Search Results - (Author, Cooperation:J. McClellan)

2011-02-25

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Cell Line ; Chromosomes, Human, Pair 7/genetics ; Cohort Studies ; Cyclic AMP/metabolism ; DNA Copy Number Variations/*genetics ; Female ; Gene Dosage/genetics ; Genes, Duplicate/*genetics ; Genetic Predisposition to Disease/*genetics ; Genome-Wide Association Study ; Humans ; Inheritance Patterns/genetics ; Male ; Pedigree ; Receptors, Vasoactive Intestinal Peptide, Type II/*genetics/metabolism ; Reproducibility of Results ; Schizophrenia/*genetics/metabolism ; Signal Transduction ; Transcription, Genetic/genetics

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

. A two-stage chemostat modified to accommodate the growth of adhesive organisms was used to determine the yield constant, Y, of a representative soil amoeba, Acanthamoeba polyphaga, utilizing as its prey Pseudomonas paucimobilis. The first stage consisted of a glucose-limited bacterial culture in steady state. The second stage consisted of a simplified predator-prey system, nongrowing bacteria serving as the limiting substrate for amoebae. A refined methodology to more accurately determine Y was developed, and Y for Acanthamoeba polyphaga in batch and continuous culture was determined to be 19.1%.

Electronic Resource

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

SYNOPSIS. Pelomyxa illinoisensis exhibits several phenomena of an interesting and uncommon nature, such as the presence of polar granules and the appearance of chromosomes through most of the resting and dividing stages of the nucleus. For these reasons and because of the importance of the nucleus as a stable characteristic in the taxonomy of amoebae, this study of the nucleus and nuclear division was undertaken.Culture methods were the same as those used for P. carolinensis. Best fixatives for nuclei were Carnoy, Flemming, 10% formalin, Duboscq-Brazil, Schaudinn and 2% osmium tetroxide. The body shape of P. illinoisensis in nuclear division is correlated with the stage of nuclear division and resembles the same stages in Amoeba proteus and P. carolinensis, with the exception of a ragged appearance of the cytoplasm of organisms containing prophase nuclei and the halo-like appearance of the pseudopods in those containing metaphase nuclei. The condensation of resting nuclei when subjected to acidified methyl green, reported by Kudo (18), occurred with all fixatives used with the exception of 10% formalin and 2% osmium tetroxide. The metaphase nuclei have a disk of polar granules on either side of the equatorial plate with fibers running from them to the chromosomes. The nature of these granules is unknown. Similarities and differences between P. illinoisensis and P. carolinensis are discussed.

Electronic Resource

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

SYNOPSIS. The responses of amebae and bacteria in a grassland soil were investigated by an overlay plaque technic developed in this laboratory. This procedure, using Aerobacter aerogenes as the food source, allowed convenient assay of significant changes in ameba populations which resulted from additions of nutrient and water. In comparison with controls, when water was added an initial increase occurred in bacterial counts followed by an increase in the numbers of amebae. Upon addition of glucose, ameba populations increased initially and then decreased with time, while populations of bacteria remained constant. The addition of hay resulted in significant increases in populations of bacteria and amebae. Plaque appearance on enumeration plates was most rapid with inocula from nutrient-treated soils.Predominant amebae recovered by this technic were species of Acanthamoeba and Hartmannella. They were estimated to be present in untreated soils at 3.2 × 103/gram. Ameba feeding experiments were used to evaluate the possible suitability of other bacteria as food. The results indicated that nonpigmented laboratory strains of bacteria were preferred, while pigmented grassland isolates were more rapidly utilized.Small soil amebae appear to be sensitive to minor soil perturbations, and the enumeration procedure developed in this study should aid in following their responses to environmental stresses.

Electronic Resource

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

SYNOPSIS. Giant multinucleated amoebae, discovered in Colorado near Ft. Collins and tentatively identified as Pelomyxa carolinensis, were successfully cultured in a manner identical with that used for P. carolinensis. The ultrastructure of the Colorado amoebae, in comparison with that of other large amoebae, was like that of P. carolinensis, but different from those of Amoeba proteus, P. illinoisensis, and P. palustris. Protoplasmic grafts between the Colorado amoebae and P. carolinensis were then exchanged by microsurgery. These grafts were well tolerated, and the recipient amoebae reproduced at a rate comparable to that of non-grafted controls. Other Colorado amoebae received grafts from P. illinoisensis, but all recipients died without cell division a few days after microsurgery. These nutritional, cytologic and transplantation-tolerance data reveal that the amoebae from Colorado are P. carolinensis.

Electronic Resource

0145-2134

Emotional disturbance ; Mental health

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Psychology

Electronic Resource

1420-9071

Cytokines ; tumor necrosis factor α ; interleukin-6 ; body temperature ; fever ; radiotelemetry ; guinea pig

Springer Online Journal Archives 1860-2000

Biology

Medicine

Abstract Tumor necrosis factor α (TNF) is released systematically during the early phase of endotoxin induced fever. To study the effects of this cytokine in guinea pigs, 2 μg TNF were intra-arterially injected as a bolus or slowly infused within 60 min. Both modes of administration induced a biphasic elevation of the animals' abdominal temperature lasting 6 h and stimulated the release of endogenous interleukin-6 (IL-6)-like activity. The second phase of the thermal response and the release of endogenous IL-6-like activity were significantly higher, when TNF was slowly infused into the animals' circulation, in spite of a transiently higher TNF-like activity after the bolus injection of TNF. Both TNF and IL-6 may therefore be regarded as candidates to trigger the febrile response in guinea pigs.

Electronic Resource

1432-0789

Protozoa ; Ciliates ; flagellates ; Nitrogen and phosphorus mineralization ; Grazing

Springer Online Journal Archives 1860-2000

Biology

Geosciences

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Summary In the present experiment, natural protozoan fauna and other microbial components in water extracts from shortgrass prairie soil were separated on the basis of size by differential filtration (8-, 5-, and 3-μm porosities). All extracts contained bacteria and fungi, along with a few very small flagellates (3-μm pore size filtrate); flagellates and a few small amoebae (5-μm pore size filtrate); and flagellates, small amoebae, and small ciliates (8-μm pore size filtrate). All microorganisms, except a few species of flagellates, were present in the centrifuge treatment. Each filtrate was added to sterile soil, and the population of each microbial group was determined after inoculation at intervals up to 80 days (at room temperature). Populations of all added groups decreased on initial addition to soil but then increased during the incubation. By following nitrogen, phosphorus, and CO2 dynamics, we observed impacts of protozoan grazing on bacteria, including mineralization of N from microbial biomass.

Electronic Resource

1432-184X

Springer Online Journal Archives 1860-2000

Biology

Abstract Bacteria (Pseudomonas), amoebae (Acanthamoeba), and nematodes (Mesodiplogaster) were raised in soil microcosms with and without glucose additions. Nematode and amoebal grazing on bacteria significantly reduced bacterial populations by the end of a 24-day incubation period. Amoebal numbers decreased in the presence of nematodes with a corresponding increase in nematode numbers which reached a maximum of 230 nematodes/g of soil in the treatment with amoebae and glucose additions. After 24 days the nematode populations in the treatments without carbon additions were dominated by resistant dauer larvae indicating the unavailability of food. Although larval numbers were high in the treatments with glucose additions, the adult component of the population was still increasing at the end of the 24-day experiment. The effect of the presence of amoebae on nematode abundance was of the same magnitude as addition of 600Μg glucose-C.

Electronic Resource

1435-165X

Key words Early-onset psychotic disorders – diagnostic stability – standardized assessments

Springer Online Journal Archives 1860-2000

Medicine

Abstract Objectives: To examine the clinical features and diagnostic stability of early-onset psychotic disorders. Methods: These data are from a two-year longitudinal prospective study of youth with psychotic disorders. Standardized diagnostic assessments are administered at baseline and at one and two-year's follow-up. Results: Fifty-one subjects have been recruited to date; 18 with schizophrenia, 14 with bipolar disorder, 7 with schizoaffective disorder, 1 with an organic psychosis, and 11 subjects whose symptoms where either questionable and/or did not meet diagnostic criteria for another disorder (classified as psychosis nos). Thirty-nine subjects were reassessed at year one, twenty-four at year two. Three subjects have been lost to follow-up. The study diagnosis was the same as the first onset diagnosis (prior to entering the study) in 50 % of subjects. Over the two-year period of the study, the diagnosis remained unchanged in over 90 % of subjects. Subjects with schizophrenia had higher ratings of premorbid impairment, including social withdrawal and dysfunctional peer relationships, than those with bipolar disorder. At the one-year follow-up, subjects with schizophrenia and schizoaffective disorder had significantly higher rates of delusions, bizarre behavior, and negative symptoms than those with bipolar disorder. Subjects with bipolar disorder tended to have cyclical courses, whereas those with schizophrenia and schizoaffective disorder were often chronically impaired. Subjects with psychosis nos had higher rates of dissociative symptoms and histories of child maltreatment. Conclusions: Early-onset psychotic disorders can be reliably diagnosed using standardized assessments and are stable over a two-year period. Compared to bipolar disorder, schizophrenia is associated with a poorer premorbid history, and persistent positive and negative symptoms.

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