Plasma membrane intrinsic proteins of Beta vulgaris L.

The plasma membrane (PM) of higher plants contains numerous proteins; however, due to their low abundance, only a few have been identified and characterized by direct biochemical approaches. The major intrinsic protein (MIP) family is a class of highly hydrophobic integral membrane proteins thought to function as channels that facilitate the passage of water, small solutes, and possibly other moieties through the membrane. A family of PM intrinsic proteins was purified and characterized from PM vesicles derived from storage tissue of Beta vulgaris L.

Cerebral arteriovenous malformations: flow quantitation by means of two-dimensional cardiac-gated phase-contrast MR imaging.

Purpose: To test two-dimensional cardiac-gated phase-contrast (2DGPC) magnetic resonance (MR) imaging in the evaluation of cerebral arteriovenous malformations (AVMs) and the alterations in flow that accompany embolization therapy.

Materials And Methods: A 2DGPC sequence was used to measure flow velocity in the feeding vessels and corresponding contralateral vessels (CCVs) of seven patients (six men and one woman, 21-55 years of age; mean, 37 years) with cerebral AVMs and in the vessels of four healthy volunteers (all men; mean age, 22 years).

Results: In the patients, the flow in the feeding vessels exceeded the flow in the CCVs by a margin far greater than the asymmetry in flow in the volunteers.

Linkage of a locus for autosomal dominant familial spastic paraplegia to chromosome 2p markers.

'Pure' autosomal dominant familial spastic paraplegia (SPG) is a neurodegenerative disease which clinically manifests as spasticity of the lower limbs. Dominantly inherited SPG is known to be clinically heterogenous and has been classified into late-onset and early-onset types, based on the age of onset of symptoms. We tested five autosomal dominant SPG families for genetic linkage and established linkage to chromogene 2p markers (Z(theta) = 3.

Inhibition of yeast (1,3)-beta-glucan synthase by phospholipase A2 and its reaction products.

Fungal (1,3)-beta-glucan synthases are sensitive to a wide range of lipophilic inhibitors and it has been proposed that enzyme activity is highly sensitive to perturbations of the membrane environment. Yeast membranes were exposed to phospholipases and various lipophilic compounds, and the resultant effects on glucan synthase activity were ascertained. Glucan synthase from Saccharomyces cerevisiae was rapidly inactivated by phospholipase A2 (PLA2), and to a lesser extent by phospholipase C.

Carotid plaque formation and its evaluation with angiography, ultrasound, and MR angiography.

The accurate assessment of carotid artery disease is an important challenge for magnetic resonance (MR) angiography. Studies indicate that the detection and grading of stenosis and the evaluation of plaque morphology are all important steps in the clinical assessment of atherosclerosis. The prevalence of significant carotid artery stenosis in the elderly population and even in patients with symptoms of carotid artery disease is low; clinical risk seems to correlate more closely with plaque morphology and surface characterization than with the degree of stenosis.

Use of cilofungin as direct fluorescent probe for monitoring antifungal drug-membrane interaction.

Cilofungin is an antifungal cyclopeptide which inhibits cell wall (1,3)-beta-glucan biosynthesis in fungal organisms, and its action against Candida albicans (1,3)-beta-glucan synthase has been widely studied. Since glucan synthase inactivation is thought to partially result from perturbations of the membrane lipid environment, the interaction of cilofungin with fungal membranes and phosphatidylcholine membrane vesicles was studied. Cilofungin, which contains two independent aromatic groups, has an excitation maximum of 270 nm and an emission maximum of 317 nm in aqueous solution.

Familial Sneddon's syndrome: clinical, hematologic, and radiographic findings in two brothers.

We present the clinical, hematologic, and radiographic findings in two brothers with Sneddon's syndrome (stroke and livedo reticularis) and antiphospholipid antibodies. Patient 1 had anticardiolipin antibody and patient 2 had lupus anticoagulant, which we detected only upon repeated blood testing. One should test for both anticardiolipin antibody and lupus anticoagulant and repeat the screenings before determining a Sneddon's syndrome patient's antiphospholipid antibody status.

Limited proteolysis of (1,3)-beta-glucan (callose) synthase from Beta vulgaris L: topology of protease-sensitive sites and polypeptide identification using Pronase E.

Plasma membrane (PM) vesicles of defined sidedness were obtained from Beta vulgaris L. and subjected to limited proteolysis to investigate the topology and subunit composition of UDP-glucose: (1,3)-beta-glucan (callose) synthase (CalS). Latency experiments demonstrated that protease-sensitive sites on the CalS complex are located primarily at the cytoplasmic face of the PM, with little or no CalS inactivation occurring as the result of proteolysis at the apoplastic face.

Identification of vascular structures as a major source of signal contrast in high resolution 2D and 3D functional activation imaging of the motor cortex at 1.5T: preliminary results.

We have measured the T2* signal response associated with cortical activation due to finger motion at 1.5 Tesla. Both thin slice 2D and 3D images show signal intensity changes which vary from 2% to 32% depending on volunteer, echo time, slice thickness, and in-plane resolution.

Intrinsic and extrinsic carpal ligaments: evaluation by three-dimensional Fourier transform MR imaging.

Objective: As evaluation of the anatomic and functional integrity of intrinsic and extrinsic carpal ligaments with conventional imaging methods is difficult, we designed a study to evaluate the ability of three-dimensional Fourier transform MR imaging to show the carpal ligaments.

Subjects And Methods: We obtained coronal MR images of 15 cadaveric wrists and 15 wrists of patients, using three-dimensional volume acquisition with a gradient-recalled echo sequence and a 1.5-T magnet.

Use of Vicryl (polyglactin-910) mesh implant for repair of orbital floor fracture causing diplopia: a study of 28 patients over 5 years.

Over the past 5 years, Vicryl mesh (polyglactin-910) implants were used successfully to reconstruct the orbital floor in 28 patients with significant preoperative diplopia due to orbital floor fractures. The layered mesh is available in 26.5 x 24 cm sheets, each of which is folded onto itself into 24 layers and packaged; 24 layers are approximately 4 mm thick.

Inhibition and Ultraviolet-Induced Chemical Modification of UDP-Glucose:(1,3)-beta-Glucan (Callose) Synthase by Chlorpromazine : Mechanism of Chlorpromazine Binding to the Plant Plasma Membrane.

UDP-glucose:(1,3)-beta-glucan (callose) synthase (CS) from storage tissue of red beet (Beta vulgaris L.) was strongly inhibited by the phenothiazine drug chlorpromazine (CPZ). In the absence of ultraviolet irradiation, CPZ was a noncompetitive inhibitor with 50% inhibitory concentration values for plasma membrane and solubilized CS of 100 and 90 mum, respectively.

Rapid Enrichment of CHAPS-Solubilized UDP-Glucose: (1,3)-beta-Glucan (Callose) Synthase from Beta vulgaris L. by Product Entrapment : Entrapment Mechanisms and Polypeptide Characterization.

Rapid enrichment of CHAPS-solubilized UDP-glucose:(1,3)-beta-glucan (callose) synthase from storage tissue of red beet (Beta vulgaris L.) is obtained when the preparation is incubated with an enzyme assay mixture, then centrifuged and the enzyme released from the callose pellet with a buffer containing EDTA and CHAPS (20-fold purification relative to microsomes). When centrifuged at high speed (80,000g), the enzyme can also be pelleted in the absence of substrate (UDP-Glc) or synthesis of callose, due to nonspecific aggregation of proteins caused by excess cations and insufficient detergent in the assay buffer.

Developmental Regulation of the (1,3)-beta-Glucan (Callose) Synthase from Tomato : Possible Role of Endogenous Phospholipases.

Activity levels of UDP-glucose: (1,3)-beta-glucan (callose) synthase in microsomal membranes of pericarp tissue from tomato fruit (Lycoperisicon esculentum Mill, cv Rutgers) were determined during development and ripening. Addition of the phospholipase inhibitors O-phosphorylcholine and glycerol-1-phosphate to homogenization buffers was necessary to preserve enzyme activity during homogenization and membrane isolation. Enzyme activity declined 90% from the immature green to the red ripe stage.

Identification of the UDP-glucose-binding polypeptide of callose synthase from Beta vulgaris L. by photoaffinity labeling with 5-azido-UDP-glucose.

The photoaffinity probe 5-azidouridine 5'-[beta-32P]diphosphate glucose (5N3[32P]UDP-Glc) was used to identify a 57-kDa polypeptide as a strong candidate for the UDP-Glc-binding polypeptide of UDP-glucose: (1,3)-beta-glucan (callose) synthase from red beet (Beta vulgaris L.) storage tissue. Unlabeled 5N3UDP-Glc was a competitive inhibitor of callose synthase with a Ki of 310 microM.

An ambulance rotation as part of the general practice residency program.

This article describes a unique educational experience by using the ambulance as an extension of emergency medicine training for a general practice resident. The rotation enables the resident to deliver independent and spontaneous medical care in an emergent setting. A specific set of educational objectives were developed and used for this rotation.

Effects of native and oxidized phenolic compounds on sucrase activity in rat brush border membrane vesicles.

The effects of dietary phenolic compounds on intestinal sucrase were investigated in brush border membrane vesicles purified from rat small intestine. Screening experiments were conducted with different classes of phenolic compounds in both oxidized and native forms. The most potent inhibitor was native tannic acid at 0.

Dietary phenolic compounds: inhibition of Na+-dependent D-glucose uptake in rat intestinal brush border membrane vesicles.

The effects of phenolic compounds on Na+-dependent D-glucose transport were investigated in brush border membrane vesicles isolated from rat small intestine. Screening experiments were conducted with different classes of phenolic compounds in both their native and oxidized forms. Pretreatment of vesicles with tannic acid (1 mg/ml) completely abolished the characteristic overshoot of active glucose accumulation.

UDP-Glucose: (1,3)-beta-Glucan Synthase from Daucus carota L. : Characterization, Photoaffinity Labeling, and Solubilization.

The membrane-bound UDP-glucose-beta-(1,3)-glucan synthase from Daucus carota L. was characterized and a solubilization procedure was developed. The enzyme exhibited maximal activity in the presence of 0.

Susceptibility of UDP-Glucose:(1,3)-beta-Glucan Synthase to Inactivation by Phospholipases and Trypsin.

UDP-glucose:(1,3)-beta-glucan synthase from Beta vulgaris L. was rapidly inactivated by treatment with phospholipases C, D, and A(2). Enzyme activity could not be restored to the phospholipase-treated enzyme by the addition of phosphatidylethanolamine or other phospholipids.