Dynamic computed tomography with low- and high-molecular-mass contrast agents to assess microvascular permeability modifications in a model of liver fibrosis

2002 ◽  
Vol 103 (2) ◽  
pp. 213-216 ◽  
Author(s):  
Roland MATERNE ◽  
Laurence ANNET ◽  
Stéphane DECHAMBRE ◽  
Christine SEMPOUX ◽  
Anne M. SMITH ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Contrast Agents ◽  
Molecular Mass ◽  
Hepatic Fibrosis ◽  
Mean Transit Time ◽  
Distribution Volume ◽  
High Molecular Mass ◽  
Permeability Changes ◽  
Molecular Masses ◽  
The Mean

Interstitial collagen formation and transformation of the fenestrated hepatic sinusoids into continuous capillaries are major ultrastructural changes that occur in liver cirrhosis and fibrosis. These modifications lead to progressive restriction of blood–liver exchanges. The purpose of our study was to evaluate the permeability changes in a model of hepatic fibrosis by using dynamic computed tomography (CT) enhanced with contrast agents of different molecular masses. Dynamic single-section CT of the liver was performed after intravenous bolus administration of a low-molecular-mass contrast agent (iobitridol) and an experimental high-molecular-mass agent (P840) in normal control rabbits and in rabbits with hepatic fibrosis. Hepatic, aortic and portal venous time–density curves were fitted with a dual-input one-compartmental model to calculate the hepatic mean transit time and distribution volume of the contrast agents. In the rabbits with liver fibrosis, the mean transit time of the high-molecular-mass agent was shorter than that of the low-molecular-mass agent (10.0±1.8s and 12.0±1.2s respectively; P<0.05). The distribution volume accessible to the high-molecular-mass agent was also smaller (22.2±4.8% compared with 32.0±6.7%; P<0.01). In the normal rabbits, the mean transit times of the high- and low-molecular-mass agents did not differ significantly, and nor did their distribution volumes. Our results demonstrate decreased sinusoidal permeability for the high-molecular-mass agent P840 in a model of hepatic fibrosis. Non-invasive assessment of permeability changes in liver fibrosis can be performed with dynamic CT and contrast agents of different molecular masses.

scholarly journals Identification of two highly sialylated human tear-fluid DMBT1 isoforms: the major high-molecular-mass glycoproteins in human tears

2002 ◽  
Vol 366 (2) ◽  
pp. 511-520 ◽  
Author(s):  
Benjamin L. SCHULZ ◽  
David OXLEY ◽  
Nicolle H. PACKER ◽  
Niclas G. KARLSSON
Keyword(s):  
Molecular Mass ◽  
Peptide Mass Fingerprinting ◽  
High Molecular Mass ◽  
Tear Fluid ◽  
Protein Variant ◽  
Peptide Mass ◽  
Composite Gel ◽  
Molecular Masses ◽  
Protein Components ◽  
Sialyl Lea

Human open eye tear fluid was separated by low-percentage SDS/PAGE to detect high-molecular-mass protein components. Two bands were found with apparent molecular masses of 330 and 270kDa respectively. By peptide-mass fingerprinting after tryptic digestion, the proteins were found to be isoforms of the DMBT1 gene product, with over 30% of the predicted protein covered by the tryptic peptides. By using gradient SDS/agarose/polyacrylamide composite gel electrophoresis and staining for glycosylation, it was shown that the two isoforms were the major high-molecular-mass glycoproteins of >200kDa in human tear fluid. Western blotting showed that the proteins expressed sialyl-Lea. After the release of oligosaccharides by reductive β-elimination from protein blotted on to PVDF membrane, it was revealed by liquid chromatography-MS that the O-linked oligosaccharides were comprised mainly of highly sialylated oligosaccharides with up to 16 monosaccharide units. A majority of the oligosaccharides could be described by the formula dHex0→2NeuAc1→xHexxHexNAcx(-ol), x = 1–6, where Hex stands for hexose, dHex for deoxyhexose, HexNAc for N-acetylhexosamine and NeuAc for N-acetylneuraminate. The number of sialic acids in the formula is less than 5. Interpretation of collision-induced fragmentation tandem MS confirmed the presence of sialic acid and suggested the presence of previously undescribed structures carrying the sialyl-Lea epitopes. Small amounts of neutral and sulphated species were also present. This is the first time that O-linked oligosaccharides have been detected and described from protein variant of the DMBT1 gene.

T cell syncytia induced by HIV release. T cell chemoattractants: demonstration with a newly developed single cell chemotaxis chamber

1998 ◽  
Vol 111 (1) ◽  
pp. 99-109 ◽  
Author(s):  
D.C. Shutt ◽  
L.M. Jenkins ◽  
E.J. Carolan ◽  
J. Stapleton ◽  
K.J. Daniels ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
T Cell ◽  
Molecular Mass ◽  
Conditioned Medium ◽  
Single Cells ◽  
High Molecular Mass ◽  
Molecular Masses ◽  
Mass Factor ◽  
Mass Activity ◽  
Cell Chemotaxis

A chemotaxis chamber has been developed to analyze both the velocity and the directionality of individual T cells in gradients of high molecular mass molecules over long periods of time. Employing this chamber, it is demonstrated that syncytia induced by HIV in SUP-T1 cell cultures release two T cell chemoattractants with approximate molecular masses of 30 and 120 kDa. Neither uninfected single cells nor polyethylene glycol-induced syncytia release detectable chemoattractant, suggesting that these chemoattractants are linked to HIV infection. Soluble gp120 functions as a T cell chemoattractant and the addition of anti-gp120 antibody to syncytium-conditioned medium blocks the high molecular mass chemoattractant activity but not the low molecular mass activity. The addition of anti-CD4 antibody to syncytium-conditioned medium also blocks the high molecular mass chemoattractant activity but not the low molecular mass activity. These results demonstrate that HIV-induced T cell syncytia release a low and a high molecular mass T cell chemoattractant, and suggest that the high molecular mass factor is gp120 and that it functions through the CD4 receptor.

scholarly journals Application Value of Magnetic Resonance Perfusion Imaging in the Early Diagnosis of Rat Hepatic Fibrosis

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Guohua Fan ◽  
Yang Ya ◽  
Xiaoqiong Ni ◽  
Jinpeng Hou ◽  
Rui Yu
Keyword(s):  
Liver Fibrosis ◽  
Early Diagnosis ◽  
Hepatic Fibrosis ◽  
Mean Transit Time ◽  
Fibrosis Stage ◽  
Time Signal ◽  
Control Group ◽  
Magnetic Resonance Perfusion ◽  
Time To Peak ◽  
And Control

Objective. To assess the application value of perfusion-weighted imaging (PWI) in early diagnosis, quantitation, and hepatic fibrosis staging by analyzing the related parameters in hepatic fibrosis. Methods. A total of 60 rats were randomly divided into the hepatic fibrosis and control groups, and carbon tetrachloride (CCL4) was used to establish the liver fibrosis model. All rats underwent PWI examination, and the trend of the time-signal intensity curve (TIC, automatically generated by the software) was observed. Also, the perfusion parameters, maximum signal reduction ratio (SRRmax), time to peak (TTP), and mean transit time (MTT), were analyzed and compared with pathological staging. Results. The TIC curve was characterized by slow wash-in and wash-out with a low and wide peak. The PWI perfusion parameters were statistically significant in specific groups (P<0.05): SRRmax values (control group and F3, F4), TTP, and MTT values (control group and F2–F4, F1 and F3, F1 and F4, and F2 and F4 in addition to TTP values for F1 and F2). Pearson’s correlation analysis showed a negative correlation of SRRmax with hepatic fibrosis stage (r = −0.439, P<0.05), while TTP and MTT values were positively correlated with hepatic fibrosis stage (TTP, r = 0.798; MTT, r = 0.647; all P<0.001). Conclusions. PWI perfusion parameters reflect the degree of hepatic fibrosis, especially TTP and MTT, and PWI is recommended for the early diagnosis of liver fibrosis for timely intervention and treatment of the disease and delaying its progression.

scholarly journals Non-Invasive Markers of Liver Fibrosis in Children with Chronic Hepatic Disorders

2020 ◽  
Vol 7 (3) ◽  
Author(s):  
Iraj Shahramian ◽  
Manijeh Khalili ◽  
Alireza Sargazi ◽  
Alireza Dechal ◽  
Mostafa Bazi ◽  
...  
Keyword(s):  
Chronic Hepatitis ◽  
Liver Fibrosis ◽  
Hepatic Fibrosis ◽  
Sensitivity And Specificity ◽  
Pediatric Population ◽  
Advanced Fibrosis ◽  
Non Invasive ◽  
The Mean ◽  
Biopsy Examination ◽  
Center Study

Background: The applicability of non-invasive markers for predicting hepatic fibrosis in the pediatric population with chronic liver abnormalities is unclear. Objectives: We investigated the applicability of common non-invasive liver fibrosis parameters for detecting liver fibrosis in children with chronic hepatitis. Methods: This was a double-center study in Amir-Almomenin Hospital of Zabol and Namazi Hospital of Shiraz (2015 - 2017). Liver fibrosis was confirmed by biopsy examination. AST to platelet ratio (APRI), AST to ALT ratio (AAR), and Fibrosis-4 (FIB-4) were evaluated. Results: Out of 47 patients, 23 (48.9%) were females, and 24 (51.1%) were males. The mean age was 9.8 ± 11.3 months. APRI and FIB-4 correlated with fibrosis stages (r = 0.1 and r = 0.2, respectively). APRI showed an AUC of 0.541 for detecting non-advanced fibrosis (stages 0, 1, and 2). AAR and FIB-4 represented AUCs of 0.622 and 0.592 for advanced fibrosis and cirrhosis, respectively. The highest sensitivity of APRI (70%) was obtained at the cut-off point of 0.81 for cirrhosis. The highest specificities for APRI were observed at 0.66 (68%) and 1.37 (68%) for fibrotic stages 0 and 2, respectively. At the thresholds of 0.71 and 0.59, AAR rendered 78% sensitivity and 90% specificity for advanced fibrosis (stages 3 and 4) and no fibrosis (stage = 0), respectively. FIB-4 showed the highest sensitivity and specificity (70% and 60%) at the cut-off point of 0.21 for detecting cirrhosis. Conclusions: APRI, FIB-4, and AAR can be regarded as useful markers in predicting fibrotic transformation in children with various etiologies of chronic hepatitis.

Assessment of macroprolactinemia inpatients with prolactinoma

2017 ◽  
Vol 43 (1) ◽  
pp. 71-75
Author(s):  
Sema Ciftci Dogansen ◽  
Gulsah Yenidunya Yalin ◽  
Sema Yarman
Keyword(s):  
Polyethylene Glycol ◽  
Molecular Mass ◽  
Clinical Features ◽  
Prolactin Level ◽  
High Molecular Mass ◽  
Benign Condition ◽  
Significant Difference ◽  
Negative Findings ◽  
The Mean ◽  
Polyethylene Glycol Precipitation

AbstractPurpose:Macroprolactin, the high-molecular mass prolactin isoform, is considered to be an inactive product with extrapituitary origin. Although macroprolactinemia is considered a benign condition, there is evidence of overlapping clinical features among patients with hyperprolactinemia. Data on the prevalence of macroprolactinemia in prolactinomas is also quite limited. The aim of this study was to assess the prevalence of macroprolactinemia in our patients with prolactinoma.Methods:The study included patients with macroprolactinoma (n=50) and microprolactinoma (n=16). Prolactin level was measured with an electrochemiluminescent immunoassay, and macroprolactinemia was defined as the percentage of prolactin recovery <40% after the polyethylene glycol precipitation.Results:Macroprolactinemia was not detected in our patients with prolactinoma (the percentage of PRL recovery range; 55%–96%). The mean percentage of prolactin recovery was similar in patients with macroprolactinoma and microprolactinoma (67.7%±8.0% and 70%±9.4%, respectively, p=0.96).Conclusion:Macroprolactinemia is generally associated with negative findings on pituitary imaging. Although the monomeric prolactin is dominant, rarely macroprolactin may also be present in prolactinomas. We did not detect presence of macroprolactin in any of the patients and there was no statistically significant difference between micro- and macroprolactinomas in terms of prolactin recovery.

scholarly journals Poly(Aspartic Acid) Degradation by aSphingomonas sp. Isolated from Freshwater

1999 ◽  
Vol 65 (9) ◽  
pp. 4268-4270 ◽  
Author(s):  
Kenji Tabata ◽  
Ken-Ichi Kasuya ◽  
Hideki Abe ◽  
Kozue Masuda ◽  
Yoshiharu Doi
Keyword(s):  
Molecular Mass ◽  
River Water ◽  
Aspartic Acid ◽  
Cell Extract ◽  
High Molecular Mass ◽  
Acid Degradation ◽  
Degrading Bacterium ◽  
Molecular Masses ◽  
Bacterium Strain

ABSTRACT A poly(aspartic acid) degrading bacterium (strain KT-1 [JCM10459]) was isolated from river water and identified as a member of the genus Sphingomonas. The isolate degraded only poly(aspartic acid)s of low molecular masses (<5 kDa), while the cell extract hydrolyzed high-molecular-mass poly(aspartic acid)s of 5 to 150 kDa to yield aspartic acid monomer.

Characterization of dissolved material during the initial phase of softwood kraft pulping

TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 37-43 ◽  
Author(s):  
HANNU PAKKANEN ◽  
TEEMU PALOHEIMO ◽  
RAIMO ALÉN
Keyword(s):  
Mass Transfer ◽  
Molecular Mass ◽  
Initial Phase ◽  
Degradation Products ◽  
Kraft Pulping ◽  
Reaction Products ◽  
Cooking Temperature ◽  
Molecular Masses ◽  
Aliphatic Carboxylic Acids

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.

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