Aminotetralin drugs and D3 receptor functions. What may partially selective D3 receptor ligands tell us about dopamine D3 receptor functions?

The dopamine D3 receptor gene was identified by Sokoloff and colleagues in 1990. This finding rapidly gained the interest of the scientific community because this unexpected dopamine receptor subtype may play an important role in the antipsychotic activity of neuroleptic drugs. It recognizes most neuroleptics with a high affinity, and its brain distribution is restricted mainly to the ventral part of the striatal complex.

Phylogenetic inferences from chloroplast chlB gene sequences of Nephrolepis exaltata (Filicopsida), Ephedra altissima (Gnetopsida), and diverse land plants.

The chloroplast chlB gene, involved in light-independent protochlorophyllide reduction, has been reported present in algae, in one bryophyte and some gymnosperms, but absent from various angiosperms. In this study, the complete or nearly complete chlB gene sequences from the fern Nephrolepis exaltata and the seed plant Ephedra altissima were determined. Comparison of five available land plant chlB sequences with a similar set of rbcL sequences, encoding the large subunit of ribulose 1,5-bisphosphate carboxylase, showed that the chlB rate of nonsynonymous substitution was about fourfold higher than for rbcL, while the chlB phylogeny resulted in a better resolution of the clades surveyed.

Inverse correlation between the proportion of salivary bacteria inhibiting Streptococcus mutans and the percentage of untreated carious teeth.

To evaluate the role of inhibitory substances produced by bacteria in the oral cavity, we estimated, by a deferred test on Todd-Hewitt agar enriched with hemin and vitamin K, the proportion of bacteria that inhibited or stimulated the growth of Streptococcus mutans and Porphyromonas gingivalis, from the saliva of 109 patients (54 males and 55 females) attending our dental clinics. The patients, aged from 8 to 75 years old (mean: 31 +/- 18 years), were randomly selected whatever the reason for their visit. The results, evaluated with the Spearman rank test, indicated that there was no statistically significant (P > 0.

Mechanisms for the development of genetically variable mycorrhizal mycelia in the ectomycorrhizal fungus Laccaria bicolor.

An in vitro study investigated mechanisms for the development of genetically variable mycorrhizal mycelia for Laccaria bicolor. Seedlings of jack pine (Pinus banksiana) grown nonaseptically in an autoclaved soil substrate were given different L. bicolor inoculum treatments.

Caffeine metabolism in cystic fibrosis: enhanced xanthine oxidase activity.

Study Objective: To characterize the activities of the P450 mixed-function oxidase CYP1A2 as well as the cytosolic enzymes N-acetyltransferase and xanthine oxidase using caffeine as a probe in children with cystic fibrosis compared to age-matched healthy control subjects.

Methods: After administration of caffeine (cola beverage) to 12 children with cystic fibrosis (age range, 5 to 11 years) and 12 healthy control subjects (age range, 5 to 12 years), urine was collected for 4 hours. Caffeine metabolites were determined by HPLC, and urinary caffeine metabolite ratios were computed to determine liver enzyme activities.

Comparison of ribosomal DNA length and restriction site polymorphisms in Gremmeniella and Ascocalyx isolates.

The small subunit (SSU) and the internal transcribed spacer (ITS) of nuclear ribosomal DNA genes from 27 specimens of the fungal genera Gremmeniella and Ascocalyx were amplified by PCR. Length polymorphisms were observed in the SSU and allowed the differentiation of four groups among the isolates tested: (i) Ascocalyx abietis; (ii) Gremmeniella isolates from Picea spp.; (iii) Gremmeniella isolates from Abies balsamea; and (iv) Gremmeniella isolates from Abies sacchalinensis, Larix spp.

Pharmacokinetic properties of clarithromycin: A comparison with erythromycin and azithromycin.

Objective: To compare the pharmacokinetic properties of two new macrolide antibiotics, clarithromycin and azithromycin, with those of the prototype macrolide, erythromycin.

Data Sources: Primarily peer review journals were searched for papers describing the pharmacokinetics of these new macrolides.

Study Selection: Fifteen in vitro and clinical studies of clarithromycin and azithromycin and one clinical abstract on clarithromycin from the past four years were selected for review.

Amino acid sequence of a non-specific wheat phospholipid transfer protein and its conformation as revealed by infrared and Raman spectroscopy. Role of disulfide bridges and phospholipids in the stabilization of the alpha-helix structure.

A wheat non specific phospholipid transfer protein has been isolated from wheat seeds and its amino acid sequence reveals that it is composed of 90 residues for a molecular weight of 9607. From the comparison of its sequence with those of the eight known proteins of the same family, hypotheses on the role of some conserved residues in the transfer activity can be made. The conformation of this protein has been studied by Raman and Fourier transform infrared spectroscopy and this is the first report on the structure of non specific plant phospholipid transfer proteins.

Conformation of wheat gluten proteins. Comparison between functional and solution states as determined by infrared spectroscopy.

The conformation of wheat gluten proteins in their functional hydrated solid state (doughy state) has been studied for the first time using attenuated total reflection infrared spectroscopy. The amide I band of functional gluten proteins reveals that, in addition to beta-turns and alpha-helices, these proteins contain a significant amount of intra- and intermolecular extended beta-sheet structures. It appears that the solubilization of gluten proteins results in a major decrease of the amount of beta-sheet structures accompanied by an increase of the content of the beta-turn and alpha-helical conformations.

Investigation of the interaction between melittin and dipalmitoylphosphatidylglycerol bilayers by vibrational spectroscopy.

Melittin is shown to affect the structure of the charged phospholipid dipalmitoylphosphatidylglycerol (DPPG). In the gel phase, the presence of melittin leads to (i) an increased lipid interchain vibrational coupling, (ii) a shift of the rectangular to hexagonal lipid packing transition toward low temperatures, (iii) a very small conformational disordering effect, (iv) a decrease of the polarity or hydrogen bonding capability of the lipid ester group surrounding, (v) an important decrease of the water content in the complexes where the remaining water has a more disordered structure than bulk water, and (vi) an interlamellar repeat distance of 79 A. All these observations are rationalized by the following model: adjacent bilayers of DPPG are bridged by tetramers of melittin through electrostatic interactions inducing surface charge neutralization and partial dehydration of the complexes.

Structure and dynamics of dimyristoylphosphatidic acid/calcium complexes by 2H NMR, infrared, spectroscopies and small-angle x-ray diffraction.

The structural and dynamic properties of complexes of dimyristoylphosphatidic acid (DMPA) and calcium ions have been characterized by 2H NMR, Raman, and infrared spectroscopies and small-angle X-ray diffraction. All techniques used show that these complexes do not undergo a cooperative thermotropic phase transition. Small-angle X-ray diffraction unambiguously demonstrates that the structure of the lipid molecules of the DMPA/Ca2+ complexes remains lamellar even at a temperature as high as 85 degrees C.

The interaction of 3,5-pyrazolidinedione drugs with receptors for f-Met-Leu-Phe on human neutrophil leukocytes: a study of the structure-activity relationship.

The 3,5-pyrazolidinedione (3,5-P) drugs, phenylbutazone and sulfinpyrazone, have been reported to bind to receptors for the chemotactic peptide, f-Met-Leu-Phe, and to behave as functional antagonists of f-Met-Leu-Phe in human and rabbit neutrophils. To explore the structure-activity relationship of this family of drugs for f-Met-Leu-Phe receptor binding, 36 drugs with the 3,5-P structure, a structure related to antipyrine, or an unrelated structure were tested as competitors for the binding of f-Met-Leu-Phe-Lys-fluorescein isothiocyanate on human neutrophils by flow cytometric analysis. Only drugs possessing the 3,5-P ring were significant competitors.

The nutritive value for sheep of quackgrass and timothy hays harvested at two stages of growth.

Thirty-two wethers were used to compare the nutritive value of Climax timothy (Phleum pratense L.) and quackgrass (Agropyron repens L. Beauv.

Coupled changes between lipid order and polypeptide conformation at the membrane surface. A 2H NMR and Raman study of polylysine-phosphatidic acid systems.

Thermotropism and segmental chain order parameters of sn-2-perdeuteriated dimyristoyl-phosphatidic acid (DMPA)-water dispersions, with and without poly(L-lysine) (PLL) of different molecular weights, have been investigated by solid-state deuterium NMR spectroscopy. The segmental chain order parameter profile of this negatively charged lipid is similar to that already found for other lipids. Addition of long PLL (MW = 200,000) increases the temperature, Tc, of the lipid gel-to-fluid phase transition, whereas short PLL (MW = 4000) has practically no effect on Tc.

Study of the structure of N-acyldipalmitoylphosphatidylethanolamines in aqueous dispersion by infrared and Raman spectroscopies.

The effect of the headgroup chain length on the structure and on the thermotropic behavior of N-acyldipalmitoylphosphatidylethanolamines (N-acyl-DPPEs) has been studied by infrared and Raman spectroscopies. The results show that the N-acyl-DPPEs can be divided in two classes depending on the N-acyl chain length. When the N-acyl chain contains 10 carbon atoms or more, it penetrates into the bilayer while it remains at the level of the glycerol backbone for shorter N-acyl chains.

Altered disposition of fleroxacin in patients with cystic fibrosis.

Thirteen patients with cystic fibrosis and 12 healthy control volunteers received a single oral 800 mg dose of fleroxacin and 800 mg every day for 5 days. Interstitial fluid penetration was studied by the suction-induced blister technique. Fleroxacin and its two major metabolites, N-demethyl and N-oxide, were analyzed in plasma and urine by HPLC.

Bacitracin U.S.P. contains a factor that stimulates receptors for 5-hydroxytryptamine on rabbit aortic strips.

Bacitracin (BAC) U.S.P.

Gentamicin-induced chronotoxicity: use of body temperature as a circadian marker rhythm.

Aminoglycoside antibiotics produce varying degrees of ototoxicity, dependent on dosage time, in animals synchronized for rhythm study. Herein, we illustrate the use of an economical and reliable system to telemeter body temperature of laboratory animals as an endogenous marker rhythm for gentamicin-induced ototoxicity. Two groups of 3 male Sprague-Dawley rats (250-400 gm) were housed in separate cages in a temperature-controlled room programmed with a 12:12 LD schedule and monitored for hearing thresholds at the frequencies of 8kHz, 16 kHz, 24 kHz and 32 kHz at 2-week intervals.

Communication of verbal information by community pharmacists.

Communication of verbal information on prescribed drugs is recognized as an important function of the pharmacist. This article describes and analyzes the communication behavior adopted by community pharmacists in the province of Quebec. Data were collected by means of two questionnaires mailed to a random sample of 634 community pharmacists.

Effects of intrahypothalamic injections of GABA, muscimol, pentobarbital, and L-glutamic acid on feed intake of satiated sheep.

Five wethers were surgically prepared with cranial implants to study the role of gabaminergic neural pathways on the hypothalamic control of feeding behaviour in ruminants. In the first experiment, the animals were injected (1 microL) with a physiological Tyrode (0.95%) solution, muscimol (0.

Comparison between pentobarbital- and muscimol-induced feeding in satiated sheep.

Twenty sheep were used to study the mechanisms by which the intracerebral administration of pentobarbital and of muscimol induces feeding in ruminants. Injections of 1 mumol calcium induced a weak feeding response at 1 h postinjection compared with control values (108 vs. 63 g, p less than 0.

BAY-K-8644-stimulated amylase secretion from pancreatic acinar cells.

Pancreatic acinar cells do not contain depolarization-sensitive calcium channels. Nonetheless, in the current study, the calcium channel activator, BAY-K-8644, was found to stimulate a time- and concentration-dependent increase in the spontaneous release of amylase. Secretion was dependent on the presence of extracellular calcium in the incubation medium.