The interaction of bacterial endotoxins, deep rough mutant lipopolysaccharide LPS Re and the 'endotoxic principle' lipid A, with recombinant human serum albumin (rHSA) was investigated with a variety of physical techniques and biological assays. With Fourier-transform infrared spectroscopy and differential scanning calorimetry, the influence of albumin on the acyl chain melting behavior of the endotoxins was measured. Also, the effect on the functional groups of the endotoxins, in particular with respect to their orientation, was studied, including competition experiments with polymyxin B.
View Article and Find Full Text PDFWe used phage display to generate surrogate peptides that define the hotspots involved in protein-protein interaction between insulin and the insulin receptor. All of the peptides competed for insulin binding and had affinity constants in the high nanomolar to low micromolar range. Based on competition studies, peptides were grouped into non-overlapping Sites 1, 2, or 3.
View Article and Find Full Text PDFSialic acids are a group of carboxylated amino sugars important for a variety of cellular functions. N-Acetylneuraminic acid (Neu5Ac) is the predominant sialic acid in nature. Neu5Ac-9-phosphate synthase catalyzes the formation of Neu5Ac-9-phosphate from N-acetylmannosamine-6-phosphate and phosphoenolpyruvate.
View Article and Find Full Text PDFJ Renin Angiotensin Aldosterone Syst
June 2001
Angiotensin II (Ang II) acts as a neuromodulator/neurotransmitter in specific brain nuclei involved in the regulation of blood pressure and volume homeostasis. It also induces a highly differentiated transcription factor expression in these nuclei. We investigated whether adrenoceptors, which modulate other central actions of angiotensin II like the vasopressin release, also play a role in the AT1 receptor-mediated expression of the transcription factors (TF) c-Fos, c-Jun and Krox-24 in the rat brain.
View Article and Find Full Text PDFBackground: Modern drug discovery is concerned with identification and validation of novel protein targets from among the 30,000 genes or more postulated to be present in the human genome. While protein-protein interactions may be central to many disease indications, it has been difficult to identify new chemical entities capable of regulating these interactions as either agonists or antagonists.
Results: In this paper, we show that peptide complements (or surrogates) derived from highly diverse random phage display libraries can be used for the identification of the expected natural biological partners for protein and non-protein targets.
Substance P, the principal neurokinin peptide in the mammalian brain and the natural ligand for the NK(1) tachykinin receptor, plays an integrative role in the regulation of cardiovascular, neuroendocrine and behavioural responses to stress. In rats, stimulation of periventricular NK(1) receptors in the forebrain induces a distinct pattern of cardiovascular responses which is accompanied by intense grooming behaviour. Ligands for NK(3) receptors induce a different pattern of cardiovascular and behavioural responses which comprises an increased release of vasopressin from the posterior pituitary and wet-dog shakes behaviour.
View Article and Find Full Text PDFTo elucidate how enzymes adapt to extreme environmental conditions, a comparative study with a thermostable alpha-amylase from Bacillus licheniformis (BLA) and its mesophilic homologue from Bacillus amyloliquefaciens (BAA) was performed. We measured conformational stability, catalytic activity, and conformational fluctuations on the picosecond time scale for both enzymes as a function of temperature. The objective of this study is to analyze how these properties are related to each other.
View Article and Find Full Text PDFObjectives: This study examined long-term response to an individual preventive intervention for high-risk college drinkers relative to the natural history of college drinking.
Methods: A single-session, individualized preventive intervention was evaluated within a randomized controlled trial with college freshmen who reported drinking heavily while in high school. An additional group randomly selected from the entire screening pool provided a normative comparison.
Objectives: This study investigated the role of angiotensin receptor subtype 1 (AT1) and angiotensin receptor subtype 2 (AT2) in the regulation of Na+-H+ exchanger (NHE) and Na+-HCO3 symporter (NBC) in the infarcted myocardium.
Background: The cardiac renin-angiotensin system is activated after myocardial infarction (MI), and both angiotensin AT1 and AT2 receptors are upregulated in the myocardium.
Methods: Na+-H+ exchanger isoform-1 and NBC-1 gene expression were determined by reverse transcription polymerase chain reaction and Northern blot analysis; protein levels by Western blot analysis; and activity by measurement of H+ transport in left ventricular (LV) free wall, interventricular septum (IS) and right ventricle (RV) after induction of MI.
J Psychoactive Drugs
September 2001
One-size-fits-all therapy has not worked well for a majority of substance users seeking help. New approaches to substance abuse treatment are desperately needed. Traditional models of service delivery offer little, if any, help to people who may not choose abstinence as a goal.
View Article and Find Full Text PDFAddict Behav
October 2001
Depression often hinders behavior change among people who abuse alcohol; it adversely affects self-efficacy and is associated with poor outcomes. However, the Transtheoretical Stages of Change Model suggests that personal discomfort, namely if the costs of drinking outweigh the benefits, may lead to behavior change. Often such alcohol-related consequences are associated with depression.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
April 2001
ANG II has been implicated in neuroplastic processes via stimulation of inducible transcription factors (ITF) in the brain. In the present study, we investigated the effects of acute vs. repetitive once daily intracerebroventricular injections of ANG II for 7 days on the expression of ITF and constitutive transcription factor (CTF) and the AT1 receptor in the median preoptic area (MnPO), the subfornical organ (SFO), and the hypothalamic paraventricular (PVN) and supraoptic nuclei (SON).
View Article and Find Full Text PDFCurr Opin Nephrol Hypertens
March 2001
The signalling mechanisms and biological significance of the angiotensin II type 2 receptor have long been unknown. In recent years, studies, first in cell culture models but now increasingly also in vivo, have shed some light on the molecular events occurring after a stimulation of the receptor with its ligand as well as on its physiological effects and its significance for pathophysiological processes. There is increasing evidence that the angiotensin II type 2 receptor is involved in different pathophysiological processes, such as myocardial infarction, heart and kidney failure, and stroke.
View Article and Find Full Text PDFBiochem Soc Trans
December 2000
A previously cloned cDNA from Helianthus annuus codes for a fusion protein composed of an N-terminal cytochrome b(5) and a C-terminal desaturase domain. For a functional identification, this cDNA was expressed in Saccharomyces cerevisiae and the structures of sphingolipid long-chain bases were analysed. The expression of this sunflower enzyme resulted in the formation of new Delta(8)-trans/cis-phytosphingenine from C(18)- and C(20)-phytosphinganine present in wild-type yeast cells.
View Article and Find Full Text PDFThe Diogenesis Process is an integrated drug discovery platform that allows target validation, partner identification, and the identification of small molecule drug candidates for protein:protein interactions. Diogenesis utilizes the well-established methods of peptide display, synthetic and recombinant peptide production, in vitro biochemical and cell-based testing to form a universal drug discovery engine with distinct advantages over competing protocols. The process creates a library of diverse peptides, and selects rare and unique binders that identify and simplify surface "hot spots" on protein targets through which target activity can be regulated.
View Article and Find Full Text PDFPsychol Addict Behav
September 2000
Executive cognitive functions (ECFs) seem important for motivating change and self-regulation of problem drinking. Evidence for executive cognitive deficits have been found among heavy-drinking college students. Although college students who abuse alcohol often experience a variety of negative consequences related to their drinking behavior, executive cognitive dysfunction may interfere with recognizing consequences and responding skillfully to avoid future harm.
View Article and Find Full Text PDFBrain Res Mol Brain Res
May 2000
To investigate the influence of AT(2) receptor stimulation on the ERK pathway and elucidate potential mechanisms of angiotensin II (ANG II)-mediated neuronal differentiation, we analysed tyrosine phosphorylation and activity of ERK after ANG II treatment of both quiescent and NGF-treated PC12W cells. Tyrosine phosphorylation of ERK1 and ERK2 corresponded with the activity of ERK. While ANG II induced an initial activation of ERK in quiescent cells, the NGF-mediated plateau of ERK-stimulation was lowered by costimulation with ANG II.
View Article and Find Full Text PDFThe transtheoretical model posits that contemplating change in substance abuse involves weighing the costs of substance use against the benefits. One of the common aversive consequences of substance misuse is personal loss. Indeed, higher total number of losses of unspecified recency and importance have predicted greater motivation to change substance use patterns.
View Article and Find Full Text PDFNonadherence with asthma medications is a significant problem associated with unnecessary functional limitations. The development of measures to assess psychological factors important to adherence with medication regimens among adult patients with asthma is described in the present report. The results indicated that the reliability and validity of the newly designed measures were adequate.
View Article and Find Full Text PDFThe interaction of aqueous phospholipid dispersions of negatively charged 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol, sodium salt (DMPG) with the divalent cations Mg(2+), Ca(2+) and Sr(2+) at equimolar ratios in 100 mM NaCl at pH 7 was investigated by Fourier transform infrared spectroscopy. The binding of the three cations induces a crystalline-like gel phase with highly ordered and rigid all-trans acyl chains. These features are observed after storage below room temperature for 24 h.
View Article and Find Full Text PDFDepression is the most common comorbid psychiatric illness in patients with alcohol dependence. This double-blind study tested the efficacy of nefazodone versus placebo for the treatment of depression in actively drinking alcohol-dependent patients who were also participating in weekly group treatment for alcoholism. Sixty-four subjects with major depression disorder and alcohol dependence with a history of at least one prior episode of depression when not drinking were randomly assigned to receive 12 weeks of either nefazodone or placebo and participated in a weekly psychoeducational group on alcoholism.
View Article and Find Full Text PDFWe have examined the mixing properties of phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), the major components of many bacterial membranes. The phase transition behavior of dilute aqueous suspensions of PE:PG mixtures with different chain lengths (n = 14, 16) in 0.1 M NaCl at pH 7 and pH 2 was investigated by differential scanning calorimetry (DSC).
View Article and Find Full Text PDFJ Psychoactive Drugs
September 1999
Substance abuse has been associated with cognitive dysfunction, such as problems with attention, reasoning, and memory. Certain psychiatric disorders also have been associated with cognitive difficulties, thus placing dually-diagnosed patients at high risk for cognitive impairment that could interfere with successful entry into or completion of therapy. Twenty-two dually-disordered inpatients were administered the Brief Readiness to Change Questionnaire to measure levels of motivation to change substance use, and a neuropsychological test battery that included the Wechsler Adult Intelligence Scale-Revised (WAIS-R), the Halstead Category Test (HCT), and the Wechsler Memory Scale-Revised (WMS-R).
View Article and Find Full Text PDFDifferential scanning calorimetry (DSC) and film balance measurements were performed to study the interactions of the GalNAcbeta1-->4(NeuAcalpha2-->3)Galbeta1-->4Glc1 -->1'Cer (GM2)-activator protein with phospholipid/ganglioside vesicles and monolayers. The nonglycosylated form of the GM2-activator protein, added to unilamellar lipid vesicles of different composition, causes differential effects on the gel to liquid-crystalline phase transition peaks. The phase transition temperature (Tm) of pure dimyristoylglycerophosphocholine (DMPC) bilayer is slightly decreased.
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