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T Hofmann

Publications and source records attributed to T Hofmann.

At least 19 recordsLinked to original sources

Radiofrequency tissue volume reduction of the soft palate and UPPP in the treatment of snoring.

The purpose of this study was to evaluate the efficiency of radiofrequency tissue volume reduction (RFTVR) and uvulopalatopharyngoplasty (UPPP) in the treatment of snoring in a prospective clinical trial of 79 patients consecutively undergoing surgery for snoring. Seventy-nine patients with primary snoring or mild OSAS (obstructive sleep apnea syndrome) were enrolled in this clinical trial (66 males and 13 females). According to the anatomical findings (the size of the tonsils and uvula), the patients underwent UPPP/TE of the RFTVR of the soft palate. Forty-seven patients had UPPP/TE (age 45.81+/-12.11 years; median AHI: 8; range 1-29). Thirty-two patients were treated with RFTVR of the soft palate (age 48.10+/-10.92; median AHI: 5.0; range 0-26). The average number of treatments was 2.2. All patients underwent preoperative polysomnography to exclude severe OSAS. Pre- and postoperative snoring scores were evaluated from the patients with bed partners. Postoperative follow-up data were collected at a median of 4 months after treatment; 85.1% of the UPPP group and 53.1% of the RFTVR group underwent postoperative polysomnography. Subjective snoring scores of all study participants were evaluated. Preoperatively, there was no statistically significant difference of subjective symptoms, age and BMI between the two groups. The snoring scores improved statistically significantly in both groups (P <0.001 in the UPPP group; P =0.001 in the RFTVR group). After UPPP/TE snoring improved in 37 patients (78.7%), and 29 (61.7%) thereof were free of bothersome snoring; no change was found in 9 patients (19.2%), and 1 (2.1%) worsened. In the RFTVR group, snoring improved in 15 (46.9%), and 9 (28.1%) thereof were free of bothersome snoring; no change was found in 13 patients (50%), and 1 worsened (3.1%). Preoperative AHI was statistically higher (P =0.016) and mean minimal oxygen saturation significantly lower (P =0.002) in the UPPP group. In the UPPP group AHI and HI showed statistically significant improvement postoperatively (P =0.025 and P =0.034, respectively). After RFTVR, no statistically significant change of AHI, HI or oxygen saturation was found. Besides limited mucosal erosions (15%) after RFTVR and foreign body sensations (<10%) after UPPP/TE, no side effects were observed. The success rate of RFTVR of the soft palate is lower compared to the more invasive technique of UPPP. Due to its minimally invasive character, RFTVR is suitable as first-step treatment for snoring, but patients should be counseled about possible success rates and different treatment options.

Catheter Ablation↗

HCHs and DDTs in sediment-dwelling animals from the Yangtze Estuary, China.

HCHs and DDTs in sediment-dwelling animals including mollusks and crabs from the Yangtze Estuary were determined by GC-ECD. Levels of t-HCH were in the range of 1.2-5.5 ng g(-1) and averaged 3.5 ng g(-1) in mollusks, while t-DDT concentrations ranged from 26.0 to 68.8 ng g(-1), with a mean of 34.5 ng g(-1). In crabs t-HCH concentrations varied from 2.0 to 25.7 ng g(-1) and averaged 13.8 ng g(-1), whereas the concentrations of t-DDT were in the range of 1.5-24.8 ng g(-1) with a mean value of 5.9 ng g(-1). The HCHs and DDTs levels depend on geographical position and sources, showing the high levels at fresh water area in the estuary, such as XP, CM and LHK sites, and lower at brackish water area, such as FX site, and little difference between species. Results also indicate there was no significant relationship between t-HCH (t-DDT) concentrations and lipid contents both in mollusks and crabs because of non-equilibrium state under a specific estuarine dynamics; smaller individuals accumulated more HCHs and DDTs than larger individuals of mollusks at LHK site, showing different uptake rate for these pesticides; moreover, HCHs and DDTs levels were lower in female crab bodies than male crab bodies suggesting that the release of spawning. BSAFs (Biota- Sediment Accumulation Factors) from sediment-dwelling animals for HCHs and DDTs show a significant "one high with two low" and "one low with two high" effect in the Yangtze Estuary.

Animals↗

[Improved analysis of left ventricular function using three-dimensional echocardiography].

Left ventricular geometry and function are important pathophysiologic and prognostic parameters. However, especially in patients with cardiac pathologies left ventricular geometry can be complex. Quantification of left ventricular volumes using conventional two-dimensional echocardiography is only possible when simplifying assumptions of left ventricular geometry are made. In contrast three-dimensional echocardiography allows direct quantification of left ventricular volumes even in complex distortions of left ventricular shape. The availability of real-time three-dimensional echocardiography has brought this technique into clinical practice. Three-dimensional echocardiography is a technique that may be used as a routine echocardiographic method in the near future.

Cardiac Volume↗

Chemoselective synthesis of peptides containing major advanced glycation end-products of lysine and arginine.

Useful methodologies have been developed, enabling the straightforward synthesis of peptides containing N(epsilon)-(carboxymethyl)-L-lysine (CML) and N(epsilon)-(carboxyethyl)-L-lysine (CEL), the major glycation end-products of lysine. These lysine derivatives were successfully incorporated into growing peptide chains via standard Fmoc/Ot-Bu peptide synthesis procedures. For the synthesis of peptides containing major glycation end-products of arginine, synthetic routes have been developed enabling the transformation of ornithine residues in peptides into the well-known arginine-derived advanced glycation end-products (AGEs) Glarg, carboxymethyl-L-arginine (CMA), MG-H1, MG-H2, MG-H3, and carboxyethyl-L-arginine (CEA), respectively, by means of special modifying agents. Furthermore, it was shown that Glarg-containing peptides become quantitatively hydrolyzed into CMA-peptides under physiologic conditions. A similar reaction was observed in case of a MG-H3-peptide, which turned into a CEA-peptide under these conditions.

Amino Acid Sequence↗

Critical period for a teratogenic VLA-4 antagonist: Developmental effects and comparison of embryo drug concentrations of teratogenic and non-teratogenic VLA-4 antagonists.

BACKGROUND: Integrins such as VLA-4 (Very late antigen 4, integrin alpha4beta1) play key roles in cell-cell interactions that are critical for development. Homozygous null knockouts of the VLA-4 alpha4-subunit or VCAM-1 (VLA-4 cell surface ligand) in mice result in failure of the allantois and chorion to fuse leading to interrupted placentation and cardiac development and embryo lethality. Embryo-fetal studies of three VLA-4 antagonists, IVL745, IVL984, and HMR1031 [Crofts et al., Birth Defects Res B 71:55-68 (this issue), 2004] with exposure on gestation days (GD) 6-17 (rat), 6-18 (rabbit) or 6-15 (mouse) showed that only IVL984 treatment resulted in embryo lethality and cardiac defects. Objectives of the current study were to determine the critical period for inducing IVL984-related embryo-fetal effects, and to test the hypothesis that these effects were due to higher embryo drug concentrations. METHODS: IVL984 was administered at 40 mg/kg/day to pregnant rats on GD 4 and 5, GD 6 and 7, GD 8 and 9, GD 10 and 11, or GD 12 and 13. Animals were euthanized on GD 21 and uteri and fetuses were examined. A treatment period of GD 10-12 was selected for subsequent toxicokinetic (TK) studies in which IVL984, HMR1031, or IVL745 was administered to pregnant rats and rabbits. On GD 12, maternal plasma, extra-embryonic tissue (placenta and amniotic fluid), and embryonic tissue were collected and analyzed for drug concentrations. RESULTS: In the IVL984 critical period study in pregnant rats, treatment on GD 10 and 11 resulted in increased post-implantation loss, skeletal variations, and spiral septal defects similar to those observed in standard embryo-fetal development studies with treatment throughout organogenesis. There were no embryo-fetal effects after treatment on GD 4 and 5, GD 6 and 7, or GD 8 and 9. There was a single aorta malformation after treatment on GD 12 and 13. In the TK studies, IVL745, HMR1031, and IVL984 were all detectable in embryonic tissue and there was no evidence for accumulation. Rat and rabbit embryo exposures (AUC or dose-adjusted AUC) on GD 12 could not explain the observed teratology (IVL984<HMR1031<IVL745). Further analyses incorporating pharmacological activity, clearance, and protein binding data provided a positive correlation between embryonic exposure and teratogenic potency. CONCLUSIONS: The critical period for IVL984 in the rat, GD 10 to 11, corresponds to the expression of alpha-4 integrin on the chorion and VCAM-1 on the allantois and myocardium as well as chorioallantoic fusion and formation of the spiral septum. Embryo drug levels adjusted for pharmacological activity, clearance, and protein binding provide a possible explanation for the differing teratogenic potency of IVL984, HMR1031, and IVL745.

Abnormalities, Drug-Induced↗

Different embryo-fetal toxicity effects for three VLA-4 antagonists.

BACKGROUND: VLA-4 (Very late antigen 4, integrin alpha4beta1) plays an important role in cell-cell interactions that are critical for development. Homozygous null knockouts of the alpha4 subunit of VLA-4 or VCAM-1 (cell surface ligand to VLA-4) in mice result in abnormal placental and cardiac development and embryo lethality. Objectives of the current study were to assess and compare the teratogenic potential of three VLA-4 antagonists. METHODS: IVL745, HMR1031, and IVL984 were each evaluated by the subcutaneous route in standard embryo-fetal developmental toxicity studies in rats and rabbits. IVL984 was also evaluated in mice. Fetuses were examined externally, viscerally, and skeletally. RESULTS: IVL745 did not cause significant maternal or fetal effects at doses up to 100 or 250 mg/kg/day in rats or rabbits, respectively. HMR1031 treatment resulted in marked maternal toxicity and slight fetal toxicity at the highest tested doses of 200 and 75 mg/kg/day in rats and rabbits, respectively. HMR1031 embryo-fetal effects consisted of slightly lower body weight and crown-rump length in rats and minor sternebral defects in rabbits. IVL984 treatment resulted in minimal maternal effects at doses up to 40, 15, and 100 mg/kg/day in rats, rabbits, and mice, respectively (excluding abortions in rabbits). However, marked developmental effects were observed at the lowest tested IVL984 doses, 1, 0.2, and 3 mg/kg/day in rats, rabbits, and mice, respectively. IVL984 embryo-fetal effects consisted of increased total post-implantation loss due to early resorptions and high incidences of cardiac malformations and skeletal malformations and/or variations. Notably, spiral septal defects were observed in up to 76% of rat fetuses and up to 58% of rabbit fetuses. CONCLUSIONS: Dramatic differences in teratogenic potential were observed: IVL745 was not teratogenic, HMR1031 caused slight embryo-fetal effects at maternally-toxic doses, and IVL984 was a potent teratogen at doses where direct maternal toxicity was limited to abortions in rabbits. Prominent effects of IVL984 included embryo lethality and cardiac malformations including spiral septal defects in three species.

Abnormalities, Drug-Induced↗

Profile identification of disease-associated humoral antigens using AMIDA, a novel proteomics-based technology.

We describe AMIDA (autoantibody-mediated identification of antigens), a novel target identification technology based on the immunoprecipitation of disease-specific antigens by autologous serum antibodies followed by two-dimensional electrophoretic separation, and their identification via mass spectrometry. Twenty-seven potential carcinoma antigens were identified including proteins of hitherto unknown function. Validation of one of the identified antigens, cytokeratin 8, revealed its de novo expression in hyperplastic tissue, gradual overexpression with increasing malignancy, and ectopic localization on the cell surface. Furthermore, a strong prevalence of CK8-specific antibodies occurred in the serum of cancer patients already at early disease stages. In situ hybridization for one marker of unknown function, KIAA1273/TOB3, demonstrated its strong overexpression in head and neck carcinomas, thus making it a likely tumor antigen candidate. Eventually, AMIDA could foster significant improvements for the diagnosis and therapy of human diseases eliciting a humoral immune response, and allows for the rapid identification of new target molecules.

Allergy and Immunology↗

Prognostic significance of the signal averaged electrocardiogram in patients with chronic stable coronary artery disease. Analysis in the time domain and by spectral temporal mapping.

BACKGROUND: Ventricular late potentials detected by the signal averaged electrocardiogram (SAECG) have been used to predict cardiac death in patients after recent myocardial infarction. The goal of this study was to investigate the prognostic significance of the SAECG in a population of chronic coronary artery disease, with and without previous myocardial infarction. METHODS: SAECG was recorded in 698 patients with angiographically proven coronary artery disease and analyzed by time domain analysis (TDA) and by spectral temporal mapping (STM). Cardiac death or ventricular fibrillation (= cardiac event) were used as the primary endpoint for follow-up (25 to 33 months). RESULTS: A cardiac event occurred in 46 out of 698 patients (6.6%). An abnormal SAECG using TDA was found in 43% of patients with a cardiac event, as compared to 21.7% in those without (p<0.0005). The probability of a cardiac event during follow-up was 4.4% when TDA and STM were both normal, 9.5% and 10.2% when either STM or TDA were abnormal and 28.5% when both were abnormal. A duration of the averaged QRS complex of more than 120 ms and a left ventricular ejection fraction of less than 45% were the only independent predictors of a cardiac event. Logistic regression analysis could predict a cardiac event with a sensitivity of 54% and a specificity of 88%. CONCLUSIONS: In patients with chronic coronary artery disease the duration of the signal averaged QRS complex and left ventricular ejection fraction are independent predictors of cardiac death or ventricular fibrillation.

Adult↗

An unrandomized prospective comparison of urinary continence, bowel symptoms and the need for further procedures in patients with and with no adjuvant radiation after radical prostatectomy.

OBJECTIVE: To prospectively assess, using a questionnaire-based study, the relative differences and changes in urinary continence and bowel symptoms, and the need for further surgery, within the first year after radical retropubic prostatectomy (RRP) in patients with and with no adjuvant radiotherapy (aRT). PATIENTS AND METHODS: The study included 96 men with clinically organ-confined adenocarcinoma of the prostate who underwent RRP between March 1998 and June 1999. A subset of 36 patients was recommended aRT of the prostatic fossa (median dose 54 Gy) because of positive surgical margins and/or seminal vesicle involvement. Using a mailed questionnaire all patients were prospectively assessed at 4-month intervals for the first year after RRP. RESULTS: Valid data were analysed from 83 patients (overall response rate 86%), of whom 30 (36%) had received aRT. At 4 months a significantly lower proportion used no pads and significantly more used 1 pad/day in the aRT than in the RRP group (both P < 0.05). Eight and 12 months after RRP there was no statistically significant difference between the groups in urinary incontinence. However, 53% of men in the aRT group had stool urgency and 13% reported fecal incontinence at 4 months, compared with 1.9% and none (both P < 0.01) of the RRP group. At 1 year after RRP bowel symptoms and fecal continence improved in the aRT group and there was no significant difference for these symptoms between the groups. Starting aRT early (< or = 12 weeks after RP) or late (> 12 weeks) had no significant effect on urinary continence, bowel symptoms and fecal incontinence. Apart from dilatation of urethral strictures in one patient in each group, no further procedures were reported during the follow-up. CONCLUSION: A moderate dose of aRT after RRP had a temporary effect on subjective urinary continence at 4 months but not at 8 and 12 months. More patients receiving aRT reported significant bowel symptoms at 4 and 8 months than those with RRP only, but at 1 year most of these symptoms had resolved and there were no significant differences between the groups.

Adenocarcinoma↗

Functional and immunophenotypic characteristics of isolated CD105(+) and fibroblast(+) stromal cells from AML: implications for their plasticity along endothelial lineage.

BACKGROUND: In vitro cultures of BM cells from newly diagnosed patients with AML displayed a defective BM stromal compartment, with a reduced number of fibroblast-colony-forming unit (CFU-F: 1 +/- 1.25 SD) and a decreased proliferative ability. The purposes of our study were: 1). to select BM mesenchymal stem cells (MSC) and BM-derived stromal cells (BMDSCs) from AML patients at diagnosis and from healthy subjects, using an immunomagnetic system and either anti-CD105 or anti-fibroblast MAbs; 2). to study the immunophenotypic and functional properties of freshly isolated and cultured mesenchymal cells; 3). to test the in vitro plasticity of the selected cells to differentiate towards an endothelial phenotype. METHODS: Fresh mononuclear cells obtained from BM of 20 patients newly diagnosed with AML and from eight healthy subjects were selected by using anti-fibroblast and anti-CD105 MAbs. Freshly isolated cells were analyzed, characterized by flow cytometry using a wide panel of MAbs and seeded in long-term culture medium to assess CFU-F formation. The level of confluence after 30 days and functional capacity in a long-term colony-forming cell culture (LTC-CFC) were tested. Furthermore, the cultured selected cell populations were assayed for their ability to differentiate into an endothelial-like cell phenotype with the addition of vascular endothelial growth factor (VEFG) and endothelial cell growth supplement (ECGS). RESULTS: In normal subjects the selection produced an increase of the CFU-F number of 2.6-fold with anti-fibroblast MAb and 2.7-fold with the anti-CD105 MAb. Anti-fibroblast and anti-CD105 MAb selection from AML BM cells resulted in a statistically significant greater count of CFU-F that was respectively 10.6-fold (P = 0.04) and 14.4-fold (P = 0.00001) higher in comparison with the unselected AML samples. Interestingly, in 80% of AML samples immunoselection was also able to restore the capacity of the CFU-F to proliferate and form confluent stromal layers. The isolation of those layers sustained the proliferation and differentiation of hematopoietic stem cells in the LTC-CFC. The phenotypic profile of cultured BMDSCs was different from that of the freshly isolated cells, and changed in relation to the culture conditions: CD105+ selected cells cultured with VEGF and ECGS expressed endothelial markers, a finding that suggests that this cell subpopulation may have the potential to differentiate toward an endothelial-like phenotype. DISCUSSION: We report that immunomagnetic selection represents a valid tool for the selection of BM mesenchymal cells in samples obtained from both healthy subjects and patients with AML. This technique was able to rescue two functional and immunophenotypic compartments related to two different selected populations. In particular, the CD105+ cells isolated in AML displayed, after stimulation with VEGF and ECGS, the ability to change towards an endothelial-like cell phenotype, thus revealing an unexpected plasticity. Both CD105+ and fibroblast+ cells once successfully isolated might represent sources of mesenchymal cells populations useful for in vitro investigations and, above all, as therapeutic devices.

Adult↗

Influence of molecular weight fractions isolated from roasted malt on the enzyme activities of NADPH-cytochrome c-reductase and glutathione-S-transferase in Caco-2 cells.

In the present study, water-soluble nonenzymatic browning products (melanoidins) formed in roasted malt were separated, quantified, and investigated for their effects on detoxifying mechanisms in intestinal Caco-2 cells. The melanoidins were prepared from roasted malt by hot water extraction, and the water-soluble compounds were separated into different molecular weight (MW) fractions by gel filtration chromatography. By monitoring the effluent at 300 nm, seven molecular fractions I-VII were consecutively collected, revealing that approximately 2.3% of the water-soluble compounds had mean MWs between 10000 and 30000 Da. Thus, the bulk of water-soluble malt melanoidins consisted of MW > 30000 Da, among which approximately 58% showed mean MWs between 60000 Da and 100000 Da, whereas approximately 32% exhibited mean MWs of 200000 Da. Biotransformation enzyme activities of NADPH-cytochrome c-reductase (CCR) and glutathione-S-transferase (GST) were analyzed in Caco-2 Cells after 48 h of exposure to the different MW fractions. The low MW fraction of 10000 Da was most effective in activating the CCR and the GST activities (+122 and +33% vs control, respectively). The majority of the mid molecular weight compounds tested showed an activating effect on CCR activity and an inhibitory effect on GST activity. These effects were most pronounced for compounds of up to 70000 Da and >200000 Da but less distinct for fractions of an average molecular weight of 100000 Da.

Caco-2 Cells↗

Low molecular weight heparin for prevention of thromboembolic complications in cardioversion--rationale and design of the ACE study (Anticoagulation in Cardioversion using Enoxaparin).

The modality and duration of anticoagulation before, during, and after cardioversion of atrial fibrillation--either with or without guidance by transesophageal echocardiography (TEE)--is still an unresolved issue. Intravenous infusion of unfractionated heparin until effective anticoagulation with phenprocoumon or warfarin is used as the standard therapy. However, this approach may be associated with several days of hospitalization because of the necessity for intravenous heparin administration. Moreover, there may be an increased risk of bleeding complications or, conversely, episodes of undercoagulation. Low-molecular weight heparin is an attractive alternative as it not only provide a safe and predictable level of anticoagulation with fewer side effects but can also be administered safely on an outpatient basis. In addition, no anticoagulation monitoring is needed. The ACE study (Anticoagulation in Cardioversion using Enoxaparin) is a randomized, prospective, open-label multicenter trial comparing the safety and efficacy of subcutaneous enoxaparin with intravenous heparin/oral phenprocoumon before and after cardioversion (stratified to TEE guidance or no TEE guidance). This article presents the rationale, design and status of the ACE study.

Administration, Oral↗

Studies on the inhibition of tumor cell growth and microtubule assembly by 3-hydroxy-4-[(E)-(2-furyl)methylidene]methyl-3-cyclopentene-1,2-dione, an intensively coloured Maillard reaction product.

Very recently, 3-hydroxy-4-[(E)-(2-furyl)methylidene]methyl-3-cyclopentene-1,2-dione (1) has been successfully identified as an intensively coloured Maillard product formed from glucose and L-proline upon thermal food processing. Using a biomimetic synthetic strategy, reference material of compound 1 was prepared and purified, and then used to study its effect on the growth of human tumor cells. Compound 1 was found to potently inhibit the growth of human tumor cells in vitro. Using a reporter gene assay we could show that in growth inhibitory concentrations compound 1 effectively inhibits the phosphorylation of the transcription factor Elk-1. In addition, 1 was found to affect the microtubule skeleton. The human mammary carcinoma cell line MCF-7 exhibits a decrease of the microtubule organisation when treated for 24 h with 1 (> or =20 microM). At concentrations of 30 microM and above a loss of microtubule integrity is observed after 1 h incubation. In vitro studies demonstrated that the polymerisation and, to a minor extent, also the depolymerisation of tubulin, isolated and purified from bovine brain, is inhibited in a dose-dependent manner at concentrations of 30 microM and above. This is the first time that a non-enzymatically formed browning compound of known structure was reported to effectively inhibit tumor cell growth and microtubule assembly.

Animals↗

[The role of MRI for the evaluation of atrial septal defects before and after percutaneous occlusion with the amplatzer septal occluder(R)].

PURPOSE: Evaluation of morphologic and functional MRI of atrial septal defects (ASD) before and after percutaneous occlusion with the Amplatzer Septal Occluder (AOC). Comparison of MRI with transesophageal echocardiography (TEE), balloon measurement (IVBM) and cardiac catheterization with shunt quantification (CCSQ). MATERIALS AND METHODS: Twenty patients with ASD were examined before and three months after AOC implantation. ECG-triggered, breath-hold T1-weighted Turbo Spin Echo Segmented FLASH 2D and dynamic turbo-FLASH-GRE sequences after application of 0.2 mmol gadolinium DTPA per kg body weight were obtained in a 1.5 T MRI system. Defect size, and distance to coronal sinus (CS) and right upper pulmonary vein (RUPV) were determined for pre-interventional planning, and the AOC size was measured quantitatively for post-interventional follow-up. The shunts were evaluated qualitatively (occurrence of jets), semiquantitatively (jet length, turbulence square product) and quantitatively (flow measurement in the thoracic aorta and in the left and right pulmonary arteries). RESULTS: The average size of the ASD measured by MRI was 17.6 mm (11 - 24.8 mm) in the axial view, 15.9 mm (10.8 - 28.9 mm) in the sagittal view and 16.4 mm (12.1 - 24.8 mm) in the short axis view. In comparison, the average defect size was 15 mm (8 - 24 mm) by TEE and 20 mm (13 - 27 mm) by IVBM. The average distance to the RUPV was 17 mm (9.6 - 21.9 mm) and to the CS 11.2 mm (5 - 17 mm). The AOC was visualized with only minimal artifacts. Qualitative analysis of the MRI findings revealed an occurrence of jets in 17/20 patients. Semiquantitative analysis documented a high correlation for jet length and square product of the turbulence to defect size r = 0.81 resp. r = 0.82. Mean QP/QS-ratio measured by MR-volumetry was 1.6 +/- 0.29 and by MR-flow 1.6 +/- 0.26. The corresponding measurements were 1.7 +/- 0.3 for TEE and 1.5 +/- 0.5 for CCSQ. In comparison to TEE, the correlation coefficient was r = 0.96 for MR-volumetry and r = 0.85 for MR-flow measurement. CONCLUSION: MRI is found to be a valuable diagnostic method for pre-interventional planning and post-interventional follow-up of atrial septal defects occluded by the Amplatzer septal occluder.

Adult↗

Determination of the molecular weight distribution of non-enzymatic browning products formed by roasting of glucose and glycine and studies on their effects on NADPH-cytochrome c-reductase and glutathione-S-transferase in Caco-2 cells.

After thermal treatment of a mixture of glucose and glycine for 2 h at 125 degrees C, about 60% of the starting material was converted into non-soluble, black pigments, whereas 40% of the mixture was still water-soluble. Dialysis of the latter fraction revealed 30.4% of low molecular weight compounds (LMWs; MW < 10,000 Da) and 10.0% high-molecular weight products (HMWs; MW > or = 10,000 Da). The water-soluble Maillard reaction products (MRPs) were separated by gel permeation chromatography and ultrafiltration, revealing that 60% of the water-soluble products of the total carbohydrate/amino acid mixture had MWs < 1,000 Da and consisted mainly of non-coloured reaction products. MRPs with MWs between 1,000 and 30,000 Da were found in comparatively low yields (about 1.3%). In contrast, about 31.1% of the MRPs exhibited MWs > 30,000 Da, amongst which 14.5% showed MWs > 100,000 Da, thus indicating an oligomerisation of LMWs to melanoidins under roasting conditions. To investigate the physiological effects of these MRPs, xenobiotic enzyme activities were analysed in intestinal Caco-2 cells. For Phase-I NADPH-cytochrome c-reductase, the activity in the presence of the LMW and HMW fraction was decreased by 13% and 22%, respectively. Phase-II glutathione-S-transferase activity decreased by 15% and 18%, respectively, after incubation with the LMW and the HMW fractions. Considering the different yields, 30% and 10%, respectively, of the LMW and the HMW fractions, the total amount of the LMW fraction present in the glucose-glycine mixture is more active in modulating these enzyme activities than that of the HMW fraction.

Caco-2 Cells↗

[Laser-assisted transcanalicular dacryocystorhinostomy. Initial results].

BACKGROUND: Endoscopes for direct examination of the mucosa and disorders of the lacrimal drainage system have been available for four years. This had led to the wish to be able to treat lacrimal disorders by endoscopes and laser. PATIENTS AND METHODS: Since September 1997 we have treated 48 patients by laser-assisted transcanalicular dacryocystorhinostomy (DCR) using a KTP laser, including all those with stenosis to the nasolacrimal duct and all those with postsaccal stenosis. A bony window with diameter of 5 x 5 mm was created. Bicanalicular intubation into the nose was performed and was left for 3-6 months. RESULTS: We found 40 patients to have patent lacrimal pathway and no symptoms, 4 watering in cold weather, and 4 a restenosis. CONCLUSIONS: The KTP-laser is sufficiently powerful to create bony windows at least 5 mm in diameter, and a transcanalicular laser-assisted DCR is therefore possible.

Dacryocystorhinostomy↗