julilili42/papers huggingface dataset:
In Vitro Test of New Biomaterials for the Development of a Bioartificial Pancreas
2001-11-01

A bstract : The implantation of macroencapsulated islets has the potential to restore endogenous insulin secretion in type 1 diabetics, with no need for lifetime immunosuppression. To match the physiological fluctuations of blood glucose concentrations with appropriate insulin release, the macroencapsulation material must combine immunoprotection with optimal diffusion properties for glucose and insulin. The impact of chemical modifications of polysulphone (PSU) capillary polymers with a cutoff of 50 kD on glucose‐induced insulin secretion of macroencapsulated rat islets was studied in perifusion experiments. The insulin release of free‐floating islets showed the typical rapid response to glucose stimulation. Total insulin release (AUC between minute 30 and 120 of perifusion) reached 117 ± 22 ng/ml. Blending PSU with polyvinylpyrrolidone or sodium‐dodecyl‐sulfate was not suitable for islet macroencapsulation, since glucose‐induced insulin release was absent or disturbed. Hydroxy‐methylation (CH 2 OH) of PSU improved the secretory behavior of macroencapsulated islets depending on the degree of PSU substitution (DS 0.8, AUC 62 ± 15 ng/ml; DS 1.8, 111 ± 24 ng/ml). In highly substituted PSU‐capillaries the kinetics of glucose‐induced insulin release was very similar to that observed in free‐floating islets. Two consecutive glucose stimulations potentiated insulin release of free‐floating islets during the second period of stimulation. Furthermore, freshly isolated macroencapsulated islets responded with more efficient insulin secretion after the initial priming. In conclusion, in vitro membrane screening identified highly substituted hydroxy‐methylated PSU as the material of choice for islet encapsulation in a bioartificial pancreas.
Neonatal rat cartilage has the capacity for tissue regeneration
2001-11-01

One of the most relevant issues in future medicine is tissue regeneration. Transplantation medicine alone cannot solve the problem of incurable conditions of vital organs. One approach to this might be the replication of the spontaneous regeneration that is found in embryonic/neonatal tissue. In this study, a tissue model for basic investigation of regeneration mechanisms in vivo was established. We demonstrated by histology and immunohistochemical staining for types I and II collagen that neonatal rat cartilage unlike adult cartilage has the capacity for rapid scarfree regeneration after full‐thickness incision. The underlying mechanism was identified in the preserved proliferative capacity of neonatal chondrocytes. This in vivo model should prove useful in further studies of the role of cellular (e.g., GA cell cycle regulators) and extracellular (e.g., cytokines) factors in tissue regeneration and wound healing.
Akute Nebennierenrindeninsuffizienz als Folge einer heparin-induzierten Thrombozytopenie mit bilateralem hämorrhagischem Nebenniereninfarkt
2001-11-01

A 56 year old male developed bilateral massive adrenal haemorrhage (BMAH) resulting in chronic adrenal insufficiency in the course of heparin-induced thrombocytopenia (HIT)-syndrome. Thrombosis of the central adrenal vein (CAV) with subsequent adrenal haemorrhagic infarction is the most probable cause of the rare association of HIT and BMAH. The exorbitantly high catecholamine plasma levels within the CAV in addition to immunogenic platelet activation are discussed as possible underlying pathophysiological mechanisms.
Rearing in different photic and chromatic environments modifies spectral responses of cone horizontal cells in adult fish retina
2001-11-01

We investigated chromatic processing in the outer retina of the cichlid fish Aequidens pulcher . Intracellular recordings from cone-specific horizontal cells (CHCs) revealed that the two morphologically identified types (H1 and H2) also have different spectral responses. H1-L cells hyperpolarize to all wavelengths (“luminosity”). H2-Cb cells depolarize to long wavelengths and hyperpolarize to short wavelengths (“chromaticity”, biphasic). Furthermore, we verified by immunocytochemistry that H2-Cb cells of A. pulcher predominantly contact the middle-wavelength-sensitive (MWS) members of double cones. Developmental plasticity in the cone–CHC networks was induced by rearing fish under conditions of spectral deprivation and different levels of white light. H1-L spectral responses were unaffected by the rearing conditions. Different intensity levels of white light and deprivation of long wavelengths during rearing both induced changes in the spectral responses of H2-Cb. Deprivation of short and middle wavelengths had no effect. Our results indicate that spectral processing in the outer retina of fishes can be modulated in response to different visual experiences and suggest that developmental fine tuning of the color-vision system occurs at early levels of visual processing.
A New Antibacterial Diterpene from the Roots ofSalvia caespitosa
2001-11-01

From the roots of Saliva caespitosa Montbret and Aucher ex. Bentham a new diterpene 6beta-hydroxyisopimaric acid (1) has been isolated together with four known diterpenes, one new triterpenoid, 3-acetylvergatic acid (2), as well as five known triterpenoids, two steroids and a flavone. The structures of the compounds were established by spectroscopic analyses. The isolated compounds were tested against standard bacterial strains. Only the new diterpene, 6beta-hydroxyisopimaric acid has strong activity (MIC 9 microg/ml) against S. aureus and (MIC 18 microg/ml) against S. epidermidis as well as against B. subtilis (MIC 9 microg/ml).
Acute adrenocortical insufficiency due to heparin-induced thrombocytopenia with subsequent bilateral haemorrhagic infarction of the adrenal glands.
2001-11-01

A 56 year old male developed bilateral massive adrenal haemorrhage (BMAH) resulting in chronic adrenal insufficiency in the course of heparin-induced thrombocytopenia (HIT)-syndrome. Thrombosis of the central adrenal vein (CAV) with subsequent adrenal haemorrhagic infarction is the most probable cause of the rare association of HIT and BMAH. The exorbitantly high catecholamine plasma levels within the CAV in addition to immunogenic platelet activation are discussed as possible underlying pathophysiological mechanisms.
Generation of Chronic Myelogenous Leukemia-Specific T Cells in Cytokine-Modified Autologous Mixed Lymphocyte/Tumor Cell Cultures
2001-11-01

Chronic myelogenous leukemia (CML) may be amenable to cell-based adoptive immunotherapy, as suggested by the graft-versus-leukemia effect of bone marrow transplantation and the therapeutic benefit of donor leukocyte infusions. Specific adoptive immunotherapy without bone marrow transplantation might be more effective and less cost-intensive. Professional antigen-presenting cells, the dendritic cells, from patients with CML are derived from the malignant clone and may stimulate antileukemia T-cell responses. Autologous T cells may also be able to recognize tumor antigens on CML cells directly. Here, the authors show that CD4 and CD8 T-cell responses to autologous CML cells can be generated in vitro rapidly and effectively by performing modified autologous mixed lymphocyte/tumor cell cultures (MLTC) in serum-free medium in the presence of cytokines known to support dendritic cell differentiation. MLTC-sensitized T cells secreted large amounts of the type 1 cytokine interferon-gamma, as well as interleukin (IL)-2. However, they also secreted a variety of other cytokines, including the type 2-subtype cytokine IL-13 but not the classic type 2 cytokines IL-4, IL-5, and IL-10. Monoclonal populations of CML-specific CD4 cells could be derived from these lines in limited numbers but showed markedly enhanced reactivity. This suggests that CML-specific T cells are relatively rare in these autologous MTLC-derived sensitized populations, but that their isolation and propagation would yield much more potent antitumor effector cells for use in adoptive immunotherapy without the need for bone marrow transplantation.
L-tryptophan contaminant ‘peak E’ induces the release of IL-5 and IL-10 by peripheral blood mononuclear cells from patients with functional somatic syndromes
2001-11-01

Summary In 1989, the development of eosinophilia myalgia syndrome (EMS) was observed in some patients after the intake of l-tryptophan containing several contaminants, including 1,1′-ethylidenebis[l-tryptophan] (‘peak E’). Since l-tryptophan has been taken particularly by individuals suffering from functional somatic syndromes (FSS), such as fibromyalgia syndrome (FMS), we put forward the hypothesis that EMS may have developed preferentially in patients with FSS as an allergic reaction towards the contaminant peak E. We therefore studied the immunological reactivity towards l-tryptophan and peak E in these individuals (n = 12) and compared these data with those obtained in 12 healthy controls and 12 patients with other chronic disorders. Peripheral blood mononuclear cells (PBMC) were cultured for 7 days with pure l-tryptophan and peak E. Supernatant fluids were collected at day 7. The type 2 cytokines IL-4, IL-5 and IL-10, and the type 1 cytokines IL-2 and IFN-γ, were determined by a double sandwich ELISA. PBMC from seven of the 12 FSS patients, but only three of the 24 controls, produced cytokines after incubation with peak E (P &amp;lt; 0·05). Interestingly, six of the seven FSS patients reacting with peak E produced IL-5 and/or IL-10. In contrast, PBMC from only one patient with other chronic disorders and one healthy control secreted type 2 cytokines in response to peak E. The observed heightened type 2 reactivity towards the more immunogenic contaminant 1,1′-ethylidenebis[l-tryptophan] in FSS patients may therefore be taken as an additional argument for our concept that EMS may have developed as a kind of drug-induced allergic disease.
Interpenetrierende Clusterstränge in der Kristallstruktur von K0,77Nb6Cl15 / Interpenetrating Cluster Chains in the Structure of K0.77Nb6Cl15
2001-11-01

The solid state reaction of KCl, NbCl 5 and Nb powder at 760 °C yielded black crystals of KNb 6 Cl 15 . The structure of the compound has been determined using single-crystal X-ray methods. KNb 6 Cl 15 crystallizes in the orthorhombic space group Pmma (no. 51) with lattice constants a = 1780.1(2), b = 1341.4(1), and c = 925.5(1) pm, Z = 4, and R1 = 0.039 for all 2727 observed reflections. [(Nb 6 Cl 12 i )Cl 6/2 a-a ] - anions in the structure are linked via two Cl a-a bridges to form one set of linear and one set of kinked chains along the crystallographic c and a directions. Four remaining Cl a-a bridges interconnect both sets of chains to a three-dimensional network. The potassium occupancy on a 4k site was refined to a value of 0.384(3) consistent with the formula K 0.77 Nb 6 Cl 15- . Ternäre Niobchloride des Formeltyps ANb 6 Cl 15 wurden bereits verschiedentlich beschrieben. Verbindungen mit A = Li [1] und Na [2] kristallisieren kubisch (Ia3̅d) mit identischen Schweratomstrukturen. Die Alkalimetall-Ionen Li (KZ = 4) und Na (KZ = 6 ) besetzen in den Strukturen ANb 6 Cl 15 aber unterschiedliche Splitlagen und sind dynamisch fehlgeordnet. Die Vertreter mit A = In und TI [3] kristallisieren orthorhombisch (Pmma). Ihre Kationen befinden sich in zweifach überdachten, würfelförmigen Cl-Umgebungen (KZ = 10). Die Kenntnis des Formeltyps ANb 6 Cl 15 mit schweren Alkalimetallen ist noch unvollständig. Einkristallstrukturuntersuchungen für A = Rb, Cs ergaben Kationenfehlordnungen [4, 5]. Für die Verbindung KNb 6 Cl 15 wurde eine Einkristallstrukturbestimmung durchgeführt (Tab. 1). Die Verbindung kristallisiert orthorhombisch in der Raumgruppe Pmma (Nr. 51) mit den Gitterkonstanten a = 1780,1(2), b = 1341,4(1) und c = 925,5(1) pm mit Z = 4 und ist isotyp zu den Inund TI-Verbindungen. Die Besetzung der K-Position (4k-Lage, mx-Punktsymmetrie) wurde zu 0,384(3) verfeinert, was der Zusammensetzung K 0.77 Nb 6 Cl 15 entspricht (Tab. 2) # . Die Nb-Nb-Abstände in KNb 6 Cl 15 liegen zwischen 291,47(6) und 296,45(7) pm, die Bindungslängen Nb-Cl I betragen 243,3(1) - 247,18(9) und die Nb-Cl a -Abstände 258,7(2) - 271,40(9) pm.
Parietal gamma-band activity during auditory spatial precueing of motor responses
2001-11-01

Magnetoencephalographic gamma-band activity (GBA) was used to investigate synchronization of cortical networks in putative auditory dorsal stream areas during the transformation of auditory spatial information into motor preparation. GBA was compared between lateralized vowels precueing either ipsi- or contralateral responses in two experiments with randomized versus blocked task presentation. In both studies, parietal GBA was higher for the contralateral than the ipsilateral precues. Spectral amplitudes at 54-64 Hz were maximal at 120 ms post precue onset during randomized presentations, while in the blocked task 62-72 Hz activity was present at precue onset and less peaked. These findings suggest a fast activation of parietal networks when auditory spatial precues are used to plan contralateral responses.
Two novel prevalent polymorphisms in the hormone-sensitive lipase gene have no effect on insulin sensitivity of lipolysis and glucose disposal
2001-11-01

Free fatty acids released during triglyceride lipolysis play an important role in obesity-associated insulin resistance of glucose disposal. Individual sensitivity of lipolysis to the suppressive effect of insulin varies greatly among healthy subjects. It is possible that genetic factors contribute to this variation. Among the many proteins involved in the regulation of lipolysis, hormone-sensitive lipase (HSL) represents a prime candidate for genetic variants contributing to the biological variation of insulin sensitivity of lipolysis. We determined the insulin sensitivity of lipolysis (suppression of isotopically [primed-continuous infusion of d5 glycerol] measured glycerol rate of appearance) and of glucose disposal, using a three-step (n = 20) or standard (n = 53) hyperinsulinemic euglycemic clamp in 73 healthy, unrelated subjects. To assess the possible role of genetic polymorphisms, we directly sequenced the coding region of the HSL gene and the noncoding exon B from these subjects. We identified two silent mutations and three amino acid polymorphisms: Arg262Met (prevalence, 5%), Glu620Asp (prevalence, 31%) and Ser681Ile (prevalence, 22%). The latter two are located in the regulatory domain of HSL but neither had a significant impact on insulin sensitivity of lipolysis or glucose disposal (with and without adjustment for obesity and age as covariates; all P values > 0.20). We conclude that a number of genetic polymorphisms in HSL exist, some of which are highly prevalent. Neither of the polymorphisms we identified in the coding region, however, contributed measurably to the biological variation of insulin sensitivity in our lean, healthy population.
Neuropsychological deficits in cerebellar syndromes
2001-11-01

Interest in the role of the cerebellum in cognitive functioning has been increasing in recent years, based on both theoretical considerations and empirical evidence. This review attempts to critically evaluate neuropsychological studies based on standardized testing of patients with selective cerebellar dysfunction. Findings are considered which address possible cerebellar influence on motor adaptation and habituation, motor skill acquisition, classical conditioning of motor responses, temporal processing, general intellectual abilities, frontal lobe functions, visuospatial abilities, memory and non-motor skill learning, and language. Deficits in motor learning and temporal processing are consistently observed in patients with cerebellar syndromes, while deficits in frontal lobe functions, visuospatial processing, memory, non-motor skill learning and language dysfunction have been reported in several studies, but have not been replicated in others. Methodological factors which may account for such discrepancies are discussed.
Mark detection in low-energy electron-beam lithography
2001-11-01

An implementation of the Rau-detector has been investigated with respect to its use for mark detection in low-energy electron-beam lithography. The generation of signals from marks commonly used in electron-beam lithography is discussed. With this detector, images of trenches etched into silicon were obtained with electron energies as low as 1 keV. Signal-to-noise ratio and bandwidth were determined from line scans across sequences of etched trenches. The trench depth has been varied from 40 to 500 nm. The measurements have also been performed with resist coated trenches. It is demonstrated that the Rau-detector is well suited for mark detection in low-energy electron- beam lithography systems. Due to its small size, it leads itself to microcolumn application.
THERMODYNAMICAL DESCRIPTION OF HEAVY ION COLLISIONS
2001-11-01

We analyze the thermodynamical state of nuclear matter in transport\\ndescriptions of heavy ion reactions. We determine thermodynamical variables\\nfrom an analysis of local momentum space distributions and compare to blast\\nmodel parameters from an analysis of fragment energy spectra. These\\ndescriptions are applied to spectator and fireball matter in semi-central and\\ncentral Au+Au collisions at SIS-energies, respectively.\\n
CAN WE DETERMINE THE NUCLEAR EQUATION OF STATE FROM HEAVY ION COLLISIONS?
2001-11-01

We discuss the problems involved in extracting the nuclear equation-of-state\\nfrom heavy-ion collisions. We demonstrate that the equation of state becomes\\neffectively softer in non-equilibrium and this effect is observable in terms of\\ncollective flow effects. Thus, non-equilibrium effects must be included in\\ntransport descriptions on the level of the effective mean fields. A comparison\\nwith transverse momentum, rapidity, and centrality selected flow data show the\\nreliability and limitations of the underlying interaction which was derived\\nfrom microscopic Dirac-Brueckner (DB) results.\\n
ChemInform Abstract: Structure and Electrochemical Study of Nb3Cl8.
2001-11-06

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of a Model System for the Macrocyclic Subunit of the Oximidines.
2001-11-06

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Electromagnetomotive force fields in noninertial reference frames and accelerated superconducting quantum interferometers
2001-11-08

We discuss the prospects of detecting with high precision the force fields related to noninertiality in superconducting circuits. Special emphasis is laid on the perfectly conducting and perfect diamagnetism analogues of the Tolman-Stewart respectively Barnett effects. The influence of acceleration and rotation on the electrodynamics of superconducting interferometers is explicitly described. In particular, we show how motion induced changes of the oscillation frequency of the local Josephson oscillators in superconducting quantum interference filters can be used for precision measurements of acceleration in free space.
Saposins (sap) A and C activate the degradation of galactosylsphingosine
2001-11-09

As previously shown for [ 3 H‐galactosyl]ceramide, the breakdown of [ 3 H‐galactosyl]sphingosine was reduced in prosaposin‐deficient skin fibroblast homogenates. Galactosylsphingosine hydrolysis was also deficient in cell homogenates from Krabbe's disease (β‐galactocerebrosidase‐deficient) patients, but not acid β‐galactosidase‐deficient patients. Moreover, hydrolysis of galactosylsphingosine in the prosaposin‐deficient cell homogenates could be partially restored by adding pure saposin A or C, thereby identifying these saposins as essential facilitators of galactosylsphingosine hydrolysis. By contrast, saposins B and D had little effect on galactosylsphingosine hydrolysis in the prosaposin‐deficient cells. The reduced galactosylsphingosine turnover in prosaposin‐deficiency suggests that there could be a pathogenetic cerebral accumulation of galactosylsphingosine in this disorder.
Alkaline liquid chromatography/electrospray ionization skimmer collision‐induced dissociation mass spectrometry for phosphopeptide screening
2001-11-09

Abstract A rapid on‐line method for the identification of phosphorylated peptides in enzymatic protein digests by specific marker ion signals is described. In our study we investigated the use of alkaline conditions together with a previously described method for selective and sensitive detection of phosphopeptide ions combining high‐performance capillary liquid chromatography (LC) and electrospray ionization mass spectrometry (ESI‐MS). 1, , 2 Phosphorylation‐specific marker ions ( m/z 79, PO 3 − , and m/z 97, H 2 PO 4 − ) were generated by skimmer collision‐induced dissociation (sCID) in the negative‐ion mode. The method was evaluated and validated for mono‐phosphorylated synthetic peptides using different alkaline pH values and CID offsets. Alkaline conditions (pH 10.5) enhance the generation of phosphopeptide‐specific fragment ions from serine‐ and tyrosine‐phosphorylated peptides, and enable the use of m/z 79 (PO 3 − ) and m/z 97 (H 2 PO 4 − ) as phosphorylation‐specific marker traces. Note that HPLC separation in trifluoroacetic acid containing solvents impairs the use of m/z 97 (C 2 F 3 O − fragment ion at m/z 97) as a phosphorylation‐specific marker. The optimized method was applied for the detection of phosphorylated peptides in a tryptic β‐casein digest. The expected mono‐ and tetra‐phosphorylated peptides were detected and rapidly identified by μLC/ESI‐sCID‐MS and μLC/ESI‐MS analysis. Copyright © 2001 John Wiley &amp; Sons, Ltd.
Bose-Einstein Condensation in a Surface Microtrap
2001-11-13

Bose-Einstein condensation has been achieved in a magnetic surface microtrap with 4 x 10(5) (87)Rb atoms. The strongly anisotropic trapping potential is generated by a microstructure which consists of microfabricated linear copper conductor of widths ranging from 3 to 30 microm. After loading a high number of atoms from a pulsed thermal source directly into a magneto-optical trap the magnetically stored atoms are transferred into the microtrap by adiabatic transformation of the trapping potential. In the microtrap the atoms are cooled to condensation using forced rf-evaporation. The complete in vacuo trap design is compatible with ultrahigh vacuum below 2 x 10(-11) mbar.