julilili42/papers huggingface dataset:
Insulin Resistance and Insulin Sensitizers
2001-01-01

Insulin resistance is a key factor in the pathogenesis of type 2 diabetes mellitus and a co-factor in the development of dyslipidaemia, hypertension and atherosclerosis. The causes of insulin resistance include factors such as obesity and physical inactivity, and there may also be genetic factors. The mechanism of obesity-related insulin resistance involves the release of factors from adipocytes which exert a negative effect on glucose metabolism: free fatty acids, tumour necrosis factor-α and the recently discovered hormone, resistin. The two resulting abnormalities observed consistently in glucose-intolerant states are impaired suppression of endogenous glucose production, and impaired stimulation of glucose uptake. Among the genetic factors, a polymorphism (Pro12Ala) in the peroxisome proliferator-activated receptor (PPAR) γ is associated with a reduced risk of type 2 diabetes mellitus and increased insulin sensitivity, primarily that of lipolysis. On the other hand, the association with insulin resistance of a common polymorphism (Gly972Arg) in the insulin receptor substrate 1, long believed to be a plausible candidate gene, is weak at best. This polymorphism may instead be associated with reduced insulin secretion, which, in view of the recent recognition of the insulin signalling system in β-cells, results in the development of a novel pathogenic concept. Finally, fine-mapping and positional cloning of the susceptibility locus on chromosome 2 resulted in the identification of a polymorphism (UCSNP-43 G/A) in the calpain-10 gene. In non-diabetic Pima Indians, this polymorphism was associated with insulin resistance of glucose disposal. The pharmacological treatment of insulin resistance has recently acquired a novel class of agents: the thiazolidinediones. They act through regulation of PPARγ-dependent genes and probably interfere favourably with factors released from adipocytes which mediate obesity-associated insulin resistance.
Experiences using gas sensors on an autonomous mobile robot
2001-01-01

This paper reports on experiences concerning the deployment of gas sensors on an autonomous mobile robot. It particularly addresses the suitability of the developed system to localize a distant odour source. First experiments were undertaken in which the robot was ordered to move along different weakly ventilated corridors, while keeping track of its center (framing a '1D' scenario). The measured sensor values show evident peaks that roughly indicate the location of the odour source, if the robot moves with a speed not too low. In this case the system proved to be well suited to detect even weak odour sources. Otherwise the observed course of the received values show many peaks hardly correlated with the location of the odour source. Several investigations were performed to clear up this behaviour but it is still not possible to make concluding statements about the reasons. Finally the setup to perform experiments in a '2D' scenario is described and concerning results of first investigations are presented. It was shown that the utilized system is also capable of detecting a distant odour source in a 2D environment and that the somewhat harder localization task has to account for some weak airflow even in closed, unventilated rooms.
Lipid-independent effects of an estrogen–statin combination: inhibition of expression of adhesion molecules and plasminogen activator inhibitor-1 in human endothelial cell cultures
2001-01-01

In summary, an estrogen-statin therapy is able to elicit lipid-independent positive modulations on the expression of cell adhesion molecules and the synthesis of PAI-1. The estrogen-statin combination showed partially additive effects and no negative, antagonistic actions. Since the combination of statins with hormone replacement therapy may attain clinical significance in preventing cardiovascular disease, it seems worthwhile to elucidate further the direct vascular effects of this combination therapy, especially in postmenopausal women with pre-existing coronary disease.
Sodium hydride/hexamethylphosphoric triamide: a new and efficient reagent towards the synthesis of protected 1,2- and 5,6-enopyranosides
2001-01-01

A new method for the elimination of hydrogen halides and p-toluenesulfonic acid from sugar moieties using sodium hydride (NaH) in hexamethylphosphoric triamide (HMPA) at room temperature is reported. NaH/HMPA has several advantages compared to NaH/DMF: elimination products are produced in high yields even from sterically hindered starting materials, and not only from halides, but also tosylates.
Detection and quantification ofCBFB/MYH11 fusion transcripts in patients with inv(16)-positive acute myeloblastic leukemia by real-time RT-PCR
2001-01-01

We used a newly established real-time RT-PCR assay for the quantification of the leukemia-specific CBFB/MYH11 transcripts in inv(16)-positive acute myeloblastic leukemia. CBFB/MYH11 could be quantified over a five log range, with a detection limit of 10 molecules of a CBFB/MYH11 plasmid and a 1:10(5) dilution of RNA of the inv(16)-positive ME-1 cell line, respectively. The fusion transcripts were also quantified in 19 patients with acute myeloblastic leukemia and an inv(16) at initial diagnosis. The expression of CBFB/MYH11 varied over a two log range without correlation to clinical response or relapse rate. In nine patients, CBFB/MYH11 was also quantified during/after chemotherapy and autologous or allogeneic stem cell transplantation. All of these patients showed a similar decline of CBFB/MYH11 after intensive therapy. Six of these patients are in complete remission with a stable low-level or absent CBFB/MYH11 expression. Three patients relapsed, and their CBFB/MYH11 transcripts rose again to pretreatment levels. In two patients, this increase in CBFB/MYH11 could be detected by real-time PCR before hematological relapse. These data indicate that real-time RT-PCR can be used for the sensitive detection and quantification of CBFB/MYH11 transcripts in the follow-up of patients with inv(16)-positive AML.
Comparison of Cytology and Nuclear Matrix Protein 22 for the Detection and Follow-Up of Bladder Cancer
2001-01-01

&lt;i&gt;Objectives: &lt;/i&gt;This study was designed to determine the clinical usefulness of the nuclear matrix protein 22 (NMP 22) test for the detection of bladder cancer in comparison to urine cytology. &lt;i&gt;Methods: &lt;/i&gt;84 patients suffering from bladder cancer or suspected bladder cancer, 25 patients with benign urological lesions and 60 healthy controls participated in a prospective study. Freshly voided spot urine samples were taken for cytological examination and determination of NMP 22 levels by enzyme-linked immunoassay. &lt;i&gt;Results: &lt;/i&gt;The sensitivity of the NMP 22 test according to the tumor grading was (results of cytology in brackets): G1 25.0% (20.0%); G2 68.2% (59.1%), and G3 100.0% (66.7); overall sensitivity was 62.5% (45.0%). The sensitivity for superficial bladder cancer was 46.7% (36.7%) and for invasive bladder cancer 90.0% (70.0%). The specificity was 65.9% (88.9%). &lt;i&gt;Conclusions: &lt;/i&gt;NMP 22 is a reliable tool for detecting invasive bladder cancer. Results for the frequently occurring low grade superficial bladder cancer are as poor as those obtained with cytology. In addition benign lesions such as urolithiasis or urinary tract infection lead to false-positive results. Therefore cystoscopy has to be performed when trying to detect and follow-up bladder cancer.
Effect of medroxyprogesterone acetate and norethisterone on serum-stimulated and estradiol-inhibited proliferation of human coronary artery smooth muscle cells
2001-01-01

These data suggest that MPA may antagonize beneficial antiatherosclerotic estradiol effects on the vasculature, whereas NET may be neutral in this respect. However, these effects occurred at supraphysiological concentrations. Because these concentrations might be reached in the target tissues, the clinical relevance for treatment of patients with cardiovascular risk cannot be excluded.
Quantitation of TGF‐β1 mRNA in porcine mesangial cells by comparative kinetic RT/PCR: Comparison with ribonuclease protection assay and in situ hybridization
2001-01-01

Abstract Gene expression can be examined with different techniques including ribonuclease protection assay (RPA), in situ hybridisation (ISH), and quantitative reverse transcription–polymerase chain reaction (RT/PCR). These methods differ considerably in their sensitivity and precision in detecting and quantifying low abundance mRNA. Although there is evidence that RT/PCR can be performed in a quantitative manner, the quantitative capacity of this method is generally underestimated. To demonstrate that the comparative kinetic RT/PCR strategy—which uses a housekeeping gene as internal standard—is a quantitative method to detect significant differences in mRNA levels between different samples, the inhibitory effect of heparin on phorbol 12‐myristate 13‐acetate (PMA)‐induced‐TGF‐β1 mRNA expression was evaluated by RT/PCR and RPA, the standard method of mRNA quantification, and the results were compared. The reproducibility of RT/PCR amplification was calculated by comparing the quantity of G3PDH and TGF‐β1 PCR products, generated during the exponential phases, estimated from two different RT/PCR (G3PDH, r = 0.968, P = 0.0000; TGF‐β1, r = 0.966, P = 0.0000). The quantitative capacity of comparative kinetic RT/PCR was demonstrated by comparing the results obtained from RPA and RT/PCR using linear regression analysis. Starting from the same RNA extraction, but using only 1% of the RNA for the RT/PCR compared to RPA, significant correlation was observed ( r = 0.984, P = 0.0004). Moreover the morphometric analysis of ISH signal was applied for the semi‐quantitative evaluation of the expression and localisation of TGF‐β1 mRNA in the entire cell population. Our results demonstrate the close similarity of the RT/PCR and RPA methods in giving quantitative information on mRNA expression and indicate the possibility to adopt the comparative kinetic RT/PCR as reliable quantitative method of mRNA analysis. J. Clin. Lab. Anal. 15:215–222, 2001. © 2001 Wiley‐Liss, Inc.
Evidence for Distinct Mechanisms in the Shapingof the CD4 T Cell Repertoire in Histologically DistinctMyasthenia Gravis – Associated Thymomas
2001-01-01

The major histocompatibility complex (MHC) class II is involved both in thymocyte maturation and peptide presentation and might thus play a key role in the pathogenesis of paraneoplastic myasthenia gravis (MG) in thymomas. To further investigate this issue, we analyzed and scored the expression of epithelial class II expression in 35 thymomas (medullary, MDT; mixed, MXT; cortical and well differentiated thymic carcinoma, CT / WDTC) and correlated it with the histological tumor subtype, prevalence of MG and thymocyte maturation, which was analyzed by flow cytometry and RT‐PCR. Our results show that both MHC class II expression and thymocyte maturation are highly dependent on the histological tumor subtype. CT / WDTC retain features of the normal outer thymic cortex, namely substantial MHC class II expression together with normal early thymocyte maturation until late phases of positive selection, but disturbed terminal thymopoiesis. By contrast, MDT and MXT retain features of the normal inner cortex and the medulla with low to absent class II expression and highly abnormal early thymocyte maturation including impaired positive selection, while terminal T cell maturation in MXT appeared undisturbed. There was no correlation between MHC class II expression and MG status for a given tumor subtype. In conclusion, our results provide evidence for a different histogenesis of cortical thymomas and well differentiated carcinomas on the one hand and mixed and medullary thymomas on the other. Decreased expression levels of MHC class II, although of crucial importance for abnormal intratumorous maturation, are not sufficient to explain the emergence of paraneoplastic MG.
Synthesis of a Model System for the Macrocyclic Subunit of the Oximidines
2001-01-01

Cross-coupling reaction of aryl triflate 1 and vinyl stannane 13 provided salicylic acid derivative 15. This compound was converted to the dihydroxy acid 16, which provided in a size-selective macrolactonization the two macrolides 17 and 18 in a ratio of 60 : 40. Compound 17 is a model of the macrocyclic core of the oximidines.
The effect of medroxyprogesterone acetate and norethisterone on the estradiol stimulated proliferation in MCF-7 cells: comparison of continuous combined versus sequential combined estradiol/progestin treatment.
2001-01-01

Different regimen types and different progestins do lead to significantly different effects on the proliferation of a breast cancer cell line. These findings might be useful in the elucidation of potential mechanisms involved in the clinical situation.
O-phospho-L-tyrosine protects TP53 wild-type cells against ionizing radiation
2001-01-01

O-phospho-L-tyrosine (P-Tyr) has been reported previously to inhibit growth of several cancer cell lines at mM concentrations. In the present study, we investigated the effect of this compound on tumor cells and normal cells in combination with radiation exposure. It could be demonstrated for the first time that P-Tyr at microM concentrations protects TP53 wild-type cells against ionizing radiation (SF4 minus BBI = 0.28, SF4 plus BBI = 0.45). On the contrary, human transformed or tumor cell lines characterized by mutated or functional inactivated TP53 were not altered or increased in their radiation sensitivity (SF4 minus BBI = 0.32, SF4 plus BBI = 0.22). Treatment of wild-type TP53 cells with P-Tyr induced stabilization of TP53 within 3 and 16 hours and a subsequent increase in CDKN1A expression after treatment. Consequently, a 16-hours pretreatment of cells with P-Tyr led to a significant radioprotective effect. This was not observed in cell lines with mutated TP53, which shows no radioprotection by P-Tyr. Thus, the present data suggest that P-Tyr-mediated radioprotection is dependent on preirradiation stabilization of TP53. The results indicate that P-Tyr is a radioprotective agent that can potentially be very useful and easy to deliver for radiation protection in general and especially in radiation therapy of TP53-mutated tumors.
Unusual chromosomal mosaicism as a cause of mental retardation and congenital malformations in a familial reciprocal translocation carrier, t(17;22)(q24.2;q11.23)
2001-01-01

Familial reciprocal translocations are generally without phenotypic effect, although there is some evidence for a small excess of mental retardation and congenital malformations (MR/CM) in children carrying familial reciprocal translocations. Possible mechanisms whereby such translocations could have a phenotypic effect include cryptic unbalanced rearrangements, uniparental disomy, and disruption of putative genes at the breakpoints, unmasking recessive alleles on the normal homologs. Mosaicism for a supernumerary derivative chromosome in a carrier of a familial reciprocal translocation has not yet been described. We report a boy presenting with MR/CM and a familial reciprocal translocation, t(17;22)(q24.2;q11.23), inherited from the mother. Cytogenetic analysis of peripheral blood lymphocytes showed a balanced karyotype in all 32 analyzed metaphase spreads. Molecular genetic analysis was consistent with biparental origin of the normal homologs. In metaphase spreads from skin fibroblasts a supernumerary chromosome was found in all 24 cells analyzed and could be identified as der(22)t(17;22)(q24.2;q11.23). Several possible segregation modes at meiosis I followed by meiosis II or postzygotic nondisjunction of the der(22) might have led to this unusual chromosomal mosaicism. We propose hidden mosaicism as a possible cause for MR/CM in patients who apparently carry a balanced familial reciprocal translocation.
Fast acceleration-encoded magnetic resonance imaging
2001-01-01

Direct acceleration imaging with high spatial resolution was implemented and tested. The well-known principle of phase encoding motion components was applied. Suitable gradient switching provides a signal phase shift proportional to the acceleration perpendicular to the slice in the first scan of the sequences. An additional scan serving as a reference was recorded for compensation of phase effects due to magnetic field inhomogeneities. The first scan compensated for phase shifts from undesired first- and second-order motions; the second scan was completely insensitive to velocity and acceleration in all directions. Advantages of the proposed two-step technique compared to former approaches with Fourier acceleration encoding (with several phase encoding steps) are relatively short echo times and short total measuring times. On the other hand, the new approach does not allow us to assess the velocity or acceleration spectrum simultaneously. The capabilities of the sequences were tested on a modern 1.5 T whole body MR unit providing relatively high gradient amplitudes (25 mT/m) and short rise times (600 micros to maximum amplitude). The results from a mechanical acceleration phantom showed a standard deviation of 0.3 m/s2 in sequences with an acceleration range between -12 and 12 m/s2. This range covers the expected maximum acceleration in the human aorta of 10 m/s2. Further tests were performed on a stenosis phantom with a variable volume flow rate to assess the flow characteristics and possible displacement artifacts of the sequences. Preliminary examinations of volunteers demonstrate the potential applicability of the technique in vivo.
Synthesis, characterisation, and fluorescence spectroscopic mobility studies of fluorene labeled inorganic–organic hybrid polymers
2001-01-01

In the attempt to find catalyst supports with improved accessibilities for tethered transition metal complexes, a series of inorganic–organic hybrid polymers was synthesised by sol–gel processing of three different silyl-functionalised alkyl derivatives. The resulting materials were characterised by solid-state NMR spectroscopy, BET measurements and elemental analysis. Molecular mobilities in the solvent-swollen polymers were determined by fluorescence spectroscopy. As fluorescent probe, fluorene was covalently attached to the polymer matrix by a T-silyl-functionalised alkyl spacer. The rotational mobilities of the probe were determined by steady-state and time-resolved fluorescence depolarisation experiments. Translational mobilities of molecular species dissolved in the liquid phase were investigated by the kinetics of luminescence quenching after pulsed laser excitation. Both rotational and translational mobilities in hybrid materials are significantly higher than in conventional Q-type polysiloxanes. However, the mobilities are still about one to two orders of magnitude lower than in homogeneous solutions, and thus contribute to the reduced accessibilities of matrix bound transition metal catalysts. The highest mobilities were observed in dichloromethane and organic ethers, which have the strongest swelling capabilities for the hybrid polymers. Compared to D-silyl polymers, mobilities in T-silyl based materials are significantly higher.
Fine structure of the cyrtophorid ciliate Chlamydodon mnemosyne Ehrenberg, 1837
2001-01-01

Summary. Chlamydodon mnemosyne is a bottom-dwelling cyrtophorid ciliate found in brackish water ponds. The morphology of nondividers is described based upon light microscopy of living and silver stained cells. In addition we provide a detailed descrip tion of the ultrastructure of the cells. C. mnemosyne is dorsoventrally flattened and ciliated only on the ventral surface which is separated from the dorsal surface by a peculiar transversally striped band at the margin of the cells. This band consists of regularly arranged C- shaped clasps with a complex multilayered fine structure. The somatic ciliature is subdivided in right and left fields of kineties flanking a medial field of 4 postoral kineties. The somatic monokinetids are associated with tubular and fibrillar cytoskeletal elements according to the phyllopharyngid pattern, the most pronounced feature being a pack of subkinetal microtubules. Similar to other cyrtophorid ciliates the oral ci liature consists of an inner and an outer circumoral kinety as well as a preoral kinety all of which are built up from dikinetids with their ant erior kinetosome bearing the cilium. The oral apparatus consists of an inner ring of cytopharyngeal lamellae and an outer ring of 9 large and 2 small anteriorly positioned nematodesmal rods resulting in the bilateral appearance of the cytopharyngeal basket. The rods are capped with so ca lled dentes which harbour a barren kinetosome each. The detailed ultrastructural description provided here serves as a basis for studies on the morphogenesis of C. mnemosyne, part of which are presented in an accompanying paper (Bardele and Kurth 2001).
Venous leg ulcers and microcirculation.
2001-01-01

Incompetence of venous valves do not lead per se to trophic skin changes of the lower limb. In severely concerned patients suffering from dermatoliposclerosis or venous leg ulcers retrograde pressure waves were detected in the nutritive capillaries of the skin by the "servo nulling" pressure measurement during simulated calf muscle contraction. Between the degree of trophic skin change and the capillary density and cutaneous oxygen partial pressure a close correlation was found. Healing of venous ulcers occurred only if the cutaneous microangiopathy in the ulcer area improved. Capillary density and transcutaneous oxygen partial pressure were of prognostic impact as to healing of venous ulcers.
Aleukemic Leukemia Cutis Presenting as Benign-appearing Exanthema
2001-01-01

Aleukemic leukemia cutis is a rare condition characterized by the infiltration of the skin by leukemic cells before their appearance in the peripheral blood or bone marrow. We report here a 62-year-old seemingly healthy patient who presented with disseminated erythematous maculae. A skin biopsy showed leukemia cutis of monocytic type. No involvement of bone marrow or peripheral blood was found. The patient developed acute monocytic leukemia 7 months later. We present this case to illustrate how leukemia cutis can masquerade as a clinically benign-appearing cutaneous eruption without leukemic changes in blood or bone marrow. To confirm the diagnosis of aleukemic leukemia cutis, immunohistochemistry of the skin lesions as well as a complete staging procedure is necessary.
Vibrotactile characteristics of different tissues in endoscopic otolaryngologic surgery - in vivo and ex vivo measurements
2001-01-01

The measurement of mechanical tissue impedance by determining resonance frequency with the help of a tactile sensor is one method of compensating for sensory deficits in endoscopic surgery. In principle, this electromechanic vibrotactile sensor can be integrated into an operating instrument. The operator would thereby receive indirect feedback on the tactile properties of the tissue. We examined freshly resected tissues using the first prototype vibrotactile sensor. Measurements on resected carcinoma of the oropharynx demonstrated the possibility of differentiating between carcinoma, healthy mucosa and carcinomatous-infiltrated mucosa. Subsequent in vivo measurements in the oropharynx and oral-cavity regions of 20 patients confirmed these results. We found that, in the oral cavity, tumours of > 1 cm diameter could be distinguished from the surrounding mucosa. Tumours of the soft palate and tonsillary region could not be clearly delimited, because of stimulation of the surrounding tissue.