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At least 559 records · Page 31Linked to original sources
PubMed1997

[A significant increase in superficial sensation, a number of years after a peripheral neurologic lesion, using transcutaneous vibratory stimulation].

A patient with sensory changes in the territory of the ulnar nerve due to a partial nerve lesion 19 years previously, was treated by Transcutaneous Vibratory Stimulation. The effectiveness of this treatment was verified by subjective criteria and by the following tests: Moving and Static Two-Point discrimination Test, Light-touch-Deep-pressure (Semmes-Weinstein) Test, Ninhydrin sweat Test and Wrinkle Test. These tests document both a marked improvement in superficial sensitivity and partial regulation of sympathetic nervous system function.

Adult↗
PubMedDate not supplied

Enzymatic degradation of liposome-grafted poly(hydroxyethyl L-glutamine).

Liposomes coated with poly(hydroxyethyl L-glutamine) (PHEG) show prolonged circulation times and biodistribution patterns comparable to PEG-coated liposomes. While PEG is a nondegradable polymer, PHEG is expected to be hydrolyzed by proteases. In this study the enzymatic degradability of PHEG both in its free form and grafted onto liposomes was investigated, using the proteases papain, pronase E, and cathepsin B. Enzymatic action was monitored with a ninhydrin assay, which quantifies amine groups formed due to hydrolysis of amide bonds, and the degradation products were characterized by MALDI-ToF mass spectrometry. PHEG, both in its free form and when grafted onto liposomes, showed degradation into low molecular weight peptides by the enzymes. Thus, we present a polymer-coated long-circulating liposome with an enzymatically degradable coating polymer, avoiding the risk of cellular accumulation.

Enzymes↗
PubMed1989

Carboxypeptidase-mediated release of methotrexate from methotrexate alpha-peptides.

Methotrexate (MTX) alpha-peptides containing representative neutral (alanine), acidic (aspartic acid), and basic (arginine) amino acids were synthesized by a regiospecific route. Purity and authenticity of MTX-Ala, MTX-Asp, and MTX-Arg were established by TLC, HPLC, elemental analysis, and NMR and absorbance spectra. These peptides were hydrolyzed by carboxypeptidases to yield MTX and the amino acids. Reactions were monitored by using a ninhydrin assay for the amino acids and HPLC and spectrophotometric assays for MTX. Pancreatic carboxypeptidase A (CP-A) hydrolyzed MTX-Ala and, at a much slower rate, MTX-Asp and MTX-Arg. MTX-Ala was also a substrate for pancreatic carboxypeptidase B (CP-B); marginal activity was observed with this enzyme and MTX-Arg. Human serum hydrolyzed only MTX-Arg; biphasic inhibition of this activity by 2-(mercaptomethyl)-3-(guanidinoethyl)thiopropionate was consistent with the known presence of two types of endogenous carboxypeptidase (CP-N). Cytotoxicity of the MTX peptides toward L1210 cells in culture was enhanced considerably in the presence of the appropriate carboxypeptidases. MTX-Ala was much less toxic than MTX (ID50 values of 2.0 X 10(-6) M and 2.4 x 10(-8) M, respectively), but in the presence of CP-A the ID50 of the peptide improved to 8.5 X 10(-8) M. Similar results were obtained with MTX-Asp/CP-A and MTX-Ala/CP-B combinations. MTX-Arg showed good cytotoxicity (ID50 of 5.0 X 10(-8) M), due to CP-N activity in the fetal bovine serum of the culture medium; inclusion of CP-B lowered the ID50 to that of MTX. Possible clinical uses of MTX peptides are discussed.

Amino Acids↗
PubMed2006

Novel photoinduced grafting-chemical reaction sequence for the construction of a glycosylation surface.

Carbohydrates play a major role in many recognition events, such as blood coagulation, immune response, fertilization, cell growth, embryogenesis, and cellular signal transfer, which are essential for the survival of living entities. Synthetic carbohydrate-based polymers, so-called glycopolymers, are emerging as important well-defined tools for investigating carbohydrate-based biological processes and for simulating various functions of carbohydrates. In this work, we present a facile strategy for the formation of glycopolymer tethered on polypropylene microporous membrane surface. Acrylamide was grafted onto the polypropylene microporous membrane surface by photoinduced graft polymerization in the presence of benzophenone. The amide groups of grafted poly(acrylamide) were then transformed to primary amine groups by the Hofmann rearrangement reaction. Quantificational evaluation of the rearrangement reaction was carried out by ninhydrin method and mass weighting. Sugar moieties were coupled with the grafted functional layer to form glycopolymer by the reaction between primary amine groups and carbohydrate lactones. The grafting of acrylamide, the conversion of amide groups to amine groups, and the coupling of sugar moieties were confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy combined with surface morphology observation by scanning electron microscopy.

Carbohydrates↗
PubMed1974

Hydrolysis of bradykinin and its higher homologues by angiotensin-converting enzyme.

The hydrolysis of bradykinin and its higher homologues by angiotensin-converting enzyme has been investigated by using an automated ninhydrin technique. The results show an inverse relationship of hydrolysis rate with size and charge of the peptide, which parallels the inactivation in the pulmonary circulation and offers an explanation for the selectivity of metabolism of these kinins by the lungs.

Amino Acid Sequence↗
PubMed1979

Faecal methylamine in normal and uraemic subjects.

1. A ninhydrin-reacting substance seen during ion-exchange chromatography of faecal dialysate obtained in vivo from normal and uraemic subjects has been isolated and identified as methylamine. 2. Faecal dialysate concentrations of methylamine were higher in uraemic subjects and were related to the degree of renal impairment (P less than 0.05). 3. Methylamine concentrations in faecal dialysate and centrifugate were not significantly different.

Centrifugation↗
PubMed2001

Treatment of focal hyperhidrosis with botulinum toxin type A: long-term follow-up in 61 patients.

BACKGROUND: The blocking action of botulinum toxin type A (BTX-A) on cholinergically innervated sweat glands has been used successfully to treat patients with focal hyperhidrosis. OBJECTIVES: To investigate the long-term efficacy and safety of intradermal injections of BTX-A. METHODS: We performed an open-label study in 61 patients treated over a period of 3 years for axillary or palmar hyperhidrosis. A total dose of 400 mU BTX-A (Dysport) was injected into both axillae or 460 mU BTX-A (Dysport) into both palms. The injections were repeated after relapse. Objective quantification of sweat production was performed using digitized ninhydrin-stained sheets. RESULTS: Four weeks after BTX-A treatment the median reduction in sweat production was 71% compared with baseline (P < 0.001) in the axillary group and 42% (P = 0.005) in the palmar group. Subjective assessment of sweat production by the patients using a visual analogue scale (0, no sweating; 100, the most severe sweating) showed a significant reduction in both the axillary (P < 0.001) and palmar groups (P < 0.001). Secondary disturbances due to focal hyperhidrosis interfering with daily activities were markedly improved in both groups. The median time interval between the sets of injections was 34 weeks for axillary hyperhidrosis and 25 weeks for palmar hyperhidrosis. The treatment of palmar hyperhidrosis was complicated by transient but not disabling weakness of the small hand muscles in nine of 21 patients. CONCLUSIONS: Repeated intradermal injections of BTX-A in patients with axillary and palmar hyperhidrosis are as effective as first treatments.

Adult↗
PubMed1998

Detection of carboxypeptidases as taxonomic markers for gram-negative bacteria.

The use of seven benzoyl-L-amino acids for the detection of carboxypeptidase activities in strains of Gram-negative aerobic and facultatively anaerobic bacteria is reported. A simple overnight assay was designed using ninhydrin for the demonstration of the amino acid released by hydrolysis. Detection of carboxypeptidase activity was shown to have some taxonomic relevance within the Enterobacteriaceae; it was also useful for differentiation within the genus Acinetobacter and for distinction between Pseudomonas aeruginosa and Pseudomonas fluorescens.

Amino Acids↗
PubMed1997

A novel algorithm for the coupling control in solid-phase peptide synthesis.

This paper describes a new method for the evaluation of conductimetric data collected during the in-line monitoring of the coupling step in solid-phase peptide synthesis. The control scheme relies on a feed-forward artificial neural network algorithm which can predict the final yield of the reaction within its initial 5 min by analyzing the conductivity signal profile. The yield values predicted by the artificial neural network algorithm result in good accordance with the data obtained by the commonly used ninhydrin test.

Algorithms↗
PubMed1984

A comparison of 3 systems for quantifying gingival crevicular fluid with respect to linearity and the effects of qualitative differences in fluids.

This investigation compares the Periotron 6000, Periotron 600, and ninhydrin area systems for quantifying gingival fluid. All systems have highly significant (p less than 0.001) linear relationships between measurements and fluid volumes. Additional curvilinear components have virtually no clinically significant implications. Qualitative differences in fluid only have clinically significant implications for the Periotron 600. When both quantitative and qualitative properties of gingival crevicular fluid are being investigated, the Periotron 6000 is the system of choice.

Blood↗
PubMed1991

A new method for carbon isotopic analysis of protein.

The reaction of ninhydrin with amino acids can be used in carbon isotopic studies of protein. The reaction can be applied to extract as carbon dioxide only peptide-bonded carbon in proteinaceous material, thus avoiding most, if not all, contaminants. Test radiocarbon dates on ancient bone indicate that the method provides reliable ages, and stable carbon isotopic data suggest that our understanding of isotopic dietary reconstruction needs detailed examination. The technique should also be useful in biochemical tracing experiments and in global carbon budget studies, and the underlying principle may be applicable to other isotopes and molecules.

Animals↗
PubMed1995

Evaluation of disk method for hippurate hydrolysis by Campylobacter species.

A disk method for hippurate hydrolysis was compared with the ninhydrin tube method by using 140 genetically confirmed Campylobacter strains. Results were similar for 129 (92%) strains when the inoculum size for the disk method was standardized. Six strains (4.2%) showed variable results by each method. Our results conflict with those obtained in studies by others, who found the two methods to be dissimilar.

Animals↗
PubMed2000

Induction of BGT-1 and amino acid system A transport activities in endothelial cells exposed to hyperosmolarity.

We studied the responses to hypertonicity of cultured endothelial cells from swine pulmonary arteries. In 0.5 osmol/kgH(2)O medium, initial cell shrinkage was followed by a regulatory volume increase (RVI), complete after 1 h, concomitant with an increase in cellular K(+) content. Then the activity of amino acid transport System A increased, accompanied by an accumulation of ninhydrin-positive solutes (NPS), reaching a peak at approximately 6 h. The subsequent decline in System A activity was paralleled by an induction of the betaine-GABA transporter (BGT-1), detected as increases of BGT-1 mRNA and of transport activity, which peaked at approximately 24 h. Inhibitors of transcription or translation prevented induction of both transport activities. The increased expression of BGT-1, which involved activation of "tonicity-responsive enhancer," was inhibited by 5 mM extracellular betaine. Cellular K(+) concentration gradually declined after the accumulation of NPS and during the induction of BGT-1. This very effective adaptation to hypertonicity suggests it has a physiological role.

Amino Acid Transport Systems↗
PubMed1990

A method for histochemical demonstration of protein-bound amino groups by light microscopy.

We have established an efficient method for the histochemical demonstration of protein-bound amino groups by light microscopy, using a ninhydrin or alloxan-thiocarbohydrazide-silver proteinate (NHY or ALX-TCH-SP) sequence followed by a physical development (PD) procedure. As a result of the present experimental studies on Carnoy's solution-fixed paraffin sections of a series of rat tissues, including three types of major salivary glands, liver, pancreas, stomach, duodenum, jejunum, colon, kidney, prostate, and spleen, the sensitivity and specificity of the new method were found to be sufficient. In the tissues tested, protein-bound amino groups were visualized by distinct brownish or blackish reaction products. Comparisons of the particular method with the NHY or ALX-Schiff methods employed hitherto have substantiated the fact that the former method leads to apparently higher visibility of reaction products than the latter.

Alloxan↗
PubMed1998

Screening system for urease inhibitors using 13C-NMR.

Urease inhibitors are candidate drugs to treat infection with the human pathogen, Helicobacter pylori, which produces a potent urease [urea amidohydrolase; EC 3.5.1.5]. We developed a screening system based on 13C-NMR measurement of the time course of decrease in the signal of 13C-urea in the presence of urease. The effect on urease activity of known inhibitors, hydroxamic acids, L-ascorbic acid, 2,2'-dipyridyl disulfide and ninhydrin, was speedily and conveniently measured by this method.

Binding, Competitive↗
PubMed1977

Evaluation of an electronic device for gingival fluid quantitation.

A number of factors which might affect the readings of the HAR-600 GCFM were studied: 1. The readings were higher when the filter paper strips were placed between the fron halves of the upper and lower counterparts than when they were placed between the rear halves. No differences in readings were observed when the strips were placed in the middle, the left, or the right areas of the counterparts. 2. The higher the fluid viscosity the lower the reading. Salt water (0.9% NaCl) gave a lower reading than deionized water. 3. Increased room temperature or relative humidity led to higher readings, especially when the fluid volume exceeded 0.2 microliter. 4. More reading time was required for high viscosity fluid, low temperature, and high relative humidity. The HAR-600 GCFM readings and the lengths of ninhydrin-stained areas were compared. Both methods were able to reflect the amounts of serum absorbed.

Animals↗
PubMed2002

Novel sensitive spectrophotometric method for the trace determination of cyanide in industrial effluent.

The high toxicity of the cyanide ion at low concentration necessitates its analysis in a variety of environmental samples with a very low cyanide content. A new sensitive spectrophotometric method has been developed for the trace determination of cyanide with ninhydrin (NH) in an alkaline medium. Beer's law is obeyed in the range of cyanide concentration 0.04-0.24 microg cm(-3), and the molar absorptivity at 590 nm is 2.20 x 10(5) dm3 mol(-1) cm(-1). The Sandell's sensitivity of the product is 0.000118 microg cm(-2). The optimum reaction conditions and other important analytical parameters have been investigated. The results obtained by using the proposed method for environmental samples agree well with those obtained by the Aldridge standard method.

Cyanides↗