Effect of neurotensin on pancreatic function in man

The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs.     

Taxonomic Diversity of Bacteria and Their Filterable Forms in the Soils of Eastern Antarctica (Larsemann Hills and Bunger Hills)

Microbiology - Increasing interest in microbial communities of Arctic and Antarctic extreme environments, their taxonomic diversity, and forms and mechanisms of adaptation of inhabitants of...     

Comparison of the adaptive potential of the Arthrobacter oxydans and Acinetobacter lwoffii isolates from permafrost sedimentary rock and the analogous collection strains

A comparative study was conducted on the adaptive mechanisms of the strains Arthrobacter oxydans K14 and Acinetobacter lwoffii EK30A isolated from permafrost subsoil sediments and of those of the analogous collection strains (Ac-1114 Type and BSW-27, respectively). In each pair of the strains compared, the strains differed in terms of (i) growth-related, physiological, and biochemical properties; (ii) resistance to stress factors; (iii) capacity for generation of dormant forms (DFs) under growth arrest conditions, and (iv) intrapopulation production of phase variants. The strains isolated from permafrost displayed a lower growth rate but were more resistant to repeated freezing-thawing treatment than the collection strains. Under the same growth conditions, the permafrost strains formed larger numbers of cystlike anabiotic DFs, extraordinarily small cells, and forms that became nonculturable during long-term storage. Resuscitation of the nonculturable forms resulted in a 2- to-7-fold increase in the percentage of FISH-detectable metabolically active cells. The permafrost strains were also distinguished by increased genome lability. This facilitated their dissociation into intrapopulation variants with phenotypically distinct colonial and morphological properties and different antibiotic resistance. The phenotypic variability was more prominent in Arthrobacter (for which it was not reported previously) than in Acinetobacter. In the populations produced by plating the dormant bacterial forms, the qualitative and quantitative characteristics of the phase variant spectra varied depending on the formation conditions and the composition of the solid media used for the plating. Thus, the permafrost isolates of A. oxydans and Ac. lwoffii were distinguished from their collection analogs by a more manifest adaptive potential including stress resistance, the intensity of DF generation under growth arrest conditions, and increased intrapopulation variability.     

Mercury-resistant bacteria from permafrost sediments and prospects for their use in comparative studies of mercury resistance determinants

Mercury-resistant bacteria were isolated from permafrost sediments of Kolyma lowland and Canada existing over five thousand to two million years. Their content was shown to vary within the range 0.001-2.9% and to depend on the amount of mercury in sampling sites (coefficient of correlation 0.75). A collection of mercury-resistant bacterial strains was created. In this collection, various representatives of both Gram-positive bacteria (Bacillus, Exiguobacterium, Micrococcus, Arthrobacter) and Gram-negative bacteria (Pseudomonas, Acinetobacter, Plesiomonas, Myxobacteriales) were identified. Most resistant bacteria were found to contain determinants homologous to mer-operons of contemporary bacteria. The isolated strains of paleobacteria are proposed to be used for a comparative structural study of contemporary and ancient plasmids and transposons carrying mercury resistance determinants.     

Isolation of antibiotic resistance bacterial strains from Eastern Siberia permafrost sediments

A collection of bacterial antibiotic resistance strains isolated from arctic permafrost subsoil sediments of various age and genesis was created. The collection included approximately 100 strains of Gram-positive (Firmicutes, Arthrobacter) and Gram-negative bacteria (Bacteroidetes, γ-Proteobacteria, and α-Proteobacteria) resistant to aminoglycoside antibiotics (gentamicin, kanamycin, and streptomycin), chloramphenicol and tetracycline. Antibiotic resistance spectra were shown to differ in Gram-positive and Gram-negative bacteria. Multidrug resistance strains were found for the first time in ancient bacteria. In studies of the molecular nature of determinants for streptomycin resistance, determinants of the two types were detected: strA-strB genes coding for aminoglycoside phosphotransferases and genes aadA encoding aminoglycoside adenylyltransferases. These genes proved to be highly homologous to those of contemporary bacteria.     

Synthesis of Anabiosis Autoinducers by Non-Spore-Forming Bacteria as a Mechanism Regulating Their Activity in Soil and Subsoil Sedimentary Rocks

Non-spore-forming bacteria of the genera Arthrobacterand Micrococcus, isolated from permafrost subsoil, were found to produce greater amounts of the d ₁extracellular factor than closely related collection strains isolated from soil. The effect of this factor, responsible for cell transition to anabiosis, was not species-specific. Thus, the d ₁preparation isolated from the culture liquid of the permafrost isolate Arthrobacter globiformis245 produced an effect on the collection strain Arthrobacter globiformisB-1112 and also on Micrococcus luteusand Bacillus cereus.The d ₁preparation from the permafrost isolate of Arthrobacterdiffered from the chemical analogue of this factor, 4-n-hexylresorcinol, in the level of the induced cell response, which may have resulted from different cell sensitivity to various homologs of alkylhydroxybenzenes contained in the d ₁preparation. Thus, additional evidence was obtained indicating that autoregulation of bacterial growth and development is implemented at the level of intercellular interactions in microbial communities. Abundant production of the d ₁anabiosis-inducing factors by bacteria isolated from permafrost subsoil is probably a result of special antistress mechanisms responsible for the survival of these bacteria under extreme conditions of natural long-term cooling.     

Peripartum Cardiomyopathy Presenting With Ventricular Tachycardia: A Rare Presentation

A 25-year-old previously asymptomatic pregnant woman at 36 weeks'' gestation was noticed to have repetitive monomorphic ventricular tachycardia. A dilated left ventricle with moderately reduced systolic function was found on echocardiographic examination. This is a very rare presentation of peripartum cardiomyopathy (PPCMP) presenting with repetitive monomorphic ventricular tachycardia.     

Microbial Communities of Soils and Soil-like Bodies in Extreme Conditions of East Antarctica

Paleontological Journal - Results of an integrated study of microbial communities in soils and soil-like bodies formed in the wet intermountain valleys of East Antarctic oases under moss-, lichen-,...