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Thompson SL, Bardia A, Tan A, Barton D, Kottschade L, Sloan J, Christensen B, Smith D, Loprinzi C. Levetiracetam for the treatment of hot flashes: A pilot study. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.9116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
9116 Background: Hot flashes affect 75 % to 90 % of women transitioning to menopause and are a major cause of morbidity among breast cancer survivors. Levetiracetam, a popular anticonvulsant, is a centrally active agent that anecdotally appeared to reduce hot flashes in clinical practice. This phase II trial sought to evaluate the efficacy of levetiracetam in reducing hot flashes among women with a history of breast cancer or women who did not wish to take estrogen therapy for fear of an increased risk of breast cancer. Methods: Women who were experiencing bothersome hot flashes (≥ 14 times per week, for ≥ 1 month) were eligible. A single arm pilot study design based on previous work was used with a planned sample size of 30 patients. The patients did not receive any study medication during the first week (baseline week). At the beginning of the second week, patients were started on levetiracetam (500 mg), and were to increase the dose by 500 mg each week to a goal of 1,000 mg twice daily. Hot flash diaries were completed daily. The primary endpoint was hot flash score (frequency times average severity). The change from week 1 (baseline) to week 5, the last treatment week, was analyzed by paired t-test and related Wilcoxon procedures. Results: A total of 30 women were enrolled onto this study in eight months. All patients were eligible. 19 women completed all 4 weeks of the study treatment and provided complete data. After treatment with levetiracetam for 4 weeks, mean hot flash scores were reduced by 57% (95% CI 39%-75%), while mean hot flash frequencies were reduced by 53% (95% CI 38%-68%), reductions being greater than what would be expected with a placebo. There were significant improvements, compared to baseline week data, in sweating, hot flash distress, and satisfaction with hot flash control. Eight subjects stopped the study drug due to treatment related adverse events (grade I/II), with the most frequently reported being somnolence, fatigue and dizziness. Conclusions: While levetiracetam appears to be a promising therapy for the treatment of hot flashes, further study is needed to better substantiate the toxicity and efficacy of this drug before it can be more definitively recommended for use in clinical practice. No significant financial relationships to disclose.
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Green REA, Christensen B, Melo B, Monette G, Bayley M, Hebert D, Inness E, Mcilroy W. Is there a trade-off between cognitive and motor recovery after traumatic brain injury due to competition for limited neural resources? Brain Cogn 2006; 60:199-201. [PMID: 16646119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The status of neurorehabilitation for traumatic brain injury (TBI) is under active debate because of a dearth of research findings demonstrating effectiveness. This may be due, in part, to limitations in our understanding of basic mechanisms of cognitive and motor recovery,including those that might impede recovery. In this regard, we examined whether overall recovery following TBI might be undermined by competition between cognitive and motor functions for finite neural resources during recovery. In this preliminary study, 21 moderately and severely impaired patients were administered cognitive and motor assessments at 1, 4, and 12 months post-TBI, and recovery of cognitive and motor functions was measured using regression residuals. Negative correlations between recovery of cognitive versus motor functions were used as the index of competition. We found suggestive evidence that there may indeed be a trade-off between the recovery of cognitive and motor functions after TBI. Implications for rehabilitation are discussed.
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Green REA, Melo B, Christensen B, Ngo L, Skene C. Evidence of transient enhancement to cognitive functioning in healthy young adults through environmental enrichment: implications for rehabilitation after brain injury. Brain Cogn 2006; 60:201-3. [PMID: 16646120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We examined preliminarily whether intensive mental activity can transiently enhance higher cognitive functioning in healthy adults. Ten healthy participants performed intensive mental activity for 2 weeks. The intervention entailed daily memorization of multiple prose passages and performance of demanding, speeded mental arithmetic.Neuropsychological testing was conducted before and after the intervention, using alternate forms. (The intervention and neuropsychological tests were different.) Findings in the intervention group were compared to those of a convenience control sample who had performed a near-identical neuropsychological assessment and follow-up in a different study, but who did not perform the intervention. The purpose was to rule out practice effects as the cause of any observed improvement in the intervention group. The intervention group showed improvement on six/eight measures. The non-intervention group showed improvement on only two. Results suggest cognitive capacity can be enhanced in healthy individuals after a period of intensive cognitive stimulation. Implications for rehabilitation are discussed.
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Schindler AE, Christensen B, Henkel A, Oettel M, Moore C. High-dose pilot study with the novel progestogen dienogestin patients with endometriosis. Gynecol Endocrinol 2006; 22:9-17. [PMID: 16522528 DOI: 10.1080/09513590500431482] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
High-dose dienogest (20 mg/day) was used for the treatment of endometriosis in women aged 18-52 years after laparoscopic and histological diagnosis of endometriosis and staging according to the revised American Fertility Society criteria. Treatment efficacy was analyzed objectively by second-look laparoscopy, and serum hormone measurements and evaluation of endometriosis-related symptoms were performed done and side-effects recorded. Compared with other high-dose progestin therapies, treatment with dienogest was shown to be effective even in stage IV endometriosis. The side-effect profile of the high-dose dienogest treatment appears to be highly favorable compared with other treatments. Neither the menopausal symptoms caused by therapy with gonadotropin-releasing hormone agonists nor the adverse androgen-related effects induced by danazol were observed. Therefore, long-term high-dose dienogest therapy can be recommended particularly for women with progressive endometriosis.
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Johansen IR, Hauch AM, Christensen B, Parving A. Longitudinal study of hearing impairment in children. Int J Pediatr Otorhinolaryngol 2004; 68:1157-65. [PMID: 15302146 DOI: 10.1016/j.ijporl.2004.04.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2003] [Revised: 03/26/2004] [Accepted: 04/02/2004] [Indexed: 10/26/2022]
Abstract
The aim of this study is to evaluate the frequency of progression in permanent childhood hearing impairment (PHI) and to relate potential specific factors to the eventual progression. A description is made of the true longitudinal hearing thresholds in four groups of children according to different observation periods and being part of a prospective pediatric audiological registry-based study established in 1989. At the time of data collection the registry included 1373 children born after 1/1-1970 with a PHI > 20 dB in either the right or the left ear at any pure tone frequency. The children were subdivided according to the following observation periods: 1-3 years (N=266), >3-5 years (N=148), >5-10 years (N=212) and >10 years (N=62). The differences from the first to the most recent audiometric thresholds were analysed for the right and left ears separately, at the pure tone frequencies 250, 500, 1000, 2000, 4000 and 8000 Hz, for the average of 500, 1000, 2000 and 4000 Hz, for the average of 2000 and 4000 Hz and for the average of 4000 and 8000 Hz. Those showing a progression >15 dB for the average across 500-4000 Hz were analysed for age at onset and aetiology of hearing impairment, showing that genetic factors are predominant in progressive PHI. It was also found that progression in PHI is most frequent in early childhood but found only in 5.7% after the age of 4 years.
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Westwood DA, Pavlovic-King J, Christensen B. Time-varying effects of a size-contrast illusion on grasping are not correlated with illusory perception. J Vis 2004. [DOI: 10.1167/4.8.839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Abstract
OBJECTIVE In July 2001 the World Health Organization (WHO) launched their "Guidelines for hearing aids and services for developing countries". The objective of this study was to evaluate the clinical outcome of an analogue, low-cost, behind-the-ear hearing aid (BTE-HA) that met the minimum technical requirements outlined by the WHO. MATERIAL AND METHODS A total of 25 subjects (17 males, 8 females; median age 74 years; range 50-86 years) were recruited among patients referred for audiological evaluation who consented to participate in the trial. All subjects had a hearing loss of < or = 60 dB HL at 2 kHz, were mobile and mentally unimpaired; 13 were experienced users of HAs, 3 suffered from mixed conductive/sensorineural hearing impairment (HI) and the remainder had pure sensorineural HI. Based on pure-tone, speech and impedance audiometry the BTE-HAs were fitted, using the National Acoustic Laboratories-R (NAL-R) prescription rule, 21 binaurally and 4 monaurally. All fittings were validated by insertion gain measurements, and the immediate benefit was measured by means of the speech recognition score in background noise (SRSN; signal:noise ratio = 10 dB) without and with the HA. After a 6-week trial period a structured interview based on the International Outcome Inventory for Hearing Aids (IOI-HAs) was performed. RESULTS The results showed that the amplification of the HA deviated significantly from the NAL-R target at all frequencies, giving significantly more amplification at 500 and 1000 Hz despite maximum bass-cut, whenever relevant, and significantly less amplification as required at 2, 3 and 4 kHz. The median SRSN without HA was 48% (range 0-96%), which improved significantly to 80% (range 24-100%) with HA. The median individual difference in SRSN without and with HA was 20% (range 0-72%). The total IOI-HA score with the test HA was 4.1 (range 2.6-4.6), showing that it offered subjectively high satisfaction and reduction in limitations of activity. CONCLUSIONS The low-cost HA: (i) provides benefit to the hearing-impaired person; (ii) offers poor amplification in the high frequencies; and (iii) gives subjective satisfaction similar to that for modern available HAs.
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Hawkins KA, Addington J, Keefe RSE, Christensen B, Perkins DO, Zipurksy R, Woods SW, Miller TJ, Marquez E, Breier A, McGlashan TH. Neuropsychological status of subjects at high risk for a first episode of psychosis. Schizophr Res 2004; 67:115-22. [PMID: 14984870 DOI: 10.1016/j.schres.2003.08.007] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2002] [Revised: 08/02/2003] [Accepted: 08/12/2003] [Indexed: 10/26/2022]
Abstract
Thirty-six subjects aged 16 years or older judged at risk for a first episode of psychosis within a North American multi-site study of the schizophrenia prodrome [McGlashan et al., Schizophr. Res. (2003); Miller et al., Schizophr. Res. (2003)] performed at levels intermediate to population norms and data reported for schizophrenia samples on a comprehensive neuropsychological exam. In the context of normal intelligence, this intermediate status suggests that, as a group, these subjects are not fully normal in neuropsychological functioning. Conversely, the finding that they do not show the levels of impairment commonly observed in schizophrenia, including within the first episode, suggests that prodromal interventions might conceivably prevent, delay, or lessen the severity of declines associated with first psychotic episodes.
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Christensen B, Kølvraa S, Lykke-Hansen L, Lörch T, Gohel D, Smidt-Jensen S, Bang J, Philip J. Studies on the isolation and identification of fetal nucleated red blood cells in the circulation of pregnant women before and after chorion villus sampling. Fetal Diagn Ther 2003; 18:376-84. [PMID: 12913351 DOI: 10.1159/000071983] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2002] [Accepted: 11/18/2002] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To investigate the feasibility of various molecular forms of hemoglobin as markers for fetal nucleated red blood cells (NRBCs). METHODS The presence of epsilon and gamma globin positive NRBCs was investigated in pure fetal blood and in blood from pregnant women before and after chorion biopsy. Maternal samples were enriched for NRBCs by various conventional methods, including limited enrichment by only positive CD71 selection or single density gradient. We searched for fetal cells on slides by automated scanning. Fetal cells were defined by (1) the presence of epsilon or gamma globin and (2) simultaneously by the presence of a Y chromosome signal. RESULTS 18 of 25 gamma globin positive cells identified in blood samples after chorion biopsy were chromosome Y signal positive, and 1 cell had two X chromosome signals. 263 of 339 epsilon globin positive cells identified in blood samples after chorion biopsy were hybridized with X and Y chromosome probes. None had two X signals, and 249 were Y positive. In blood samples before chorion biopsy, only 1 epsilon globin positive fetal NRBC and no epsilon globin positive maternal NRBCs were found. CONCLUSIONS Epsilon globin may be specific for fetal NRBCs. Only 1 epsilon globin positive fetal cell was identified in 1 of 12 blood samples before chorion biopsy, representing a total of 182 ml of maternal blood. This suggests that most fetal cells found in maternal blood by fluorescence in situ hybridization methods may not be NRBCs.
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Schumacher A, Seljeflot I, Sommervoll L, Christensen B, Otterstad JE, Arnesen H. Increased levels of markers of vascular inflammation in patients with coronary heart disease. Scand J Clin Lab Invest 2002; 62:59-68. [PMID: 12002414 DOI: 10.1080/003655102753517217] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Elevated levels of soluble cell adhesion molecules (sCAMs), inflammatory cytokines and C-reactive protein (CRP) have been associated with atherosclerotic disease states. The aim of the present study was to evaluate whether circulating levels of vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1), E- and P-selectin were significantly elevated in patients with coronary heart disease (CHD) compared with healthy controls, and to study possible associations between these sCAMs, tumour necrosis factor alpha (TNFalpha). interleukin-6 (IL-6), CRP and major CHD risk factors. The study included 193 patients in various stages of CHD and 193 matched controls. To evaluate any possible influence of acute phase reaction, reinvestigation was performed after 6 months. After adjustment for major CHD risk factors, sVCAM-1, sICAM-1, P-selectin, IL-6 and CRP remained significantly elevated in the CHD patients (p for all <0.001). In multivariate analysis sVCAM-1 was predicted by age (p=0.015), sICAM-1 by smoking (p<0.001) and total cholesterol (p=0.026), E-selectin by body mass index (BMI) (p=0.004) and P-selectin by male gender (p=0.015). TNFalpha significantly predicted sICAM-1 and E-selectin levels, while IL-6 predicted CRP but none of the sCAMs measured. This might indicate that TNFalpha, but not IL-6, plays a major role in the regulation of sCAM levels in vivo.
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Christensen B. [Minimally invasive methods to create a neovagina]. ZENTRALBLATT FUR GYNAKOLOGIE 2002; 124:313-6. [PMID: 12384816 DOI: 10.1055/s-2002-34746] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
There are several methods to construct a vagina in case of a congenital vaginal agenesis. The significance of minimal-invasive technics, especially the laparascopian Vecchietti operation, increases continuously. The sigmoid neovagina was performed up to now per laparotomiam only. By performing it endoscopically, the postoperative discomfort for the patient was reduced in comparance to laparatomian operation. Some disadvantages of the laparoscopy Vecchietti operation and advantages of the sigmoid neovagina convinced us to support and develop this endoscopic method.
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Blaas HGK, Eriksson AG, Salvesen KA, Isaksen CV, Christensen B, Møllerløkken G, Eik-Nes SH. Brains and faces in holoprosencephaly: pre- and postnatal description of 30 cases. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2002; 19:24-38. [PMID: 11851965 DOI: 10.1046/j.0960-7692.2001.00154.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
OBJECTIVE To investigate the prenatal appearance of the holoprosencephaly spectrum. METHODS A database of 1750 fetuses with congenital anomalies identified by ultrasound was prospectively collected from 1987 to 2000. Among them, 30 cases (1.7%) with holoprosencephaly were prenatally identified and described. RESULTS The prevalence of holoprosencephaly in the Health Region of the National Center for Fetal Medicine in Norway was 1.26 : 10 000; the sex distribution (male : female) was 1.4 : 1. Holoprosencephaly was found in one dichorionic twin pregnancy and one pair of conjoined twins. Among the 30 cases of holoprosencephaly, 18 were alobar, five were semilobar, two were lobar, two were lobar variants, and three were anencephalic. The facial features varied considerably. Sixty-seven per cent (20/30) had associated structural anomalies that were not related to the cerebral and facial holoprosencephaly condition. Thirty-seven per cent (11/30) had detectable chromosome aberrations and 23% (7/30) had nonchromosomal syndromal origin. The size or shape of the head was abnormal in 83% (25/30) of holoprosencephaly cases. CONCLUSION This study indicates that holoprosencephaly represents a heterogeneous entity with different etiologies and clinical appearances. The fact that holoprosencephaly features are found associated with particular conditions such as fronto-nasal dysplasia (2/30; 6.7%), agnathia-otocephaly (3/30; 10%), and anencephaly (3/30; 10%), suggests that these may be underreported conditions in other large holoprosencephaly series.
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Utzon J, Olsen PS, Bay-Nielsen M, Andersen KB, Christensen B, Endahl LA, Krarup T, Lucht U, Ottesen BS, Schroeder TV, Kehlet H. [Evaluation of surgical interventions in Denmark]. Ugeskr Laeger 2001; 163:5662-4. [PMID: 11665468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Christensen B, Christiansen T, Gombert AK, Thykaer J, Nielsen J. Simple and robust method for estimation of the split between the oxidative pentose phosphate pathway and the Embden-Meyerhof-Parnas pathway in microorganisms. Biotechnol Bioeng 2001; 74:517-23. [PMID: 11494219 DOI: 10.1002/bit.1143] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The flux through the oxidative pentose phosphate (PP) pathway was estimated in Bacillus clausii, Saccharomyces cerevisiae, and Penicillium chrysogenum growing in chemostats with [1-(13)C]glucose as the limiting substrate. The flux calculations were based on a simple algebraic expression that is valid irrespective of isotope rearrangements arising from reversibilities of the reactions in the PP pathway and the upper part of the Embden-Meyerhof-Parnas pathway. The algebraically calculated fluxes were validated by comparing the results with estimates obtained using a numerical method that includes the entire central carbon metabolism. Setting the glucose uptake rate to 100, the algebraic expression yielded estimates of the PP pathway flux in B. clausii, S. cerevisiae, and P. chrysogenum of 20, 42, and 75, respectively. These results are in accordance with the results from the numerical method. The information on the labeling patterns of glucose and the proteinogenic amino acids were obtained using gas chromatography / mass spectrometry, which is a very sensitive technique, and therefore only a small amount of biomass is needed for the analysis. Furthermore, the method developed in this study is fast and readily accessible, as the calculations are based on a simple algebraic expression.
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Christensen B, Mosdol A, Retterstol L, Landaas S, Thelle DS. Abstention from filtered coffee reduces the concentrations of plasma homocysteine and serum cholesterol--a randomized controlled trial. Am J Clin Nutr 2001; 74:302-7. [PMID: 11522552 DOI: 10.1093/ajcn/74.3.302] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Elevated concentrations of plasma total homocysteine (tHcy) and serum total cholesterol are risk factors for ischemic heart disease (IHD). Previous studies showed that the consumption of very high doses of unfiltered coffee increases tHcy and total cholesterol. OBJECTIVE A prospective intervention study was performed to assess the effects of coffee consumption on the concentrations of tHcy and total cholesterol by using doses and brewing methods common in southeastern Norway. DESIGN The study was an unblinded, controlled trial with 191 healthy, nonsmoking, coffee-drinking volunteers aged 24-69 y randomly assigned to 3 groups who were asked to consume for 6 consecutive weeks no coffee, 1-3 cups (approximately 175-525 mL)/d, or > or =4 cups (approximately 700 mL)/d prepared in the manner to which they were accustomed. Blood samples were drawn when the subjects were randomly assigned and at 3 and 6 wk of the trial. Dietary data were collected by questionnaire. RESULTS Ninety-seven percent of the participants reported being regular consumers of caffeinated filtered coffee. Abstention from coffee for 6 wk was associated with a decrease in the tHcy concentration of 1.08 micromol/L and a decrease in the total cholesterol concentration of 0.28 mmol/L in participants who had been drinking on average 4 cups of filtered coffee daily for the past year. Adjustments for several possible confounders did not alter the results. CONCLUSION Abstention from filtered coffee in doses that are commonly consumed was associated with lower concentrations of tHcy and total cholesterol.
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Melchiorsen CR, Jensen NB, Christensen B, Vaever Jokumsen K, Villadsen J. Dynamics of pyruvate metabolism in Lactococcus lactis. Biotechnol Bioeng 2001; 74:271-9. [PMID: 11410851 DOI: 10.1002/bit.1117] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The pyruvate metabolism in the lactic acid bacterium Lactococcus lactis was studied in anaerobic cultures under transient conditions. During growth of L. lactis in continuous culture at high dilution rate, homolactic product formation was observed, i.e., lactate was produced as the major end product. At a lower dilution rate, the pyruvate metabolism shifted towards mixed acid-product formation where formate, acetate, and ethanol were produced in addition to lactate. The regulation of the shift in pyruvate metabolism was investigated by monitoring the dynamic behavior of L. lactis in continuous cultures subjected to step changes in dilution rate. Both shift-up and shift-down experiments were carried out, and these experiments showed that the enzyme pyruvate formate-lyase (PFL) plays a key role in the regulation of the shift. Pyruvate formate-lyase in vivo activity was regulated both at the level of gene expression and by allosteric modulation of the enzyme. A simple mathematical model was proposed to estimate the relative significance of the regulatory mechanisms involved.
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Verhoeff NP, Kapur S, Hussey D, Lee M, Christensen B, Papatheodorou G, Zipursky RB. A simple method to measure baseline occupancy of neostriatal dopamine D2 receptors by dopamine in vivo in healthy subjects. Neuropsychopharmacology 2001; 25:213-23. [PMID: 11425505 DOI: 10.1016/s0893-133x(01)00231-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effect of endogenous dopamine (DA) on measurement of neostriatal DA D(2) receptor binding potential (D(2)RBP) in vivo was evaluated with positron emission tomography (PET) and the radiotracer [11C]raclopride by comparing the D(2)RBP before and after acute DA depletion. DA depletion was achieved by per-oral administration of 4.5 g alpha-methyl-para-tyrosine (AMPT) given in 25 h. Six healthy subjects completed the protocol. The AMPT treatment increased D(2)RBP significantly from 3.11 +/- 0.25 to 3.68 +/- 0.23 and decreased plasma levels of the DA metabolite homovanillic acid by 71 +/- 11% and levels of the norepinephrine metabolite 3-methoxy-4-hydroxyphenethyleneglycol by 53 +/- 7%. Increase in D(2)RBP correlated with decrease in attentiveness and with increase in errors of commission from Conners' Continuous Performance Test. On AMPT, a significant decrease in subjective happiness scores was observed. The results imply that a noninvasive [11C]raclopride PET protocol coupled with relatively brief administration of a rather low total dose of AMPT resulted in measurable acute DA depletion that might provide estimates of synaptic neostriatal DA concentration.
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Jonsbu E, Christensen B, Nielsen J. Changes of in vivo fluxes through central metabolic pathways during the production of nystatin by Streptomyces noursei in batch culture. Appl Microbiol Biotechnol 2001; 56:93-100. [PMID: 11499953 DOI: 10.1007/s002530100613] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The central carbon metabolism of the nystatin-producing strain Streptomyces noursei ATCC 11455 was evaluated by 13C-labelling experiments. A batch fermentation was examined during the idiophase by GC-MS measurements of the labelling patterns of amino acids in the biomass. The labelling patterns of the amino acids and calculated fluxes of the central metabolism showed that changes in the primary and secondary metabolisms occurred simultaneously. Changes in the profiles for the integrated fluxes showed a decreased flux through the pentose phosphate pathway and an increased flux in the tricarboxylic acid cycle relative to the glucose uptake rate when the culture entered a phase with reduced specific growth rate and enhanced nystatin yield. The flux through the pentose phosphate pathway seemed to be adjusted according to the NADPH requirement during the different phases of the batch fermentation.
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Parving A, Parving I, Erlendsson A, Christensen B. Some experiences with hearing disability/handicap and quality of life measures. AUDIOLOGY : OFFICIAL ORGAN OF THE INTERNATIONAL SOCIETY OF AUDIOLOGY 2001; 40:208-14. [PMID: 11521713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
To achieve detailed information on the outcome of hearing rehabilitation in a clinical setting, measurements of hearing disability and hearing handicap have been introduced, and the present study describes the preliminary experiences with these measures in a series of hearing-impaired subjects referred for audiological evaluation. To outline hearing disability/hearing handicap (HD/HH), before continuation or initiation of treatment, the Gothenburg profile and a generic health-related quality of life--the SF-36 questionnaire--were used to evaluate any adverse effects resulting from hearing disorders. The Gothenburg profile and the SF-36 questionnaire were mailed to 634 subjects appointed for audiological examination with a request to complete the questionnaires at home. Three questions were enclosed concerning the capacity to complete the questionnaires, showing that 1.9 per cent were incapable of completing them, 17.5 per cent needed assistance, 43.5 per cent completed the questionnaires, and 37.1 per cent did not respond to them. Thus the response rate was only 55.5 per cent and, in addition, these responses were characterised by missing data. An arbitrary criterion of an average score per question of >3 for the averaged HD and HH items respectively was applied, resulting in 72.7 per cent indicating HD, whereas 30.3 per cent indicated HH according to the items in the profile. Significant differences in hearing levels were found between those experiencing HD and HH having a score >3 and those with a score <3. When analysing the general health status, general perception of health and social functioning, significantly lower scores were found for those experiencing HD/HH, whereas no significant differences were found between the total sample of hearing-impaired subjects and the age-matched population for these parameters. It is concluded that the present procedure cannot be implemented as a routine outcome measure in a clinical setting and alternative outcome measures should be considered.
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Holven KB, Holm T, Aukrust P, Christensen B, Kjekshus J, Andreassen AK, Gullestad L, Hagve TA, Svilaas A, Ose L, Nenseter MS. Effect of folic acid treatment on endothelium-dependent vasodilation and nitric oxide-derived end products in hyperhomocysteinemic subjects. Am J Med 2001; 110:536-42. [PMID: 11343667 DOI: 10.1016/s0002-9343(01)00696-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE An elevated plasma homocysteine concentration is an independent risk factor for cardiovascular diseases. In this study, we tested the hypothesis that hyperhomocysteinemia induces endothelial dysfunction mediated, at least in part, through nitric oxide-dependent mechanisms and that folic acid supplementation improves endothelial function in hyperhomocysteinemic subjects. SUBJECTS AND METHODS Endothelial function was evaluated in healthy controls and hyperhomocysteinemic subjects by measuring plasma levels of the nitric oxide-derived end products nitrite and nitrate and by assessing vasodilatory responses in the skin microcirculation and forearm vasculature. In the subjects with hyperhomocysteinemia, these measurements were repeated after 6 weeks and 12 months of folic acid supplementation. RESULTS Compared with healthy controls, hyperhomocysteinemic subjects had significantly lower median plasma levels of nitric oxide-derived end products (12.1 microM [range 4.4 to 41.8] versus 24.6 microM [13.6 to 53.2]; P <0.001), a significantly lower endothelium-dependent vasodilatory response to acetylcholine (P <0.01), hyperemic response in the microcirculation (P <0.01), and total forearm blood flow during reactive hyperemia (P = 0.01). There was no significant difference in the endothelium-independent response. Folic acid treatment for 12 months increased the plasma level of nitric oxide-derived end products by 121% (95% confidence interval [CI], 72% to 170%), the vasodilatory response to acetylcholine by 124% (95% CI, 36% to 212%), and the ischemia-mediated hyperemic responses in the microcirculation by 60% (95% CI, 25% to 96%) and in the forearm vasculature by 47% (95% CI, 21% to 73%). CONCLUSIONS Homocysteine appears to induce its atherogenic effect, at least in part, by depressing endothelial function, possibly through nitric oxide-dependent mechanisms. This effect can be reversed by folic acid supplementation.
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Schultz LN, Schmidt P, Tabor A, Bryndorf T, Christensen B, Lundsteen C. Cryptic familial t(11;18)(q25;q23) incidentally detected by interphase FISH. Clin Genet 2001; 59:279-83. [PMID: 11298685 DOI: 10.1034/j.1399-0004.2001.590411.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
During a prospective prenatal study of numerical abnormalities of chromosomes 13, 18, 21, X and Y using locus-specific probes, we incidentally found a case with only one signal for chromosome 18 per cell in a chorionic villus sampling (CVS) associated with an otherwise apparently normal G-banded karyotype. This led us to discover a cryptic t(11;18) segregating in a four-generation family. The CVS was performed because of mental retardation in the brother to the father of the fetus. A subtelomeric chromosome 18 probe revealed one signal on 18qter and one on 11qter of the father. Thus the father had a balanced reciprocal t(11;18) in spite of the apparently normal G-banded karyotype. Using the same probes, we found an unbalanced translocation 46,XX,-18,+der (18)t(11;18)-(q25;q23)pat in the fetus. Further investigation of the family showed the translocation in balanced and unbalanced form in four generations in mentally normal and retarded individuals, respectively. The study emphasizes the need for a follow-up with molecular cytogenetic techniques in dysmorphic and retarded children.
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Christensen B. Use of antibiotics to treat bacteriuria of pregnancy in the Nordic countries. Which antibiotics are appropriate to treat bacteriuria of pregnancy? Int J Antimicrob Agents 2001; 17:283-5. [PMID: 11295409 DOI: 10.1016/s0924-8579(00)00349-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bacteriuria in pregnancy with or without clinical symptoms is frequent and increases the risk of pyelonephritis, preterm labour, and low birth weight infants. Commonly used antibiotics such as ampicillin (pivampicillin), amoxicillin, trimethoprim, and sulphonamide are currently associated with a high degree of resistance of the most common pathogen in the urinary tract, Escherichia coli. During the past few decades a number of new and efficient antibacterial antibiotics have been developed. The presumption that a specific drug is safe for both the pregnant woman and the foetus depends on how widely the drug has been used. A recent survey among general practitioners and obstetricians in Denmark, Finland, Norway, and Sweden confirmed that the beta-lactam antibiotic pivmecillinam and nitrofurantoin are the most commonly used agents in the treatment of bacteriuria in pregnancy in the Nordic countries. However, a surprisingly high number of physicians reported that they prescribe sulphonamides during the first two trimesters in spite of resistance of E. coli and possible adverse effects on the foetus.
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Katzman DK, Christensen B, Young AR, Zipursky RB. Starving the brain: structural abnormalities and cognitive impairment in adolescents with anorexia nervosa. SEMINARS IN CLINICAL NEUROPSYCHIATRY 2001; 6:146-52. [PMID: 11296314 DOI: 10.1053/scnp.2001.22263] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Anorexia nervosa (AN) is one of the most common chronic illnesses afflicting adolescent girls and is associated severe medical complications. The structural abnormalities found in the brain of adolescents with AN are among the earliest and most striking physical consequences. In the past, it had been assumed that the brain abnormalities found in patients with AN reverse with weight-recovery. Recent evidence has shown that not all of these changes are completely reversible with weight recovery. To date, very little is known about the functional significance of these brain abnormalities. Several studies have shown that cognitive dysfunction is also a common feature of AN. Although current evidence suggests that there may be some degree of improvement in cognition with weight-recovery, it is unclear whether cognition recovers fully or equally across all neuropsychological domains. Furthermore, it remains unknown whether the reported functional consequences are associated with these structural brain changes. This article will review the current literature on structural brain abnormalities and cognitive dysfunction in adolescents with AN.
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Høgh AM, Hviid TV, Christensen B, Sørensen S, Larsen RD, Smidt-Jensen S, Bang J, Philip J. zeta-, epsilon-, and gamma-Globin mRNA in blood samples and CD71(+) cell fractions from fetuses and from pregnant and nonpregnant women, with special attention to identification of fetal erythroblasts. Clin Chem 2001; 47:645-53. [PMID: 11274013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
BACKGROUND Information about the appearance of gamma-, epsilon-, and zeta-globin mRNAs in fetal erythroblasts during gestation and about the presence and amounts of these mRNAs in pregnant and nonpregnant women is important from the perspective of using these molecules as a marker of fetal erythroblasts. A specific marker is necessary for isolation and identification of fetal nucleated red blood cells from maternal blood samples for use in antenatal diagnosis of fetal genetic or chromosomal abnormalities. METHODS We used a very sensitive reverse transcription-PCR (RT-PCR) method, coamplification analysis of gamma- and epsilon-globin cDNA, and quantitative analysis of gamma-globin mRNA based on competitive RT-PCR to investigate these aspects. RESULTS All adult whole-blood samples were negative for epsilon- and zeta-globin mRNA. Analyses of CD71(+) cell fractions showed that specimens from 19 of 20 nonpregnant and 10 of 14 pregnant women (at 9-13 weeks of gestation) were positive for gamma-globin mRNA (Fisher's exact test, P = 0.13), and those from 3 of 20 nonpregnant and 5 of 14 pregnant women were positive for zeta-globin mRNA (Fisher's exact test, P = 0.23). No epsilon-globin mRNA was detected in CD71(+) cell fractions from 1-mL blood samples from adults. CD71(+) cell fractions from eight fetal blood samples (at 17-20 weeks of gestation) were positive for all three globin mRNAs. We found no statistically significant difference between the amounts of gamma-globin mRNA in pregnant and nonpregnant women. CONCLUSIONS This study indicates that epsilon-globin mRNA might function as a marker for fetal CD71(+) cells early in pregnancy. Although gamma-globin mRNA can be detected in CD71(+) cell fractions from most adults, these transcripts also may be of use because of a marked difference between adult and fetal values.
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Gombert AK, Moreira dos Santos M, Christensen B, Nielsen J. Network identification and flux quantification in the central metabolism of Saccharomyces cerevisiae under different conditions of glucose repression. J Bacteriol 2001; 183:1441-51. [PMID: 11157958 PMCID: PMC95019 DOI: 10.1128/jb.183.4.1441-1451.2001] [Citation(s) in RCA: 277] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2000] [Accepted: 11/23/2000] [Indexed: 11/20/2022] Open
Abstract
The network structure and the metabolic fluxes in central carbon metabolism were characterized in aerobically grown cells of Saccharomyces cerevisiae. The cells were grown under both high and low glucose concentrations, i.e., either in a chemostat at steady state with a specific growth rate of 0.1 h(-1) or in a batch culture with a specific growth rate of 0.37 h(-1). Experiments were carried out using [1-(13)C]glucose as the limiting substrate, and the resulting summed fractional labelings of intracellular metabolites were measured by gas chromatography coupled to mass spectrometry. The data were used as inputs to a flux estimation routine that involved appropriate mathematical modelling of the central carbon metabolism of S. cerevisiae. The results showed that the analysis is very robust, and it was possible to quantify the fluxes in the central carbon metabolism under both growth conditions. In the batch culture, 16.2 of every 100 molecules of glucose consumed by the cells entered the pentose-phosphate pathway, whereas the same relative flux was 44.2 per 100 molecules in the chemostat. The tricarboxylic acid cycle does not operate as a cycle in batch-growing cells, in contrast to the chemostat condition. Quantitative evidence was also found for threonine aldolase and malic enzyme activities, in accordance with published data. Disruption of the MIG1 gene did not cause changes in the metabolic network structure or in the flux pattern.
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