Inhibitory Mechanism of the Outer Membrane Growth of Chronic Subdural Hematomas

2017 ◽  
Vol 34 (11) ◽  
pp. 1996-2000 ◽  
Author(s):  
Koji Osuka ◽  
Yasuo Watanabe ◽  
Nobuteru Usuda ◽  
Masahiro Aoyama ◽  
Kenichiro Iwami ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Inhibitory Mechanism ◽  
Subdural Hematomas ◽  
Membrane Growth

The role of exudation in chronic subdural hematomas

2007 ◽  
Vol 107 (2) ◽  
pp. 290-295 ◽  
Author(s):  
Mehmet Tokmak ◽  
A. Celal Iplikcioglu ◽  
Sirzat Bek ◽  
Cem Atilla Gökduman ◽  
Mustafa Erdal
Keyword(s):  
Outer Membrane ◽  
Clinical Status ◽  
Ct Scans ◽  
Subdural Hematomas ◽  
The Mean ◽  
Grade 3 ◽  
Age Range ◽  
Exudation Rate

Object Chronic subdural hematomas (SDHs) are a local inflammatory process that causes the formation of a granulation tissue often referred to as the external or outer membrane. This membrane has abnormally permeable macrocapillaries. Therefore, exudation from the macrocapillaries in the outer membrane of chronic SDH may play an important role in the enlargement of chronic SDH. In this study the authors investigated the role of exudation in chronic SDH. Methods The authors examined 24 patients (16 men and eight women; age range 38–86 years [mean age 61.4 years]) with 27 chronic SDHs. The clinical status of the patients was evaluated according to the classification described by Markwalder. The diagnosis was established on computed tomography (CT) scans in all cases. The authors also used the Nomura Classification for judging the lesion's appearance on CT scans. Immediately after the diagnosis, all patients were administered 20 mCi (740 mBq) technetium-99m human serum albumin. Four hours later, blood and SDH samples were taken and radioactivity levels were measured in each. The ratio of activity of the samples taken from chronic SDH to the radioactivity of blood was determined as a percentage and defined as the exudation rate. On the follow-up CT scan obtained on postoperative Day 20, subdural collections thicker than 5 mm were determined to be a reaccumulation. Results The correlations between the exudation rate and age of the patients, clinical grades, CT appearances, and amount of reaccumulation were investigated. In this series the average exudation rate was 13.24% (range 2.05–28.88%). The mean exudation rates according to the clinical grades assigned to patients were as follows: Grade 0, 8.67 ± 5.64% (three patients); Grade 1, 5.07 ± 1.43% (eight patients); Grade 2, 17.87 ± 3.73% (seven patients); and Grade 3, 19.65 ± 7.67% (six patients). Exudation rates in patients with Grades 2 and 3 were significantly higher than those in Grades 0 and 1 (p < 0.05). The mean exudation rates according to the lesion's appearance on CT scans were found as follows: hypodense appearance, 6.55 ± 4.52% (eight patients); isodense appearance, 11.07 ± 6.32% (five patients); hyperdense appearance, 19.47 ± 13.61% (three patients); and mixed-density appearance, 17.40 ± 5.80% (nine patients). The differences among the groups were significant (p < 0.05). The average exudation rate was statistically higher in the patients with reaccumulation (16.30 ± 8.16%) than that in the patients without reaccumulation (9.96 ± 6.84%) (p < 0.05). Conclusions The exudation rate in chronic SDH is correlated with a higher clinical grade (Markwalder Grade 2 or 3), mixed-density CT appearance, and reaccumulation. Therefore, exudation from macrocapillaries in the outer membrane of chronic SDH probably plays an important role in the pathophysiology and the growth of chronic SDH.

scholarly journals Vasular Endothelial Growth Factor and Its Receptors Expression in Outer Membrane of Chronic Subdural Hematomas

2000 ◽  
Vol 9 (12) ◽  
pp. 796-801 ◽  
Author(s):  
Satoru Sugiyama ◽  
Seiichi Yamada ◽  
Ryo Nishikawa ◽  
Mitsuyoshi Hasebe ◽  
Akihiro Miyoshi ◽  
...  
Keyword(s):  
Growth Factor ◽  
Outer Membrane ◽  
Subdural Hematomas ◽  
Endothelial Growth Factor

The role of endothelial gap junctions in the enlargement of chronic subdural hematomas

1983 ◽  
Vol 59 (2) ◽  
pp. 298-303 ◽  
Author(s):  
Tetsumori Yamashima ◽  
Shinjiro Yamamoto ◽  
Reinhard L. Friede
Keyword(s):  
Electron Microscopy ◽  
Gap Junctions ◽  
Outer Membrane ◽  
Blood Cells ◽  
Amorphous Material ◽  
Blood Components ◽  
Content Type ◽  
Subdural Hematomas ◽  
Fine Print

✓ The structure of macrocapillaries (also called “sinusoids”) in the outer membrane of chronic subdural hematomas was investigated by electron microscopy, with particular attention paid to vascular permeability. One characteristic of macrocapillaries is the frequent formation of gap junctions between adjacent endothelial cells. In endothelial gap junctions 0.6 to 8 µm in diameter, numerous blood components, including red blood cells and plasma, can be seen squeezing or spilling into the interstitial space of the outer membrane. Irregularly deformed erythrocytes are located around the macrocapillaries, and amorphous material is seen among scattered thin collagen fibers. It is suggested that endothelial gap junctions of macrocapillaries play an important role in the leakage of blood, causing enlargement of chronic subdural hematomas.

scholarly journals Role of Pseudomonas putida tol-oprL Gene Products in Uptake of Solutes through the Cytoplasmic Membrane

2003 ◽  
Vol 185 (16) ◽  
pp. 4707-4716 ◽  
Author(s):  
María A. Llamas ◽  
José J. Rodríguez-Herva ◽  
Robert E. W. Hancock ◽  
Wilbert Bitter ◽  
Jan Tommassen ◽  
...  
Keyword(s):  
Growth Rate ◽  
Pseudomonas Putida ◽  
Outer Membrane ◽  
Cytoplasmic Membrane ◽  
Carbon Sources ◽  
Membrane Integrity ◽  
Mutant Strains ◽  
Transport Defect ◽  
Membrane Growth

ABSTRACT Proteins of the Tol-Pal (Tol-OprL) system play a key role in the maintenance of outer membrane integrity and cell morphology in gram-negative bacteria. Here we describe an additional role for this system in the transport of various carbon sources across the cytoplasmic membrane. Growth of Pseudomonas putida tol-oprL mutant strains in minimal medium with glycerol, fructose, or arginine was impaired, and the growth rate with succinate, proline, or sucrose as the carbon source was lower than the growth rate of the parental strain. Assays with radiolabeled substrates revealed that the rates of uptake of these compounds by mutant cells were lower than the rates of uptake by the wild-type strain. The pattern and amount of outer membrane protein in the P. putida tol-oprL mutants were not changed, suggesting that the transport defect was not in the outer membrane. Consistently, the uptake of radiolabeled glucose and glycerol in spheroplasts was defective in the P. putida tol-oprL mutant strains, suggesting that there was a defect at the cytoplasmic membrane level. Generation of a proton motive force appeared to be unaffected in these mutants. To rule out the possibility that the uptake defect was due to a lack of specific transporter proteins, the PutP symporter was overproduced, but this overproduction did not enhance proline uptake in the tol-oprL mutants. These results suggest that the Tol-OprL system is necessary for appropriate functioning of certain uptake systems at the level of the cytoplasmic membrane.

Topography of Outer Membrane Growth in E. coli

1973 ◽  
Vol 245 (141) ◽  
pp. 38-39 ◽  
Author(s):  
K. J. BEGG ◽  
W. D. DONACHIE
Keyword(s):  
Outer Membrane ◽  
E Coli ◽  
Membrane Growth

scholarly journals Expression of the TGF-β–ALK-1 Pathway in Dura and the Outer Membrane of Chronic Subdural Hematomas

2014 ◽  
Vol 54 (5) ◽  
pp. 357-362 ◽  
Author(s):  
Atsushi SAITO ◽  
Ayumi NARISAWA ◽  
Hiroki TAKASAWA ◽  
Takahiro MORITA ◽  
Seiya SANNOHE ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Subdural Hematomas

Molecular Structure of the Outermost Cell Wall Component of Spirillum Serpens

1977 ◽  
Vol 35 ◽  
pp. 342-343
Author(s):  
Wah Chiu ◽  
David Grano
Keyword(s):  
Molecular Structure ◽  
Cell Wall ◽  
Outer Membrane ◽  
Gel Electrophoresis ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Cell Wall Component ◽  
Protein Components ◽  
Exposure Technique ◽  
Structural Aspects

The periodic structure external to the outer membrane of Spirillum serpens VHA has been isolated by similar procedures to those used by Buckmire and Murray (1). From SDS gel electrophoresis, we have found that the isolated fragments contain several protein components, and that the crystalline structure is composed of a glycoprotein component with a molecular weight of ∽ 140,000 daltons (2). Under an electron microscopic examination, we have visualized the hexagonally-packed glycoprotein subunits, as well as the bilayer profile of the outer membrane. In this paper, we will discuss some structural aspects of the crystalline glycoproteins, based on computer-reconstructed images of the external cell wall fragments.The specimens were prepared for electron microscopy in two ways: negatively stained with 1% PTA, and maintained in a frozen-hydrated state (3). The micrographs were taken with a JEM-100B electron microscope with a field emission gun. The minimum exposure technique was essential for imaging the frozen- hydrated specimens.

Cryo-Electron Microscopy and Correlation Averaging of Frozen-Hydrated, Polymorphic 2D Crystals of the Mitochondrial Outer Membrane Channel

1990 ◽  
Vol 48 (1) ◽  
pp. 100-101
Author(s):  
Xiao-Wei Guo
Keyword(s):  
Outer Membrane ◽  
Hexagonal Lattice ◽  
Mitochondrial Outer Membrane ◽  
Rectangular Lattice ◽  
Electron Microscopic ◽  
Cryo Electron Microscopy ◽  
Voltage Dependent ◽  
Outer Membrane Channel ◽  
2D Crystals ◽  
Vdac Channel

Voltage-dependent, anion-selective channels (VDAC) are formed in the mitochondrial outer membrane (mitOM) by a 30-kDa polypeptide. These channels form ordered 2D arrays when mitOMs from Neurospora crassa are treated with soluble phospholipase A2. We obtain low-dose electron microscopic images of unstained specimens of VDAC crystals preserved in vitreous ice, using a Philips EM420 equipped with a Gatan cryo-transfer stage. We then use correlation analysis to compute average projections of the channel crystals. The procedure involves Fourier-filtration of a region within a crystal field to obtain a preliminary average that is subsequently cross-correlated with the entire crystal. Subregions are windowed from the crystal image at coordinates of peaks in the cross-correlation function (CCF, see Figures 1 and 2) and summed to form averages (Figure 3).The VDAC channel forms several different types of crystalline arrays in mitOMs. The polymorph first observed during phospholipase treatment is a parallelogram array (a=13 run, b=11.5 run, θ==109°) containing 6 water-filled pores per unit cell. Figure 1 shows the CCF of a sub-field of such an “oblique” array used to compute the correlation average of Figure 3A. With increased phospholipase treatment, other polymorphs are observed, often co-existing within the same crystal. For example, two distinct (but closely related) types of lattices occur in the field corresponding to the CCF of Figure 2: a “contracted” version of the parallelogram lattice (a=13 run, b=10 run, θ=99°), and a near-rectangular lattice (a=8.5 run, b=5 nm). The pattern of maxima in this CCF suggests that a third, near-hexagonal lattice (a=4.5 nm) may also be present. The correlation averages of Figures 3B-D were computed from polycrystalline fields, using peak coordinates in regions of CCFs corresponding to each of the three lattice types.

Plasminogen-Plasmin System IX. Specific Binding of Tranexamic Acid to Plasmin

1975 ◽  
Vol 33 (03) ◽  
pp. 573-585 ◽  
Author(s):  
Masahiro Iwamoto
Keyword(s):  
Tranexamic Acid ◽  
Affinity Chromatography ◽  
Dissociation Constant ◽  
Factor Xiii ◽  
Specific Binding ◽  
The Other ◽  
Inhibitory Mechanism ◽  
Binding Studies ◽  
Similar Affinity ◽  
Fibrin Structure

SummaryInteractions between tranexamic acid and protein were studied in respect of the antifibrinolytic actions of tranexamic acid. Tranexamic acid did neither show any interaction with fibrinogen or fibrin, nor was incorporated into cross-linked fibrin structure by the action of factor XIII. On the other hand, tranexamic acid bound to human plasmin with a dissociation constant of 3.5 × 10−5 M, which was very close to the inhibition constant (3.6 × 10−5 M) for this compound in inhibiting plasmin-induced fibrinolysis. The binding site of tranexamic acid on plasmin was not the catalytic site of plasmin, because TLCK-blocked plasmin also showed a similar affinity to tranexamic acid (the dissociation constant, 2.9–4.8 × 10−5 M).In the binding studies with the highly purified plasminogen and TLCK-plasmin preparations which were obtained by affinity chromatography on lysine-substituted Sepharose, the molar binding ratio was shown to be 1.5–1.6 moles tranexamic acid per one mole protein.On the basis of these and other findings, a model for the inhibitory mechanism of tranexamic acid is presented.

Sign in / Sign up

Export Citation Format

Share Document