Genetic transformation system in the archaebacterium Methanobacterium thermoautotrophicum Marburg.

A wild-type strain of Methanobacterium thermoautotrophicum Marburg was transformed by DNA from strains resistant to 5-fluorouracil. Recipient cells were grown without selection on gellan gum (GELRITE) plates with DNA. Drug-resistant cells were recovered by replica plating the resulting colonies onto drug plates. Transformation required high-molecular-weight DNA with appropriate markers and was not observed on agar or in liquid media under a variety of conditions.     

Expression of a maize sucrose phosphate synthase in tomato alters leaf carbohydrate partitioning.

We isolated a complementary DNA sequence for the enzyme sucrose phosphate synthase (SPS) from maize utilizing a limited amino acid sequence. The 3509-bp cDNA encodes a 1068-amino acid polypeptide. The identity of the cDNA was confirmed by the ability of the cloned sequence to direct sucrose phosphate synthesis in Escherichia coli. Because no plant-specific factors were necessary for enzymatic activity, we can conclude that SPS enzyme activity is conferred by a single gene product. Sequence comparisons showed that SPS is distantly related to the enzyme sucrose synthase. When expressed from a ribulose bisphosphate carboxylase small subunit promoter in transgenic tomatoes, total SPS activity was boosted up to sixfold in leaves and appeared to be physiologically uncoupled from the tomato regulation mechanism. The elevated SPS activity caused a reduction of starch and increase of sucrose in the tomato leaves. This result clearly demonstrates that SPS is involved in the regulation of carbon partitioning in the leaves.     

Fascioloides magna (Bassi, 1875) in feral swine from southern Texas.

Between 1971 and 1975, Fascioloides magna was found in 46 of 67 (69%) feral swine (Sus scrofa) in southern Texas. Flukes were recovered from swine in areas where F. magna commonly has been recovered from white-tailed deer and cattle. One to 12 flukes were recovered from each infected animal. Their presence was indicated by black hematin pigment on the liver and various other internal organs. Eggs were not detected in the gallbladder or feces of infected animals although mature flukes and eggs were recovered in the livers suggesting that, like cattle, feral swine can be infected but are aberrant hosts for the parasite and do not disseminate eggs.     

Scots pine growing on forested mires in Abernethy Forest,Strathspey, Scotland

Summary

A substantial proportion of the Abernethy Forest Reserve has Scots pine (Pinus sylvestris) growing on the surfaces of a variety of mires. The hydrology of the mires has been affected by drainage and peat cutting but this area is unusual in having had a long period of protection from grazing by domestic stock. There are three main types of pine populations found on these mires. Woodland bog comprises predominantly bog vegetation with abundant pine seedlings due to the heavy seed rain from the surrounding woodland. Only a few very small trees survive, which are stunted, heavily diseased and have very low seed production. Wooded bog also comprises predominately bog vegetation but there are scattered mature trees of a moderate height with an open canopy. The trees are fertile and can form uneven aged stands with regeneration. Bog woodland is a predominantly woodland vegetation with tall, dense tree cover on deep peat. The trees are well grown with a dense canopy. A few remnants of bog vegetation remain in the ground flora although most have been replaced by woodland bryophytes and shrubs. Each of these three types is described and their development is discussed.     

The footprint of antibody bound to pig cells: evidence of complex surface topology

The disaccharide Gal(alpha)1-3Gal is found on more than 45 different molecules on the endothelium of porcine cells and has recently attracted considerable interest, being the major target recognized by xenoreactive antibodies. In this study, the distribution and topology of Gal(alpha)1-3Gal on porcine endothelial cells was examined to access whether some Gal(alpha)1-3Gal-containing molecules might be preferentially recognized by antibodies binding to Gal(alpha)1-3Gal. Thirteen percent of the Gal(alpha)1-3Gal was found on glycolipid and 87% on glycoproteins. Of all the glycoproteins and glycolipids containing Gal(alpha)1-3Gal, two molecules, fibronectin and the integrin beta1 subunit, were most intensely labeled by galactose oxidase, suggesting that these molecules may be preferentially exposed on the apical surface of the endothelium. Binding of anti-Gal(alpha)1-3Gal antibodies to endothelial cell surfaces significantly diminished labeling of fibronectin and the integrin beta1 subunit by galactose oxidase, indicating that these glycoproteins are targets for the antibodies when binding to intact porcine cells.     

IL-11 and IL-11Rα immunolocalisation at primate implantation sites supports a role for IL-11 in placentation and fetal development

Embryo implantation, endometrial stromal cell decidualization and formation of a functional placenta are critical processes in the establishment and maintenance of pregnancy. Interleukin (IL)-11 signalling is essential for adequate decidualization in the mouse uterus and IL-11 promotes decidualization in the human. IL-11 action is mediated via binding to the specific IL-11 receptor α (IL-11Rα). The present study examined immunoreactive IL-11 and IL-11Rα in cycling rhesus monkey endometrium, at implantation sites in cynomolgus and rhesus monkeys and in human first trimester decidua and defined distinct spatial and temporal patterns. In cycling rhesus monkey endometrium, IL-11 and IL-11Rα increased in both basalis and functionalis regions during the secretory compared with the proliferative phase, with changing cellular locations in luminal and glandular epithelium and stroma. The patterns were similar overall to those previously described in human endometrium. Differences were seen in immunostaining during implantation in cynomologus and rhesus monkey. In the cynomolgus, very little staining for IL-11 or IL-11Rα was seen in syncytio- and cyto-trophoblast cells in the villi between days 12 and 150 of pregnancy although there was moderate staining in cytotrophoblast in the shell between days 12 and 17 and in subpopulations of cytotrophoblast cells invading the arteries at day 17. By contrast in the rhesus monkey between days 24 and 35 of pregnancy and in human first trimester placenta, cyto- and syncytio-trophoblast in the villi but not cytotrophoblast in the shell were positively stained. The most intense staining for both IL-11 and IL-11Rα was present within the decidua in the maternal component of implantation sites in all three primates but moderate staining was also present in maternal vascular smooth muscle and glands perivascular cells and epithelial plaques. These results are consistent with a role for IL-11 both during decidualization and placentation in primates.     

Bryostatin-1 attenuates TNF-induced epithelial barrier dysfunction: role of novel PKC isozymes

Tumor necrosis factor (TNF) increases epithelial permeability in many model systems. Protein kinase C (PKC) isozymes regulate epithelial barrier function and alter ligand-receptor interactions. We sought to define the impact of PKC on TNF-induced barrier dysfunction in T84 intestinal epithelia. TNF induced a dose- and time-dependent fall in transepithelial electrical resistance (TER) and an increase in [(3)H]mannitol flux. The TNF-induced fall in TER was not PKC mediated but was prevented by pretreatment with bryostatin-1, a PKC agonist. As demonstrated by a pattern of sensitivity to pharmacological inhibitors of PKC, this epithelial barrier preservation was mediated by novel PKC isozymes. Bryostatin-1 reduced TNF receptor (TNF-R1) surface availability, as demonstrated by radiolabeled TNF binding and cell surface biotinylation assays, and increased TNF-R1 receptor shedding. The pattern of sensitivity to isozyme-selective PKC inhibitors suggested that these effects were mediated by activation of PKC-epsilon. In addition, after bryostatin-1 treatment, PKC-delta and TNF-R1 became associated, as determined by mutual coimmunoprecipitation assay, which has been shown to lead to receptor desensitization in neutrophils. TNF-induced barrier dysfunction occurs independently of PKC, but selective modulation of novel PKC isozymes may regulate TNF-R1 signaling.     

S-adenosyl-L-homocysteine hydrolase is necessary for aldosterone-induced activity of epithelial Na(+) channels

The A6 cell line was used to study the role ofS-adenosyl-L-homocysteine hydrolase (SAHHase) inthe aldosterone-induced activation of the epithelial Na⁺channel (ENaC). Because aldosterone increases methylation of severaldifferent molecules, and because this methylation is associated withincreased Na⁺ reabsorption, we tested the hypothesis thataldosterone increases the expression and activity of SAHHase protein.The rationale for this work is that general methylation may be promotedby activation of SAHHase, the only enzyme known to metabolize SAH, apotent end-product inhibitor of methylation. Although aldosteroneincreased SAHHase activity, steroid did not affect SAHHase expression.Antisense SAHHase oligonucleotide decreased SAHHaseexpression and activity. Moreover, this oligonucleotide, as well as apharmacological inhibitor of SAHHase, decreased aldosterone-inducedactivity of ENaC via a decrease in ENaC open probability. The kineticsof ENaC in cells treated with antisense plus aldosterone were similarto those reported previously for the channel in the absence of steroid. This is the first report showing that active SAHHase, in part, increases ENaC open probability by reducing the transition rate fromopen states in response to aldosterone. Thus aldosterone-induced SAHHase activity plays a critical role in shifting ENaC from a gatingmode with short open and closed times to one with longer open andclosed times.

     

Accelerated hand bone mineral density loss is associated with progressive joint damage in hands and feet in recent-onset rheumatoid arthritis

Introduction

To investigate whether accelerated hand bone mineral density (BMD) loss is associated with progressive joint damage in hands and feet in the first year of rheumatoid arthritis (RA) and whether it is an independent predictor of subsequent progressive total joint damage after 4 years.

Methods

In 256 recent-onset RA patients, baseline and 1-year hand BMD was measured in metacarpals 2-4 by digital X-ray radiogrammetry. Joint damage in hands and feet were scored in random order according to the Sharp-van der Heijde method at baseline and yearly up to 4 years.

Results

68% of the patients had accelerated hand BMD loss (>-0.003 g/cm²) in the first year of RA. Hand BMD loss was associated with progressive joint damage after 1 year both in hands and feet with odds ratios (OR) (95% confidence intervals [CI]) of 5.3 (1.3-20.9) and 3.1 (1.0-9.7). In univariate analysis, hand BMD loss in the first year was a predictor of subsequent progressive total joint damage after 4 years with an OR (95% CI) of 3.1 (1.3-7.6). Multivariate analysis showed that only progressive joint damage in the first year and anti-citrullinated protein antibody positivity were independent predictors of long-term progressive joint damage.

Conclusions

In the first year of RA, accelerated hand BMD loss is associated with progressive joint damage in both hands and feet. Hand BMD loss in the first year of recent-onset RA predicts subsequent progressive total joint damage, however not independent of progressive joint damage in the first year.