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1.
Ann Oncol ; 35(1): 91-97, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37871703

ABSTRACT

BACKGROUND: The antibody-drug conjugates sacituzumab govitecan (SG) and enfortumab vedotin (EV) are standard monotherapies for metastatic urothelial carcinoma (mUC). Given the different targets and payloads, we evaluated the safety and efficacy of SG + EV in a phase I trial in mUC (NCT04724018). PATIENTS AND METHODS: Patients with mUC and Eastern Cooperative Oncology Group performance status ≤1 who had progressed on platinum and/or immunotherapy were enrolled. SG + EV were administered on days 1 + 8 of a 21-day cycle until progression or unacceptable toxicity. Primary endpoint was the incidence of dose-limiting toxicities during cycle 1. The number of patients treated at each of four pre-specified dose levels (DLs) and the maximum tolerated doses in combination (MTD) were determined using a Bayesian Optimal Interval design. Objective response, progression-free survival, and overall survival were secondary endpoints. RESULTS: Between May 2021 and April 2023, 24 patients were enrolled; 1 patient never started therapy and was excluded from the analysis. Median age was 70 years (range 41-88 years); 11 patients received ≥3 lines of therapy. Seventy-eight percent (18/23) of patients experienced grade ≥3 adverse event (AE) regardless of attribution at any DL, with one grade 5 AE (pneumonitis possibly related to EV). The recommended phase II doses are SG 8 mg/kg with EV 1.25 mg/kg with granulocyte colony-stimulating factor support; MTDs are SG 10 mg/kg with EV 1.25 mg/kg. The objective response rate was 70% (16/23, 95% confidence interval 47% to 87%) with three complete responses; three patients had progressive disease as best response. With a median follow-up of 14 months, 9/23 patients have ongoing response including 6 responses lasting over 12 months. CONCLUSIONS: The combination of SG + EV was assessed at different DLs and a safe dose for phase II was identified. The combination had encouraging activity in patients with mUC with high response rates, including clinically significant complete responses. Additional study of this combination is warranted.


Subject(s)
Antibodies, Monoclonal, Humanized , Antibodies, Monoclonal , Camptothecin/analogs & derivatives , Carcinoma, Transitional Cell , Immunoconjugates , Urinary Bladder Neoplasms , Humans , Adult , Middle Aged , Aged , Aged, 80 and over , Bayes Theorem , Urinary Bladder Neoplasms/drug therapy , Immunoconjugates/adverse effects
2.
Endocr Connect ; 12(3)2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36524811

ABSTRACT

Objective: The primary objective of this study is to establish maternal reference values of anti-Müllerian hormone (AMH) in a fertile multi-ethnic urban pregnant population and to evaluate the effect of gestational age. The secondary objective of this study is to explore the association between AMH and placental biomarkers. Design: This study was embedded in the Generation R Study, an ongoing population-based prospective cohort study from early pregnancy onwards. Setting: City of Rotterdam, the Netherlands, out of hospital setting. Patients: In 5806 women, serum AMH levels were determined in early pregnancy (median 13.5 weeks; 95% range 10.5-17.2). Intervention(s): None. Main outcome measures: Maternal AMH levels in early pregnancy and its association with placental biomarkers, including human chorionic gonadotrophin (hCG), soluble fms-like tyrosine kinase-1 (sFLT), and placental growth factor (PLGF). Results: A nomogram of AMH in early pregnancy was developed. Serum AMH levels showed a decline with advancing gestational age. Higher AMH levels were associated with a higher level of the placental biomarkers hCG and sFLT in early pregnancy. This last association was predominantly mediated by hCG. AMH levels were negatively associated with PLGF levels. Conclusion: In this large study, we show that AMH levels in early pregnancy decrease with advancing gestational age. The association between AMH and the placental biomarkers hCG, sFLT, and PLGF suggests a better placental development with lower vascular resistance in mothers with higher AMH levels. Hence, AMH might be useful in predicting adverse pregnancy outcomes due to impaired placental development.

3.
Ann Oncol ; 33(3): 340-346, 2022 03.
Article in English | MEDLINE | ID: mdl-34958894

ABSTRACT

BACKGROUND: Vaccination is an important preventive health measure to protect against symptomatic and severe COVID-19. Impaired immunity secondary to an underlying malignancy or recent receipt of antineoplastic systemic therapies can result in less robust antibody titers following vaccination and possible risk of breakthrough infection. As clinical trials evaluating COVID-19 vaccines largely excluded patients with a history of cancer and those on active immunosuppression (including chemotherapy), limited evidence is available to inform the clinical efficacy of COVID-19 vaccination across the spectrum of patients with cancer. PATIENTS AND METHODS: We describe the clinical features of patients with cancer who developed symptomatic COVID-19 following vaccination and compare weighted outcomes with those of contemporary unvaccinated patients, after adjustment for confounders, using data from the multi-institutional COVID-19 and Cancer Consortium (CCC19). RESULTS: Patients with cancer who develop COVID-19 following vaccination have substantial comorbidities and can present with severe and even lethal infection. Patients harboring hematologic malignancies are over-represented among vaccinated patients with cancer who develop symptomatic COVID-19. CONCLUSIONS: Vaccination against COVID-19 remains an essential strategy in protecting vulnerable populations, including patients with cancer. Patients with cancer who develop breakthrough infection despite full vaccination, however, remain at risk of severe outcomes. A multilayered public health mitigation approach that includes vaccination of close contacts, boosters, social distancing, and mask-wearing should be continued for the foreseeable future.


Subject(s)
COVID-19 , Neoplasms , COVID-19 Vaccines , Humans , Neoplasms/complications , SARS-CoV-2 , Vaccination
4.
Ned Tijdschr Geneeskd ; 1642020 07 02.
Article in Dutch | MEDLINE | ID: mdl-32757509

ABSTRACT

BACKGROUND: Physicians are often guided by laboratory values. When a clinical presentation does not match laboratory values, one must consider the possibility that these values may be falsely increased or decreased. A common cause is analytical interference. CASE DESCRIPTION: A 57-year-old male, presenting with fatigue and palpitations, had high TSH and normal FT4 values. Although there were no fitting clinical symptoms for these values, the patient was treated with levothyroxine assuming he had subclinical hypothyroidism. TSH levels remained high, however, whereas FT4 levels increased and the patient developed thyrotoxicosis. Eventually, it was discovered that the TSH was falsely elevated. CONCLUSION: The patient turned out to have macro TSH, where TSH forms conjunctions with IgG into larger molecules. These conjugates cause a rarely occurring interference during laboratory analysis, resulting in a falsely increased TSH value.


Subject(s)
Hypothyroidism/diagnosis , Immunoglobulin G/blood , Thyroid Function Tests/adverse effects , Thyrotropin/blood , Thyroxine/blood , False Positive Reactions , Humans , Hyperthyroidism/diagnosis , Hypothyroidism/drug therapy , Male , Middle Aged , Reference Values , Thyroid Function Tests/methods , Thyrotoxicosis/chemically induced , Thyroxine/therapeutic use
5.
Ultrasound Obstet Gynecol ; 56(6): 872-878, 2020 12.
Article in English | MEDLINE | ID: mdl-31975510

ABSTRACT

OBJECTIVES: Arginine vasopressin (AVP) and atrial natriuretic peptide (ANP) may contribute to the pathogenesis of pre-eclampsia (PE), but their role remains to be elucidated. Our aims were to evaluate the surrogates of AVP and ANP, C-terminal pro-AVP (copeptin) and mid-regional pro-ANP (MR-proANP), as biomarkers for the prediction of PE-related pregnancy complications and whether they are associated with angiogenic markers and/or clinical manifestations of PE. METHODS: This was a retrospective analysis of a prospective cohort study that enrolled pregnant women with suspected or confirmed PE, between December 2013 and April 2016. From each patient, a blood sample was obtained at study entry and serum levels of copeptin, MR-proANP, soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) were measured. We evaluated the ability of sFlt-1, PlGF, sFlt-1/PlGF ratio, copeptin and MR-proANP, assessed either alone or combined with traditional predictors (gestational age, parity, diastolic blood pressure and proteinuria), to predict maternal complications and fetal/neonatal complications. Models were compared using concordance statistic (C-index). RESULTS: A total of 526 women were evaluated in the study. Women with confirmed PE displayed elevated serum copeptin and MR-proANP levels in comparison to those with suspected PE but no hypertensive disease of pregnancy. When combined with traditional predictors, the sFlt-1/PlGF ratio displayed a higher C-index than copeptin and MR-proANP (0.76, 0.63 and 0.67, respectively, vs 0.60 for the traditional predictors alone) for the prediction of maternal complications. Similarly, for the prediction of fetal/neonatal complications, the sFlt-1/PlGF ratio displayed a higher C-index than copeptin and MR-proANP when added to the traditional model (0.83, 0.79 and 0.80, respectively, vs 0.79 for the traditional predictors alone). When subdividing women according to sFlt-1/PlGF ratio (≥ 85 vs < 85), no differences in copeptin levels were observed, while MR-proANP level was elevated in women with sFlt-1/PlGF ratio ≥ 85. Multiple regression analysis revealed that copeptin and MR-proANP were independent determinants of proteinuria. CONCLUSIONS: Copeptin and MR-proANP have limited value in predicting PE-related complications when compared with the sFlt-1/PlGF ratio. However, both copeptin and MR-proANP were associated with proteinuria, with copeptin exerting this effect independently of the sFlt-1/PlGF ratio. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.


Subject(s)
Atrial Natriuretic Factor/blood , Glycopeptides/blood , Maternal Serum Screening Tests/statistics & numerical data , Pre-Eclampsia/blood , Pre-Eclampsia/diagnosis , Adult , Biomarkers/blood , Female , Gestational Age , Humans , Maternal Serum Screening Tests/methods , Placenta Growth Factor/blood , Predictive Value of Tests , Pregnancy , Prospective Studies , Retrospective Studies , Vascular Endothelial Growth Factor Receptor-1/blood
6.
Article in English | MEDLINE | ID: mdl-28567293

ABSTRACT

We present a patient (87 years, female) who was admitted to the emergency department because of loss of consciousness. Previous medical history included advanced-stage hepatocellular carcinoma and associated weight loss. She was found on the ground in an unresponsive state by her daughter and was determined to be hypoglycaemic. Upon bolus administration of 100 mL intravenous glucose (10%), glucose levels increased to 2.9 mmol/L and the patient regained full consciousness. She was admitted to the hospital for further examination, and treatment and continuous intravenous glucose infusion was initiated. As the patient was known to suffer from advanced-stage hepatocellular carcinoma, tumour-associated hypoglycaemia was suspected. Insulin, c-peptide and IGF1 concentrations were indeed low, cortisol concentration was high and IGF2 and Pro-IGF2 were borderline low and borderline high normal respectively. IGF2:IGF1 ratio was 23, confirming the diagnosis of non-islet cell tumour hypoglycaemia. During the initial phase of treatment, euglycaemia was maintained by continuous variable glucose infusion (5%, varying between 1 and 2 L/24 h), and the patient was advised to eat small snacks throughout the day. After euglycaemia was established and the diagnosis was confirmed, prednisolone was started (30 mg, 1 dd) and glucose infusions were halted. Under prednisolone treatment, glucose levels were slightly increased and no further hypoglycaemic episodes occurred. At her request, no surgery was performed. After 19 days, the patient was discharged to a hospice and died 3 weeks later. LEARNING POINTS: Hepatocellular carcinoma may be associated with non-islet cell tumour hypoglycaemia (NICTH).NICTH-induced hypoglycaemia is associated with low insulin and IGF1.Measurement of IGF2 only (without measurement of Pro-IGF2 and IGF1) may be insufficient to prove NICTH.

7.
Article in English | MEDLINE | ID: mdl-28458904

ABSTRACT

SUMMARY: We present a case of iatrogenic Cushing's syndrome, induced by treatment with fluticasone furoate (1-2 dd, 27.5 µg in each nostril) in a pediatric patient treated for congenital HIV. The pediatric patient described in this case report is a young girl of African descent, treated for congenital HIV with a combination therapy of Lopinavir/Ritonavir (1 dd 320/80 mg), Lamivudine (1 dd 160 mg) and Abacavir (1 dd 320 mg). Our pediatric patient presented with typical Cushingoid features (i.e. striae of the upper legs, full moon face, increased body and facial hair) within weeks after starting fluticasone furoate therapy, which was exacerbated after increasing the dose to 2 dd because of complaints of unresolved rhinitis. Biochemical analysis fitted iatrogenic Cushing's syndrome, with a repeatedly low cortisol (<0.03 µM, ref 0.14-0.60 µM) and low ACTH (9 pg/mL, ref 9-52 pg/mL) without signs of adrenal insufficiency. No other biochemical abnormalities that could point to adrenal or pituitary dysfunction were detected; electrolytes, thyroid and gonadal function, and IGF-1 were within the normal range. Pharmacogenetic analysis revealed that the pediatric patient carried the CYP3A4 *1B/*1G and CYP3A5 *3/*3 genotype (associated with a partial and complete loss of enzyme activity, respectively) which is associated with the development of iatrogenic Cushing's syndrome in patients treated for HIV due to the strong inhibition of CYP3 enzymes by Ritonavir. Upon discontinuation of fluticasone treatment, the pediatric patient improved both clinically and biochemically with normalisation of cortisol and ACTH within a couple of weeks. LEARNING POINTS: Fluticasone therapy may induce iatrogenic Cushing's syndrome in a patient treated with anti-retroviral therapy.Pharmacogenetic analysis, in particular CYP3A genotyping, provides useful information in patients treated for HIV with respect to possible future steroid treatment.Fluticasone furoate is not detected in the Siemens Immulite cortisol binding assay.

8.
Sci Rep ; 5: 8875, 2015 Mar 09.
Article in English | MEDLINE | ID: mdl-25748167

ABSTRACT

Plasma glucose levels provide the cornerstone of diabetes evaluation. Unfortunately, glucose levels drop in vitro due to glycolysis. Guidelines provide suitable conditions which minimize glycolysis, such as immediate centrifugation or the use of ice/water slurry storage containers. For obvious practical reasons, most laboratories use blood collection tubes containing glycolysis inhibitors. We describe the effect of a variety of commonly used blood collection tubes on in vitro stability of glucose. Furthermore, we looked at the validity of the assumption that glycolytic activity is minimal when blood is kept in an ice/water slurry. Sodium fluoride alone does not reduce in vitro glycolysis in the first 120 minutes after phlebotomy. Addition of citrate almost completely prevented in vitro glycolysis, but showed a positive bias (0.2 mmol/l) compared to control. This is partly due to a small drop in glucose level in control blood, drawn according to the current guidelines. This drop occurs within 15 minutes, in which glycolysis has been described to be minimal and acceptable. NaF-EDTA-citrate based test tubes provide the best pre-analytical condition available. Furthermore, glucose levels are not stable in heparinized blood placed in an ice/water slurry. We strongly advise the use of NaF-EDTA-citrate based test tubes in diabetes research.


Subject(s)
Artifacts , Blood Glucose/chemistry , Blood Specimen Collection/methods , Citrates/chemistry , Ice , Sodium Fluoride/chemistry , Blood Glucose/analysis , Female , Glycolysis/drug effects , Humans , Male
9.
Br J Pharmacol ; 170(4): 908-18, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23957854

ABSTRACT

BACKGROUND AND PURPOSE: Topiramate improves insulin sensitivity, in addition to its antiepileptic action. However, the underlying mechanism is unknown. Therefore, the present study was aimed at investigating the mechanism of the insulin-sensitizing effect of topiramate both in vivo and in vitro. EXPERIMENTAL APPROACH: Male C57Bl/6J mice were fed a run-in high-fat diet for 6 weeks, before receiving topiramate or vehicle mixed in high-fat diet for an additional 6 weeks. Insulin sensitivity was assessed by hyperinsulinaemic-euglycaemic clamp. The extent to which the insulin sensitizing effects of topiramate were mediated through the CNS were determined by concomitant i.c.v. infusion of vehicle or tolbutamide, an inhibitor of ATP-sensitive potassium channels in neurons. The direct effects of topiramate on insulin signalling and glucose uptake were assessed in vivo and in cultured muscle cells. KEY RESULTS: In hyperinsulinaemic-euglycaemic clamp conditions, therapeutic plasma concentrations of topiramate (∼4 µg·mL(-1) ) improved insulin sensitivity (glucose infusion rate + 58%). Using 2-deoxy-D-[(3) H]glucose, we established that topiramate improved the insulin-mediated glucose uptake by heart (+92%), muscle (+116%) and adipose tissue (+586%). Upon i.c.v. tolbutamide, the insulin-sensitizing effect of topiramate was completely abrogated. Topiramate did not directly affect glucose uptake or insulin signalling neither in vivo nor in cultured muscle cells. CONCLUSION AND IMPLICATIONS: In conclusion, topiramate stimulates insulin-mediated glucose uptake in vivo through the CNS. These observations illustrate the possibility of pharmacological modulation of peripheral insulin resistance through a target in the CNS.


Subject(s)
Anticonvulsants/pharmacology , Central Nervous System/drug effects , Fructose/analogs & derivatives , Insulin Resistance , KATP Channels/antagonists & inhibitors , Muscle Fibers, Skeletal/drug effects , Potassium Channel Blockers/pharmacology , Animals , Anticonvulsants/administration & dosage , Blood Glucose/drug effects , Blood Glucose/metabolism , Cell Line , Central Nervous System/metabolism , Diet, High-Fat , Disease Models, Animal , Fructose/administration & dosage , Fructose/pharmacology , Infusions, Intraventricular , Insulin/blood , KATP Channels/metabolism , Male , Mice , Mice, Inbred C57BL , Muscle Fibers, Skeletal/metabolism , Potassium Channel Blockers/administration & dosage , Signal Transduction/drug effects , Topiramate
10.
Genes Brain Behav ; 12(5): 564-75, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23682998

ABSTRACT

Cortical-striatal circuit dysfunction in mental illness may enhance addiction vulnerability. Neonatal ventral hippocampal lesions (NVHL) model this dual diagnosis causality by producing a schizophrenia syndrome with enhanced responsiveness to addictive drugs. Rat genome-wide microarrays containing >24 000 probesets were used to examine separate and co-occurring effects of NVHLs and cocaine sensitization (15 mg/kg/day × 5 days) on gene expression within medial prefrontal cortex (MPFC), nucleus accumbens (NAC), and caudate-putamen (CAPU). Two weeks after NVHLs robustly amplified cocaine behavioral sensitization, brains were harvested for genes of interest defined as those altered at P < 0.001 by NVHL or cocaine effects or interactions. Among 135 genes so impacted, NVHLs altered twofold more than cocaine, with half of all changes in the NAC. Although no genes were changed in the same direction by both NVHL and cocaine history, the anatomy and directionality of significant changes suggested synergy on the neural circuit level generative of compounded behavioral phenotypes: NVHL predominantly downregulated expression in MPFC and NAC while NVHL and cocaine history mostly upregulated CAPU expression. From 75 named genes altered by NVHL or cocaine, 27 had expression levels that correlated significantly with degree of behavioral sensitization, including 11 downregulated by NVHL in MPFC/NAC, and 10 upregulated by NVHL or cocaine in CAPU. These findings suggest that structural and functional impoverishment of prefrontal-cortical-accumbens circuits in mental illness is associated with abnormal striatal plasticity compounding with that in addictive disease. Polygenetic interactions impacting neuronal signaling and morphology within these networks likely contribute to addiction vulnerability in mental illness.


Subject(s)
Cocaine-Related Disorders/metabolism , Cocaine/pharmacology , Nucleus Accumbens/metabolism , Prefrontal Cortex/metabolism , Putamen/metabolism , Transcription, Genetic , Animals , Cocaine-Related Disorders/genetics , Gene Expression Profiling , Hippocampus/pathology , Male , Nucleus Accumbens/drug effects , Prefrontal Cortex/drug effects , Putamen/drug effects , Rats , Rats, Sprague-Dawley
11.
Phys Rev Lett ; 108(18): 183901, 2012 May 04.
Article in English | MEDLINE | ID: mdl-22681076

ABSTRACT

We demonstrate a new technique for absolute distance measurement with a femtosecond frequency comb laser, based on unraveling the output of an interferometer to distinct comb modes with 1 GHz spacing. From the fringe patterns that are captured with a camera, a distance is derived by combining spectral and homodyne interferometry, exploiting about 9000 continuous wave lasers. This results in a measurement accuracy far within an optical fringe (λ/30), combined with a large range of nonambiguity (15 cm). Our technique merges multiwavelength interferometry and spectral interferometry, within a single scheme.

12.
Neuroscience ; 190: 37-42, 2011 Sep 08.
Article in English | MEDLINE | ID: mdl-21683126

ABSTRACT

Previously selected amyloid beta recognizing heavy chain antibody fragments (VHH) affinity binders derived from the Camelid heavy chain antibody repertoire were tested for their propensity to cross the blood-brain barrier (BBB) using an established in vitro BBB co-culture system. Of all tested VHH, ni3A showed highest transmigration efficiency which is, in part, facilitated by a three amino acid substitutions in its N-terminal domain. Additional studies indicated that the mechanism of transcellular passage of ni3A is by active transport. As VHH ni3A combines the ability to recognize amyloid beta and to cross the BBB, it has potential as a tool for non-invasive in vivo imaging and as efficient local drug targeting moiety in patients suffering from cerebral amyloidosis such as Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA).


Subject(s)
Amyloid beta-Peptides/immunology , Blood-Brain Barrier/metabolism , Brain/metabolism , Immunoglobulin Heavy Chains/metabolism , Alzheimer Disease/metabolism , Biological Transport/physiology , Down Syndrome/metabolism , Humans , Immunoglobulin Fragments/metabolism
13.
Exp Diabetes Res ; 2011: 928523, 2011.
Article in English | MEDLINE | ID: mdl-21603181

ABSTRACT

High fat feeding induces a variety of obese and lean phenotypes in inbred rodents. Compared to Diet Resistant (DR) rodents, Diet Induced Obese (DIO) rodents are insulin resistant and have a reduced dopamine receptor D2 (DRD2) mediated tone. We hypothesized that this differing dopaminergic tone contributes to the distinct metabolic profiles of these animals. C57Bl6 mice were classified as DIO or DR based on their weight gain during 10 weeks of high fat feeding. Subsequently DIO mice were treated with the DRD2 agonist bromocriptine and DR mice with the DRD2 antagonist haloperidol for 2 weeks. Compared to DR mice, the bodyweight of DIO mice was higher and their insulin sensitivity decreased. Haloperidol treatment reduced the voluntary activity and energy expenditure of DR mice and induced insulin resistance in these mice. Conversely, bromocriptine treatment tended to reduce bodyweight and voluntary activity, and reinforce insulin action in DIO mice. These results show that DRD2 activation partly redirects high fat diet induced metabolic anomalies in obesity-prone mice. Conversely, blocking DRD2 induces an adverse metabolic profile in mice that are inherently resistant to the deleterious effects of high fat food. This suggests that dopaminergic neurotransmission is involved in the control of metabolic phenotype.


Subject(s)
Dopamine Agonists/therapeutic use , Dopamine Antagonists/toxicity , Energy Metabolism/drug effects , Obesity/drug therapy , Receptors, Dopamine D2/physiology , Synaptic Transmission/drug effects , Animals , Behavior, Animal/drug effects , Body Weight/drug effects , Bromocriptine/therapeutic use , Dietary Fats/adverse effects , Dopamine D2 Receptor Antagonists , Haloperidol/toxicity , Insulin Resistance , Male , Mice , Mice, Inbred C57BL , Mice, Obese , Motor Activity/drug effects , Obesity/chemically induced , Obesity/metabolism , Phenotype , Random Allocation , Receptors, Dopamine D2/agonists
14.
Opt Express ; 19(7): 6549-62, 2011 Mar 28.
Article in English | MEDLINE | ID: mdl-21451683

ABSTRACT

We experimentally demonstrate long distance measurements with a femtosecond frequency comb laser using dispersive interferometry. The distance is derived from the unwrapped spectral phase of the dispersed interferometer output and the repetition frequency of the laser. For an interferometer length of 50 m this approach has been compared to an independent phase counting laser interferometer. The obtained mutual agreement is better than 1.5 µm (3×10(-8)), with a statistical averaging of less than 200 nm. Our experiments demonstrate that dispersive interferometry with a frequency comb laser is a powerful method for accurate and non-incremental measurement of long distances.


Subject(s)
Algorithms , Interferometry/instrumentation , Lasers , Signal Processing, Computer-Assisted/instrumentation , Equipment Design , Equipment Failure Analysis
15.
Opt Express ; 19(4): 3406-17, 2011 Feb 14.
Article in English | MEDLINE | ID: mdl-21369163

ABSTRACT

We investigate general properties of the interferograms from a frequency comb laser in a non-linear dispersive medium. The focus is on interferograms at large delay distances and in particular on their broadening, the fringe formation and shape. It is observed that at large delay distances the interferograms spread linearly and that its shape is determined by the source spectral profile. It is also shown that each intensity point of the interferogram is formed by the contribution of one dominant stationary frequency. This stationary frequency is seen to vary as a function of the path length difference even within the interferogram. We also show that the contributing stationary frequency remains constant if the evolution of a particular fringe is followed in the successive interferograms found periodically at different path length differences. This can be used to measure very large distances in dispersive media.

16.
Behav Brain Res ; 218(2): 346-9, 2011 Apr 15.
Article in English | MEDLINE | ID: mdl-21184782

ABSTRACT

Alcohol abuse in schizophrenia exceeds rates in the general population and worsens illness outcomes. Neonatal ventral hippocampal lesion (NVHL) rats model multiple schizophrenia dimensions including addiction vulnerability. This study compared NVHL vs. SHAM-controls in operant alcohol seeking and consumption. NVHLs enhanced consumption of combined ethanol/sucrose solution but neither ethanol or sucrose only solutions, consistent with increased vulnerability specific to carbohydrate-laden alcohol beverages typically consumed in early stages of human alcoholism.


Subject(s)
Alcohol Drinking/physiopathology , Behavior, Animal/physiology , Drug-Seeking Behavior/physiology , Hippocampus/physiopathology , Schizophrenia/physiopathology , Alcohol Drinking/psychology , Analysis of Variance , Animals , Disease Models, Animal , Extinction, Psychological/physiology , Male , Rats , Rats, Sprague-Dawley , Schizophrenic Psychology
17.
Phys Rev Lett ; 102(22): 223901, 2009 Jun 05.
Article in English | MEDLINE | ID: mdl-19658865

ABSTRACT

Direct frequency comb spectroscopy of trapped ions is demonstrated for the first time. It is shown that the 4s ;{2}S_{1/2}-4p ;{2}P_{3/2} transition in calcium ions can be excited directly with a frequency comb laser that is up-converted to 393 nm. Detection of the transition is performed using a shelving scheme to suppress the background signal from nonresonant comb modes. The measured transition frequency of f=761 905 012.7(0.5) MHz presents an improvement in accuracy of more than 2 orders of magnitude.

18.
Opt Lett ; 34(13): 1982-4, 2009 Jul 01.
Article in English | MEDLINE | ID: mdl-19571973

ABSTRACT

We experimentally demonstrate that a femtosecond frequency comb laser can be applied as a tool for long-distance measurement in air. Our method is based on the measurement of cross correlation between individual pulses in a Michelson interferometer. From the position of the correlation functions, distances of up to 50 m have been measured. We have compared this measurement to a counting laser interferometer, showing an agreement with the measured distance within 2 microm (4x10(-8) at 50 m).

19.
Opt Express ; 17(11): 9300-13, 2009 May 25.
Article in English | MEDLINE | ID: mdl-19466182

ABSTRACT

Interferometric measurement of distance using a femtosecond frequency comb is demonstrated and compared with a counting interferometer displacement measurement. A numerical model of pulse propagation in air is developed and the results are compared with experimental data for short distances. The relative agreement for distance measurement in known laboratory conditions is better than 10(-7). According to the model, similar precision seems feasible even for long-distance measurement in air if conditions are sufficiently known. It is demonstrated that the relative width of the interferogram envelope even decreases with the measured length, and a fringe contrast higher than 90% could be obtained for kilometer distances in air, if optimal spectral width for that length and wavelength is used. The possibility of comb radiation delivery to the interferometer by an optical fiber is shown by model and experiment, which is important from a practical point of view.


Subject(s)
Air , Algorithms , Atmosphere/analysis , Atmosphere/chemistry , Interferometry/instrumentation , Lasers , Computer-Aided Design , Equipment Design , Equipment Failure Analysis , Light , Reproducibility of Results , Scattering, Radiation , Sensitivity and Specificity
20.
Hautarzt ; 57(7): 610-7, 2006 Jul.
Article in German | MEDLINE | ID: mdl-16673107

ABSTRACT

BACKGROUND: The purpose of this study was to categorize enlarged superficial lymph nodes as benign or malignant using sonomorphologic features and vascularization pattern. PATIENTS AND METHODS: Enlarged superficial lymph nodes in 57 patients were assessed with B-mode and contrast-enhanced power Doppler sonography. Morphology and vascularization were evaluated. The lymph nodes were categorized as benign or malignant. Correlation was made with histology and follow-up results. RESULTS: In 55 patients, 40 lymph nodes were correctly categorized as benign and 15 lymph nodes correctly as malignant. The most reliable criteria were shape and vascularization pattern. Intact hilar vessels and branching indicated benign enlargement, destruction of the hilum with vessels running peripherally along the capsule indicated metastatic destruction. Two benign lymph nodes were considered malignant (false positive). CONCLUSION: B-mode ultrasound along with contrast-enhanced power Doppler ultrasound is an easy, cost-effective, and reliable tool for differentiation and categorization of enlarged superficial lymph nodes.


Subject(s)
Lymph Nodes/diagnostic imaging , Lymphatic Metastasis/diagnostic imaging , Ultrasonography, Doppler, Color , Adolescent , Adult , Aged , Aged, 80 and over , Child , Diagnosis, Differential , False Positive Reactions , Female , Humans , Male , Middle Aged
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