In vitro spontaneous parthenogenetic activation of golden hamster oocytes.

Parthenogenetic activation is a major hurdle to be cleared for the examination of the human sperm chromosome after intracytoplasmic injection (ICSI) into golden hamster oocytes. Various factors that affect spontaneous activation of hamster oocytes were, therefore, investigated in this study. We collected cumulus-oocyte complexes (COC) from the oviducts of superovulated females and washed them thoroughly with Ca2+-containing or Ca2+-free TALP-HEPES medium (handling media).

Frontal white matter biochemical abnormalities in late-life major depression detected with proton magnetic resonance spectroscopy.

Objective: Neuroanatomical abnormalities have been identified in patients with late-life mood disorders by using magnetic resonance imaging. This study examined the biochemical correlates of late-life major depression in the frontal gray and white matter by using single-voxel proton spectroscopy.

Method: Twenty elderly patients with major depression and 18 comparison subjects similar in age and gender to the patients were scanned on a 1.

Volume-localized two-dimensional correlated magnetic resonance spectroscopy of human breast cancer.

A localized 2D correlation spectroscopic sequence (L-COSY) was implemented and applied in human breast cancer in vivo to evaluate the water to fat (both saturated and unsaturated) ratios and also to identify choline. Being in agreement with the conventional 1D magnetic resonance spectroscopy (MRS) results, elevated water to lipids ratios were found in breast cancers and choline was observed only in a few cancer patients.

Localized two-dimensional shift correlated MR spectroscopy of human brain.

A two-dimensional (2D) chemical shift correlated MR spectroscopic (COSY) sequence integrated into a new volume localization technique (90 degrees -180 degrees -90 degrees ) is proposed for whole-body MR spectroscopy (MRS). Using the product operator formalism, a theoretical calculation of the volume localization as well as the coherence transfer efficiencies in 2D MRS is presented. Phantom model solutions were used to test and optimize the efficiency of the proposed sequence.

Oxygen access to the active site of cholesterol oxidase through a narrow channel is gated by an Arg-Glu pair.

Cholesterol oxidase is a monomeric flavoenzyme that catalyzes the oxidation and isomerization of cholesterol to cholest-4-en-3-one. Two forms of the enzyme are known, one containing the cofactor non-covalently bound to the protein and one in which the cofactor is covalently linked to a histidine residue. The x-ray structure of the enzyme from Brevibacterium sterolicum containing covalently bound FAD has been determined and refined to 1.

Correction method for determining anteroposterior diameter of the cervical spinal canal on lateral radiographs.

Measurement of the anteroposterior diameter of the cervical spinal canal may prove unreliable because of the rotatory effect of degenerative disease. Nevertheless, this measuring error may be corrected by performing dual midpoint measurements between the posterior vertebral body and spinolaminar line when less than 10 degrees of rotation is present.

Menstrual cycle-related brain metabolite changes using 1H magnetic resonance spectroscopy in premenopausal women: a pilot study.

Proton magnetic resonance spectroscopy (1H-MRS) was used to assess neurochemical brain changes across the menstrual cycle in five women with premenstrual dysphoric disorder (PMDD) and six control subjects. Women with PMDD and control subjects were scanned on days 8 and 26 within one menstrual cycle (i.e.

Decreased anterior cingulate myo-inositol/creatine spectroscopy resonance with lithium treatment in children with bipolar disorder.

This project was designed to compare differences in brain proton spectra between children and adolescents with bipolar disorder (BPD) and gender and age-matched normal controls, and to measure changes in myo-inositol levels following lithium therapy, utilizing in vivo proton magnetic resonance spectroscopy (1H MRS). A single voxel (2x2x2 cm3) was placed in brain anterior cingulate cortex for acquisition of the 1H spectra at baseline and after acute (7 days) lithium administration in 11 children (mean age 11.4 years) diagnosed with BPD, and in 11 normal controls.

Constraint-based assembly of tertiary protein structures from secondary structure elements.

A challenge in computational protein folding is to assemble secondary structure elements-helices and strands-into well-packed tertiary structures. Particularly difficult is the formation of beta-sheets from strands, because they involve large conformational searches at the same time as precise packing and hydrogen bonding. Here we describe a method, called Geocore-2, that (1) grows chains one monomer or secondary structure at a time, then (2) disconnects the loops and performs a fast rigid-body docking step to achieve canonical packings, then (3) in the case of intrasheet strand packing, adjusts the side-chain rotamers; and finally (4) reattaches loops.

Predicting the structures of 18 peptides using Geocore.

We describe an extensive test of Geocore, an ab initio peptide folding algorithm. We studied 18 short molecules for which there are structures in the Protein Data Bank; chains are up to 31 monomers long. Except for the very shortest peptides, an extremely simple energy function is sufficient to discriminate the true native state from more than 10(8) lowest energy conformations that are searched explicitly for each peptide.

The effects of glucose-induced oxidative stress on growth and extracellular matrix gene expression of vascular smooth muscle cells.

Vascular smooth muscle cell (VSMC) dysfunction plays a role in diabetic macrovasculopathy and this may include abnormalities in growth characteristics and the extracellular matrix. As the actual mechanisms by which glucose induces VSMC dysfunction remain unclear, the aim of this study was to assess the potential role of glucose-induced oxidative stress. Porcine aortic VSMCs were cultured for 10 days in either 5 mmol/l normal glucose or 25 mmol/l D-glucose (high glucose).

Glucose-induced oxidative stress in vascular contractile cells: comparison of aortic smooth muscle cells and retinal pericytes.

Free radical-mediated damage to vascular cells may be involved in the pathogenesis of diabetic vasculopathy. The aim of this study was to compare the extent of glucose-induced oxidative stress in both vascular smooth muscle cells (VSMCs) and pericytes and the effect on antioxidant enzyme gene expression and activities. Porcine aortic VSMC and retinal pericytes were cultured in either 5 or 25 mmol/l glucose for 10 days.

Changing pattern of desmocollin 3 expression accompanies epidermal organisation during skin development.

The adhesive core of the desmosome is composed of cadherin-like glycoproteins of 2 families, desmocollins and desmogleins. The desmosomal cadherins show distinct patterns of expression in adult epidermis, and we have suggested that the desmocollins have a functional role in regulating the differentiation and/or morphogenesis of that epithelium (North et al. [1996] Proc.

X-ray absorption and resonance raman spectroscopy of human myeloperoxidase at neutral and acid pH.

Myeloperoxidase (MPO), an important enzyme in the oxygen-dependent host defense system of human polymorphonuclear leukocytes, utilizes hydrogen peroxide to catalyze the production of hypochlorous acid, an oxidizing bactericidal agent. While MPO shows significant sequence homology with other peroxidases and this homology is particularly striking among the active-site residues, MPO exhibits unusual spectral features and the unique ability to catalyze the oxidation of chloride ions. We have investigated the MPO active-site with X-ray absorption (XAS) and resonance Raman (RRS) spectroscopies at neutral pH and also at the physiological acidic pH (pH approximately 3) and have compared these results with those of horseradish peroxidase (HRP).

Cloning of a G protein-activated inwardly rectifying potassium channel from human cerebellum.

Based on sequence homology with the rat atrial G protein-coupled muscarinic potassium channel (GIRK1 or KGA1/KGB1), a human cDNA encoding a G protein-activated inwardly rectifying K+ channel (HGIRK1) was isolated. The cDNA encodes a protein of 501 amino acids and shares 99% identity to rat GIRK1 in its total amino acid sequence. Southern blot analysis of genomic DNA indicates a high degree of conservation among various species.

Folding proteins with a simple energy function and extensive conformational searching.

We describe a computer algorithm for predicting the three-dimensional structures of proteins using only their amino acid sequences. The method differs from others in two ways: (1) it uses very few energy parameters, representing hydrophobic and polar interactions, and (2) it uses a new "constraint-based exhaustive" searching method, which appears to be among the fastest and most complete search methods yet available for realistic protein models. It finds a relatively small number of low-energy conformations, among which are native-like conformations, for crambin (1CRN), avian pancreatic polypeptide (1PPT), melittin (2MLT), and apamin.

Differential effects of lectins on recombinant glutamate receptors.

The effects of the lectins concanavalin A, succinyl concanavalin A, wheat-germ agglutinin and soybean agglutinin were studied at recombinant ionotropic glutamate receptors expressed in Xenopus oocytes. Homomeric and heteromeric receptors from each of the three major classes of ionotropic glutamate receptors (N-methyl-D-asparate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainate) were studied. The lectins potentiated homomeric configurations of kainate, AMPA and NMDA receptors to a greater degree than the corresponding heteromeric configurations although the rank order of the lectin potentiating effects was the same for both homomeric and heteromeric receptors within a given glutamate receptor class.

Resonance Raman study on the iron-sulfur centers of Desulfovibrio gigas aldehyde oxidoreductase.

Resonance Raman spectra of the molybdenum containing aldehyde oxidoreductase from Desulfovibrio gigas were recorded at liquid nitrogen temperature with various excitation wavelengths. The spectra indicate that all the iron atoms are organised in [2Fe-2S] type centers consistent with cysteine ligations. No vibrational modes involving molybdenum could be clearly identified.

Demonstration of antibodies to bovine desmocollin isoforms in certain pemphigus sera.

We have shown previously that IgG antibodies in certain pemphigus sera, particularly endemic Brazilian pemphigus foliaceus (BPF) sera, react with bovine desmocollins (Dsc), which are transmembranous glycoproteins of desmosome junctions. Desmocollins occur as three different isoforms (Dsc 1, 2 and 3), all of which are represented in the epidermis. In this study, we examined sera of various pemphigus types by immunoblotting purified bovine desmosomes and bovine Dsc 1, 2 and 3 fusion proteins, expressed in pGEX expression vectors.

Characterisation of a desmocollin isoform (bovine DSC3) exclusively expressed in lower layers of stratified epithelia.

Desmocollins are cadherin-like glycoproteins involved in cell adhesion and plaque formation in desmosome junctions. Three distinct isoforms, the products of different genes, have been found in bovine tissues. We have reported previously that one of these, DSC3, is expressed only in basal and lower suprabasal layers of stratified epithelia.

A case of pemphigus vulgaris showing reactivity with pemphigus antigens (Dsg1 and Dsg3) and desmocollins.

Both pemphigus vulgaris antigen (PVA; Dsg3) and pemphigus foliaceus antigen (PFA; Dsg1) are members of the desmoglein subfamily of the cadherin supergene family. Another desmosomal cadherin, desmocollin, is occasionally recognized by certain pemphigus sera. We present a 38-year-old Japanese male who showed clinically and histopathologically typical features of pemphigus vulgaris, whose sera reacted with all PVA, PFA, and desmocollins using immunoblotting of both human epidermis and bovine snout epidermis.

[Serum lipid-associated sialic acid (LSA) in diagnosing and monitoring ovarian cancer].

Serum from 161 patients with ovarian cancer, 28 patients with benign gynecologic disorders and 22 healthy women, was assayed for levels of tumor marker LSA, which were compared with CA125. The results showed that in the patients with ovarian cancer, the sensitivities of LSA and CA125 for the patients prior to surgery were 83.0% and 92.

Principles of protein folding--a perspective from simple exact models.

General principles of protein structure, stability, and folding kinetics have recently been explored in computer simulations of simple exact lattice models. These models represent protein chains at a rudimentary level, but they involve few parameters, approximations, or implicit biases, and they allow complete explorations of conformational and sequence spaces. Such simulations have resulted in testable predictions that are sometimes unanticipated: The folding code is mainly binary and delocalized throughout the amino acid sequence.

Isolation and identification of a protoheme IX derivative released during autolytic cleavage of human myeloperoxidase.

Myeloperoxidase (MPO) is a functionally important component of the normal human neutrophil host defense system. This enzyme possesses a dimeric structure composed of two heavy-subunit/light-subunit protomers, with a heme-like prosthetic group covalently linked to each heavy subunit. Although MPO exhibits unusual spectral and enzymatic properties, the nature of the prosthetic group and its mode of linkage with the apoenzyme have not been determined.

A test of lattice protein folding algorithms.

We report a blind test of lattice-model-based search strategies for finding global minima of model protein chains. One of us (E.I.