Intramolecular Inhibition by Imidazole in Acid-Catalyzed Hydrolysis of Protected Carbohydrates.

The present study reveals an unexpected anomaly observed in the acid-catalyzed hydrolysis of the 5,6-O-isopropylidene group in 3-O-protected D-gluco- and D-allofuranose derivatives. Although the removal of the 5,6-O-isopropylidene protecting group is typically rapid and quantitative under acidic conditions, an unexpected inhibition of this reaction is observed for the two C3-epimers, 3-O-imidazole sulfonyl moiety. X-ray data show a two-faced imidazole ring orientation in the crystal, while solution state NOE data reveal a critical interaction type between the isopropylidene and the imidazole rings.

Rheoencephalography: A non-invasive method for neuromonitoring.

In neurocritical care, the gold standard method is intracranial pressure (ICP) monitoring for the patient's lifesaving. Since it is an invasive method, it is desirable to use an alternative, noninvasive technique. The computerized real-time invasive cerebral blood flow (CBF) autoregulation (AR) monitoring calculates the status of CBF AR, called the pressure reactivity index (PRx).

Acetyl group for proper protection of β-sugar-amino acids used in SPPS.

The synthesis of D-glucosamine-1-carboxylic acid based β-sugar amino acids (β-SAAs) is typically performed in nine consecutive steps via an inefficient OAc → Br → CN conversion protocol with low overall yield. Here, we present the improved and more efficient synthesis of both Fmoc-GlcAPC-OH and Fmoc-GlcAPC(Ac)-OH, β-SAAs consisting of only 4-5 synthetic steps. Their active ester and amide bond formation with glycine methyl ester (H-Gly-OMe) was completed and monitored by H NMR.

Synthesis of chimera oligopeptide including furanoid β-sugar amino acid derivatives with free OHs: mild but successful removal of the 1,2-O-isopropylidene from the building block.

Complementary to hydrophobic five membered ring β-amino acids (e.g. ACPC), β-sugar amino acids (β-SAAs) have found increasing application as hydrophilic building blocks of foldamers and α/β chimeric peptides.

Configuration-Controlled Crystal and/or Gel Formation of Protected d-Glucosamines Supported by Promiscuous Interaction Surfaces and a Conformationally Heterogeneous Solution State.

The configuration-dependent self-association mode of the two anomers of O-Ac,N-Fmoc-d-glucosamine, a foldamer building block, leading to gel and/or single crystal formation is described. The β-anomer of the sugar amino acid (2) forms a gel from various solvents (confirmed by SEM, rheology measurements, NMR, and ECD spectroscopy), whereas the α-anomer (1) does not form a gel with any solvent tested. Transition from the solution state to a gel is coupled to a concurrent shift of the Fmoc-groups: from a freely rotating (almost symmetrical) to a specific, asymmetric orientation.

α/β-Chimera peptide synthesis with cyclic β-sugar amino acids: the efficient coupling protocol.

The synthesis of α/β-chimeras comprises peptide bond formation from α- to β-, from β- to β-, and from β- to α-amino acid residues. The fine-tuned solid phase synthesis of -GXXG- chimera peptides containing the simplest achiral α-amino acid glycine and two cyclic SAAs of different ring size [X denoting cyclic β-Sugar Amino Acids (β-SAA)] is reported, variants containing Fmoc-RibAFU(ip)-OH a furanoid-, and Fmoc-GlcAPU(Me)-OH a pyranoid-type structural "Lego-element". Systematic search for the best coupling strategy with both H-β-SAA-OHs is described, including the comparison of the different coupling reagents and conditions.

C-3 epimers of sugar amino acids as foldameric building blocks: improved synthesis, useful derivatives, coupling strategies.

To obtain key sugar derivatives for making homooligomeric foldamers or α/β-chimera peptides, economic and multigram scale synthetic methods were to be developed. Though described in the literature, the cost-effective making of both 3-amino-3-deoxy-ribofuranuronic acid (H-t X-OH) and its C-3 epimeric stereoisomer, the 3-amino-3-deoxy-xylofuranuronic acid (H-c X-OH) from D-glucose is described here. The present synthetic route elaborated is (1) appropriate for large-scale synthesis; (2) reagent costs reduced (e.

Origin of problems related to Staudinger reduction in carbopeptoid syntheses.

We report the solid phase synthesis of -GG-X-GG- type α/β-carbopeptoids incorporating RibAFU(ip) (1a, tX) or XylAFU(ip) (2a, cX) sugar amino acids. Though coupling efficacy is moderate, both the lengthier synthetic route using Fmoc derivative (e.g.

Histological diagnosis determines complications of percutaneous renal biopsy: a single-center experience in 353 patients.

Background: We studied the connection between complication occurrence related to renal biopsies and histological diagnoses of the biopsy specimen. We also analyzed the distribution of diagnoses in our population.

Methods: We retrospectively studied 353 patients undergoing renal biopsy at the same center.

Sodium halide complexes of ribose derivatives and their unusual crystal structures.

Crystalline complexes of D-ribose, D-ribono-1,4-lactone and methyl β-D-ribopyranoside with sodium halides were synthesized and some of their crystal structures determined. Crystal structures of two lactone complexes and a methyl β-D-ribopyranoside reveal the mode of the salt binding and the intricate interplay of cation coordination and hydrogen bonding in these complexes. When complexed with NaBr, the ribopyranoside is in the (1)C(4) shape whereas ribose with no salt present has the (4)C(1) shape.

Transformation of aldose formazans. Novel synthesis of 2-acetamido-2-deoxypentonolactones and a new pent-2-enose formazan.

2-Acetamido-2-deoxypentonolactones were synthesized from per-O-acetylated formazans of D-ribose, D- and L-arabinose, respectively. In dimethyl sulfoxide, a novel spontaneous transformation of the per-O-acetyl-pentose formazans into new 3,4,5-tri-O-acetyl-pent-2-enose formazans has been recognized. Additional examples for the occurrence of the isomerism between pseudo-aromatic chelate and open phenylazo-phenylhydrazone system were demonstrated by (1)H NMR spectroscopy in both the unprotected pentose formazans and 3,4,5-tri-O-acetyl-pent-2-enose formazans.

Novel sequence variants of the alpha-galactosidase A gene in patients with Fabry disease.

We carried out molecular studies of 15 unrelated Hungarian families diagnosed with Fabry disease (FD). Genetic analysis of the alpha-galactosidase A gene was performed in 22 hemizygous males and 34 females. One of the female patients with severe disease phenotype showed homozygosity for the recurrent c.

The effect of an organized, nationwide breast cancer screening programme on non-organized mammography activities.

Objectives: To analyse the effect of an organized, nationwide breast cancer screening programme on non-organized mammography activities in Hungary.

Setting: The nationwide dataset of the Hungarian National Health Insurance Fund Administration covering the years 2000-2005.

Methods: Data derived from the nationwide database of the Hungarian National Health Insurance Fund Administration.

[Focal segmental glomerulosclerosis].

Focal segmental glomerulosclerosis is a glomerular injury with typical morphology detectable by light microscopy. It has different histological subtypes and clinical symptoms. These different subtypes were recently systematized (Columbia classification).

[Nephrogenic systemic fibrosis].

The nephrogenic systemic fibrosis - referred to in the literature earlier as nephrogenic fibrotizing dermopathy - is a rare clinical entity that develops in patients with renal disease. Its development has been described mainly after the usage of a gadolinium-based MRI contrast medium in patients with impaired renal function, mainly in dialysed patients. The nephrogenic systemic fibrosis is characterized by fibrosis evolving in the distal part of the extremities, and in more severe cases involving the lung, the liver, heart and skeletal muscles.

[Acute renal failure caused by plant extract].

The authors review the case of a 30 years old female patient presenting with a 48 hours-standing anuria, who permanently used products of grist of a virtuous plant, Guarana and occasionally used a parenteral non-steroid painkiller. The clinical history and laboratory results showed acute renal and hepatic failure. The histological picture of the renal biopsy specimen verified an acute tubular necrosis.

[Contrast medium induced nephropathy].

Contrast medium induced nephropathy. The wide-spread use of invasive diagnostic and therapeutic procedures makes the use of contrast media more common. Acute renal failure may develop following their intravascular administration, referred as contrast medium induced nephropathy or briefly contrast nephropathy.

Occurrence and solid-liquid partition of sulfonated naphthalene-formaldehyde condensates in the aquatic environment.

Sulfonated naphthalene-formaldehyde condensates (SNFC) are high production volume chemicals used in a variety of applications, for example, as concrete plasticizers, tanning agents, or dye dispersants. They enter the aquatic environment primarily by the wastewater path. The occurrence and fate of the monomers, which are different isomers of mono- and disulfonated naphthalene, was intensively investigated in previous studies.

Analgesic nephropathy in Hungary: the HANS study.

Background: The diagnosis of analgesic nephropathy has improved significantly with modern imaging techniques. We reviewed a large portion of the Hungarian dialysis population to obtain additional insight into the problem.

Methods: Twenty-two participating dialysis units enrolled 1400 patients on renal replacement therapy between 1 January 1995 and 1 January 1998.