Comparative intermolecular cross-relaxation studies of human hemoglobin in red blood cells and bovine serum albumin in solution.

Intermolecular cross-relaxation rate (CR) spectra [1/T(IS) (HDO) or 1/T(IS) (H(2) O) vs f(2) (ppm) profiles] for bovine serum albumin [BSA; molecular weight (MW), 66 kDa] solution, partially hydrolyzed BSA gel (BSA*gel) and packed human red blood cells (RBCs) with normal or unstable hemoglobin (Hb; MW, 65 kDa) were studied using f(2) irradiation ranging from - 100 to 100 ppm at γH(2) /2π of 250 Hz. The CR spectra for BSA*gel (pD 4.01, 0.

Equivalent cross relaxation rate image for decreasing a false negative case of sentinel lymph node biopsy.

In the breast carcinamas, sentinel lymph node biopsy (SLNB) attracts attention as technique to be settled by axillary lymph node metastasis, but existence of a false negative case is a problem. Equivalent cross relaxation rate image (ECRI) is the measurement method that we can evaluate a change of organization structure quantitatively by magnetic resonance imaging. We executed axillary ECRI as a purpose with decreasing a false negative case of SLNB.

Saturation transfer in human red blood cells with normal and unstable hemoglobin.

Saturation transfer phenomena from irradiated protein protons to observed water protons in packed human red blood cells (RBCs) with normal or unstable hemoglobin (Hb), i.e. Hb Yokohama and Hb Koeln, were studied using intermolecular cross-relaxation rates [CR; 1/T(IS)(H(2)O)], action spectra [[1-(I(infinity)/I(0))] vs f(2) (ppm), where I(0) and I(infinity) are the longitudinal magnetization of observed water protons before and after long-time f(2)-irradiation, respectively], CR spectra [CR vs f(2) (ppm)] and CR ratio vs f(2) (ppm) with f(2)-irradiation from -100 to 100 ppm at gammaH(2)/2pi of 69 or 250 Hz.

Equivalent cross-relaxation rate imaging in the synthetic copolymer gels and invasive ductal carcinomas of the breast.

The values of equivalent cross-relaxation rate (ECR) correlated well with [i] water conditions in various copolymer gels and [ii] nature of malignant cells with regard to nuclear dysplasia and mitotic potential in breast carcinomas. The synthetic copolymer gels composed of any two or three monomers among 2-hydroxyethyl methacrylate (HEMA), glycidyl methacrylate (GMA), N-vinyl-2-pyrrolidinone (N-VP), methyl methacrylate (MMA) and benzyl methacrylate (BMA). The ECR measurement was performed by using an off-resonance saturation pulse under conventional field-echo imaging at frequency within +/- 75 ppm apart from the water resonance frequency.

Effect of diabetic retinopathy on redox state of aqueous humor and serum albumin in patients with senile cataract.

Purpose: To investigate the oxidative status of albumin in the aqueous humor and serum of senile cataract patients with diabetes in order to clarify the pathogenesis of this condition.

Methods: High-performance liquid chromatography (HPLC) was employed to measure the reduced form of albumin (mercaptalbumin) and the oxidized form of albumin (nonmercaptalbumin) in serum and aqueous humor. The mercaptalbumin, nonmercaptalbumin-1, and nonmercaptalbumin-2 fractions in aqueous humor obtained at the start of cataract surgery and in serum obtained intraoperatively were analyzed by HPLC in 7 senile cataract patients with diabetic retinopathy (2 men and 5 women aged 70+/-9.

The importance of sample preservation temperature for analysis of the redox state of human serum albumin.

Background: Human serum albumin (HSA) is a mixture of human mercaptalbumin (HMA, reduced form) and nonmercaptalbumin (HNA, oxidized form).

Methods: We have developed a convenient high-performance liquid chromatographic (HPLC) system for the separation of HSA into HMA and HNA, and studied the mercapt<==>nonmercapt conversion (i.e.

Basic studies on the equivalent cross-relaxation rate imaging (equivalent CRI)--phantom studies.

We have studied saturation transfer in hydrophilic, cross-linked copolymer gels from irradiated polymer protons to observed water protons, using f2 (ppm) profiles of [1 - (I(infinity)/I(0))], [(I(0)/I(infinity)) - 1] or 1/T(IS)(H2O), where I(0) and I(infinity) are the longitudinal magnetization of the observed water protons before and after long-time-f2-irradiation on polymer protons, respectively, and 1/T(IS)(H2O) is the cross-relaxation rate. (A) [1 - (I(infinity)/I(0))] (magnetization transfer ratio, MTR) was used in magnetic resonance imaging (MRI) as the MTR imaging. 1/T(IS)(H2O) (cross-relaxation rate) was used in the imaging of the magnetization transfer rate constant.

Application of the transition state theory to water transport across cell membranes.

We have applied the transition state theory of Eyring et al. (The Theory of Rate Processes, McGraw-Hill, 1941) to water transport across cell membranes. We have then evaluated free energy (Delta F(not equal)), enthalpy (Delta H(not equal)) and entropy (Delta S(not equal)) of activation for water permeation across membranes, such as Arbacia eggs, Xenopus oocytes with or without aquaporin water channels, mammalian erythrocytes, aquaporin proteoliposomes, liposomes and collodion membrane.

Saturation transfer ratio imaging in invasive ductal carcinomas of the breast.

A prospective study was performed to investigate the correlations between saturation transfer ratio (STR) and histologic parameters of invasive ductal carcinomas in human breast. The histologic parameters investigated were the extent of fibrosis in the intercellular matrix, dysplastic changes of nuclei, and mitotic index. Twenty-seven patients with breast carcinoma were examined using an off-resonance saturation pulse in conjunction with conventional field-echo T(1)-weighted imaging at frequency offsets of 448 Hz and 1200 Hz from water resonance.

1H-NMR and raman studies on perforating trauma-induced cataract formation in a mouse lens.

In order to provide new insight into the molecular mechanism of perforating trauma-induced cataract formation in an 8-week-old ddY mouse lens, we performed an in situ investigation into changes in the water-protein and/or protein-protein interactions by using 500 MHz (1)H-NMR spectroscopy, and into structural alterations in lens proteins by using Raman spectroscopy. Cross-relaxation times of water protons in the perforated opaque lens were considerably shorter than those in the intact transparent lens, whereas there was no significant difference in water content, suggesting a drastic change in water-protein and protein-protein interactions in the perforated lens. In addition, there was no significant difference in the intensity ratios of several key Raman bands between intact and perforated lenses, indicating that no significant local and overall conformational changes in lens protein itself occur in the perforated lens.

H-NMR and CD studies on the structural transition of serum albumin in the acidic region--the N-->F transition.

Helical content (f(alpha)) of bovine mercaptalbumin (BMA) showed the characteristic two-step decrease in the acidic region, one corresponding to the N-->F transition (pH 4.40-->3.75; f(alpha), 0.

Structural characterization of the molten globule and native states of ovalbumin: a 1H NMR study.

Molecular characteristics of ovalbumin (OVA) in the acidic (pD 3.08, the E-form) and neutral [pD 7.29, the N-form (native form)] regions were studied by measuring effective radii, 1H NMR spectra, spin-echo 1H NMR spectra and cross-relaxation times (TIS) from irradiated to observed protein protons which are particularly sensitive for detection of the mobile segments and/or structural looseness in proteins.

Conformational changes in seventeen cystine disulfide bridges of bovine serum albumin proved by Raman spectroscopy.

Conformational changes in cystine disulfide bridges of bovine serum albumin during acid-induced isomerization (N --> F and F --> E transitions) have been studied with Raman spectroscopy. In an X-ray crystallographic study of human serum albumin, Carter and Ho reported that all disulfide bridges of the albumin molecule are in the gauche-gauche-gauche conformation [1]. On the other hand, the solution structure of bovine serum albumin examined by Raman spectroscopy differs from its crystal structure in the conformation of some of the disulfide bridges.

Alteration of redox state of human serum albumin in patients under anesthesia and invasive surgery.

Human serum albumin is a mixture of mercapt- (HMA, reduced form) and nonmercaptalbumin (HNA, oxidized form). We studied the mercapt<-->nonmercapt conversion of human serum albumin, which reflects the redox state of the extracellular fluids, in cardiac and other common surgical_ patients using high-performance liquid chromatography. Mean values of [(HMA)/(HMA+HNA)]+/-standard deviation, fHMA+/-sigma], for patients who received common surgery (group 1) and cardiac surgery (group 2) at the start of anesthesia were 0.

Cross-relaxation times of normal and biochemically induced osteoarthritic rabbit knee cartilages.

We measured the spin-lattice relaxation times (T1) of water protons and intermolecular cross-relaxation times (T(IS)) from irradiated protein protons (f2-irradiation at 1.95 or -4.00 ppm) of rabbit normal and monoiodoacetate-induced degenerated knee articular cartilages to observed water protons.

Comparative 1H-NMR studies on the physical state of water in soft contact lens and mouse lens.

The physical state of water in mouse lenses (2-, 4- or 8-wk-old) and soft contact lenses (SCLs, water content from 18.4 to 79.2%) were studied by measuring spin-lattice relaxation times (T1) and apparent intermolecular cross-relaxation times (TIS) from irradiated protein or polymer protons to water protons, using 360 MHz 1H-NMR spectrometer at 25 degrees C.

Spin-lattice relaxation times of water in polarized and depolarized rabbit vagus nerves.

Spin-lattice relaxation times (T1) of intracellular water of the nonmyelinated fibers of rabbit cervical vagus nerve were measured using a paramagnetic shift reagent, s-FDF. Spin-lattice relaxation decay curves were composed of the fast (T1,F) and slow (T1,S) relaxation components. The mean values of T1,F and T1,S in the polarized nerve fibers at 25 degrees C were 0.

Age-related change in redox state of human serum albumin.

Human serum albumin (HSA) is the mixture of human mercaptalbumin (HMA, reduced form) and human nonmercaptalbumin (HNA, oxidized form). We developed a rapid and concise HPLC system to obtain the clear resolution of HSA into HMA and HNA, using an Asahipak GS-520H column. The mean value of the fraction of HMA (f(HMA)) for healthy young male subjects was 0.

The kinetic studies on the intramolecular SH, S-S exchange reaction of bovine mercaptalbumin.

Bovine mercaptalbumin (BMA) has 17 disulfide bonds and one SH group at Cys-34 which catalyzes the intramolecular SH, S-S exchange reaction (N-A isomerization, molecular aging) in the alkaline region at low ionic strength, resulting in the formation of the aged form (A-form). The aging reaction was completely reversible and strongly affected by environmental factors, such as pH, temperature, ionic strength, Ca2+, nonbranched short-chain fatty acids, etc. Disulfide configuration (or pairing of disulfide bonds) was affected by the environmental factors.

Increased oxidized form of human serum albumin in patients with diabetes mellitus.

High-performance liquid chromatographic (HPLC) analysis of human serum albumin (HSA) on Asahipak GS-520H columns at neutral pH (6.87) showed a clear resolution of human mercaptalbumin (HMA) and nonmercaptalbumin (HNA), which are reduced and oxidized form of HSA, respectively. We studied the conversion of HMA to HNA (mercapt-nonmercapt conversion) as an index of oxidative change of the tissues and organs in 28 normal subjects and in a total of 47 patients with non-insulin dependent diabetes mellitus (NIDDM).

Proton NMR studies on ischemic rat brain tissue.

The spin-lattice relaxation time (T1) of water protons and the cross-relaxation time (TIS) between irradiated protein protons and observed water protons were measured in order to study water-macromolecular interactions in ischemic rat brain tissues. Tissues were obtained by bilateral common carotid artery occlusion from stroke-prone spontaneously hypertensive rats. Water, Na, and K contents were measured in ischemic brain tissue at the same time.