We purified from pea (Pisum sativum) tissue an Ϸ40 kDa reversibly glycosylated polypeptide (RGP1) that can be glycosylated by UDP-Glc, UDP-Xyl, or UDP-Gal, and isolated a cDNA encoding it, apparently derived from a single-copy gene (Rgp1). Its predicted translation product has 364 aminoacyl residues and molecular mass of 41.5 kDa. RGP1 appears to be a membrane-peripheral protein. Immunogold labeling localizes it specifically to trans-Golgi dictyosomal cisternae. Along with other evidence, this suggests that RGP1 is involved in synthesis of xyloglucan and possibly other hemicelluloses. Corn (Zea mays) contains a biochemically similar and structurally homologous RGP1, which has been thought (it now seems mistakenly) to function in starch synthesis. The expressed sequence database also reveals close homologs of pea Rgp1 in Arabidopsis and rice (Oryza sativa). Rice possesses, in addition, a distinct but homologous sequence (Rgp2). RGP1 provides a polypeptide marker for Golgi membranes that should be useful in plant membrane studies.

Sudden death is one of the more frequent causes of death for hemodialysis patients, but the underlying mechanisms, contribution of arrhythmia, and associations with serum chemistries or the dialysis procedure are incompletely understood. To study this, implantable loop recorders were utilized for continuous cardiac rhythm monitoring to detect clinically significant arrhythmias including sustained ventricular tachycardia, bradycardia, asystole, or symptomatic arrhythmias in hemodialysis patients over six months. Serum chemistries were tested pre- and post-dialysis at least weekly. Dialysis procedure data were collected at every session. Associations with clinically significant arrhythmias were assessed using negative binomial regression modeling. Sixty-six patients were implanted and 1678 events were recorded in 44 patients. The majority were bradycardias (1461), with 14 episodes of asystole and only one of sustained ventricular tachycardia. Atrial fibrillation, although not defined as clinically significant arrhythmias, was detected in 41% of patients. With thrice-weekly dialysis, the rate was highest during the first dialysis session of the week and was increased during the last 12 hours of each inter-dialytic interval, particularly the long interval. Among serum and dialytic parameters, only higher pre-dialysis serum sodium and dialysate calcium over 2.5 mEq/L were independently associated with clinically significant arrhythmias. Thus, clinically significant arrhythmias are common in hemodialysis patients, and bradycardia and asystole rather than ventricular tachycardia may be key causes of sudden death in hemodialysis patients. Associations with the temporal pattern of dialysis suggest that modification of current dialysis practices could reduce the incidence of sudden death.

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The ultrastructure of cotton (Gossypium hirsutum) seed trichomes was investigated to obtain insight into their growth behavior during the phase of rapid cell elongation. A mold and cast method of scanning electron microscopy was used to record the morphological changes in the ovular surface during the initiation and elongation of trichomes. A rapid freeze-fixation and freeze-substitution protocol was used to study the cytological features of trichomes at 2 days after anthesis. At the cytological level, attention was primarily focused on determining whether the seed trichomes display features that are characteristic of other tip-growing plant cells, including organelle zonation, polarized deposition of cell wall, axial orientation of microtubules, and microfilament meshwork at the cell apex. Our results show that cotton seed trichomes do not share any ultrastructural characteristic with other tip-growing plant cells. Rather, they show all the characteristics of cells that undergo diffuse growth. The roles of actin microfilaments and microtubules were also investigated through an in vitro administration of cytochalasin D and colchicine. Although the disruption of actin filaments did not stop trichome growth, disruption of microtubules did prevent polarized cell expansion. Based on these results, cotton seed trichomes are not tip-growing cells but expand via diffuse growth. Key words: cytoskeleton, freeze-fixation, freeze-substitution, Gossypium hirsutum, lint fibers, tip growth, trichomes.

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OSM is a frequent finding in adult patients with NS, even at a normal level of renal function. Its severity correlates with the amount and duration of proteinuria.

We associate intrinsic energy equal to hν/2 with the spin angular momentum of photon and propose a topological model based on orbifold in space and tifold in time as topological obstructions.The model is substantiated using vector wavefield disclinations. The physical photon is suggested to be a particle like topological photon and a propagating wave such that the energy hν of photon is equally divided between spin energy and translational energy corresponding to linear momentum of hν/c. The enigma of wave-particle duality finds natural resolution and the proposed model gives new insights into the phenomena of interference and emission of radiation.