The behavior of cellulose,amylose, and β-d-xylan towards anhydrous hydrogen fluoride

Cellulose, amylose, and d-glucose are converted into α-d-glucopyranosyl fluoride (3) when dissolved in anhydrous hydrogen fluoride. The fluoride subsequently undergoes condensation to afford a mixture of ligosaccharides, probably via an oxocarbonium ion. The fluoride 3 and the oligosaccharides are in an equilibrium, which was studied by ¹³C-n.m.r. spectroscopy; in dilute solution in hydrogen fluoride, the d-glucosyl fluoride is the main product present, but when the hydrogen fluoride is evaporated, the equilibrium is shifted towards the oligosaccharides. These constitute a complex mixture which was studied by methylation and subsequent analysis of the methylated alditols derived therefrom. (1→4)-β-d-Xylan and d-xylose behave similarly to the d-glucose derivatives towards hydrogen fluoride.     

Effects of residency training in family medicine v. internship training on professional attitudes and practice patterns.

OBJECTIVES: To determine whether the professional attitudes and practice patterns of physicians with residency training in family medicine differ from those of generalists with internship training. DESIGN: Mail survey conducted in 1985-86. SETTING: Province of Quebec. PARTICIPANTS: A stratified random sample of French-speaking family and general practitioners who graduated after 1972 (325 physicians with residency training and 304 with internship training) (response rate 82%). MAIN RESULTS: Physicians with residency training were 3 years younger on average than those with internship training, were more likely to be female (38% v. 18%, p less than 0.001) and were more likely to work on a salaried basis in CLSCs (public community health centres) (36% v. 14%, p less than 0.001). Even after these confounding factors were controlled for, physicians with residency training seemed to be more sensitive to the psychosocial aspects of patient care and tended to attach more importance to informing patients about useful materials and resources concerning their health problems. They were not, however, more likely to value health counselling or integrate it in medical practice. CONCLUSION: Our findings provide some evidence that the new requirement that physicians complete a residency in family medicine to obtain medical licensure in general practice in Quebec may foster a more patient-centred approach to health care.     

Chemical Communication in Necturus maculosus and his Cave-Living Relative Proteus anguinus (Proteidae,Urodela)

The chemical communication of the epigean Necturus maculosus and the cave-living Proteus anguinus are compared in laboratory conditions. In both species a specks-specific substance transferred by water could be shown, another was deposited on the substrate.     

Behavioural and morphological effects of testosterone and gonadotropins in the young male domestic duck (Anas platyrhynchos L.)

Young male domestic ducks 20–72 days old were successively injected with two hormonal preparations. The first hormone treatment included males injected with testosterone propionate (TP), human chorionic gonadotropin (HCG), pregnant mare serum (PMS), control oil injected males (C) and males injected with TP and submitted at the same time to a permanent intense light. During the second hormonal treatment all males except controls were injected with TP.Almost no behavioural effects were observed in any group of males following the first treatment. The second one, however, induced intense social display and sexual behaviour in the four TP-injected groups. Some qualitative and quantitative differences were found between groups according to the first hormone treatment to which they had been submitted. This suggests a possible role of gonadotropic hormones in the control of social behaviour in ducks. Experimental data supporting this hypothesis are briefly reviewed and discussed.     

Barley γ3-hordein: Glycosylation at an atypical site,disulfide bridge analysis,and reactivity with IgE from patients allergic to wheat

Post translational modifications of a seed storage protein, barley γ3-hordein, were determined using immunochemical and mass spectrometry methods. IgE reactivity towards this protein was measured using sera from patients diagnosed with allergies to wheat. N-glycosylation was found at an atypical Asn-Leu-Cys site. The observed glycan contains xylose. This indicates that at least some γ3-hordein molecules trafficked through the Golgi apparatus. Disulfide bridges in native γ3-hordein were almost the same as those found in wheat γ46-gliadin, except the bridge involving the cysteine included in the glycosylation site. IgE reacted more strongly towards the recombinant than the natural γ3-hordein protein. IgE binding to γ3-hordein increased when the protein sample was reduced. Glycosylation and disulfide bridges therefore decrease epitope accessibility. Thus the IgE from patients sensitized to wheat cross-react with γ3-hordein due to sequence homology with wheat allergens rather than through shared carbohydrate determinants.     

pUCL287 plasmid from Tetragenococcus halophila (Pediococcus halophilus) ATCC 33315 represents a new theta-type replicon family of lactic acid bacteria

Abstract A cryptic plasmid, pUCL287, was isolated from Tetragenococcus halophila (Pediococcus halophilus) ATCC 33315. It had a theta-type mechanism of replication in its natural host. Its minimal replicon, Rep 281, was isolated on a 1.6-kb Eco RI fragment. The Rep 287 host range included the genera Pediococcus, Enterococcus, Lactobacillus and Leuconostoc but not genus Lactococcus . Plasmids hybridizing to pUCL287 are rare among lactic acid bacteria. As assessed by hybridization, Rep2Sl is dissimilar to pAMβ1, pIP50l and pUCL22, representatives of the most common theta-type replicon groups in Gram-positive bacteria. Therefore, pUCL287 appears to represent a new theta-type replicon family from lactic acid bacteria.     

Subcellular fractionation of striatum: Sedimentation properties of dopaminergic synaptosomes

Linear sucrose density gradient centrifugation of a crude synaptosomal-mitochondrial preparation of rat striatum was performed at 82, 500g for 7.5, 15 and 30 min and 1, 4 and 20 h. After centrifugation various marker enzyme activities were measured throughout the gradients, viz. tyrosine hydroxylase (TH) and DOPA decarboxylase (DD) as markers of dopaminergic synaptosomes, lactate dehydrogenase (LDH) as a general synaptosomal marker and monoamine oxidase (MAO) as a mitochondrial marker. At all centrifugation times the distribution patterns of TH and DD activity coincided almost perfectly. Notable differences were found between the sedimentation properties of these TH/DD-containing particles and LDH-containing particles: TH and DD were symmetrically distributed in the gradient much sooner than LDH, at all centrifugation times the top of the TH and DD curves was lying deeper in the gradient than the highest LDH activity, and Th and DD became enriched in the gradients to a much greater extent than LDH. It is concluded that rat striatal dopaminergic synaptosomes form a relatively homogenous population of particles sedimenting faster into the gradients than the bulk of striatal synaptosomes does. This distinct sedimentation behaviour of the dopaminergic synaptosomes can be usefully applied for analytical purposes.