Functionally distinct high and low molecular weight species of channel catfish and mouse IL-1

Culture supernatants from channel catfish monocytes exhibit IL-1-like activity for mouse and catfish T cells. Gel filtration analyses of these supernatants indicated that there were at least two forms of IL-1-like activity, i.e. a high molecular weight form (70 kD) active on channel catfish, but not mouse, T cells and a low molecular weight form (approximately 15 kD) with activity for mouse, but not catfish, T cells. Both sizes of catfish IL-1 exhibited alpha and beta determinants as shown by Western blot analyses using antisera to human IL-1 alpha and IL-1 beta. Further evidence for the IL-1 nature of these molecules was obtained by antibody inhibition assays wherein antisera to human IL-1 alpha and IL-1 beta each neutralized approximately 50% of the catfish activities, were additive to some extent, and could be reversed by the addition of the proper human recombinant protein. In culture supernatants of murine P388D1 cells functional activities for catfish and mouse T cells were found only in high and low molecular weight fractions, respectively. Western blots with antiserum to mouse IL-1 alpha revealed IL-1 determinants in both high and low molecular fractions of the mouse cell culture supernatants. These data suggest that catfish and mammalian IL-1 molecules may be quite similar with the caveat being that functional activity for catfish T cells requires a large protein, presented as an aggregate, a polymer, or simply a single chain 70 kD protein. However, only the low molecular weight forms (30 and 15 kD) are active on mouse T cells.     

Presence of polyphosphate of low molecular weight in zygomycetes

Polyphosphate of average chain length corresponding to 10 phosphate units was detected in the mycelial extract of zygomycetes. Gel electrophoresis techniques commonly used for the separation and characterization of acidic mucopolysaccharides were successfully used for the detection, purification, and characterization of the polyphosphate.     

Fractional clearances of low molecular weight proteins in lead workers

The phenomenon of wanting to help another is a universal human experience. Individuals reach out to others in order to fulfill personal commitments, to assist loved ones, or to meet professional obligations. The purpose of this research using Parse's method was to generate the structure of this experience as lived by nurses. Findings indicate that the lived experience of wanting to help another is directing nurturing intentions amidst uplifting affirmations with others while dissonant constraints unfold new possibilities. Findings are discussed in light of Parse's theory in order to expand the knowledge base of nursing. Similarities and differences with research findings on the experiences of nurturance and caring are presented. Implications for practice and further research are specified for nurses encountering persons who express their desire to help another.     

Evidence for the presence of a kininogen-like species in a case of total deficiency of low and high molecular weight kininogens

EBI1-ligand chemokine (ELC) is a CC chemokine constitutively expressed in various lymphoid tissues and a high-affinity functional ligand for EBI1/CCR7, a seven transmembrane G-protein-coupled receptor originally identified as an Epstein-Barr virus (EBV)-inducible gene. Here we examined chemotactic activity of ELC on peripheral blood leukocytes. ELC attracted both CD4+ and CD8+ T cells, particularly efficiently after activation with IL-2 or with phytohemagglutinin (PHA) plus IL-2, as well as CD19+ B cells, but not CD16+ NK cells, CD14+ monocytes or neutrophils. Among CD3+ T cells, ELC attracted both CD45RO- naive and CD45RO+ memory subsets. ELC also induced vigorous calcium mobilization in T cells stimulated with IL-2 with an ED50 of 3 nM. ELC fused with the secreted form of alkaline phosphatase (ELC-SEAP) specifically bound to lymphocytes and this binding was blocked only by ELC among 10 CC chemokines so far tested. Notably, lymphocytes stimulated with IL-2 or T cells expanded by PHA plus IL-2 showed much higher levels of binding than fresh lymphocytes. Consistently, CCR7 mRNA was detected in CD4+ and CD8+ T cells as well as B cells, but not in NK cells, monocytes or neutrophils, and was dramatically increased in T cells upon treatment with IL-2 or with PHA plus IL-2. Like ELC mRNA, CCR7 mRNA was expressed in various lymphoid tissues. By in situ hybridization, ELC and CCR7 mRNA were detected in the parafollicular and inner cortical regions of a lymph node, and in the parafollicular regions of an appendix. Collectively, ELC and CCR7 may be involved in the trafficking of a broad spectrum of lymphocytes, especially activated T cells, into and within various lymphoid tissues.     

Multifunctional tryptophan-synthesizing enzyme. The molecular weight of the Euglena gracilis protein is unexpectedly low

After developing a suitable procedure to produce large amounts of Euglena gracilis as well as a reliable protocol to purify the multifunctional tryptophan-synthesizing enzyme derived from it (Schwarz, T., Bartholmes, P., and Kaufmann, M. (1995) Biotechnol. Appl. Biochem. 22, 179-190), we here describe structural and catalytic properties of the multifunctional tryptophan-synthesizing enzyme. The kinetic parameters kcat of all five activities and Km for the main substrates were determined. The relative molecular weight under denaturing conditions as judged by SDS-polyacrylamide gel electrophoresis is 136,000. Cross-linking as well as gel filtration experiments revealed that the enzyme exists as a homodimer. Neither intersubunit disulfide linkages nor glycosylations were detected. On the other hand, the polypeptide chains are blocked N-terminally. Complete tryptic digestion of the protomer, high pressure liquid chromatography separation of the resulting peptides, and N-terminal sequence analysis of homogenous peaks as judged by matrix-assisted laser/desorption ionization time-of-flight mass spectrometry was performed. Depending on the sequenced peptides, alignments to all entries of the SwissProt data base resulted in both strong sequence homologies to known Trp sequences and no similarities at all. Proteolytic digestion under native conditions using endoproteinase Glu-C uncovered one major cleavage site yielding a semistable, N-terminally blocked fragment with a molecular weight of 119,000. In addition, an increase in beta-elimination accompanied by a decrease in beta-replacement activity of the beta-reaction during proteolysis was observed.     

Efficacy and safety of low molecular weight heparin in renal transplantation

BACKGROUND: Deep venous thrombosis (DVT) is a common problem with potentially devastating results in patients undergoing major surgical procedures. Certain renal transplant recipients are particularly at risk for allograft loss as a consequence of renal vein and artery thrombosis. Over the past few years, low molecular weight heparin has been well established as an accepted modality of treatment and prophylaxis of DVT. The efficacy and safety of low molecular weight heparin in the prophylaxis of DVT following renal transplantation in adults has not previously been reported. METHODS: Dalteparin was administered to 120 adult renal transplant recipients postoperatively at the Oregon Health Sciences University. RESULTS: No patient developed allograft arterial or venous thrombosis. One patient developed subclavian vein thrombosis. No bleeding complications were encountered, and side effects were very minimal. CONCLUSION: Prophylaxis with dalteparin is an effective and safe modality for the prevention of thrombosis in adult patients undergoing renal transplantation.     

Oral delivery of low molecular weight heparin in rat cardiac allografts

A 44 yr-old female with severe pulmonary emphysema and reduced alpha-1-protease inhibitor (alpha1-PI) serum levels developed an acute anaphylactic reaction following the third intravenous infusion of human alpha1-PI which was administered to prevent the progression of pulmonary emphysema. Specific immunoglobulin E-antibodies against human alpha1-PI could be demonstrated in the patient's serum using an enzyme allergosorbent test. Because of the risk of further severe anaphylactic reaction, the replacement therapy with alpha1-PI was discontinued. Physicians should be aware of this rare complication.     

Alterations of low molecular weight acid phosphatase protein level in Alzheimer''s disease

We have previously reported that the activity of low molecular weight (LMW) acid phosphatase, which can remove tyrosine-linked phosphates of epidermal growth factor receptor, was significantly decreased in Alzheimer brains. In the present study, a specific antibody was prepared to analyze the protein level of this enzyme. Western blot analysis indicated that the level of LMW acid phosphatase protein was significantly reduced, whereas the activity of LMW acid phosphatase per enzyme molecule was not changed in Alzheimer brains. These results suggest that the reduction of LMW acid phosphatase activity in Alzheimer brains is due to its decreased protein level in Alzheimer's disease.     

Anticoagulation in hemodialysis with a single dose of low molecular weight heparin

The aim of this work was to compare the benefits and problems of low molecular weight heparin use in chronic hemodialysis, compared to conventional heparin. We studied 35 patients that received low molecular weight heparin (Enoxaparine, molecular weight 4000) during 115 consecutive hemodialysis procedures and conventional heparin during the subsequent 35 procedures. We assess the heparin dose, partial thromboplastin time before dialysis and at 3 and 120 min during the procedure, arterio-venous fistula compression time, clot formation in the circuit and residual volume of filters. Median total dose of conventional heparin was 6289 U (range 3000-10000) compared to 5555 U (range 2000-8000) of low molecular weight heparin. When the dose was calculated per kg of body weight, it was lower for low molecular weight heparin than for conventional heparin (87.8 U (range 33-100) vs 100 U (range 50-176)). Partial thromboplastin time achieved was lower with low molecular weight heparin, compared with conventional heparin, at 3 (64.26 vs 125.2 sec) and 120 min (39.1 vs 84.45 sec). Clot formation, arteriovenous fistula compression time and residual volume of filters were similar for both types of heparin. It is concluded that a single dose of low molecular weight heparin simplifies anticoagulation during hemodialysis, modifies less the partial thromboplastin time and does not alter filter re-utilization.     

Uptake of low molecular weight materials in an in situ preparation of the rabbit thoracic aorta

1. An in situ preparation of the rabbit thoracic aorta is described in which the integrity of the intimal endothelium is shown to be preserved. An extensive system of vasa vasorum and lymphatic vessels distributed throughout the adventitia, but not penetrating the media, are demonstrated using resin casts and lead chromate precipitation techniques and are shown to be patent in this preparation. 2. The role of the vasa vasorum in the medial uptake of low molecular weight materials is investigated as a function of luminal hydrostatic pressure and perfusion time. Comparison of uptake in vessels with and without patent vasa vasorum indicates that at physiological pressures medial uptake of 125I ions is dominated by entry from the adventitial surface. Analysis of the transmural distribution of 125I demonstrates that iodide is not retarded at the endothelial surface but a barrier exists within the intima which is tentatively identified as the internal elastic lamina. Qualitative studies show that Patent Blue V whose coloured anion has a molecular weight of 500 is able, at longer perfusion times, to penetrate this barrier. There is no circumferential variation in intimal uptake, but in contrast, adventitial uptake is rather patchy and generally more intense on the dorsal surfaces of the aorta. 3. Iodide transport across the intimal surface is argued to be predominantly diffusive in short duration experiments with an effective diffusion coefficient of (1.6 +/- 0.9) X 10(-6) cm2 min-1.     

Pharmacokinetics of a low molecular weight heparin (reviparine) in hemodialyzed patients

Low-molecular-weight heparins (LMWHs) are used to prevent clotting in hemodialysis extracorporeal blood circuits. In order to test the possibility of using reviparine (a LMWH of 3,900 D) in this indication, we studied the pharmacokinetics of the drug after a mean dose of 3,300 IU anti-Xa in 10 hemodialyzed patients. Reviparine was administered subcutaneously between two dialysis sessions and intravenously at the start of 20 dialysis sessions performed either with high (HP) or low-permeability (LP) membranes. We observed a moderate increase of the elimination half-life of reviparine (T1/2: 5 +/- 1.6 h between dialysis, 3.6 +/- 1.3 during dialysis with an HP membrane and 4.7 +/- 1.8 during dialysis with an LP membrane) versus 3.3 +/- 1 in healthy volunteers. Dialysis procedures with an HP or an LP membrane do not importantly modify the pharmacokinetics of reviparin compared with data observed in healthy volunteers. During the sessions, we observed no clotting in the extracorporeal circuit, no hemorrhagic event and no prolongation of the fistula compression times. Further clinical studies are required to define the optimal dosage of reviparine to prevent coagulation in hemodialysis blood circuits.     

Release of low molecular weight silicones and platinum from silicone breast implants

We have conducted a series of studies addressing the chemical composition of silicone gels from breast implants as well as the diffusion of low molecular weight silicones (LM-silicones) and heavy metals from intact implants into various surrounding media, namely, lipid-rich medium (soy oil), aqueous tissue culture medium (modified Dulbecco's medium, DMEM), or an emulsion consisting of DMEM plus 10% soy oil. LM-silicones in both implants and surrounding media were detected and quantitated using gas chromatography (GC) coupled with atomic emission (GC-AED) as well as mass spectrometric (GC/MS) detectors, which can detect silicones in the nanogram range. Platinum, a catalyst used in the preparation of silicone gels, was detected and quantitated using inductive argon-coupled plasma/mass spectrometry (ICP-MS), which can detect platinum in the parts per trillion range. Our results indicate that GC-detectable low molecular weight silicones contribute approximately 1-2% to the total gel mass and consist predominantly of cyclic and linear poly-(dimethylsiloxanes) ranging from 3 to 20 siloxane [(CH3)2-Si-O] units (molecular weight 200-1500). Platinum can be detected in implant gels at levels of approximately 700 micrograms/kg by ICP-MS. The major component of implant gels appears to be high molecular weight silicone polymers (HM-silicones) too large to be detected by GC. However, these HM-silicones can be converted almost quantitatively (80% by mass) to LM-silicones by heating implant gels at 150-180 degrees C for several hours. We also studied the rates at which LM-silicones and platinum leak through the intact implant outer shell into the surrounding media under a variety of conditions. Leakage of silicones was greatest when the surrounding medium was lipid-rich, and up to 10 mg/day LM-silicones was observed to diffuse into a lipid-rich medium per 250 g of implant at 37 degrees C. This rate of leakage was maintained over a 7-day experimental period. Similarly, platinum was also observed to leak through intact implants into lipid-containing media at rates of approximately 20-25 micrograms/day/250 g of implant at 37 degrees C. The rates at which both LM-silicones and platinum have been observed to leak from intact implants could lead to significant accumulation within lipid-rich tissues and should be investigated more fully in vivo.     

Mutations in CLCN5 chloride channel in Japanese patients with low molecular weight proteinuria

It was hypothesized based on previous laboratory observations and theoretical concepts that astronauts working at the "Mir" station under zero gravity conditions exhibit enhanced sensitivity to geomagnetic disturbances. The result of studies made it possible to reveal the dynamics of changes in cardiovascular characteristics separately in the main phase and the phase of storm restoration. A similar dynamics of cardiac activity was observed in experimental rabbits during geomagnetic storms.     

Comparison of biological activity of high molecular weight and low molecular weight forms of immunoreactive prolactin from human serum in cultured lymphoma NB2 cells

The aim of this study was to determine the cardiac performance of conscious healthy dogs during stimulation with dobutamine. Eight healthy unsedated beagle dogs were used. Cardiac output was measured by the thermodilution technique and blood pressures by extravascular pressure transducers. Dobutamine challenge at a dosage ranging from 27.5 to 50 micrograms kg-1 min-1 induced a significant rise in cardiac power index (CPI), cardiac index (CI), stroke index (SI) and heart rate (HR) and a significant decrease in pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR). The highest CPI was 2.05 times greater than its basal resting value. The CI was primarily responsible for this increase in CPI. The SI and HR contributed approximately 55 per cent and 45 per cent respectively of the maximal increase in CI.