Enhanced reactivity to pain in patients with rheumatoid arthritis

Introduction  

Maladaptive physiological responses to stress appear to play a role in chronic inflammatory diseases such as rheumatoid arthritis (RA). However, relatively little stress research in RA patients has involved the study of pain, the most commonly reported and most impairing stressor in RA. In the present study, we compared psychophysical and physiological responses to standardized noxious stimulation in 19 RA patients and 21 healthy controls.     

The relationship between ribosomal repeat length and genome size in Vicia

The organization of the ribosomal RNA genes was examined in several species of Vicia in an attempt to determine whether a relationship exists between genome size and ribosomal repeat length. Species within this genus exhibit a sevenfold variation in haploid DNA content. Our data suggest that species with an intermediate genome size maintain one predominant Eco RI class of ribosomal repeat of about 9 kilobases (kb). In contrast, the smallest and largest genomes of Vicia possess one major and several minor classes. The possible relationship between repeat classes among species is discussed. We examined the species with the smallest (V. villosa) and largest (V. faba) genomes in closer detail by R-loop analysis of a satellite DNA from Hoechst 33258 dye-CsCl gradients. Heterogeneity was found in the length of the ribosomal repeat for both species, but no appreciable difference was observed in the distribution of these lengths, which averaged 11–12 kb. This heterogeneity is associated with the nontranscribed spacer region. Intervening sequences were not found in either the 25S or 18S coding regions of the ribosomal repeat of either of these two plants. A putative ribosomal RNA precursor of 7 kb was identified for both species.     

The origin of indoleacetic acid and indolepropionic acid in rat and human cerebrospinal fluid

Abstract: Using a new high performance liquid chromatographic method we have measured tryptophan, 5-hydroxyindoleacetic acid (5HIAA), indoleacetic acid (IAA), and indolepropionic acid (IPA) in rat and human CSF. Experiments on rats indicate that IPA in CSF is not derived from the CNS but from bacterial metabolism in the intestine. However, IAA in CSF is derived from CNS tryptamine metabolism. Some tryptamine that is formed peripherally diffuses across the blood-brain barrier and augments the tryptamine formed within the CNS. We have concluded from our data that (i) measurements on CSF are a useful way of studying trace amine metabolism in human CNS, but it is essential to establish the anatomical and metabolic origin of any metabolite found in the CSF; and (ii) tryptamine metabolism is more important in man than in the rat.     

Increase in microbial contamination of defeathering machinery in a poultry processing plant after changes in the method of processing

The numbers of coliforms, Enterobacteriaceae and Staphylococcus aureus and the extent of their colonization of the fingers of the defeathering machinery within a poultry processing plant were increased after changes in machinery design and a reduction in the level of chlorination. Such increases and the pattern of contamination suggested that the changes had allowed an endemic flora to develop on the fingers.     

Nucleotide Sequences, Genetic Organization, and Distribution of pEU30 and pEL60 from Erwinia amylovora

The nucleotide sequences, genetic organization, and distribution of plasmids pEU30 (30,314 bp) and pEL60 (60,145 bp) from the plant pathogen Erwinia amylovora are described. The newly characterized pEU30 and pEL60 plasmids inhabited strains isolated in the western United States and Lebanon, respectively. The gene content of pEU30 resembled plasmids found in plant-associated bacteria, while that of pEL60 was most similar to IncL/M plasmids inhabiting enteric bacteria.     

Different strategies of photoacclimation by two strains of Emiliania huxleyi (Haptophyta)1

Photoacclimation involves the modification of components of the light and dark reactions to optimize photosynthesis following changes in available light. All of the energy required for photosynthesis comes from linear electron transport through PSII and PSI and is dependent upon the amount of light harvested by PSII relative to PSI (a*_PSII and a*_PSI). The amount of light harvested is determined by the effective absorption cross‐sections (σ_PSII, σ_PSI) and cellular contents of the PSII and PSI reaction center complexes (RCII, RCI). Here, we examine the effective absorption cross‐sections and reaction center contents for calcifying (B11) and noncalcifying (B92) strains of the globally important coccolithophorid Emiliania huxleyi (Lohmann) W. H. Hay et H. Mohler when grown under various photon flux densities (PFDs). The two strains displayed different “strategies” of acclimation. As growth PFD increased, B11 preferentially changed σ and the cellular content of chl a per cell over PSU “size” (the total cellular chl a content associated with the reaction center complexes); strain B92 preferentially changed PSU size over the cellular content of reaction complexes. Neither strategy was specifically consistent with the majority of previous studies from other microalgal species. For both strains, cellular light absorption for PSII and PSI was maintained close to unity across the range of growth PFDs since changes of σ_PSII and σ_PSI were reciprocated by those of RCIIs and RCIs per cell. Our results demonstrate a significant adaptive flexibility of E. huxleyi to photoacclimate. Finally, we calculated the amount of chl a associated with either photosystem to consider our interpretations of photoacclimation based on conventional determinations of PSU size.     

Giemsa banding of a human metacentric chromosome number 9

Summary Giemsa staining procedures have been used on human lymphocyte preparations to locate constitutive heterochromatin (C-bands) and to produce distinct banding patterns for each individual chromosome (G-bands). A metacentric C group chromosome has been shown by both techniques to be chromosome number 9.

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Zusammenfassung An menschlichen Lymphocyten wurde eine Giemsafärbung durchgeführt, mit dem Ziel, konstitutives Heterochromatin (C-Banden) zu lokalisieren und für jedes einzelne Chromosom besondere Bandmuster herauszuarbeiten (G-Banden). Beide Techniken erlaubten, ein metazentrisches C-Chromosom als Nr. 9 zu identifizieren.

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Supported by PHS grants RR-62 and 5-SO1-RRO-5411.     

THE SPIROCHETE AND MULTIPLE SCLEROSIS

Cultures on anaerobic medium were made of the spinal fluids of 27 patients with multiple sclerosis and 13 controls after the method described recently by Ichelson. Where Ichelson found organisms resembling spirochetes in 78 per cent of patients with multiple sclerosis, we found some form of what appeared to be a living micro-organism in 18.5 per cent. The control fluids were all sterile. The work requires confirmation and amplification.     

Long-range structural and dynamical changes induced by cofactor binding in DNA methyltransferase M.HhaI

The bacterial DNA cytosine methyltransferase M.HhaI sequence-specifically modifies DNA in an S-adenosylmethionine dependent reaction. The enzyme stabilizes the target cytosine (GCGC) into an extrahelical position, with a concomitant large movement of an active site loop involving residues 80-99. We used multidimensional, transverse relaxation-optimized NMR experiments to assign nearly 80% of all residues in the cofactor-bound enzyme form, providing a basis for detailed structural and dynamical characterization. We examined details of the previously unknown effects of the cofactor binding with M.HhaI in solution. Addition of the cofactor results in numerous structural changes throughout the protein, including those decorating the cofactor binding site, and distal residues more than 30 A away. The active site loop is involved in motions both on a picosecond to nanosecond time scale and on a microsecond to millisecond time scale and is not significantly affected by cofactor binding except for a few N-terminal residues. The cofactor also affects residues near the DNA binding cleft, suggesting a role for the cofactor in regulating DNA interactions. The allosteric properties we observed appear to be closely related to the significant amount of dynamics and dynamical changes in response to ligand binding detected in the protein.