Lactobacillus/genetics , Acetate Kinase/metabolism , Acetates/metabolism , Adenosine Triphosphate/biosynthesis , Amino Acid Sequence , Cloning, Molecular , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Escherichia coli/genetics , Gene Expression Regulation, Bacterial , Gene Expression Regulation, Enzymologic , Hydrogen-Ion Concentration , Kinetics , Lactobacillus/enzymology , Lactobacillus/metabolism , Molecular Sequence Data , Organophosphates/metabolism , Phosphorylation , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Temperature
8.
J Basic Microbiol ; 41(6): 339-49, 2001.
Article in English | MEDLINE | ID: mdl-11802544

ABSTRACT

The phosphotransacetylase (PTA) (EC 2.3.1.8) catalyzes a key branch point reaction in the carbohydrate pathway of Lactobacillus sanfranciscensis. In this report, we describe the cloning of the pta gene. The DNA sequence analysis revealed a 987 bp open reading frame encoding a protein with a molecular mass of 35.5 kD. These are the first studies on a PTA of an organism representative for the heterofermentative lactic acid bacteria. Unlike in most other bacteria analysed so far, in L. sanfranciscensis the pta gene is not adjacent located to the gene encoding acetate-kinase. The PTA was heterologously expressed as a biotinylated fusion protein in E. coli and purified to homogeneity. Rate dependence on all substrates followed Michaelis-Menten kinetics. The apparent Km values for acetylphosphate and CoA (forward reaction) were 1.3 and 0.1 mM, respectively. The apparent Vmax was 194 U/mg. The enzyme also catalyzed in vitro the reverse reaction with apparent Km values for acetylCoA and phosphate of 0.6 and 6.7 mM, respectively (Vmax of 38 U/mg). The PTA showed a wide range of temperature for optimal activity (49 degrees C to 58 degrees C). It was inactivated after 15 min at 60 degrees C. Its activity was not affected by addition of MgCl2 (10 mM) or KCl (100 mM).


Subject(s)
Lactobacillus/enzymology , Phosphate Acetyltransferase/genetics , Amino Acid Sequence , Cloning, Molecular , Molecular Sequence Data , Phosphate Acetyltransferase/chemistry , Phosphate Acetyltransferase/metabolism , Temperature
9.
Antonie Van Leeuwenhoek ; 76(1-4): 403-11, 1999.
Article in English | MEDLINE | ID: mdl-10532397

ABSTRACT

Sourdough is the foremost cereal fermentation performed in a variety of technologies with almost any cereal. The lactobacilli studied most intensely include Lactobacillus sanfranciscensis, L. reuteri and L. pontis isolated from traditional and modern rye and wheat fermentations. Molecular biology tools are available for their rapid identification and monitoring throughout a process. The currently available insight on their metabolism can be used to explain their prevalence in this environment and their interactions. Key genes of the sugar degradation pathway were cloned and characterised from L. sanfranciscensis. In addition some strains were found to have special properties including the production of antagonistic compounds or the adhesion to human intestinal cells.


Subject(s)
Edible Grain/microbiology , Lactobacillus/physiology , Bacterial Adhesion , Fermentation , Humans , Intestinal Mucosa/microbiology , Intestinal Mucosa/physiology , Lactobacillus/genetics , Maltose/metabolism , Molecular Biology/methods , Secale/microbiology , Triticum/microbiology
10.
J Immunol ; 159(6): 2685-92, 1997 Sep 15.
Article in English | MEDLINE | ID: mdl-9300688

ABSTRACT

We examined binding of soluble intercellular adhesion molecule-1 (ICAM-1) dimers and a range of ICAM-1-coated particles to activated T cells. Lymphocyte function-associated antigen-1 (LFA-1) on the surface of activated T cells did not bind soluble ICAM-1 dimers with high affinity. In contrast, activated T cells adhered avidly to ICAM-1-coated planar surfaces. Between these two extremes, a range of ICAM-1-bearing particles was tested for binding. Activated T cells bound particles of 1-microm diameter or larger, but did not bind particles of 0.5-microm diameter or smaller. This threshold was eliminated, and all forms of ICAM-1 bound to LFA-1 when LFA-1 was converted to a high affinity form with an activating antibody. We show that high affinity LFA-1 is generated only as a consequence of an initial low affinity interaction of LFA-1 with ICAM-1 under physiological conditions. Therefore, the selectivity of cell surface LFA-1 for cell-sized particles bearing ICAM-1 appears to be due to the maintenance of low affinity LFA-1 on the surface of activated T cells. These findings alter the definition of inside-out signaling for LFA-1.


Subject(s)
Cell Communication/immunology , Intercellular Adhesion Molecule-1/metabolism , Lymphocyte Activation/immunology , Lymphocyte Function-Associated Antigen-1/metabolism , T-Lymphocytes/immunology , Cell Adhesion/immunology , Cells, Cultured , Flow Cytometry , Humans , T-Lymphocytes/metabolism
11.
J Exp Med ; 186(5): 719-30, 1997 Aug 29.
Article in English | MEDLINE | ID: mdl-9271587

ABSTRACT

The I domain of lymphocyte function-associated antigen (LFA)-1 contains an intercellular adhesion molecule (ICAM)-1 and ICAM-3 binding site, but the relationship of this site to regulated adhesion is unknown. To study the adhesive properties of the LFA-1 I domain, we stably expressed a GPI-anchored form of this I domain (I-GPI) on the surface of baby hamster kidney cells. I-GPI cells bound soluble ICAM-1 (sICAM-1) with a low avidity and affinity. Flow cell experiments demonstrated a specific rolling interaction of I-GPI cells on bilayers containing purified full length ICAM-1 or ICAM-3. The LFA-1 activating antibody MEM-83, or its Fab fragment, decreased the rolling velocity of I-GPI cells on ICAM-1-containing membranes. In contrast, the interaction of I-GPI cells with ICAM-3 was blocked by MEM-83. Rolling of I-GPI cells was dependent on the presence of Mg2+. Mn2+ only partially substituted for Mg2+, giving rise to a small fraction of rolling cells and increased rolling velocity. This suggests that the I domain acts as a transient, Mg2+-dependent binding module that cooperates with another Mn2+-stimulated site in LFA-1 to give rise to the stable interaction of intact LFA-1 with ICAM-1.


Subject(s)
Antigens, CD , Antigens, Differentiation , Cell Adhesion Molecules/metabolism , Intercellular Adhesion Molecule-1/metabolism , Lymphocyte Function-Associated Antigen-1/chemistry , T-Lymphocytes/metabolism , Animals , Antibodies, Monoclonal/immunology , Binding Sites , Binding, Competitive , Blotting, Western , Cell Adhesion , Cell Line , Cell Movement , Cloning, Molecular , Cricetinae , Glycosylphosphatidylinositols/chemistry , Glycosylphosphatidylinositols/genetics , Glycosylphosphatidylinositols/metabolism , Lymphocyte Function-Associated Antigen-1/genetics , Lymphocyte Function-Associated Antigen-1/metabolism , Magnesium/pharmacology , Microscopy, Video , Phosphatidylinositol Diacylglycerol-Lyase , T-Lymphocytes/immunology , Tumor Cells, Cultured , Type C Phospholipases/metabolism
12.
Arch Environ Health ; 51(4): 266-74, 1996.
Article in English | MEDLINE | ID: mdl-8757406

ABSTRACT

Possible associations between adult leukemia incidence and proximity-based surrogate measures of potential for exposure to radioactive emissions from the Pilgrim nuclear power plant in Plymouth, Massachusetts, were investigated. Included in this study were 105 nonchronic lymphocytic leukemia cases, diagnosed between 1978 and 1986 at age 13 y or older, that occurred in 22 towns near Pilgrim; population controls numbered 208. Residence within 4 mi (6.4 km) of Pilgrim during "high-emissions" years was related to case-control status (adjusted odds ratio [OR] = 3.88, 95% confidence interval [95% CI] = 0.81-10.64). A high "exposure" score (i.e., a value that accounted for downwind time) was also related to case-control status (OR = 3.46, 95% CI = 1.50-7.96). Some statistically significant dose-response trends were found. Cautious interpretation of associations is warranted in light of the low levels of reported emissions.


Subject(s)
Air Pollution, Radioactive/adverse effects , Environmental Exposure/adverse effects , Leukemia/epidemiology , Power Plants , Residence Characteristics , Adolescent , Adult , Aged , Aged, 80 and over , Air Pollution, Radioactive/statistics & numerical data , Case-Control Studies , Confounding Factors, Epidemiologic , Dose-Response Relationship, Radiation , Environmental Exposure/statistics & numerical data , Female , Humans , Incidence , Leukemia/etiology , Male , Massachusetts/epidemiology , Middle Aged , Power Plants/statistics & numerical data , Random Allocation , Residence Characteristics/statistics & numerical data
13.
J Clin Microbiol ; 34(5): 1086-90, 1996 May.
Article in English | MEDLINE | ID: mdl-8727881

ABSTRACT

Ribotyping is a molecular method for the characterization, identification, and typing of bacterial isolates that has value in epidemiological studies. To demonstrate the utility of this technique for typing of Listeria monocytogenes, four outbreaks of epizootic listeriosis in ruminants were investigated through coordinated detection and characterization methods utilizing classical microbiology and nucleic acid-based techniques. L. monocytogenes strains isolated from clinical samples and the silage consumed by the affected animals were ribotyped to establish the causal relationship between feed and the disease outbreak. For all but one outbreak, we were able to isolate L. monocytogenes strains represented by the same ribotype from both clinical and silage samples. Additional L. monocytogenes strains with ribotypes different from those of the respective clinical samples were isolated from all silage samples. This indicates that a diverse population of L. monocytogenes strains exists in farm environments, of which some may be more likely than others to cause disease.


Subject(s)
Disease Outbreaks/veterinary , Listeria monocytogenes/classification , Listeria monocytogenes/genetics , Listeriosis/veterinary , Abortion, Veterinary/epidemiology , Abortion, Veterinary/microbiology , Animal Feed/microbiology , Animals , Bacterial Typing Techniques , Cattle , Cattle Diseases/epidemiology , Cattle Diseases/microbiology , Female , Genetic Variation , Goat Diseases/epidemiology , Goat Diseases/microbiology , Goats , Listeria monocytogenes/isolation & purification , Listeriosis/epidemiology , Listeriosis/microbiology , Polymerase Chain Reaction , Pregnancy , Sheep , Sheep Diseases/epidemiology , Sheep Diseases/microbiology
14.
J Exp Med ; 182(5): 1231-41, 1995 Nov 01.
Article in English | MEDLINE | ID: mdl-7595194

ABSTRACT

Intercellular adhesion molecule-1 (ICAM-1, CD54) is a ligand for the integrins lymphocyte function associated-1 (LFA-1, CD11a/CD18) and complement receptor-3 (Mac-1, CD11b/CD18) making it an important participant in many immune and inflammatory processes. Modified recombinant soluble ICAM-1 formed dimers. This result indicated that the ectodomain of ICAM-1 contains homophilic interaction sites. Soluble ICAM-1 dimers bind to solid-phase purified LFA-1 with high avidity (dissociation constant [Kd] = 8 nM) in contrast to soluble ICAM-1 monomers whose binding was not measurable. Cell surface ICAM-1 was found to be dimeric based on two distinct criteria. First, a monoclonal antibody specific for monomeric soluble ICAM-1, CA7, binds normal ICAM-1 poorly at the cell surface; this antibody, however, binds strongly to two mutant forms of ICAM-1 when expressed at the cell surface, thus identifying elements required for dimer formation. Second, chemical cross-linking of cell surface ICAM-1 on transfected cells and tumor necrosis factor-activated endothelial cells results in conversion of a portion of ICAM-1 to a covalent dimer. Cell surface ICAM-1 dimers are more potent ligands for LFA-1-dependent adhesion than ICAM-1 monomers. While many extracellular matrix-associated ligands of integrins are multimeric, this is the first evidence of specific, functionally important homodimerization of a cell surface integrin ligand.


Subject(s)
Cell Adhesion , Intercellular Adhesion Molecule-1/chemistry , Lymphocyte Function-Associated Antigen-1/physiology , Protein Conformation , Animals , Antibodies, Monoclonal/immunology , B-Lymphocytes/cytology , Cell Line, Transformed , Cells, Cultured , Chlorocebus aethiops , Cricetinae , Endothelium, Vascular/cytology , Humans , Intercellular Adhesion Molecule-1/immunology , Intercellular Adhesion Molecule-1/physiology , Protein Binding , Recombinant Proteins/chemistry , Solubility
15.
Appl Environ Microbiol ; 61(10): 3724-8, 1995 Oct.
Article in English | MEDLINE | ID: mdl-7487008

ABSTRACT

A PCR-based assay for Listeria monocytogenes that uses the hydrolysis of an internal fluorogenic probe to monitor the amplification of the target has been formatted. The fluorogenic 5' nuclease PCR assay takes advantage of the endogenous 5' --> 3' nuclease activity of Taq DNA polymerase to digest a probe which is labelled with two fluorescent dyes and hybridizes to the amplicon during PCR. When the probe is intact, the two fluorophores interact such that the emission of the reporter dye is quenched. During amplification, the probe is hydrolyzed, relieving the quenching of the reporter and resulting in an increase in its fluorescence intensity. This change in reporter dye fluorescence is quantitative for the amount of PCR product and, under appropriate conditions, for the amount of template. We have applied the fluorogenic 5' nuclease PCR assay to detect L. monocytogenes, using an 858-bp amplicon of hemolysin (hlyA) as the target. Maximum sensitivity was achieved by evaluating various fluorogenic probes and then optimizing the assay components and cycling parameters. With crude cell lysates, the total assay could be completed in 3 h with a detection limit of approximately 50 CFU. Quantification was linear over a range of 5 x 10(1) to 5 x 10(5) CFU.


Subject(s)
Fluorescent Dyes , Listeria monocytogenes/genetics , Listeria monocytogenes/isolation & purification , Polymerase Chain Reaction/methods , Animals , Base Sequence , DNA Probes/genetics , DNA-Directed DNA Polymerase , Evaluation Studies as Topic , Humans , Molecular Sequence Data , Polymerase Chain Reaction/statistics & numerical data , Sensitivity and Specificity , Taq Polymerase
16.
Eur J Biochem ; 228(2): 297-304, 1995 Mar 01.
Article in English | MEDLINE | ID: mdl-7705342

ABSTRACT

The protein auxilin is a coat component of brain clathrin-coated vesicles. It interacts directly with the heavy chain of clathrin and supports its assembly into regular cages [Ahle, S. & Ungewickell, E. (1990) J. Cell Biol. 111, 19-29]. The combined open reading frames of three cow brain cDNA clones with a total of 4531 nucleotides predict a molecular mass of 99,504 Da for auxilin. The coding region is followed by a very long untranslated region of at least 1670 nucleotides. By Northern analysis, auxilin transcripts are found only in brain tissue. Auxilin is not related to any of the previously sequenced clathrin-binding proteins, but the region of positions 50-350 is 29% identical (similarity 56%) to the corresponding region of the actin-binding protein tensin from chicken fibroblasts. Recombinant auxilin expressed in and purified from bacteria by affinity chromatography is functional with respect to clathrin binding.


Subject(s)
Clathrin/chemistry , Nerve Tissue Proteins/chemistry , Phosphoproteins/chemistry , Adaptor Proteins, Vesicular Transport , Amino Acid Sequence , Animals , Base Sequence , Cattle , Chickens , Cloning, Molecular , Escherichia coli/genetics , Microfilament Proteins/chemistry , Molecular Sequence Data , Nerve Tissue Proteins/biosynthesis , Nerve Tissue Proteins/genetics , Phosphoproteins/biosynthesis , Phosphoproteins/genetics , RNA, Messenger/analysis , Recombinant Proteins/biosynthesis , Tensins
19.
Nature ; 356(6372): 799-801, 1992 Apr 30.
Article in English | MEDLINE | ID: mdl-1574119

ABSTRACT

The CD4 and CD8 molecules are transmembrane glycoproteins expressed by functionally distinct subsets of mature T cells. CD4+ and CD8+ T cells recognize antigens on major histocompatibility complex (MHC) class II-bearing and class I-bearing target cells respectively. The ability of monoclonal antibodies against CD4 and CD8 to block antigen recognition by T cells, as well as cell-cell adhesion assays, indicate that CD4 and CD8 bind to nonpolymorphic determinants of class II or class I MHC. Here we demonstrate that soluble recombinant HLA-DR4 molecules from insect cells and HLA-DR-derived peptides bind to immobilized recombinant soluble CD4. CD4 binds recombinant soluble DR4 heterodimers, as well as the soluble DR4-beta chain alone. Furthermore, two out of twelve DR4-beta peptides could interact specifically with CD4. These findings show that CD4 interacts with a region of MHC class II molecules analogous to a previously identified loop in class I MHC proteins that binds CD8 (refs 8, 9).


Subject(s)
CD4 Antigens/metabolism , HLA-DR4 Antigen/metabolism , Amino Acid Sequence , Animals , Binding Sites , Chromatography, Affinity , Immunoblotting , In Vitro Techniques , Insecta , Molecular Sequence Data , Polymerase Chain Reaction , Recombinant Proteins/metabolism , Substrate Specificity
20.
Vaccine ; 9(7): 512-4, 1991 Jul.
Article in English | MEDLINE | ID: mdl-1716809

ABSTRACT

It has been shown that pre-immunization with a protein can inhibit the antibody response to a new B-cell sequence which is coupled to the protein (epitope-specific suppression). By utilizing a peptide with carrier function from the protein, rather than the entire protein, the antibody response to the new B-cell sequence is enhanced in protein-primed mice. The present results extend this observation by showing that mice which have been pre-immunized with a protein followed by a B-cell sequence linked to a carrier peptide from the protein produce an enhanced antibody response to a new B-cell sequence linked to the same carrier peptide sequence. This indicates that it would be possible to reuse a carrier peptide sequence coupled with newly defined protective B-cell epitopes in a given individual to achieve immunity against new pathogens.


Subject(s)
Antibody Formation , Antigens, Protozoan/immunology , Immunization , Peptide Fragments/immunology , Protozoan Proteins , Tetanus Toxoid/immunology , Adjuvants, Immunologic , Amino Acid Sequence , Animals , B-Lymphocytes/immunology , Enzyme-Linked Immunosorbent Assay , Epitopes/immunology , Female , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Muramidase/immunology , Plasmodium falciparum/immunology
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