A meristic, morphometric and biochemical investigation of Atlantic menhaden, Brevoortia tyrannus (Latrobe)

Juvenile Atlantic menhaden, Brevoortia tyrannus , were collected from estuarine waters of the Atlantic coast of the United States. Those collected north of latitude 40°N had lower numbers of total and trunk vertebrae, ventral scutes and interhaemal spines, and shallower heads, smaller eyes, shorter predorsal lengths, and lower frequencies of the fastest allele observed at the transferrin locus than those collected south of Long Island. Although the evidence is still inconclusive, the potential for at least two subpopulations still exists: one which spawns in the spring and early summer and is responsible for the primary recruitment in the northern North Atlantic area, and one which spawns in the autumn and winter and contributes the majority of recruitment in the middle and southern North Atlantic areas of the United States.     

Differing roles of mitochondrial nitric oxide synthase in cardiomyocytes and urothelial cells

The existence of mitochondrial nitric oxide (NO) synthase (mtNOS) has been controversial since it was first reported in 1995. We have addressed this issue by making direct microsensor measurements of NO production in the mitochondria isolated from mouse hearts. Mitochondrial NO production was stimulated by Ca2+ and inhibited by blocking electrogenic Ca2+ uptake or by using NOS antagonists. Cardiac mtNOS was identified as the neuronal isoform by the absence of NO production in the mitochondria of mice lacking the neuronal but not the endothelial or inducible isoforms. In cardiomyocytes from dystrophin-deficient (mdx) mice, elevated intracellular Ca2+, increased mitochondrial NO production, slower oxidative phosphorylation, and decreased ATP production were detected. Inhibition of mtNOS increased contractility in mdx but not in wild-type cardiomyocytes, indicating that mtNOS may protect the cells from overcontracting. mtNOS was also implicated in radiation-induced cell damage. In irradiated rat/mouse urinary bladders, we have evidence that mitochondrially produced NO damages the urothelial "umbrella" cells that line the bladder lumen. This damage disrupts the permeability barrier thereby creating the potential to develop radiation cystitis. RT-PCR and Southern blot analyses indicate that mtNOS is restricted to the umbrella cells, which scanning electron micrographs show are selectively damaged by radiation. Simultaneous microsensor measurements demonstrate that radiation increases NO and peroxynitrite (ONOO-) production in these cells, which can be prevented by transfection with manganese superoxide dismutase (MnSOD) or instillation of NOS antagonists during irradiation or irradiation of bladders devoid of mtNOS. These studies demonstrate that mtNOS is in the cardiomyocytes and urothelial cells, that it is derived from the neuronal isoform, and that it can be either protective or detrimental.     

Nuclear protein matrix of seminal vesicle epithelium

Nuclear protein matrix was isolated from guinea pig seminal vesicle epithelium and liver. The two matrices were similar in fine structure as seen by transmission electron microscopy, in protein electropherograms, and in percent composition relative to protein, DNA, and RNA. Scanning electron microscopy was used to examine intact seminal vesicle nuclei, nuclei after treatment with Triton X-100 and DNAse I, and purified nuclear matrix. The matrix surface presented a 'porous' appearance by both scanning and transmission electron microscopy. The matrices of liver and seminal vesicle epithelium (SVE) and the intact nuclei of SVE were assayed for specific binding of free synthetic androgen, 17 alpha-methyltrienolone (R1881). Saturable specific binding was demonstrable for seminal vesicle matrix but not for liver matrix. Maximal binding of androgen occurred at a concentration of approximately 12 nM and was demonstrated to be 1.34 +/- 0.22 pmol of R1881 per mg of seminal vesicle matrix protein; the Kd was approximately 8 nM. The binding of labeled R1881 to matrix could be inhibited with low concentrations of unlabeled androgens, but not with estrogens or other steroids. Our data indicate that the binding of androgen to matrix could account for at least 21% of the binding to intact nuclei.     

Role of ultrasonography in diagnosing early rheumatoid arthritis and remission of rheumatoid arthritis - a systematic review of the literature

Introduction

Ultrasonography (US) might have an added value to clinical examination in diagnosing early rheumatoid arthritis (RA) and assessing remission of RA. We aimed to clarify the added value of US in RA in these situations performing a systematic review.

Methods

A systematic literature search was performed for RA, US, diagnosis and remission. Methodological quality was assessed; the wide variability in the design of studies prohibited pooling of results.

Results

Six papers on the added value of US diagnosing early RA were found, in which at least bilateral metacarpophalangeal (MCP), wrists and metatarsophalangeal (MTP) joints were scanned. Compared to clinical examination, US was superior with regard to detecting synovitis and predicting progression to persistent arthritis or RA. Eleven papers on assessing remission were identified, in which at least the wrist and the MCP joints of the dominant hand were scanned. Often US detected inflammation in patients clinically in remission, irrespective of the remission criteria used. Power Doppler signs of synovitis predicted X-ray progression and future flare in patients clinically in remission.

Conclusions

US appears to have added value to clinical examination for diagnosing of RA when scanning at least MCP, wrist and MTP joints, and, when evaluating remission of RA, scanning at least wrist and MCP joints of the dominant hand. For both purposes primarily power Doppler US might be used since its results are less equivocal than those of greyscale US.     

Natal homing in juvenile loggerhead turtles (Caretta caretta)

Juvenile loggerhead turtles (Caretta caretta) from West Atlantic nesting beaches occupy oceanic (pelagic) habitats in the eastern Atlantic and Mediterranean, whereas larger juvenile turtles occupy shallow (neritic) habitats along the continental coastline of North America. Hence the switch from oceanic to neritic stage can involve a trans-oceanic migration. Several researchers have suggested that at the end of the oceanic phase, juveniles are homing to feeding habitats in the vicinity of their natal rookery. To test the hypothesis of juvenile homing behaviour, we surveyed 10 juvenile feeding zones across the eastern USA with mitochondrial DNA control region sequences (N = 1437) and compared these samples to potential source (nesting) populations in the Atlantic Ocean and Mediterranean Sea (N = 465). The results indicated a shallow, but significant, population structure of neritic juveniles (PhiST = 0.0088, P = 0.016), and haplotype frequency differences were significantly correlated between coastal feeding populations and adjacent nesting populations (Mantel test R2 = 0.52, P = 0.001). Mixed stock analyses (using a Bayesian algorithm) indicated that juveniles occurred at elevated frequency in the vicinity of their natal rookery. Hence, all lines of evidence supported the hypothesis of juvenile homing in loggerhead turtles. While not as precise as the homing of breeding adults, this behaviour nonetheless places juvenile turtles in the vicinity of their natal nesting colonies. Some of the coastal hazards that affect declining nesting populations may also affect the next generation of turtles feeding in nearby habitats.     

Biology of marrow stromal cell lines derived from long-term bone marrow cultures of Trp53-deficient mice.

To investigate the effect of Trp53 (formerly known as p53) on stromal cells of the hematopoietic microenvironment, long-term bone marrow cultures were established from mice in which the Trp53 gene had been inactivated by homologous recombination (Trp53(-/-)) or their wild-type littermates (Trp53(+/+)). Long-term bone marrow cultures from Trp53(-/-) mice continued to produce nonadherent cells for 22 weeks, while Trp53(+/+) cultures ceased production after 15 weeks. There was a significant increase in the number of nonadherent cells produced in Trp53(-/-) long-term bone marrow cultures beginning at week 9 and continuing to week 22 (P < 0.02). The Trp53(-/-) cultures also showed significantly increased cobblestone island formation indicative of early hematopoietic stem cell-containing colonies beginning at week 10 (P < 0.01). Cobblestone islands persisted until weeks 15 and 22 in Trp53(+/+) and Trp53(-/-) cultures, respectively. Co-cultivation experiments in which Trp53(+/+) Sca1(+)lin- enriched hematopoietic stem cells were plated on Trp53(-/-) stromal cells showed increased cobblestone island formation compared to Trp53(-/-) Scal+lin- cells plated on Trp53(+/+) or Trp53(-/-) stromal cells. Radiation survival curves for clonal bone marrow stromal cells revealed a similar D0 for the Trp53(+/+) and Trp53(-/-) cell lines (1.62 +/- 0.16 and 1.49 +/- 0. 08 Gy, respectively; P = 0.408), and similar n (8.60 +/- 3.23 and 10.71 +/- 0.78, respectively) (P = 0.491). Cell cycle analysis demonstrated a G2/M-phase arrest that occurred 6 h after irradiation for both Trp53(+/+) and Trp53(-/-) stromal cell lines. After 10 Gy irradiation, there was no significant increase in the frequency of apoptosis detected in Trp53(+/+) compared to Trp53(-/-) marrow stromal cell lines. In the stromal cell lines, ICAM-1 was constitutively expressed on Trp53(+/+) but not Trp53(-/-) cells; however, a 24-h exposure to TNF-alpha induced detectable ICAM-1 on Trp53(-/-) cells and increased expression on Trp53(+/+) cells. To test the effect of Trp53 on the radiation biology of hematopoietic progenitor cells, the 32D cl 3 cell line was compared with a subclone in which expression of an E6 inserted transgene accelerates ubiquitin-dependent degradation of Trp53, thus preventing accumulation of Trp53 after genotoxic stress. The radiation survival curves were similar with no significant difference in the D0 or n, or in the percentage of cells undergoing apoptosis after 10 Gy irradiation between the two cell lines. Cells of the 32D-E6 cell line displayed a G2/M-phase arrest 6 h after 10 Gy, while cells of the parent line exhibited both a G2/M-phase arrest and a G1-phase arrest at 24 and 48 h. The results suggest a complex mechanism of action of Trp53 on the interactions between stromal and hematopoietic cells in long-term bone marrow cultures.     

Regulation of the anaphase-promoting complex-separase cascade by transforming growth factor-beta modulates mitotic progression in bone marrow stromal cells

Alteration of the tumor microenvironment by aberrant stromal cells influences many aspects of cell biology, including differentiation of stem cells and tumor metastasis. The role of transforming growth factor (TGF)-β signaling in stromal cells of the tissue microenvironment is critical to both pathways. We examined murine marrow stromal cells with deletion of Smad3 and found that they have an altered cell cycle profile, with a higher fraction of cells in G2/M phase. Deletion of Smad3 significantly abrogates TGF-β signaling and suppresses phosphorylation of CDC27–anaphase-promoting complex (APC) during mitosis, thereby resulting in elevated cyclin-dependent kinase (CDK)1 activity via increased levels of cyclin B. Enhanced CDK1 activity due to deregulation of APC leads in turn to hyperphosphorylation of separase, impeding chromatid separation. A residue Ser1126Ala mutation in separase specifically abolished separase hyperphosphorylation in Smad3-deficient cells. The present results unveil a new function for the TGF-β pathway in the regulation of APC to mediate chromatid separation during mitosis.     

Starch as a sugar reservoir for nematode-induced syncytia

The plant parasitic nematode Heterodera schachtii invades the roots of Arabidopsis thaliana to induce nematode feeding structures in the central cylinder. During nematode development, the parasites feed exclusively from these structures. Thus, high sugar import and specific sugar processing of the affected plant cells is crucial for nematode development. In the present work, we found starch accumulation in nematode feeding structures and therefore studied the expression genes involved in the starch metabolic pathway. The importance of starch synthesis was further shown using the Atss1 mutant line. As it is rather surprising to find starch accumulation in cells characterised by a high nutrient loss, we speculate that starch serves as long- and short-term carbohydrate storage to compensate the staggering feeding behaviour of the parasites.Key words: Heterodera schachtii, Arabidopsis, nematode, starch metabolism, syncytiaThe obligate plant parasitic nematode Heterodera schachtii is entirely dependent on a system of nutrient supply provided by the plant. Host plants—among those the model plant Arabidopsis thaliana—have to endure invasion of second stage juveniles and the establishment of nematode feeding structures in the plant''s vascular cylinder. For induction of the specific feeding structures, the juveniles pierce one single plant cell with their stylet and inject secretions, thus triggering the formation of a syncytium by local cell walls dissolutions.¹ Further, the central vacuole of the syncytial cells disintegrates, nuclei enlarge and many organelles proliferate.¹ About 24 hours after feeding site induction, the nematode juveniles start feeding in repetitive cycles.² Syncytia have previously been described as strong sinks in the plant''s transport system.³ Thus, in the recent years several studies were carried out to discover solute supply to syncytial cells.^4–7 To our present knowledge, syncytia are symplasmically isolated in the first days of nematode development. During that period, the nematodes depend on transport protein activity in the syncytia plasmamembranes. At later stages plasmodesmata appear to open to the phloem elements, facilitating symplasmic transport.Incoming solutes may either be taken up by the feeding nematode or are synthesised and catalysed by the syncytium''s metabolism. Due to the microscopically observable high density of the cytosol¹ and the increased osmotic pressure,⁸ syncytia appear to accumulate high solute concentrations. In fact, significantly increased sucrose levels have been found in syncytia in comparison to non-infected control roots.⁷ In case of high sugar levels, plant cells generally synthesize starch in order to reduce emerging osmotic stress.⁹ The aim of the work of Hofmann et al.,¹⁰ was to elucidate if starch is utilised as carbohydrate storage in nematode-induced syncytia and to study expression of genes involved in starch metabolism with an emphasis on nematode development.Starch levels of nematode induced syncytia and roots of non-infected plants grown on sand/soil culture were measured by high performance liquid chromatography (HPLC). The results showed a high accumulation of starch in syncytia that was steadily decreasing during nematode development. The accumulation of starch could further be localised within syncytial cells by electron microscopy. Based on these results, we studied the gene expression of the starch metabolic pathway by Affymetrix gene chip analysis. About half of the 56 involved genes were significantly upregulated in syncytia compared to the control and only two genes were significantly downregulated. Thus, the high induction of the gene expression is consistent with the high starch accumulation. Finally, we applied an Arabidopsis mutant line lacking starch synthase I expression that has been described previously.¹¹ Starch synthase I was the second highest upregulated gene in syncytia. It catalyses the linkage of ADP-glucose to the non-reducing end of an a-glucan, forming the linear glucose chains of amylopectin. In a nematode infection assay we were able to prove the significant importance of the gene for nematode development.With the presented results, we can unambiguously prove the accumulation of starch and the induction of the gene expression of the starch metabolic pathway in nematode-induced syncytia. The primary question however is: why do syncytia accumulate soluble sugars and starch although their metabolism is highly induced and nematodes withdraw solutes during continuously repeating feeding cycles?One explanation may be found where least expected—in nematode feeding. It is the feeding activity that induced solute import mechanisms into syncytia resulting in a newly formed sink tissue. However, during moulting events to the third, the fourth juvenile stage and to the adult stage nematodes interrupt feeding for about 20 hours.² During this period sugar supply mechanisms will most probably not be altered thus leading to increasing levels of sugars in the syncytium. Starch may serve as short-term carbohydrate buffering sugar excess. Further, starch may serve as long-term carbohydrate storage during nematode development. In the early stages of juvenile development nematodes withdraw considerably small quantities (about 0,8-times the syncytium volume a day).¹² At later stages, nutrient demand increases so that adult fertilised females require 4-times the syncytium volume per day in order to accomplish egg production.¹² Thus, excessive sugar supply in the first days may be accumulated as starch that gets degraded at later stages when more energy is required from the parasites. Consequently, starch reserve serves as both short-term and long-term carbohydrate storage in nematode-induced syncytia in order to buffer changing feeding pattern of the parasites.? Open in a separate windowFigure 1Arabidopsis wild-type Columbia-0 plants were grown in sand/soil culture. Nematode-induced syncytia and non-infected control roots were harvested at 10, 15 and 20 days after inoculation (dai) and starch content was measured as glucose (Glc) equivalents. Values are means ± SE, n = 3. Different letters indicate significant variations (p < 0.05). © ASPBOpen in a separate windowFigure 2Transmission electron microscope picture of a cross-section of a syncytium associated with female fourth stage juvenile (H. schachtii) induced in roots of Arabidopsis. Bar = 2 µm. S, syncytium; Se, sieve tube; arrow, plastid; asterisk, starch granule. © ASPB     

Immunoglobulin G galactosylation and sialylation are associated with pregnancy-induced improvement of rheumatoid arthritis and the postpartum flare: results from a large prospective cohort study

Introduction  

Improvement of rheumatoid arthritis (RA) during pregnancy has been causatively associated with increased galactosylation of immunoglobulin G (IgG) N-glycans. Since previous studies were small, did not include the postpartum flare and did not study sialylation, these issues were addressed in the present study.     

Antioxidant-chemoprevention diet ameliorates late effects of total-body irradiation and supplements radioprotection by MnSOD-plasmid liposome administration

Abstract Many acute and chronic effects of ionizing radiation are mediated by reactive oxygen species and reactive nitrogen species, which deplete antioxidant stores, leading to cellular apoptosis, stem cell depletion and accelerated aging. C57BL/6NHsd mice receiving intravenous MnSOD-PL prior to 9.5 Gy total-body irradiation (TBI) show increased survival from the acute hematopoietic syndrome, and males demonstrated improved long-term survival (Epperly et al., Radiat. Res. 170, 437-444, 2008). We evaluated the effect of an antioxidant-chemopreventive diet compared to a regular diet on long-term survival in female mice. Twenty-four hours before the LD(50/30) dose of 9.5 Gy TBI, subgroups of mice were injected intravenously with MnSOD-PL (100 μg plasmid DNA in 100 μl of liposomes). Mice on either diet treated with MnSOD-PL showed decreased death after irradiation compared to irradiated mice on the house diet alone (P = 0.031 for the house diet plus MnSOD-PL or 0.015 for antioxidant diet plus MnSOD-PL). The mice on the antioxidant-chemoprevention diet alone or with MnSOD-PL that survived 30 days after irradiation had a significant increase in survival compared to mice on the regular diet (P = 0.04 or 0.01, respectively). In addition, mice treated with MnSOD-PL only and surviving 30 days after radiation also had increased survival compared to those on the regular diet alone (P = 0.02). Survivors of acute ionizing radiation damage have ameliorated life shortening if they are fed an antioxidant-chemopreventive diet.