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PubMed1983

C Tracer Evidence for Synthesis of Choline and Betaine via Phosphoryl Base Intermediates in Salinized Sugarbeet Leaves.

Like other chenopods, sugarbeets (Beta vulgaris L. cv Great Western D-2) accumulate glycine betaine when salinized; this may be an adaptive response to stress. The pathway of betaine synthesis in leaves of salinized (150-200 millimolar NaCl) sugarbeet plants was investigated by supplying [(14)C]formate, phosphoryl[(14)C]monomethylethanolamine ([(14)C][unk] MME) or phosphoryl[(14)C]choline ([(14)C][unk] choline) to leaf discs and following (14)C incorporation into prospective intermediates. The (14)C kinetic data were used to develop a computer model of the betaine pathway.When [(14)C]formate was fed, [unk] MME, phosphoryldimethylethanolamine ([unk] DME) and [unk] choline were the most prominent methylated products at short labeling times, after which (14)C appeared in free choline and in betaine. Phosphatidylcholine labeled more slowly than [unk] choline, choline, and betaine, and behaved as a minor end product. Very little (14)C entered the free methylethanolamines. When [(14)C][unk] MME was supplied, a small amount was hydrolyzed to the free base but the major fate was conversion to [unk] DME, [unk] choline, free choline, and betaine; label also accumulated slowly in phosphatidylcholine. Label from supplied [(14)C][unk] choline entered choline and betaine rapidly, while phosphatidylcholine labeled only slowly and to a small extent.These results are consistent with the pathway [unk] MME -->[unk] DME --> [unk] choline --> choline --> --> betaine, with a minor side branch leading from [unk] choline into phosphatidylcholine. This contrasts markedly (a) with the pathway of stress-induced choline and betaine synthesis in barley, in which phosphatidylcholine apparently acts as an intermediate (Hitz, Rhodes, Hanson 1981, Plant Physiol 68: 814-822); (b) with choline biogenesis in mammalian liver and microorganisms. Computer modeling of the experimental data pointed strongly to regulation at the [unk] choline --> choline step, and also indicated that the rate of [unk] choline synthesis is subject to feedback inhibition by [unk] choline.

Journal Article↗
PubMed1986

Effect of modification of membrane phospholipid composition on phospholipid methylation in aggregating cell culture.

The effect of the presence of nitrogenous bases in the growth medium of fetal rat brain aggregating cell cultures was investigated. The presence of either N-methylethanolamine (MME) or N,N-dimethylethanolamine (DME) in the growth medium resulted in significant increase of the corresponding phospholipid, phosphatidyl-N-monomethylethanolamine (PMME) or phosphatidyl-N,N-dimethylethanolamine (PDME). They represented 28% and 32% of the total phospholipids, respectively. The presence of the new phospholipids was accompanied by a significant decrease of phosphatidylethanolamine (PE) and phosphatidylcholine (PC). Cells grown in the presence of ethanolamine or choline had only barely detectable amounts of PMME and PDME. Intact cells previously grown with the bases were incubated with [methyl-3H]methionine. Incubation of cells previously grown in presence of the bases MME and DME resulted in a marked increase of radioactivity in the corresponding phospholipids possessing one additional methyl group, PDME and PC respectively. The incorporation of S-adenosyl[methyl-3H]methionine (AdoMet) was examined in cell homogenates incubated in presence or absence of either PMME or PDME acceptors. The addition of these exogenous phospholipids caused a three-or fourfold stimulation of radioactivity incorporated into the total phospholipids of cells grown in the absence of nitrogen bases. The cells grown in presence of either MME or DME in the culture medium did not show an increased incorporation of methyl groups from AdoMet into the total phospholipids after addition of exogenous acceptors. This work suggests that MME and DME incorporated into the corresponding phospholipids function as effective substrates for phospholipid-N-methylation.

Animals↗
PubMed2003

Human masticatory muscle forces during static biting.

Muscle forces determine joint loads, but the objectives governing the mix of muscle forces involved are unknown. This study tested the hypothesis that masticatory muscle forces exerted during static biting are consistent with objectives of minimization of joint loads (MJL) or muscle effort (MME). To do this, we compared numerical model predictions with data measured from six subjects. Biting tasks which produced moments on molar and incisor teeth were modeled based on MJL or MME. The slope of predicted vs. electromyographic (EMG) data for an individual was compared with a perfect match slope of 1.00. Predictions based on MME matched best with EMG activity for molar biting (slopes, 0.89-1.16). Predictions from either or both models matched EMG results for incisor biting (best-match slopes, 0.95-1.07). Muscle forces during isometric biting appear to be consistent with objectives of MJL or MME, depending on the individual, biting location, and moment.

Adult↗
PubMed1992

Inhibition of basal and tumor necrosis factor-enhanced binding of murine tumor cells to murine endothelium by transforming growth factor-beta 1.

The adherence of cells to microvascular endothelium is important in a number of processes, including inflammatory responses and metastasis. It has been demonstrated that in human models, cytokines such as TNF, IL-1, IFN-gamma increase the adhesiveness of endothelium for cells of the immune and inflammatory system by stimulating the expression of cell adhesion molecules on endothelial cell surfaces. We and others have shown similar cytokine-induced endothelial adhesiveness for tumor cells in murine and human models. In contrast to the effect of those modulators, transforming growth factor-beta (TGF-beta) has been shown to inhibit the binding of human neutrophils and T lymphocytes to human endothelium, although the mechanism of TGF-beta action remains unknown. Little is known about the effect of TGF-beta on tumor cell-endothelial interaction. In the present study, we demonstrate that TGF-beta inhibits basal and TNF-enhanced binding of murine P815 mastocytoma cells to murine microvascular endothelium (MME). The alterations in MME mediated by TGF-beta, also lead to the inhibition of adherence of murine splenocytes, thymocytes, and human lymphoblastoid cells but do not inhibit adherence of murine B16 melanoma cells. The effect of TGF-beta is transient and inhibition of the endothelial adhesive phenotype is strongest 12 to 24 h after addition of the factor to MME. The TGF-beta-mediated inhibition of P815 basal binding to endothelium is dependent on protein synthesis because cycloheximide reverses the TGF-beta effect. TGF-beta does not appear to activate classical signal transduction pathways. Inhibitors of G proteins do not abolish TGF-beta action, protein kinase C and protein kinase A activators elicit an effect opposite to that of the factor, TGF-beta does not increase intracellular cAMP levels, and finally calcium-mobilizing agents do not mimic, but rather inhibit the effect of TGF-beta. However, TGF-beta-mediated inhibition of both basal binding and TNF-enhanced P815 binding to MME is completely abolished in the presence of the protein phosphatase inhibitor okadaic acid which suggests that TGF-beta may elicit its effect by stimulating protein phosphatase activity.

Animals↗
PubMed2004

[Ergonomic bases of improving the quality of military medical equipment].

The definitions for the concepts of quality of military medical equipment (MME) sample and quality indices are given. The general ergonomic indices of the sample quality are presented. The heterogeneity of elements of "medical specialist--military medical equipment--the wounded--environment" system is shown the successful synthesis of which requires the co-ordination of technical, constructive factors, characteristics of the sample and human (personal) factors of medical specialist. The ergonomic defects typical of MME samples are revealed and the ways to improve the ergonomic characteristics of MME samples are charted. Some ergonomic aspects to improve the MME sample quality are described.

Equipment Design↗
PubMed2006

[Anti tumor activities of lentinan and micellapist in tumor-bearing mice].

Although Lentinan (LNT) is sold as a medicine, and Micellapist (MME) sold as a food supplement, both LNT and MME are beta-glucans isolated from the Shiitake mushroom (Lentinula edodes). These two substances have been thought to be the same component of Shiitake. In the present study, we evaluated anti tumor activities of LNT and MME in tumor-bearing mice (B10.D2 mice implanted with S908D2 tumor cells) and examined the mechanism of immunopotentiation of these substances. The tumor growth was significantly suppressed in the LNT-treated group. In ex vivo evaluation, the tumor cytotoxicity was significantly reduced by a treatment of splenocytes with anti-CD8 antibody in the LNT-treated group. Furthermore, the tumor cytotoxicity of the LNT-treated group was also significantly reduced by a treatment of splenocytes with anti-CD8 antibody and its complement and with an anti-CD4 and its complement in the effector phase and the induction phase, respectively. A significant prolongation of the survival of tumor-bearing mice as compared to the untreated control group was noted in the LNT-treated group. In the mice treated intraperitoneally with LNT, CD8-positive cells appeared to have suppressed tumor cell proliferation. CD4-positive cells appeared to be involved in this activity of CD8-positive cells. On the other hand, orally administered MME has exerted no clear cytotoxic effects.

Adjuvants, Immunologic↗
PubMed1991

Determinants of focal and segmental glomerulosclerosis in the rat after renal ablation. Evidence for involvement of macrophages and lipids.

The present study was undertaken to estimate the relative impact of a number of clinicopathologic and glomerular structural changes on severity and composition of focal and segmental glomerular sclerosis (FGS) in rats subjected to renal ablation. Groups of eight 1 1/2-nephrectomized (Nx) and sham-operated (Sh) male Wistar rats were studied at intervals of 2, 4, 8, 12, and 16 weeks. At sacrifice, kidney tissue was embedded in glycolmethacrylate to achieve optimal morphology for light microscopy, immunohistochemistry, and morphometry. FGS lesions were defined by the presence of focal and segmental glomerular scarring and collapse of the glomerular tuft with increased mesangial cellularity (MC), mesangial matrix expansion (MME), and adhesions between the tuft and Bowman's capsule (Adh). The severity of FGS and extent of MC, MME, and Adh was graded seimquantitatively to establish an injury score. The dependence of FGS injury score and of the scores of MC, MME, and Adh on a variety of clinicopathologic and glomerular structural alterations, taking account of possible correlations among them, was estimated with partial correlation and multiple linear regression analysis. The structural parameters included hyalinosis (H, PAS stain), glomerular lipid deposits (GLD, Oil Red O stain), glomerular volume expansion (GVE, morphometry), glomerular cellular proliferation (labeling of S-phase cells by 5 bromo-2'-deoxyuridine, BrdU)--and glomerular influx of macrophages (m phi), T cells, natural killer cells, and granulocytes (immunohistochemistry with mouse monoclonal antibodies). The clinicopathologic variables were urinary protein excretion (UP), fasting serum cholesterol levels (FChol), body weight (BW), total wet kidney weight (KW), heart weight (HW), and systolic blood pressure (SBP). The best fitting linear regression model, explaining 91% of the total variation of the FGS injury score (multiple r2 = 0.91), included UP as the main clinical, and H as the main structural variable. MC was explained best by BrdU incorporation (multiple r2 = 0.77). The optimal regression model describing MME contained the variables H, m phi, and FChol (multiple r2 = 0.84). The extent of Adh formation was optimally described by UP, m phi, and FChol (multiple r2 = .88). In conclusion, although none of these statistically significant associations indicate causal relationships, they identify - in addition to UP, H, and cellular proliferation - FChol as a major clinical determinant and glomerular m phi influx as a major structural alteration associated with FGS in the setting of renal ablation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1978

Immunologic methods for the identification of cell types. II. Expression of normal mouse mammary epithelial cell antigens in mammary neoplasia.

Mouse mammary epithelial (MME) cell antigens were cell type-specific and were retained, to a large extent, by MME cells after neoplastic transformation. These MME cell antigens were expressed in mammary tumors of BALB/c, C3H, GRS/A, RIII, and Is/Bi mice tested and were not expressed in tumors whose normal counterpart was other than mammary tissue. They were not dependent on cell culture conditions or on the presence of murine mammary tumor virus; therefore, they can be used in an ubiquitous cell type marker for MME cells in both normal and neoplastic tissues.

Animals↗
PubMed1996

[Three-dimensional echocardiography in evaluation of left ventricular systolic function after mitral valve replacement for chronic mitral diseases with preservation of mitral apparatus].

OBJECTIVE: To assess the global left ventricular performance in 24 normal subjects, 24 patients suffered from mitral valve disease (MVD) with mitral valve replacement (MVR), and 20 patients with mitral valve replacement with preservation of mitral apparatus (MVRP). METHODS: 3DE was used in comparion with the findings of radiography (RNA), two-dimensional echocardiography (2DE), and m-mode (MME). RESULTS: EF in 10 patients with MVD as compared with RNA, 3DE showed a higher connection coefficient than 2DE and MME. The EF estimated by MME and 2DE showed no difference between NS and MVD groups, there were significant differences when compared with those examined by 3DE. Two, three months after opertion, the VED and VES in group of MVRP were significantly lower than those in group of MVR (P < 0.01), the EF of MVRP group was remarkably higher than that of MVR group (P < 0.05). CONCLUSION: 3DE has the ability to estimate the EF of left ventricle more accurately than 2DE and MMe, especially in the patients suffered from chronic MVD with LV shape deformation. The MVR with preservation of mitral apparatus for chronic MVD is beneficial to maintaining the global systolic function after surgery.

Adolescent↗
PubMed1993

Regulation of VCAM-1 expression and involvement in cell adhesion to murine microvascular endothelium.

The present studies were undertaken to examine the regulation of murine VCAM-1 expression and the involvement of this molecule in adhesive processes occurring on the surface of microvascular endothelium. Flow cytometric analyses revealed that murine microvascular endothelium (MME) in culture constitutively expresses VCAM-1 and that stimulation of MME by TNF, IL-1, or LPS, but not by PMA or staurosporine, strongly increased the surface expression of this cell adhesion molecule. Stimulation of VCAM-1 expression by TNF may be diminished by ionomycin as well as by inhibitors of protein kinases (H-7 and sangivamycin). However, TGF-beta, which strongly inhibited the adhesiveness of endothelium, had little effect on the expression of VCAM-1. A newly developed adhesion assay, based on the rosette technique, allowed us to distinguish between the adhesive properties of an individual endothelial cell and those of endothelial cell monolayers and demonstrated that inhibition of binding by TGF-beta resulted primarily from its influence on the adhesive properties of individual cells. Studies on the inhibition of cell binding by monoclonal antibodies against mouse VCAM-1 and mouse VLA-4 indicated that VCAM-1 plays a dominant role in mediating the adherence of a variety of cell types, including murine splenocytes and thymocytes, P815 mastocytoma cells, PT 18 mast/basophil cells, human Molt-4 cells, and human eosinophils, to cytokine-activated MME.

Alkaloids↗
PubMed1998

Matrix metalloproteinases (MMPs) and their physiological inhibitors (TIMPs) are differentially expressed during excisional skin wound repair.

During cutaneous wound healing a number of migratory and remodeling events occur that require the action of matrix metalloproteinases (MMPs) and their natural inhibitors (TIMPs). In this study, we analyzed the temporal and spatial expression patterns of these molecules during the healing of murine excisional skin wounds. Our data imply that defined phases of repair rely on distinct repertoires of MMP activity and TIMP counterregulation. Reepithelialization was found to be associated with active production of collagenase, 92-kDa gelatinase, and stromelysins-1 and -2 by distinct subpopulations of keratinocytes at the migrating border. Notably, no TIMP transcripts were expressed in the epidermis, but TIMP-1 expression in the wound colocalized with expression of collagenase, 92-kDa gelatinase, and stromelysin-1, albeit in distinct cells. Concomitant with the formation of an extensive hyperproliferative epithelium, TIMP-1 transcripts accumulated at the mesenchymal/epidermal border of the granulation tissue. During later phases of wound repair, we observed an increase in 72-kDa gelatinase and MT1-MMP expression, whereby the transcripts of these colocalizing MMPs were detected exclusively and at high levels in the granulation tissue. At completion of reepithelialization, the expression levels of the MMPs and TIMP-1 seen in epidermal and dermal compartments declined to near-basal levels, whereas the macrophage-specific metalloelastase (MME) reached maximum expression. In reepithelialized wound tissue, MME transcripts were detected in deep layers of reconstituted dermis and seemed to cluster around vascular structures. Systemic glucocorticoid treatment, which is known to result in impaired wound healing, led to a nearly complete shut-off of MME expression. These observations imply an additional role of macrophage-related proteolysis, independent of its classical roles during earlier, inflammatory phases of cutaneous wound repair.

Animals↗
PubMed1999

Cartilage proteoglycan degradation by a mouse transformed macrophage cell line is mediated by macrophage metalloelastase.

OBJECTIVE AND DESIGN: Identify and characterize the matrix metalloproteinase responsible for cartilage proteoglycan degradation mediated by a macrophage cell line in a cell culture model that resembles some aspects of rheumatoid pannus. MATERIALS OR SUBJECTS: Supernatants from the transformed mouse macrophage cell line J774A.1 were used to purify the proteoglycan degrading activity. METHODS: J774A.1 macrophage culture supernatants were purified by sequential column chromatography and proteins were identified by zymography, western blotting and amino acid sequence analysis. Cartilage degradation was measured using 35S labeled bovine nasal cartilage. RESULTS: The cartilage degrading proteolytic activity in the mouse macrophage supernatants proved to be due to two major proteins with approximate molecular masses of 48 kDa and 22 kDa that were identified as macrophage metalloelastase (MME). Incubation of purified MME at 37 degrees C for up to 16 h resulted in the processing of the 48 kDa protein to several novel bands including a previously undescribed protein of approximately 25 kDa without accumulation of fully processed 22 kDa protein. A number of proteinases increased the rate of this processing. J774A.1 macrophage metalloelastase degraded cartilage proteoglycan with an efficiency approximately equal to human macrophage metalloelastase (MMP-12) and matrilysin (MMP-7) and twice that of stromelysin-1 (MMP-3). CONCLUSIONS: These data identify the cartilage proteoglycan degrading metalloproteinase secreted by J774A.1 macrophages in this cell culture model as MME, and describes mechanisms of activation and processing of this enzyme that may play an important role in cartilage degradation.

Amino Acid Sequence↗
PubMed1982

Postoperative abnormalities of interventricular septal motion: two-dimensional and M-mode echocardiographic correlations.

Our hypothesis was that the postoperative abnormalities in septal motion observed by M-mode echocardiography (MME) are due to changes of either ventricular shape or of total cardiac motion within the thorax. We obtained preoperative and early and late postoperative MME and two-dimensional echocardiograms on 25 patients undergoing cardiac surgery. No patient had coronary artery disease. All patients had normal preoperative septal motion; 11 patients retained normal (group N) septal motion on postoperative MME; 14 patients developed abnormal (group A) septal motion. Comparison of these two groups revealed that the group A patients had a greater degree of posterior epicardial motion toward the chest wall during systole. This indicates a greater anterior motion of the entire heart within the thorax, which produces the observed septal motion abnormality by carrying the septum forward passively as the whole heart moves anteriorly. This excessive forward cardiac motion may be due to fixation of the heart anteriorly by postoperative sternal-cardiac adhesions. No changes in left ventricular shape, size, or function were found to be associated with abnormal septal motion, nor was septal contraction impaired. Changes in intrathoracic cardiac motion are the probable cause of septal motion abnormalities after cardiac surgery.

Aortic Valve↗
PubMed1986

The monomethylethanolamine- and dimethylethanolamine-base exchange reactions of rat-brain microsomal fraction.

The ability of crude rat-brain microsome preparations to convert DME and MME to their corresponding phospholipid was explored. In common with the other base-exchange reactions, the incorporations of DME and MME were stimulated by about 1-4 mM Ca2+, possessed slightly alkaline pH optima, were energy independent and were unaffected by exogenous phospholipids. The Km values were 0.97 mM and 0.5 mM and the Vmax values were 9.6 nmol/mg protein per h and 6.25 nmol/mg protein per h for DME and MME, respectively. The P3 fraction of the brain and heart had the highest specific activities of particles prepared from several tissues.

Animals↗
PubMed1997

Inhibitory effect of di-catechol rooperol on VCAM-1 and iNOS expression in cytokine-stimulated endothelium.

Induced expression of vascular cell adhesion molecule-1 (VCAM-1) and of nitric oxide synthase (iNOS) is believed to play a role in the pathogenesis of atherosclerosis, asthma, as well as other inflammatory disorders. In the current study we examined the effect of the di-catechol rooperol [(E)-1,5-bis (3',4'-dihydroxyphenyl) pent-4-en-1-yne] on the process of microvascular endothelial cell (MME) activation by TNF-alpha and IFN-gamma. We show that rooperol decreases VCAM-1 and iNOS mRNA levels in cytokine-activated MME with subsequent inhibition of VCAM-1 membrane expression as measured by adhesion of P815 cells to MME monolayers, and NO production, as reflected in the nitrite concentration in culture medium. The properties of rooperol now described suggest that rooperol may be an anti-inflammatory agent useful in the treatment of several inflammatory disorders.

Animals↗
PubMed2002

Intrapleural interleukin-2 induces nitric oxide production in pleural effusions from malignant mesothelioma: a possible mechanism of interleukin-2-mediated cytotoxicity?

Due to the frequent use of intrapleural interleukin-2 (IL-2) to treat pleural effusions from malignant mesothelioma (MMe), we measured nitric oxide (NO) end product nitrite (NO(2)(-)) in pleural effusions of 12 MMe patients with chronic or chronic-relapsing pleurisy. Through high performance liquid chromatography analysis, NO(2)(-) was found in the initial pleural fluid sample of all patients (156.25 pmol ml(-1)), and increased significantly following IL-2 intrapleural instillation, both at 24 (589.91 pmol ml(-1), P < or = 0.0005) and 48 h (756 pmol ml(-1), P< or = 0.0005). Even though it is difficult to argue if the large amounts of NO end product NO(2)(-) we observed is produced by IL-2-stimulated and recruited immune cells, by MMe cells themselves, or by both, it is possible that NO could contribute to the complex antitumor activity of IL-2.

Aged↗
PubMed2006

Assessing effects of metal mining effluent on fathead minnow (Pimephales promelas) reproduction in a trophic-transfer exposure system.

Assessment of effects of metal mine effluent (MME) on aquatic organisms in lab-based settings predominantly evaluates contaminant transfer through the water only with little emphasis on food-borne exposure. The effects of MME on fathead minnow (Pimephales promelas) (FHM) have been reported downstream of metal mine discharges in the Junction Creek system, Sudbury, ON, but to date, no study has investigated the significance of trophic transfer in this system. Our objective was to develop a self-sustaining trophic-transfer bioassay, using Chironomus tentans and FHM, that allowed assessment of the effects of not only water-borne (FHM-only) but also food- and water-borne (trophic-transfer) exposure to MME on FHM reproduction. Reproductive performance of FHM was assessed for 21 days under controlled laboratory conditions to obtain baseline data of various endpoints, including egg production and hatching success. Exposure to 45% (v/v) Copper Cliff mine effluent (CCME) and control treatments for both systems was then conducted for a further 21 days. It was evident that reproductive output in both the water-only and the trophic-transfer system was reduced compared to controls. It was only in the trophic-transfer system that a significant reduction in larval hatching and an increase in deformities occurred after exposure to CCME. This would suggest that contaminated food was a route of exposure causing effects on larval survival.

Animals↗
PubMed1996

The structural basis for the elastolytic activity of the 92-kDa and 72-kDa gelatinases. Role of the fibronectin type II-like repeats.

Several matrix metalloproteinases, including the 92-kDa and 72-kDa gelatinases, macrophage metalloelastase (MME), and matrilysin degrade insoluble elastin. Because elastolytically active MME and matrilysin consist only of a catalytic domain (CD), we speculated that the homologous CDs of the 92-kDa and 72-kDa gelatinases would confer their elastolytic activities. In contrast to the MME CD, the 92 and 72 CDs expressed in Escherichia coli (lacking the internal fibronectin type II-like repeats) had no elastase activity, although both were gelatinolytic and cleaved a thiopeptolide substrate at rates comparable to the full-length gelatinases. To test the role of the fibronectin type II-like repeats in elastolytic activity, we expressed the 92-kDa gelatinase CD with its fibronectin type II-like repeats (92 CD/FN) in yeast. 92 CD/FN degraded insoluble elastin with activity comparable to full-length 92-kDa gelatinase. 92 and 72 CDs lacking the fibronectin type II-like repeats did not bind elastin, whereas the parent enzymes and 92 CD/FN did bind elastin. Furthermore, recombinant 92-kDa fibronectin type II-like repeats inhibited binding of the 92-kDa gelatinase to elastin. We conclude that the 92- and 72-kDa gelatinases require the fibronectin type II-like repeats for elastase activity.

Amino Acid Sequence↗