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1.
Front Pediatr ; 11: 1145907, 2023.
Article in English | MEDLINE | ID: mdl-37404558

ABSTRACT

Introduction: To assess the observed to expected lung area to head circumference ratio (O/E LHR) in fetuses with congenital anomalies of the kidney and urinary tract (CAKUT) and to explore its value as a potential predictive factor for postnatal outcome. Methods: A retrospective single-center study was conducted on pregnancies complicated by CAKUT between 2007 and 2018. The lung-to-head ratio (LHR) was calculated for each fetus by two independent observers. Correlations between O/E LHR and various perinatal outcome factors were assessed with Spearman's rank correlation. Furthermore, nominal logistic regression was performed to assess O/E LHR as predictive factor for respiratory distress in newborn. Results: Of 64 pregnancies complicated by CAKUT, 23 were terminated. In the 41 cases of continuation of pregnancy, newborn presenting respiratory distress with need for respiratory support in the delivery room showed earlier gestational age at onset of amniotic fluid abnormalities and at birth. Although median O/E LHR and median single deepest pocket (SDP) of amniotic fluid were significantly smaller in newborn that did develop respiratory distress with need of respiratory support in the delivery room, neither O/E LHR nor SDP were accurate predictors for the development of respiratory distress. Conclusions: Our data show that O/E LHR alone cannot serve as a predictive marker for fetal outcome in pregnancies complicated by CAKUT, though it might still be a helpful parameter together with detailed renal ultrasound evaluation, onset of amniotic fluid abnormality and SDP, particularly in its extreme values.

2.
Arch Gynecol Obstet ; 305(6): 1383-1392, 2022 06.
Article in English | MEDLINE | ID: mdl-34599678

ABSTRACT

PURPOSE: Aim of our study was to compare the prognostic value of the Umbilical-to-Cerebral ratio (UCR) directly to the Cerebroplacental ratio (CPR) in the prediction of poor perinatal outcomes in pregnancies complicated by Fetal Growth Restriction (FGR). METHODS: A retrospective study was carried out on pregnant women with either a small-for-gestational age (SGA) fetus or that were diagnosed with FGR. Doppler measurements of the two subgroups were assessed and the correlation between CPR, UCR and relevant outcome parameters was evaluated by performing linear regression analysis, binary logistic analysis and receiver operator characteristic (ROC) curves. Outcomes of interest were mode of delivery, acidosis, preterm delivery, gestational age at birth as well as birthweight and centiles. RESULTS: Boxplots and Scatterplots illustrated the different distribution of CPR and UCR leading to deviant correlational relationships with adverse outcome parameters. In almost all parameters examined, UCR showed a higher independent association with preterm delivery (OR: 5.85, CI 2.23-15.34), APGAR score < 7 (OR: 3.52; CI 1.58-7.85) as well as weight under 10th centile (OR: 2.04; CI 0.97-4.28) in binary logistic regression compared to CPR which was only associated with preterm delivery (OR: 0.38; CI 0.22-0.66) and APGAR score < 7 (OR: 0.27; CI 0.06-1.13). When combined with different ultrasound parameters in order to differentiate between SGA and FGR during pregnancy, odds ratios for UCR were highly significant compared to odds ratios for CPR (OR: 0.065, 0.168-0.901; p = 0.027; OR: 0.810, 0.369-1.781; p = 0.601). ROC curves plotted for CPR and UCR showed almost identical moderate prediction performance. CONCLUSION: Since UCR is a better discriminator of Doppler values in abnormal range it presents a viable option to Doppler parameters and ratios that are used in clinical practice. UCR and CPR showed equal prognostic accuracy conserning sensitivity and specificity for adverse perinatal outcome, while adding UA PI and GA_scan increased prognostic accuracy regarding negative outcomes.


Subject(s)
Fetal Growth Retardation , Premature Birth , Female , Fetal Growth Retardation/diagnostic imaging , Gestational Age , Humans , Infant, Newborn , Middle Cerebral Artery/diagnostic imaging , Parturition , Predictive Value of Tests , Pregnancy , Pregnancy Outcome , Pulsatile Flow , Retrospective Studies , Ultrasonography, Doppler , Ultrasonography, Prenatal , Umbilical Arteries/diagnostic imaging
3.
Arch Gynecol Obstet ; 301(5): 1199-1205, 2020 05.
Article in English | MEDLINE | ID: mdl-32303887

ABSTRACT

PURPOSE: The aim of our study was to compare the maternal arterial stiffness in pregnant women with diabetic disease, hypertension and those with normal pregnancies. METHODS: A cross-sectional study was performed involving 65 pregnant women with diabetic disease (DD group), 26 pregnant women with hypertension (RR group) and 448 women with normal pregnancies (control group). The augmentation index (AIx) and the pulse wave velocity (PWV) of the right carotid artery were assessed using non-invasive sonographic wave intensity analysis. Furthermore, the reliability of the measurements was evaluated in 21 healthy women. RESULTS: Compared with the controls, the AIx and PWV were increased in the DD group [11.0 (interquartile range, IQR 7.3, 15.2) vs. 5.7 (IQR 2.4, 9.3), P < 0.001; 5.7 (IQR 5.1, 6.4) vs. 5.2 (IQR 4.6, 6.1), P = 0.001; respectively] and the RR group [9.3 (IQR 6.6, 11.5) vs. 5.7 (IQR 2.4, 9.3), P < 0.001; 7.1 (6.3, 7.9) vs. 5.2 (IQR 4.6, 6.1), P < 0.001; respectively]. The intraclass and interclass correlation coefficients were good to excellent for the AIx (ICC: 0.91, P < 0.001 and 0.74, P < 0.002; respectively) and PWV measurements (ICC: 0.71, P < 0.004 and 0.70, P < 0.005; respectively). CONCLUSION: Pregnancies complicated by diabetic disease or hypertension are associated with increased maternal arterial stiffness. The importance of wave intensity analysis needs to be verified and larger studies are needed to establish both normal and cutoff values that may be relevant for clinical decisions.


Subject(s)
Arteries/physiopathology , Blood Flow Velocity/physiology , Diabetes, Gestational/physiopathology , Hypertension, Pregnancy-Induced/physiopathology , Pulsatile Flow/physiology , Pulse Wave Analysis/methods , Vascular Stiffness/physiology , Adult , Case-Control Studies , Cross-Sectional Studies , Diabetes Mellitus/epidemiology , Diabetes Mellitus/physiopathology , Diabetes, Gestational/epidemiology , Female , Humans , Hypertension/epidemiology , Hypertension, Pregnancy-Induced/epidemiology , Middle Aged , Pregnancy , Reproducibility of Results , Risk Factors , Ultrasonography
4.
Thorac Cardiovasc Surg ; 54(1): 67-9, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16485195

ABSTRACT

Open surgery is still used to treat massive combined paraesophageal and hiatal hernias. The operative principles include repositioning of the stomach in the abdomen, resection of the hernia sac, narrowing of the hiatus, and gastropexy. We report on a case in which a life-threatening, gastro-pericardial fistula was an early complication after open surgical treatment.


Subject(s)
Gastric Fistula/etiology , Gastroplasty/adverse effects , Hernia, Hiatal/surgery , Pericardium/pathology , Vascular Fistula/etiology , Gastric Fistula/surgery , Humans , Male , Middle Aged , Pericardium/surgery , Radiography, Thoracic , Reoperation , Tomography, X-Ray Computed , Vascular Fistula/surgery
5.
Toxicol In Vitro ; 17(1): 1-17, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12537957

ABSTRACT

Cryopreservation of tissue slices greatly facilitates their use in drug metabolism research, leading to efficient use of human organ material and a decrease of laboratory animal use. In the present review, various mechanisms of cryopreservation such as equilibrium slow freezing, rapid freezing and vitrification, and their application to cryopreservation of tissue slices are discussed as well as the viability parameters often used to evaluate the success of cryopreservation. Equilibrium freezing prevents intracellular ice formation by inducing cellular dehydration, but (large) ice crystals are still formed in the interstitial space of the slices. Upon rapid freezing, (small) intra- and extracellular ice crystals are formed which slices from some tissues can resist. Vitrification prevents the formation of both intra- and extracellular ice crystals while an amorphous glass is formed of the slice liquid constituents. To vitrify, however, high molarity solutions of cryoprotectants are required that may be toxic to the slices. The use of mixtures of high molarity of cryoprotectants overcomes this problem. We conclude that vitrification is the approach that most likely will lead to the development of universal cryopreservation methods for tissue slices of various organs from various animal species. In the future this may lead to the formation of a tissue slice bank from which slices can be derived at any desirable time point for in vitro experimentation.


Subject(s)
Cryopreservation/methods , Pharmacokinetics , Tissue Fixation/methods , Humans , Reproducibility of Results , Tissue Banks , Water
6.
Cryobiology ; 45(1): 1-9, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12445545

ABSTRACT

Precision-cut liver slices are to some extent resistant to ice formation induced by rapid freezing. Susceptibility to rapid freezing damage has been shown to be (partly) dependent on intrinsic properties of cells. In the present study an attempt was made to decrease the susceptibility of rat liver slices for rapid freezing damage: the slices were pre-incubated at 37 degrees C under oxygen, prior to cryopreservation to recover from low ATP levels, impaired ion regulation and cell swelling induced by their preparation. It was shown that, unexpectedly, recovery of cellular homeostasis prior to the cryopreservation procedure by the 37 degrees C pre-incubation markedly decreased viability of rapidly frozen slices (in which ice was formed), but not of vitrified slices (in which no ice was formed), in a time- and temperature-dependent manner. UW was found to protect slices from this 'warm pre-incubation phenomenon.' Apparently, pre-incubation prior to freezing causes certain cellular alterations that render slices more susceptible to rapid freezing damage.


Subject(s)
Cryopreservation/methods , Liver , Specimen Handling/methods , Adenosine/pharmacology , Adenosine Triphosphate/metabolism , Allopurinol/pharmacology , Animals , Body Water , Calcium , Chelating Agents/pharmacology , Free Radical Scavengers/pharmacology , Glutathione/pharmacology , Insulin/pharmacology , Liver/drug effects , Liver/metabolism , Male , Microtomy , Organ Preservation Solutions/pharmacology , Oxygen/pharmacology , Potassium/pharmacology , Raffinose/pharmacology , Rats , Rats, Wistar , Temperature
7.
Drug Metab Dispos ; 30(10): 1129-36, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12228190

ABSTRACT

Various in vitro preparations were compared with respect to their ability to mimic in vivo metabolism. For this purpose, S9-liver homogenate, microsomes, cryopreserved hepatocytes, cryopreserved liver slices and fresh liver, lung, kidney, and intestinal slices were incubated with three drugs in development, which are metabolized in vivo by a wide range of biotransformation pathways. Metabolites were identified and quantified with liquid chromatography-mass spectometry/UV from the in vitro incubations and compared with metabolite patterns in feces, urine, and bile of dosed rats. In vitro systems with intact liver cells produced the same metabolites as the rat in vivo and are a valuable tool to study drug metabolism. Phase I metabolites were almost all conjugated in intact cells, whereas S9-homogenate only conjugated by sulfation and N-acetylation. Microsomes and S9-homogenate are useful to study phase I metabolism but not for the prediction of in vivo metabolism. Extra-hepatic organ slices did not form any metabolites that were not produced by liver cells, but the relative amounts of the various metabolites differed considerably. Small intestinal slices were more active than liver slices in the formation of the N-glucuronide of compound C, which is the major metabolite in vivo. When the relative contribution of liver and small intestinal slices to the metabolism of this compound was taken into account, it appeared that the in vivo metabolite pattern could be well predicted. Results indicate that for adequate prediction of in vivo metabolism, fresh or cryopreserved liver slices or hepatocytes in combination with slices of the small intestines should be used.


Subject(s)
Pharmaceutical Preparations/metabolism , Animals , Drug Evaluation, Preclinical/methods , Forecasting , In Vitro Techniques , Intestine, Small/metabolism , Kidney/metabolism , Liver/metabolism , Lung/metabolism , Male , Pharmaceutical Preparations/chemistry , Rats , Rats, Sprague-Dawley , Rats, Wistar , Species Specificity , Tissue Distribution/physiology
8.
J Anim Sci ; 80(6): 1652-62, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12078747

ABSTRACT

Four experiments were conducted to evaluate the influence of changing the proportion of supplemental degradable intake protein (DIP) from urea on forage intake, digestion, and performance by beef cattle consuming either low-quality, tallgrass prairie forage (Exp. 1, 2, and 4) or forage sorghum hay (Exp. 3). Experiments 1, 2, and 3 were intended to have four levels of supplemental DIP from urea: 0, 20, 40, and 60%. However, refusal to consume the 60% supplement by cows grazing tallgrass prairie resulted in elimination of this treatment from Exp. 1 and 2. Levels of supplemental DIP from urea in Exp. 4 were 0, 15, 30, and 45%. Supplements contained approximately 30% CP, provided sufficient DIP to maximize digestible OM intake (DOMI) of low-quality forage diets, and were fed to cows during the prepartum period. In Exp. 1, 12 Angus x Hereford steers (average initial BW = 379) were assigned to the 0, 20, and 40% treatments. Forage OM intake, DOMI, OM, and NDF digestion were not affected by urea level. In Exp. 2, 90 pregnant, Angus x Hereford cows (average initial BW = 504 kg and body condition [BC] = 5.0) were assigned to the 0, 20, and 40% treatments. Treatment had little effect on cow BW and BC changes and calf birth weight, ADG, or weaning weight. However, pregnancy rate tended to be lowest (P = 0.13) for the greatest level of urea. In Exp. 3, 120 pregnant, crossbred beef cows (average initial BW = 498 kg and BC = 4.6) were assigned to the 0, 20, 40, and 60% treatments. Prepartum BC change tended (P = 0.08) to be quadratic (least increase for 60% treatment), although BW change was not statistically significant. Treatment effect on calf birth weight was inconsistent (cubic; P = 0.03), but calf ADG and weaning weight were not affected by treatment. Pregnancy rate was not affected by prepartum treatment. In Exp. 4, 132 pregnant, Angus x Hereford cows (average initial BW = 533 and BC = 5.3) were assigned to the 0, 15, 30, and 45% treatments. Prepartum BC loss was greatest (quadratic; P = 0.04) for the high-urea (45%) treatment, although BW loss during this period declined linearly (P < 0.01). Prepartum treatment did not affect pregnancy rate, calf birth weight, or ADG. In conclusion, when sufficient DIP was offered to prepartum cows to maximize low-quality forage DOMI, urea could replace between 20 and 40% of the DIP in a high-protein (30%) supplement without significantly altering supplement palatability or cow and calf performance.


Subject(s)
Animal Feed/analysis , Cattle/physiology , Dietary Proteins/metabolism , Nitrogen/pharmacology , Pregnancy, Animal/physiology , Animal Nutritional Physiological Phenomena , Animals , Body Weight , Cattle/growth & development , Cattle/metabolism , Dietary Supplements , Digestion , Female , Male , Poaceae , Pregnancy , Pregnancy Rate , Urea/chemistry
10.
J Psychosom Res ; 50(3): 155-60, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11316508

ABSTRACT

OBJECTIVES: The practice of homeopathy rests on symptoms, which have been produced by medicinal substances in healthy volunteers, often applied at ultramolecular dilutions. It is unknown whether these symptom patterns are due to specific effects or chance fluctuation. METHODS: We tested the hypothesis that a homeopathic substance can bring about symptoms different from observation and placebo in a double-blind, placebo-controlled crossover design with baseline observation. RESULTS: 87 out of 118 healthy volunteers took both placebo and homeopathic belladonna 30CH in random sequence, after a 2-week observation period, and finished the 8-week trial. Apart from an insignificant tendency for subjects to report more symptoms with belladonna (mean number: 27.34), as compared to observation (24.26) or placebo (24.17), there was no indication that subjects reacted differently to homeopathy than to placebo or during baseline. CONCLUSION: There is no indication that belladonna 30CH produces symptoms different from placebo or from no intervention. Symptoms of a homeopathic pathogenetic trial (HPT) are most likely chance fluctuations.


Subject(s)
Atropa belladonna/therapeutic use , Homeopathy/standards , Materia Medica/pharmacology , Phytotherapy , Plants, Medicinal , Plants, Toxic , Adult , Cross-Over Studies , Dose-Response Relationship, Drug , Double-Blind Method , Female , Germany , Humans , Male , Middle Aged , Reference Values , Treatment Outcome
11.
Nucleic Acids Res ; 29(3): E11, 2001 Feb 01.
Article in English | MEDLINE | ID: mdl-11160913

ABSTRACT

Sets of RNA ladders can be synthesized by transcription of a bacteriophage-encoded RNA polymerase using 3'-deoxynucleotides as chain terminators. These ladders can be used for sequencing of DNA. Using a nicked form of phage SP6 RNA polymerase in this study substantially enhanced yields of transcriptional sequencing ladders. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) of chain-terminated RNA ladders allowed DNA sequence determination of up to 56 nt. It is also demonstrated that A-->G and C-->T variations in heterozygous and homozygous samples can be unambiguously identified by the mass spectrometric analysis. As a step towards single-tube sequencing reactions, alpha-thiotriphosphate nucleotide analogs were used to overcome problems caused by chain terminator-independent, premature termination and by the small mass difference between natural pyrimidine nucleotides.


Subject(s)
Genotype , RNA/metabolism , Sequence Analysis, DNA/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Base Sequence , DNA, Mitochondrial/chemistry , DNA, Mitochondrial/genetics , Humans , MELAS Syndrome/genetics , Point Mutation , RNA/genetics , Sensitivity and Specificity , Thionucleotides/genetics , Thionucleotides/metabolism , Transcription, Genetic
12.
Cryobiology ; 43(3): 224-37, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11888216

ABSTRACT

This study examined whether tissue vitrification, promoted by partitioning within the tissue, could be the mechanism explaining the high viability of rat liver slices, rapidly frozen after preincubation with 18% Me2SO or VS4 (a 7.5 M mixture of Me2SO, 1,2-propanediol, and formamide with weight ratio 21.5:15:2.4). To achieve this, we first determined the extent to which crystallization or vitrification occurred in cryoprotectant solutions (Me2SO and VS4) and within liver slices impregnated with these solutions. Second, we determined how these events were related to survival of slices after thawing. Water crystallization was evaluated by differential scanning calorimetry and viability was determined by histomorphological examination of the slices after culturing at 37 degrees C for 4 h. VS4-preincubated liver slices indeed behaved differently from bulk VS4 solution, because, when vitrified, they had a lower tendency to devitrify. Vitrified VS4-preincubated slices that were warmed sufficiently rapid to prevent devitrification had a high viability. When VS4 was diluted (to 75%) or if warming was not fast enough to prevent ice formation, slices had a low viability. With 45% Me2SO, low viability of cryopreserved slices was caused by cryoprotectant toxicity. Surprisingly, liver slices preincubated with 18% Me2SO or 50% VS4 had a high viability despite the formation of ice within the slice. In conclusion, tissue vitrification provides a mechanism that explains the high viability of VS4-preincubated slices after ultrarapid freezing and thawing (>800 degrees C/min). Slices that are preincubated with moderately concentrated cryoprotectant solutions (18% Me2SO, 50% VS4) and cooled rapidly (100 degrees C/min) survive cryopreservation despite the formation of ice crystals within the slice.


Subject(s)
Cryopreservation/methods , Liver , Tissue Preservation/methods , Animals , Cryoprotective Agents , Crystallization , Ice , In Vitro Techniques , Liver/anatomy & histology , Liver/physiology , Male , Rats , Rats, Wistar , Thermodynamics , Water/metabolism
13.
Drug Metab Dispos ; 28(9): 1100-6, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10950856

ABSTRACT

An existing cryopreservation method for liver slices applies 12% dimethylsulfoxide and rapid freezing. We found that cells in rat liver slices cryopreserved in this manner deteriorated rapidly upon culturing. To improve this cryopreservation method, we varied the dimethylsulfoxide concentration (0, 12, 18, and 30%), the cryopreservation medium (Williams medium E, fetal calf serum, and University of Wisconsin medium), slice thickness, and the storage period at 4 degrees C during slice preparation before cryopreservation. After thawing, slices were cultured for 4 h at 37 degrees C before their viability was evaluated by their potassium content and the number of intact cells determined histomorphologically. The biotransformation capacity of liver slices cryopreserved by the improved method was assessed by testosterone oxidation, hydroxycoumarin sulfation, and glucuronidation. Best results were obtained with 18% dimethylsulfoxide in Williams medium E: the potassium content of cryopreserved slices was higher than 65%, and the number of intact cells was higher than 60% of that in fresh slices; with 12% dimethylsulfoxide, potassium content was less than 40%, and the number of intact cells was less than 30%. Results did not differ between the three cryopreservation media. Viability of thin slices (8-10 cell layers) was better maintained than that of thicker slices (>14 cell layers). Storage at 4 degrees C of slices before cryopreservation decreased viability after cryopreservation. Both oxidative and conjugation activities were better than 60% of fresh values. Although results varied, slices cryopreserved with this improved method and cultured for 4 h retained viability between 50 and 80%, and biotransformation activity between 60 and 90% of fresh slices.


Subject(s)
Cryopreservation/standards , Freezing , Liver/metabolism , Animals , Biotransformation , Cell Survival/drug effects , Chromatography, High Pressure Liquid , Cold Temperature , Cryopreservation/methods , Dimethyl Sulfoxide/pharmacology , In Vitro Techniques , Liver/cytology , Liver/drug effects , Male , Potassium/metabolism , Rats , Rats, Wistar , Temperature , Testosterone/pharmacokinetics , Time Factors , Tissue Preservation
14.
Cryobiology ; 40(3): 250-63, 2000 May.
Article in English | MEDLINE | ID: mdl-10860624

ABSTRACT

A number of studies on the cryopreservation of precision-cut liver slices using various techniques have been reported. However, the identification of important factors that determine cell viability following cryopreservation is difficult because of large differences between the various methods published. The aim of this study was to evaluate some important factors in the freezing process in an effort to find an optimized approach to the cryopreservation of precision-cut liver slices. A comparative study of a slow and a fast freezing technique was carried out to establish any differences in tissue viability for a number of endpoints. Both freezing techniques aim at the prevention of intracellular ice formation, which is thought to be the main cause of cell death after cryopreservation. Subsequently, critical variables in the freezing process were studied more closely in order to explain the differences in viability found in the two methods in the first study. For this purpose, a full factorial experimental design was used with 16 experimental groups, allowing a number of variables to be studied at different levels in one single experiment. It is demonstrated that ATP and K(+) content and histomorphology are sensitive parameters for evaluating slice viability after cryopreservation. Subsequently, it is shown that freezing rate and the cryopreservation medium largely determine the residual viability of liver slices after cryopreservation and subsequent culturing. It is concluded that a cryopreservation protocol with a fast freezing step and using William's Medium E as cryopreservation medium was the most promising approach to successful freezing of rat liver slices of those tested in this study.


Subject(s)
Cryopreservation/methods , Liver , Tissue Preservation/methods , Adenosine Triphosphate/metabolism , Animals , Dinitrochlorobenzene/metabolism , Evaluation Studies as Topic , Glutathione/metabolism , Glutathione Transferase/metabolism , In Vitro Techniques , L-Lactate Dehydrogenase/metabolism , Liver/anatomy & histology , Liver/metabolism , Male , Microtomy , Potassium/metabolism , Proteins/metabolism , Rats , Rats, Wistar , Testosterone/metabolism , Urea/metabolism
15.
Hum Mol Genet ; 9(5): 757-63, 2000 Mar 22.
Article in English | MEDLINE | ID: mdl-10749982

ABSTRACT

Genomic imprinting is the result of a gamete-specific modification leading to parental origin-specific gene expression in somatic cells of the offspring. Several embryonal tumors show loss of imprinting of genes clustered in human chromosome 11p15.5, an important tumor suppressor gene region, harboring several normally imprinted genes. TSSC3, a gene homologous to mouse TDAG51, implicated in Fas-mediated apoptosis, is also located in this region between hNAP2 and p57 (KIP2). TSSC3 is the first apoptosis-related gene found to be imprinted in placenta, liver and fetal tissues where it is expressed from the maternal allele in normal human development. This study investigated the imprinting status of TSSC3 in human normal, adult brain and in human neuroblastomas, medulloblastomas and glioblastomas. A polymorphism in exon 1 at position 54 was used to analyze the allelic expression of the TSSC3 gene by a primer oligo base extension (PROBE) assay using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). We found that the TSSC3 gene is not imprinted in human normal, adult brain and blood. In contrast, strong allelic bias resembling imprinting could be detected in most examined tumor specimens. The results demonstrate for the first time that the tumors under investigation are associated with a retention of imprinting of a potential growth inhibitory gene.


Subject(s)
Apoptosis/genetics , Brain Neoplasms/genetics , Genomic Imprinting , Nuclear Proteins/genetics , Animals , Base Sequence , Brain/metabolism , Brain Neoplasms/pathology , DNA Methylation/drug effects , DNA Primers , Humans , Mice , Nuclear Proteins/blood , Tumor Cells, Cultured
16.
Nucleic Acids Res ; 28(8): E31, 2000 Apr 15.
Article in English | MEDLINE | ID: mdl-10734208

ABSTRACT

In this report, we describe a simple and accurate method to analyze restriction fragments using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The two complementary strands of restriction fragments are separated through hybridization to a capture probe, which is a single-stranded undigested fragment. Using the biotin-streptavidin linkage, the hybrid is immobilized on streptavidin-coated magnetic beads. After conditioning the captured restriction fragments, they are eluted from the probe and their molecular weights are determined. The proposed method greatly improves the quality, and reduces the complexity of the mass spectrum by analyzing only one of the complementary strands of restriction fragments.


Subject(s)
DNA/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Biotinylation , DNA/genetics , DNA/metabolism , DNA Probes , Deoxyribonucleases, Type II Site-Specific/metabolism , Globins/genetics , Humans , Magnetics , Nucleic Acid Hybridization , Polymerase Chain Reaction
17.
Proc Natl Acad Sci U S A ; 96(18): 10016-20, 1999 Aug 31.
Article in English | MEDLINE | ID: mdl-10468554

ABSTRACT

Silicon chips with immobilized target DNAs were used for accurate genotyping by mass spectrometry. Genomic DNAs were amplified with PCR, and the amplified products were covalently attached to chip wells via N-succinimidyl (4-iodoacetyl)aminobenzoate (SIAB) chemistry. Primer annealing, extension, and termination were performed on a 1-microl scale directly in the chip wells in parallel. Diagnostic products thus generated were detected in situ by using matrix-assisted laser desorption ionization mass spectrometry. This miniaturized method has the potential for accurate, high-throughput, low-cost identification of genetic variations.


Subject(s)
DNA/chemistry , DNA/genetics , Genotype , Polymerase Chain Reaction/methods , Silicon , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Base Sequence , Cross-Linking Reagents , DNA Primers , Microscopy, Electron, Scanning/methods , Succinimides
19.
Science ; 284(5421): 1805-11, 1999 Jun 11.
Article in English | MEDLINE | ID: mdl-10364547

ABSTRACT

Gene-targeted mice lacking the L-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor subunit GluR-A exhibited normal development, life expectancy, and fine structure of neuronal dendrites and synapses. In hippocampal CA1 pyramidal neurons, GluR-A-/- mice showed a reduction in functional AMPA receptors, with the remaining receptors preferentially targeted to synapses. Thus, the CA1 soma-patch currents were strongly reduced, but glutamatergic synaptic currents were unaltered; and evoked dendritic and spinous Ca2+ transients, Ca2+-dependent gene activation, and hippocampal field potentials were as in the wild type. In adult GluR-A-/- mice, associative long-term potentiation (LTP) was absent in CA3 to CA1 synapses, but spatial learning in the water maze was not impaired. The results suggest that CA1 hippocampal LTP is controlled by the number or subunit composition of AMPA receptors and show a dichotomy between LTP in CA1 and acquisition of spatial memory.


Subject(s)
Long-Term Potentiation/physiology , Maze Learning , Pyramidal Cells/physiology , Receptors, AMPA/physiology , Synapses/physiology , Action Potentials , Animals , Bicuculline/pharmacology , Calcium/metabolism , Dendrites/physiology , Dendrites/ultrastructure , GABA Antagonists/pharmacology , Gene Expression , Gene Targeting , Genes, Immediate-Early , Glutamic Acid/pharmacology , Glutamic Acid/physiology , Hippocampus/cytology , Hippocampus/physiology , Mice , Mice, Inbred C57BL , Pyramidal Cells/ultrastructure , Receptors, AMPA/genetics , Receptors, N-Methyl-D-Aspartate/physiology , Synapses/ultrastructure , Synaptic Transmission
20.
Int Immunol ; 11(4): 585-91, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10323212

ABSTRACT

Alloreactive T cells form an important barrier for organ transplantation. To reduce the risk of rejection patients are given immunosuppressive drugs, which increase the chance of infection and the incidence of malignancies. It has been shown that a large proportion of alloreactive T cells specifically recognize peptides present in the groove of the allogeneic MHC molecule. This implies that it might be possible to modulate the alloresponse by peptides with antagonistic properties, thus preventing rejection without the side effects of general immunosuppression. Peptide antagonists can be designed on the basis of the original agonist, yet for alloreactive T cells these agonists are usually unknown. In this study we have used a dedicated synthetic peptide library to identify agonists for HLA-DR3-specific alloreactive T cell clones. Based on these agonists, altered peptide ligands (APL) were designed. Three APL could antagonize an alloreactive T cell clone in its response against the library-derived agonist as well as in its response against the original allodeterminant, HLA-DR3. This demonstrates that peptide libraries can be used to design antagonists for alloreactive T cells without knowledge about the nature of the actual allostimulatory peptide. Since the most potent agonists are selected, this strategy permits detection of potent antagonists. The results, however, also suggest that the degree of peptide dependency of alloreactive T cell clones may dictate whether a peptide antagonist can be found for such clones. Whether peptide antagonists will be valuable in the development of donor-patient-specific immunosuppression may therefore depend on the specificity of the in vivo-generated alloreactive T cells.


Subject(s)
Ligands , Peptide Library , Peptides/chemical synthesis , T-Lymphocytes/immunology , Amino Acid Sequence , Clone Cells/immunology , HLA-DR3 Antigen/immunology , Humans , Lymphocyte Activation , Molecular Sequence Data , Peptides/immunology
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