High frequency of the 844ins68 cystathionine-beta-synthase gene variant in Down syndrome children with acute myeloid leukemia.
Explore the source record for details and available documents.
Acute Disease↗
Biomedical subjects
T Jensen
Publications and source records attributed to T Jensen.
Staining of celiac disease-relevant T cells by peptide-DQ2 multimers.
Gluten-specific T cells in the small intestinal mucosa are thought to play a central role in the pathogenesis of celiac disease (CD). The vast majority of these T cells recognize gluten peptides when presented by HLA-DQ2 (DQA1*05/DQB1*02), a molecule which immunogenetic studies have identified as conferring susceptibility to CD. We have previously identified and characterized three DQ2-restricted gluten epitopes that are recognized by intestinal T cells isolated from CD patients, two of which are immunodominant. Because almost all of the gluten epitopes are restricted by DQ2, and because we have detailed knowledge of several of these epitopes, we chose to develop peptide-DQ2 tetramers as a reagent to further investigate the role of these T cells in CD. In the present study, stable soluble DQ2 was produced such that it contained leucine zipper dimerization motif and a covalently coupled peptide. We have made four different peptide-DQ2 staining reagents, three containing the gluten epitopes and one containing a DQ2-binding self-peptide that provides a negative control for staining. We show in this study that peptide-DQ2 when adhered to plastic specifically stimulates T cell clones and that multimers comprising these molecules specifically stain peptide-specific T cell clones and lines. Interestingly, T cell activation caused severe reduction in staining intensities obtained with the multimers and an Ab to the TCR. The problem of TCR down-modulation must be taken into consideration when using class II multimers to stain T cells that may have been recently activated in vivo.
Baculoviridae↗
Radically altered T cell receptor signaling in glycopeptide-specific T cell hybridoma induced by antigen with minimal differences in the glycan group.
A T cell hybridoma raised against the synthetic glycopeptide T(72)(Tn) was used to study whether the initial TCR signaling events are markedly different when the hybridoma is stimulated with glycopeptides closely related to the cognate glycopeptide antigen. T(72)(Tn) has an alpha-D-GalNAc group O-linked to the central threonine in the decapeptide VITAFTEGLK, and the hybridoma is known to be highly specific for this carbohydrate group. T(72)(Tn)-pulsed APC induced tyrosine phosphorylation of the TCR-zeta 21- and 23-kDa proteins and the downstream p42/44 MAP kinase and strong IL-2 secretion. APC pulsed with T(72)(alpha-D-GlcNAc), which differs from T(72)(Tn) solely by the orientation of a hydroxy group in the carbohydrate structure, completely failed to induce detectable tyrosine phosphorylation and IL-2 secretion. APC pulsed with S(72)(Tn), which differs from T(72)(Tn) by not having a methyl group in the serine amino acid side chain to which the glycan is attached, induced partial tyrosine phosphorylation of the TCR-zeta 21-kDa protein, no tyrosine phosphorylation of the MAP kinases and no IL-2 production. Molecular modeling of the MHC/glycopeptide complex revealed that the dramatic difference between the stimulatory power of T(72)(Tn) and T(72)(alpha-D-GlcNAc) is mainly due to very small differences in the TCR exposed carbohydrate structure.
Cell Line↗
Stillbirth and neonatal mortality due to congenital anomalies: temporal trends and variation by small area deprivation scores in England and Wales, 1986-96.
We investigated the variation of stillbirth and neonatal mortality due to congenital anomalies in relation to small-area measures of deprivation in a population-based study in England and Wales, 1986-96. We found 10 954 stillbirths and neonatal deaths from all non-chromosomal and chromosomal anomalies during the study period out of a total of 7 487 007 live and stillbirths. The extended perinatal mortality rate (EPM rate) (defined as babies who were stillborn or died within 28 completed days after birth per 10 000 total live and stillbirths) for all chromosomal and all non-chromosomal anomalies was 1.5/10 000 and 13.2/10 000, respectively, over the whole period. The rate for non-chromosomal anomalies halved over the decade while the rate for chromosomal anomalies remained unchanged. The relative risks of EPM for chromosomal and non-chromosomal anomalies were 0.71 [0.80, 0.95] and 1.17 [95%CI 1.06, 1.30], respectively, in the group of wards with highest deprivation compared with the least deprived group. Increasing gradients of EPM with increasing deprivation were observed for (1) grouped non-chromosomal anomalies including neural tube defects, all renal and urinary anomalies, all musculoskeletal anomalies, and multiple anomalies, and (2) several specific non-chromosomal anomalies including anencephaly, limb reduction defects, diaphragm and abdominal wall defects. This study provides strong evidence that increased deprivation is associated with increased EPM due to most non-chromosomal anomalies; the finding of decreased relative risk for chromosomal anomalies is probably related to differences in maternal age distribution between deprivation groups.
Chromosome Aberrations↗
Implantable cardioverter defibrillator in a 4-month-old infant with cardiac arrest associated with a vascular heart tumor.
A previously healthy male infant was resuscitated after spontaneous ventricular fibrillation at 9 weeks of age. Echocardiography revealed three tumors in the left ventricle not amenable to complete resection. Despite treatment with antiarrhythmic agents the ventricular arrhythmias continued. When the child was 4 months old and weighed 7 kg an ICD system was implanted using epicardial sense-pacing leads and a superior vena caval lead as a subcutaneous defibrillator coil placed posterior on the left thorax. Shocks were delivered between the subcutaneous coil lead and the intraabdominally placed ICD can. This ICD array system has not been reported previously.
Defibrillators, Implantable↗
Lack of effect of fish oil supplementation on coagulation and transcapillary escape rate of albumin in insulin-dependent diabetic patients with diabetic nephropathy.
OBJECTIVE: We studied the effect of a diet supplementation with fish oil in insulin-dependent diabetic patients with nephropathy in order to evaluate whether abnormal transcapillary escape rate of albumin and procoagulant activity in these patients could be modified. METHODS: A double-blind, randomized, controlled study was carried out at a tertiary referral centre. The subjects were 29 insulin-dependent diabetic patients with nephropathy. One year of fish oil supplementation (4.6 g n-3 fatty acids/day) was compared with placebo (olive oil). The main outcome measures were N-3 fatty acid proportions of platelet lipids, transcapillary escape rate of albumin, prothrombin fragment 1 + 2, thrombin-antithrombin complexes, markers of fibrinolysis, fibrinogen, factor VII antigen and activity, thrombomodulin, von Willebrand factor, platelet factor 4 and beta-thromboglobulin. These were measured every 6 months. RESULTS: Neither transcapillary escape rate of albumin (7.4 (median) (5.0-9.8) (range) % vs. 7.0 (4.6-10.6) %) nor prothrombin fragment 1 + 2 (0.97 (0.72-2.40) nmol/L vs. 1.01 (0.59-3.11) nmol/L) changed after 12 months of fish oil supplementation. CONCLUSION: Increased transcapillary escape rate of albumin and activity could not be modified during diet supplementation with fish oil in insulin-dependent diabetic patients with nephropathy.
Antithrombin III↗
Preventing diabetic nephropathy: an audit.
In type 1 diabetic patients with microalbuminuria not receiving antihypertensive treatment, an increase in urinary albumin excretion rate (AER) of 6% to 14%/year and a risk for the development of diabetic nephropathy of 3% to 30%/year have previously been reported. The aim of the present study was to audit the effect of angiotensin converting enzyme (ACE) inhibition on the progression of microalbuminuria and development of diabetic nephropathy. We consecutively identified 227 type 1 diabetic patients with persistent microalbuminuria (urinary AER between 30 and 300mg/24h, ELISA). According to the level (> or = 100 or < 100mg/24 h) and/or rate of progression in urinary AER (>6% or < or =6%/year), patients were divided into a high-risk group (n= 177) and a low-risk group (n= 50) for development of diabetic nephropathy. According to international guidelines, all patients at high-risk were recommended ACE-inhibitor treatment. Throughout the study, 67% of the patients were treated with an ACE inhibitor. Urinary AER significantly declined by 8.3%/year (95% CI: 2.8 to 13.9) in the whole group of patients, and the risk for the development of diabetic nephropathy during follow-up was 3.5%/year. Glycaemic control and blood pressure remained unchanged during the study. The implementation of modified international guidelines regarding the use of ACE inhibition in the treatment of microalbuminuric type 1 diabetic patients reduced progression to diabetic nephropathy comparable to what has previously been reported in intervention trials.
Albuminuria↗
Serum levels of parathyroid hormone and markers of bone metabolism in patients with rheumatoid arthritis. Relationship to disease activity and glucocorticoid treatment.
OBJECTIVE: To evaluate the influence of inflammatory activity and glucocorticoid (GC) treatment on serum parathyroid hormone (s-PTH) and bone metabolism in patients with rheumatoid arthritis (RA). Furthermore, in patients with active RA, to examine the PTH secretion and Ca2+ set point before and after treatment with GC. METHODS: A range of biochemical markers of bone metabolism and calcium homeostasis were measured in 95 patients with definite RA stratified into groups according to disease activity and GC treatment. In a subgroup of 12 patients with active disease, initiating slow-acting-anti-rheumatic-drugs (SAARDs) +/- GC, the PTH secretion and calcium set point were evaluated by use of the Cica clamp technique before and after 1 month of treatment. RESULTS: S-osteocalcin, s-total alkaline phosphatase (s-TAP) and s-carboxyterminal cross-linked telopeptide of type I collagen (s-ICTP) were elevated in all groups. The levels of urine pyridinoline (Pyr) and s-albumin-corrected calcium (s-AlbCorrCa2+) were elevated in patients with active disease and patients treated with GC. S-PTH and s-phosphate were within normal ranges. S-TAP, s-ICTP, Pyr and s-AlbCorrCa2+ correlated positively with indices of disease activity. In the subgroups undergoing the Cica clamp technique, no difference in PTH responsiveness of B-Ca2+ was unveiled. CONCLUSION: Neither active disease nor GC therapy appears to induce secondary hyperparathyroidism, nor is there an alteration in PTH responsiveness of B-Ca2+ in patients with RA. The increased levels of markers of type I collagen metabolism (s-ICTP, Pyr) and s-AlbCorrCa2+ in patients with active disease and patients treated with GC may be a result of increased degradation in synovium, cartilage and bone due to the inflammatory process.
Anti-Inflammatory Agents↗
Effects of marked hyperthermia with and without dehydration on VO(2) kinetics during intense exercise.
This study determined whether marked hyperthermia alone or in combination with dehydration reduces the initial rate of rise in O(2) consumption (VO(2) on-kinetics) and the maximal rate of O(2) uptake (VO(2 max)) during intense cycling exercise. Six endurance-trained male cyclists completed four maximal cycle ergometer exercise tests (402 +/- 4 W) when euhydrated or dehydrated (4% body wt) with normal (starting esophageal temperature, 37.5 +/- 0.2 degrees C; mean skin temperature, approximately 31 degrees C) or elevated (+1 and +6 degrees C, respectively) thermal strain. In the euhydrated and normal condition, subjects reached VO(2 max) (4.7 +/- 0.2 l/min) in 228 +/- 34 s, with a mean response time of 42 +/- 2 s, and fatigued after 353 +/- 39 s. Hyperthermia alone or in combination with dehydration reduced mean response time (17-23%), VO(2 max) (16%), and performance time (51-53%) (all P < 0.01) but did not alter the absolute response time (i.e., the time to reach 63% response in the control trial, 3.2 +/- 0.1 l/min, 42 s). Reduction in VO(2 max) was accompanied by proportional decline in O(2) pulse and significantly elevated maximal heart rate (195 vs. 190 beats/min for hyperthermia vs. normal). Preventing hyperthermia in dehydrated subjects restored VO(2 max) and performance time by 65 and 50%, respectively. These results demonstrate that impaired high-intensity exercise performance with marked skin and internal body hyperthermia alone or in combination with dehydration is not associated with a diminished rate of rise in VO(2) but decreased VO(2 max).
Adult↗
Expression and function of brain-derived neurotrophin factor and its receptor, TrkB, in ovarian follicles from the domestic hen (Gallus gallus domesticus).
This report summarizes patterns of mRNA expression for the brain-derived neurotrophic factor (BDNF) together with its high-affinity neurotrophin receptor trkB within the hen ovary during follicle development, describes hormonal mechanisms for the regulation of trkB gene expression and provides preliminary evidence for a novel function for BDNF-mediated TrkB signaling within the granulosa layer. Levels of BDNF mRNA in the thecal layer and of trkB mRNA within the granulosa cell layer increase coincident with entrance of the follicle into the preovulatory hierarchy. Localization of the BDNF mRNA transcript correlates with expression of BDNF protein within the theca interna of preovulatory follicles, while localization of trkB mRNA and protein occurs extensively within the granulosa cell layer of preovulatory follicles. This pattern of expression suggests a paracrine relationship between theca and granulosa cells for BDNF signaling via TrkB. Vasoactive intestinal peptide and gonadotropin treatments stimulate increases in levels of trkB mRNA within cultured granulosa cells derived from both prehierarchal and preovulatory follicles, and this response is increased by co-treatment with 3-isobutyl-1-methylxanthine. Finally, BDNF treatment of cultured granulosa cells from preovulatory follicles results in a modest, but significant, reduction in basal progesterone production, whereas this effect was reversed by k252a, an inhibitor of Trk kinase activity. These results support the proposals that BDNF functions as a paracrine signal in hen granulosa cells and that its physiological functions may include the modulation of steroidogenesis.
Animals↗
The influence of mannose binding lectin polymorphisms on disease outcome in early polyarthritis. TIRA Group.
OBJECTIVE: To determine whether variant alleles of the mannose binding lectin (MBL) gene causing low serum concentrations of MBL are associated with increased susceptibility to rheumatoid arthritis (RA) and erosive outcome in an inception cohort of patients with early polyarthritis. METHODS: MBL and HLA-DRB1 alleles were determined by polymerase chain reaction in 68 Danish patients with incident early polyarthritis observed for one year. The associations between MBL and specific HLA-DRB1 genotypes and disease outcomes were analyzed. RESULTS: Among the patients with early polyarthritis 7.4% (5/68) and 41.2% (28/68) were homozygous and heterozygous for MBL variant alleles, compared with 2.8% (7/250) and 34.4% (86/250) of healthy controls (p = 0.09), while the corresponding figures in the patients with RA were 10% (5/50) and 42% (21/50) (p = 0.03), and in the patients with erosive RA 18.8% (3/16) and 35.3% (6/16), respectively (p = 0.004). Patients with early polyarthritis homozygous for MBL variant alleles had an increased risk of having erosive RA at inclusion by a factor of 4.7 (p = 0.02) and after one year by a factor of 3.6 (p = 0.04). MBL deficiency was associated with increased levels of C-reactive protein (CRP) and IgM rheumatoid factor (RF) at inclusion (p < 0.05). HLA-DRB1 alleles were not found to be associated with disease outcome. CONCLUSION: MBL variant alleles appear to be weak susceptibility markers for RA, and patients with early polyarthritis and homozygous for MBL structural variant alleles have a higher risk of developing early erosive RA. These findings, together with the positive association between MBL variant alleles and the increased serum levels of IgM RF and CRP, point at the MBL gene as a relevant locus in the pathophysiology of RA.
Adult↗
Radiation Therapy Oncology Group. Research Plan 2002-2006. Tumor Utilization Committee.
Explore the source record for details and available documents.
Clinical Trials, Phase III as Topic↗
Discrepancy between fibrinogen concentrations determined by clotting rate and clottability assays during the acute-phase reaction.
Assays based on clotting rate are commonly used as a routine method for determining the fibrinogen concentration in plasma. However, little is known about the influence of the acute-phase reaction on this assay. In order to disclose discrepancies between the fibrinogen concentrations obtained by a clotting rate assay (as described by Clauss) and a reference assay for total clottable protein (according to Jacobsson), we compared the fibrinogen concentrations determined by these two methods in plasma-samples collected preoperatively and on postoperative days 1, 3, and 5 in patients undergoing major elective surgery. The HMW (High Molecular Weight)-, LMW- and LMW'-fibrinogen fractions of the patient samples were also determined. In preoperative samples, good agreement between the two assays was found. In samples collected on postoperative days 1 and 3, the fibrinogen concentrations measured with the clotting rate assay were significantly higher than the concentrations measured with the total clottable protein assay (p=0.015 on both days). SDS-gel electrophoresis showed an increase in the median HMW-fraction from 69.7% (range 64.3-70.4) in preoperative samples to 85.8% (80.7-87.6) in samples drawn on day 3. The difference between fibrinogen concentrations obtained by the two methods was significantly correlated to the HMW-fraction of the samples. We conclude that during an acute-phase reaction, fibrinogen concentrations obtained by a clotting rate assay (as described by Clauss) are significantly higher than those measured by a total clottable protein assay (according to Jacobsson). The difference between the two methods correlates well with the relative HMW-fraction, indicating that the increase in HMW-fibrinogen is the main contributor to the observed discrepancy.
Acute-Phase Reaction↗
The HOPE study and diabetes. Heart Outcomes Prevention Evaluation.
Explore the source record for details and available documents.
Angiotensin-Converting Enzyme Inhibitors↗
Synthesis of tumor associated sialyl-T-glycopeptides and their immunogenicity.
Sialyl-T-glycopeptides were synthesized by solid-phase techniques, using a PEGA resin as the solid support. An appropriately protected building block containing alpha-Neu5Ac-(2 --> 3)-beta-Gal-(1 --> 3)-alpha-GalN3-(1-->) attached to Fmoc-Thr/Ser-OPfp was employed in a solid phase glycopeptide assembly of a 10-mer glycopeptide, using a general Fmoc/OPfp-ester strategy. Reduction of the azido group of the GalN3 residue was effected on solid-phase, using DTT and DBU. After acidolytic cleavage from the resin, the methyl ester of the sialic acid residue and acetyl groups were removed with 30% NaOMe/MeOH in MeOH and water pH 14, at -30 degrees C for 2 h. At this low temperature, the highly basic conditions did not result in any detectable beta-elimination. However, one O-acetyl group, located at the 2-position of the Gal was resistant to hydrolysis. To remove this remaining acetyl group, reaction with hydrazine hydrate in CHCl3 and MeOH at room temperature for 2.5 h was successful. The two target sequences of sialyl-T-glycopeptides were obtained in good yield. In contrast to the the analogs carrying the T-antigen, the Sial-T-glycopeptides were nonimmunogenic, supporting the idea that the sialylation is a method of circumventing the recognition by the immune system.
Animals↗
Effects of sustained-release methoprene and a combined formulation of liquid methoprene and Bacillus thuringiensis israelensis on insects in salt marshes.
Aquatic insects are an important component of the food web in salt marshes, therefore it is necessary to test whether pesticides used to control mosquitoes in salt marshes are safe for nontarget insects. We tested the nontarget effects of a combined formulation (duplex) of Bacillus thuringiensis israelensis (B.t.i.) and liquid methoprene (an insect development regulator) or sustained-release methoprene pellets (Altosid(R) pellets) by applying these materials to replicated salt marsh ponds at maximum label rates. Untreated ponds served as controls. We measured effects of the pesticides by rearing immature mosquitoes (Aedes dorsalis) and water boatmen (Trichocorixa reticulata) in predator-exclusion cages and by monitoring uncaged populations of invertebrates using replicated sweep-net samples. Both pesticides killed caged mosquitoes, and the activity of the Altosid(R) pellets continued through 99 days. There were no detectable effects of either pesticide on the survival or maturation of T. reticulata, or on abundances of uncaged invertebrates. The long-term activity of the pellets could help minimize mosquito abatement activity in salt marshes where there are breeding birds or endangered species. However, other studies suggest that this advantage needs to be balanced against the risks that sustained-release formulations could lead to development of resistance in mosquitoes or that initially undetected nontarget effects could build over time.
Aedes↗
Technical and clinical validation of an immunoradiometric assay for circulating parathyroid hormone-related protein.
Explore the source record for details and available documents.
Adult↗
Field efficacy of commercial antimosquito products in Illinois.
We evaluated the efficacy of commercial antimosquito products in field trials in Illinois in June 1998 by comparing mosquito landing rates. Products tested were a sonic mosquito repeller, an insect killing grid using ultraviolet light and 1-octen-3-ol as lures, mosquito smoke coils containing a pyrethroid, citronella candles, the mosquito plant Pelargonium citrosum, and a N,N-diethyl-3-methylbenzamide (deet)-impregnated wrist band. The sonic mosquito repeller, insect killing grid, and mosquito smoke coils were evaluated in 16 trials over 5 days; the citronella candles and mosquito plants in II trials over 4 days; and the wrist bands in 4 trials on 1 day. In all 3 studies, we compared landing rates with the antimosquito products to both positive (topical application of a deet formulation) and negative (no treatment) controls. The deet topical repellent had a consistently lower landing rate than all the nontopically applied products tested. However, the mosquito coils and the deet-impregnated wrist bands did significantly reduce mosquito landing rates relative to untreated controls.
Animals↗