bluuebunny/crossref_metadata_2025 huggingface dataset:
Antidepressant Treatment and Dehydroepiandrosterone Sulfate: Different Effects of Amitriptyline and Paroxetine
Authors: Deuschle Michael , Luppa Peter , Gilles Maria , Hamann Bettina , Heuser Isabella
Published: September 2004

Background: There is evidence for activation of the hypothalamus-pituitary-adrenal system in depressed patients to be associated with increased secretion of adrenal androgens. However, there is only limited information about the effect of different classes of antidepressants on the course of adrenal androgens. Methods: Dehydroepiandrosterone sulfate (DHEA-S) serum concentrations were measured in 80 patients being treated with amitriptyline (AMI) or paroxetine (PAROX) for a period of 35 days. Results: Using analysis of variance with repeated measures, we found a significant effect of treatment upon DHEA-S serum concentrations that declined more in AMI-treated (before vs. after: 1.89 ± 1.16 vs. 1.46 ± 0.96 mg/l), compared to PAROX-treated patients (1.56 ± 1.09 vs. 1.50 ± 1.04 mg/l). Conclusions: Our results show changes in DHEA-S serum concentrations during antidepressant treatment to depend on medication.
Propofol-Induced Alpha Rhythm
Authors: Feshchenko Vladimir A. , Veselis Robert A. , Reinsel Ruth A.
Published: September 2004

The electroencephalographic effects of two intravenous sedative/hypnotic drugs, propofol and thiopental, were studied at three stable blood concentrations in 52 normal healthy volunteers. The higher concentration resulted in unresponsiveness (lack of response to auditory/tactile stimuli) in all subjects. This report describes the strong frontal-central rhythms apparent in this state using a quantitative description of oscillatory systems underlying the rhythm. These rhythms occur when sedative drug concentrations are greater than those producing the well-described increase in broadband β-power associated with many sedative drugs. Propofol induces rhythms in the α-range, while thiopental produces rhythms in the β-range. Quasistationary for a period of about 1 h, these rhythms exceed the baseline α-rhythm in power. By their resonant nature, these propofol-induced rhythms are analogous to ‘the classic α-rhythm’, but quantitative characteristics of the underlying oscillatory systems are different. Baseline properties of the oscillatory system underlying the initial resting α-rhythm recover completely as drug concentration decays to negligible values.
Fluctuations of Source Locations of EEG Activity during Transition from Alertness to Sleep in Alzheimer’s Disease and Vascular Dementia
Authors: Tsuno N. , Shigeta M. , Hyoki K. , Faber P.L. , Lehmann D.
Published: September 2004

Vascular dementia (VaD) differs from Alzheimer’s disease (AD) in larger fluctuations of cognitive impairment, hypothetically because of deteriorated vigilance control. Vigilance levels are reflected by locations of EEG sources. Transition from alertness to sleep might be particularly sensitive to degradations of vigilance control. Twelve AD and 12 VaD patients (medication free, mean age 75.6 and 77.6 years, respectively, difference = n.s.), and 12 healthy elderly subjects (mean age 70.6 years), who served as controls, were studied (each group comprised 2 males and 10 females). A twenty-one-channel EEG was recorded from full alertness to the onset of sleep stage 2. Dipole source modeling, based on Fast Fourier Transform dipole approximation, yielded 3D source localizations in 7 EEG frequency bands. For each brain axis, means of source location differences between successive 20-second periods were calculated (fluctuation magnitude). EEG band-wise MANCOVAs (3 brain axes, 3 subject groups, covariate: age) showed differences in fluctuation magnitude between groups in the 10.5- to 12-Hz α2 frequency band (p = 0.0066). Post hoc ANCOVAs for the axes (3 subject groups, covariate: age) were significant on the superior-inferior axis: VaD patients had higher fluctuations than AD patients and controls, without significant difference between the latter two. Thus, larger source fluctuations in VaD might reflect the patients’ decreased vigilance control, accounting for their increased fluctuations of cognitive impairment.
Evaluation of Vitamin B6 Status and RDA in Young Koreans
Authors: Cho Youn-Ok , Kim Bo-Young
Published: September 2004

Aims and Methods: The vitamin B6 status of 294 healthy young Koreans (149 men, 145 women), aged 17–25 years, was estimated to establish the Korean Recommended Dietary Allowance (RDA) for vitamin B6. The dietary vitamin B6 intake was estimated based on a three-day recall method. Results: The average daily vitamin B6 intake of the subjects was 1.504 ± 0.825 mg/day (1.567 ± 0.968 mg/day for men and 1.439 ± 0.644 mg/day for women). The average ratio of vitamin B6 intake to daily protein intake was 0.019 ± 0.001 mg/g (0.015 ± 0.001 mg/g for men and 0.023 ± 0.001 mg/g for women). Foods from animal and plant sources provided 35.68 ± 16.16 and 64.18 ± 16.29% of total vitamin B6. Plasma pyridoxal 5′-phosphate (PLP) concentration of the subjects was 29.26 ± 16.84 nmol/l (30.52 ± 20.18 nmol/l for men and 28.21 ± 13.28 nmol/l for women). The vitamin B6 intake of the subjects whose PLP concentration was >30 nmol/l was 0.019 ± 0.001 mg vitamin B6/g protein intake (0.017 ± 0.001 and 0.023 ± 0.001 mg vitamin B6/g protein intake for men and women, respectively). The intake of vitamin B6 was significantly (p < 0.01–p < 0.001) positively correlated with the intake of all other nutrients. However, no significant correlation was found between PLP concentration and all nutrients examined. Conclusion: Our suggested adequate Korean RDA for vitamin B6 in young Koreans is 1.6 mg/day or 0.02 mg/g of protein intake in men and 1.5 mg/day or 0.02 mg/g of protein intake in women.
A Novel Role for Vernix caseosa as a Skin Cleanser
Authors: Moraille R. , Pickens W.L. , Visscher M.O. , Hoath S.B.
Published: September 2004

Objectives: Skin cleansing is a complex process involving endogenous and exogenous mechanisms. This study examines the role of vernix caseosa in the process of skin cleansing in the perinatal period. Methods: Vernix was evaluated as an exogenously applied skin cleanser using digitized image analysis which quantified residual carbon particles following a standardized cleansing assay. In addition, the detachment of vernix from human cadaveric skin and Gore-Tex® supports was investigated following timed exposures to a variety of commonly used commercial surfactants. Detachment was quantified spectrophotometrically as increased turbidity at 650 nm. Results: Image analysis showed that exogenous application of vernix exhibited a cleansing capability comparable or superior to standard skin cleansers. Dose-dependent increases in solution turbidity (vernix detachment) were seen following exposure of vernix-covered Gore-Tex vehicles to sodium laureth sulfate, sodium lauryl sulfate, and cocamidopropyl betaine solutions. Similar results were seen with cadaveric skin. Conclusions: These results demonstrate a role for vernix caseosa as a skin cleanser. Previous views of vernix as a soil or skin contaminant at birth need to be reevaluated.
Erythropoietin Increases Glutathione Peroxidase Enzyme Activity and Decreases Lipid Peroxidation Levels in Hypoxic-Ischemic Brain Injury in Neonatal Rats
Authors: Kumral Abdullah , Gonenc Sevil , Acikgoz Osman , Sonmez Atac , Genc Kursad , Yilmaz Osman , Gokmen Necati , Duman Nuray , Ozkan Hasan
Published: September 2004

Background: We have previously shown that erythropoietin (Epo) exerts neuroprotective effects in the Rice-Vannucci model of neonatal hypoxic-ischemic brain injury. However, the mechanisms of Epo protection in this model are still unclear. Objectives: In the present study, we studied the effects of systemically administered Epo on lipid peroxidation levels and antioxidant enzyme (superoxide dismutase and glutathione peroxidase) activities following hypoxic-ischemic brain injury in neonatal rats. Methods: Seven-day-old Wistar rat pups were subjected to left carotid artery occlusion followed by 2.5 h of hypoxic exposure. Brain lipid peroxidation levels and antioxidant enzyme activities were measured in the injured hemispheres 24 h after the hypoxic-ischemic insult. Results: Hypoxic-ischemic injury significantly increased the thiobarbituric acid-reactive substance levels in the injured hemispheres as compared to the control group. In addition, glutathione peroxidase activity was significantly elevated in Epo-treated animals compared to saline-treated animals and the control group. Conclusions: These results suggest that Epo exerts neuroprotective effects against hypoxic-ischemic brain injury at least partially via the modulation of antioxidant enzyme activity.
Direct Dialysis Quantification: Investigation of the Impact of Dialysate Preservation Techniques on Solute Assays
Authors: Kanagasundaram Nigel S. , Posch Amy , Larive A. Brett , Paganini Emil P. , van Lente Frederick
Published: September 2004

Aims: Urease-producing microorganisms may lower urea nitrogen (UN) during dialysate-side dosing. We investigated the impact of 3 proven preservatives (acetic acid, ceftazidime, thimerosal) on UN concentration, and the concentrations of creatinine (CR) and β2-microglobulin (β2M). Methods: The UN, CR and β2M concentrations were assayed in 3 separate aliquots from 20 spent dialysate samples (ceftazidime, 125 mg/l, or 1% thimerosal, 1 ml/l, vs. control). The β2M concentration was assayed in 10 further spent dialysate collections (concentrated glacial acetic acid, 5 ml/l, vs. control). Solute concentrations were compared with the concordance correlation coefficient (rc). Results: Ceftazidime and thimerosal had little effect on the concentrations of UN and CR (rc >0.97). For the β2M concentration, agreement remained good (rc >0.96) for ceftazidime and thimerosal (although the former tended to lower concentrations) but acetic acid was less optimal (rc = 0.893). Conclusions: Ceftazidime and thimerosal may be used as dialysate preservatives without affecting the UN or CR concentrations. Thimerosal is to be preferred when studying β2M. Acetic acid produces unacceptable inaccuracy when measuring β2M.
Acetate-Free Hemodialysis: A Feasibility Study on a Technical Alternative to Bicarbonate Dialysis
Authors: Duranti E.
Published: September 2004

This study aimed at evaluating the feasibility of an acetate-free hemodialysis (AFHD) technique, comparing it with acetate-free biofiltration (AFB) and bicarbonate dialysis (BD). The assessment of the parameters concerned: electrolyte kinetics (Na+, K+), acid-base balance (HCO3–, pH), dialysis efficiency (Kt/V), serum β2-microglobulin reduction ratio, nutritional status (normalized protein catabolic rate, serum albumin and total proteins, body mass index), hemopoietic status (hemoglobin, hematocrit), and some clinical parameters (systolic and diastolic blood pressures, heart rate, percent blood volume reduction measured by Hemoscan®). Nine patients participated in this study which was conducted using a Latin square randomized experimental design. The results of the last week of each month of the study (1 month for each technique) were analyzed by means of Anova for repeated measures. The different treatments were comparable with regard to the main dialysis parameters such as blood flow (320 ml/min) and weight loss rate (0.6 ± 0.1 kg/h), while dialysis length and dialysate conductivities were different, depending on the dialysis technique. Electrolyte kinetics and acid-base balance were similar during the three periods. The dialysis efficiency for small molecules (Kt/V of urea) was similar (between 1.4 and 1.6); however, AFB seemed to show a higher β2-microglobulin reduction rate (47.6 ± 4 vs. 4.3 ± 10% for AFHD and vs. 9.9 ± 5% for BD; p < 0.001). The nutritional and hemopoietic status maintained stable, and the hemodynamic parameters were comparable during all periods. The percent blood volume reduction at the end of the treatments was not statistically different (–14.9 ± 9.4% in AFB, –12.1 ± 5.1% in AFHD, and –12.2 ± 4.4% in BD), and these results could explain the similar hemodynamic behavior during the three periods. In conclusion, AFHD appears to be a safe technique which has all positive effects of AFB and the low costs of BD. In our opinion, it could be used in patients with few clinical impairments, usually treated with hemodialysis, in whom a biocompatible treatment is indicated.
Marital Dissolution Is Followed by an Increased Incidence of Stroke
Authors: Engström Gunnar , Khan Farhad Ali , Zia Elisabet , Jerntorp Ingela , Pessah-Rasmussen Hélène , Norrving Bo , Janzon Lars
Published: September 2004

Background: Many studies have reported lower mortality in married people. The relation between marital status and incidence of haemorrhagic and ischaemic stroke is unclear. It is largely unknown whether the risk of stroke is increased the first years after divorce or death of spouse. Methods: Incidence of first-ever stroke (n = 6,184) was followed over 10 years in a cohort consisting of all 40- to 89-year-old inhabitants (n = 118,134) in the city of Malmö, Sweden. Marital dissolution (i.e. divorce or death of spouse) prior to the date of stroke was compared in a nested case-control design (3,134 initially married stroke cases, 9,402 initially married controls). Results: As compared to the married groups, the incidence of stroke was increased in divorced men and women (RR = 1.23, CI: 1.10–1.39 and RR = 1.26, CI: 1.12–1.41, respectively) and widowed men and women (RR = 1.13, CI: 0.99–1.28 and RR = 1.13, CI: 1.02–1.24, respectively) after adjustments for age, country of birth and socioeconomic indicators. The risk of stroke was not increased in never married men. Marital dissolution was followed by increased risk of stroke, which was significant for men (adjusted odds ratio: 1.23, CI: 1.03–1.5) and borderline significant for women below 65 years of age (odds ratio: 1.45, CI: 0.99–2.14). Conclusion: The incidence of stroke is increased in divorced and widowed individuals. Never married men do not have an increased incidence. The risk of stroke is elevated during the first years after divorce or death of spouse.
Outcome of Survivors of Acute Stroke Who Require Prolonged Ventilatory Assistance and Tracheostomy
Authors: Rabinstein Alejandro A. , Wijdicks Eelco F.M.
Published: September 2004

Background and Purpose:Mechanical ventilation after stroke is associated with high mortality. However, little is known about survivors who require prolonged ventilatory assistance and tracheostomy. Our goal was to assess the rate of pulmonary complication, effect of early tracheostomy and prognosis of patients with stroke requiring prolonged ventilatory support. Methods: Retrospective review of 97 patients with stroke who required ventilatory assistance and tracheostomy admitted to a single teaching hospital between 1976 and 2000. Outcome was defined using the Glasgow Outcome Scale (GOS). Results: Poor outcome (GOS 1–3) occurred in 74% of patients at 1 year and it was associated with older age (p = 0.03), prior history of brain damage (p = 0.02), and neurological worsening after intubation (p < 0.01). However, long-term functional recovery (GOS 4–5) was possible and more likely after strokes involving the posterior circulation (p = 0.03). Pulmonary complications were prevalent and more frequent before tracheostomy (68 vs. 20% after tracheostomy) but did not determine functional outcome. Mean duration of mechanical ventilation was 11 ± 19 days and did not significantly differ between outcome groups. Early tracheostomy correlated with shorter ICU and hospital stays (p < 0.01 in both cases). Conclusions: Surviving patients with stroke who require prolonged ventilatory assistance and tracheostomy can have a better outcome than previously reported. Aggressive care is justified in patients who do not continue to deteriorate neurologically. Pulmonary complications are frequent but treatable. Early tracheostomy can shorten ICU and hospital stays and reduce costs.
Clinical Implication of Cerebral Artery Calcification on Brain CT
Authors: Sohn Young H. , Cheon Hwa Y. , Jeon Pyoung , Kang Suk Y.
Published: September 2004

Background and Purpose: Arterial calcification is a process of atherosclerosis, usually taking place within advanced atheromatous plaque. In the coronary arteries, calcification seen on computed tomography (CT) often indicates severe stenosis, and is noted in almost all patients with coronary symptoms. Calcification of the cerebral arteries is also frequently observed on brain CT, but its clinical significance has yet to be clarified. To evaluate the clinical significance of cerebral arterial calcification on brain CT, we investigated the angiographic and transcranial Doppler ultrasonography (TCD) findings of calcified cerebral arteries. Methods: The subjects were 57 patients with ischemic stroke, all of whom underwent brain CT, digital subtraction cerebral angiography and TCD. Stroke subtypes were defined according to TOAST classification. Two clinicians who were blinded in respect to the patients’ clinical history and to each other’s interpretation, determined the presence of cerebral arterial calcification and the degree of angiographic stenosis. Results: Cerebral artery calcification was noted in 23 patients (40%) out of a total of 46 arteries, consisting of 23 internal carotid, 15 vertebral, 5 basilar, 2 middle cerebral and 1 anterior cerebral artery. The patients with calcification were significantly older and more hypertensive than those without calcification. All the patients with calcification showed either large artery atherosclerosis or lacunar stroke. Hemodynamic alterations measured by TCD were rarely observed in calcified arteries. The severity and extent of the atherosclerotic changes were significantly greater in the patients with calcification than those without calcification. Conclusion: These results suggest that cerebral arterial calcification does not directly indicate hemodynamically significant atherosclerotic stenosis involving calcified segments, but indicates the underlying etiology of either large artery atherosclerosis or lacunar stroke, and raises the possibility of a diffuse atherosclerotic process being present in the cerebral circulation.
Experimental Strategies to Reverse Chronic Renal Disease
Authors: Zeisberg Michael , Kalluri Raghu
Published: September 2004

Progression of chronic nephropathies still represents a major challenge for clinical nephrologists. Specific therapies that prevent patients from requiring dialysis or transplantation are still not available. However, recent experimental studies have demonstrated that regression of advanced lesions in the kidney can be achieved. This review summarizes the recent therapeutic advances using experimental models that might translate into novel human therapies to prevent, or significantly delay, requirement of renal replacement therapy.
Effectiveness of Various Chemical Disinfectants versus Cleaning Combined with Heat Disinfection on Pseudomonas Biofilm in Hemodialysis Machines
Authors: Holmes C.J. , Degremont A. , Kubey W. , Straka P. , Man N.K.
Published: September 2004

The development of bacterial biofilms in the hydraulic circuit of hemodialysis machines is routinely prevented by frequent use of a variety of chemical and heat disinfection strategies. This study compared the effectiveness of several chemical disinfectants, commonly used either alone or in combination with a treatment regimen that involved cleaning plus heat disinfection using an in vitro Pseudomonas biofilm model. Effectiveness of these procedures was evaluated using total and viable biomass quantitation and polysaccharide and endotoxin determination. The chemical disinfection procedures were only partially successful in removing all biofilm components. Heat disinfection alone killed viable biofilm bacteria, but did not remove all the biomass components, including endotoxin. The combination of cleaning with citric acid followed by heat disinfection was the most effective in eliminating all biofilm components from the hydraulic circuit of the in vitro model.
Proarrhythmia with Non-Antiarrhythmics
Authors: Albrecht Carlos A.
Published: September 2004

In 1987, at the American College of Cardiology national meeting, a group of physicians from Europe and the United States agreed to use the term ‘arrhythmogenesis’ to refer to an aggravation or provocation of arrhythmias resulting from any cause and specifically to use the word ‘proarrhythmia’ when such arrhythmogenesis is from drug therapy. Proarrhythmia is thus, defined as the potential of cardiac and non-cardiac drugs to induce or exacerbate arrhythmias. It is a relatively common finding in the hospitalized and outpatient settings. It was recognized since the early 1980’s, but still was considered an extremely unusual event. In many instances, unfortunately the first manifestation of proarrhythmia is death. We have identified multiple conditions and non-cardiac medications that have been reported in association with this entity. Basic concepts of ion-channels of the heart are provided in this review, to help understanding the rational of the pathophysiology, which remains of paramount importance, as it gives insight to the diagnosis, that is mostly based on electrocardiographic findings. The careful detection of the presence of comordid diseases, makes it possible to prevent, recognize, avoid mistreatment and treat the condition. We present an overview of the cardiac cellular electrophysiology, mechanisms of cardiac arrhythmias and explain the substrates and targets of the pro-arrhythmic actions of non-cardiac drugs.
Hexarelin Modulates the Expression of Growth Hormone Secretagogue Receptor Type 1a mRNA at Hypothalamic and Pituitary Sites
Authors: Bresciani Elena , Nass Ralf , Torsello Antonio , Gaylinn Bruce , Avallone Roberta , Locatelli Vittorio , Thorner Michael O. , Müller Eugenio E.
Published: September 2004

Ghrelin and the synthetic growth hormone secretagogues (GHSs) activate a G-protein-coupled receptor (GHS-R) originally cloned from the pituitary, but which is also expressed in the hypothalamus, in other areas of the brain and in numerous peripheral tissues. Several studies have shown that growth hormone (GH)-releasing hormone (GHRH) is necessary for GHSs to exert maximal GH release in vivo. The exact mechanism of this synergism is not clear. Previous data suggest that GHSs can affect pituitary GHS-R mRNA expression; however, it is unknown whether this effect is age dependent and whether hypothalamic GHS-Rs are also affected. In this study, we tested whether (a) the synthetic GHS hexarelin regulates mRNA expression of its own receptor at the pituitary and/or hypothalamus and whether this effect is age dependent, and (b) whether short-term treatment with GHRH or, conversely, passive immunization against GHRH affects pituitary GHS-R1a mRNA expression in infant (10 days old) and young adult rats. GHS-R1a mRNA expression was measured with competitive reverse transcriptase-polymerase chain reaction. Hexarelin treatment significantly increased pituitary and hypothalamic GHS-R1a mRNA levels in normal infant rats, but not in normal young adult rats. In addition, hexarelin administration also stimulated pituitary GHS-R1a mRNA in infant as well as in young adult rats passively immunized against GHRH. GHRH treatment significantly enhanced pituitary GHS-R1a mRNA expression in GHRH-deprived young adult rats, though it did not affect the basal levels of GHS-R1a mRNA in normal infant and adult rats. These data further support the hypothesis that GHRH can affect GHS-R1a expression and that hexarelin upregulates the expression of its own receptor at the pituitary as well as the hypothalamus in an age-dependent fashion.
Female Age in ART: When to Stop?
Authors: Broekmans F.J. , Klinkert E.R.
Published: September 2004

With increasing age the probability of ongoing pregnancy established by the use of assisted reproduction technology (ART) decreases. As a result the question arises whether age limits for the application of ART should be established. From a literature review and ongoing research data it appears that the costs per child born greatly increase after the age of 40 for both intrauterine insemination with mild ovarian stimulation and in vitro fertilisation treatment, while in cases of 44 and over, prognosis is flat zero. The willingness to pay for extra costs will greatly determine whether and at what age strict limits should be applied. Fortunately, predictive factors for success, like the antral follicle count, may enable the identification of women over 40 and under 44 that still have favourable prospects, thereby decreasing the necessary costs per childbirth and allowing couples into ART programs that are often denied based solely on female age.
Fungal Infection but Not Type of Bacterial Infection Is Associated with a High Mortality in Primary and Secondary Infected Pancreatic Necrosis
Authors: Connor S. , Alexakis N. , Neal T. , Raraty M. , Ghaneh P. , Evans J. , Hughes M. , Rowlands P. , Garvey C.J. , Sutton R. , Neoptolemos J.P.
Published: September 2004

Introduction: Knowledge of microbiology in the prognosis of patients with necrotizing pancreatitis is incomplete. Aim: This study compared outcomes based on primary and secondary infection after surgery for pancreatic necrosis. Method: From a limited prospective database of pancreatic necrosectomy, a retrospective case note review was performed (October 1996 to April 2003). Results: 55 of 73 patients had infected pancreatic necrosis at the first necrosectomy. 25 of 47 patients had resistant bacteria to prophylactic antibiotics (n = 21) or did not receive prophylactic antibiotics (n = 4), but this was not associated with a higher mortality (9 of 25) compared to those with sensitive organisms (4 of 22). Patients with fungal infection (n = 6) had a higher initial median (95% CI) APACHE II score compared to those without (11 (9–13) verus 8.5 (7–10), p = 0.027). Five of six patients with fungal infection died compared to 13 of 47 who did not (p = 0.014). With the inclusion of secondary infections 21 (32%) of 66 patients had fungal infection with 10 (48%) deaths compared to 11 (24%) of 45 patients without fungal infection (p = 0.047). Conclusion: Whether associated with primary or secondary infected pancreatic necrosis, fungal but not bacterial infection was associated with a high mortality.
Laparoscopy and Laparoscopic Ultrasound in the Evaluation of Pancreatic and Periampullary Tumours
Authors: Doran H.E. , Bosonnet L. , Connor S. , Jones L. , Garvey C. , Hughes M. , Campbell F. , Hartley M. , Ghaneh P. , Neoptolemos J.P. , Sutton R.
Published: September 2004

Background and Aims: The pre-operative determination of resectability of pancreatic and peri-ampullary neoplasia assists the selection of patients for surgical or non-surgical treatment. This study investigated whether the addition of laparoscopy with laparoscopic ultrasound to dual-phase helical CT could improve the accuracy of assessment of resectability. Patients and Methods: Prospective study of 305 patients referred to a single unit for consideration of pancreatic resection who underwent dual-phase helical CT scanning ± laparoscopy with laparoscopic ultrasound. Data were collected on patient demographics, CT findings, assessment of operability, laparoscopic assessment (LA), surgical procedures and histology. Results: LA was undertaken in 239/305 patients, 190 of whom were considered CT resectable, and 49 CT unresectable. Of the 190 CT resectable patients, LA correctly identified unresectability in 28 (15%: metastases in 15; vascular encasement in 6; anaesthesia for laparoscopy found 7 unfit for major resection) and incorrectly in 2 (vascular encasement), but did not identify unresectability in 33; LA correctly confirmed resectability in the remainder (prediction improved, χ2 = 9.73, p < 0.01). Of the 49 CT unresectable patients, LA correctly identified resectability in 4, and incorrectly in 12, and correctly identified unresectability in the remaining 33. Sixty-six of the 305 patients did not undergo LA, of whom 23 underwent resection. Conclusion: When added to dual-phase helical CT, laparoscopy with laparoscopic ultrasound provides valuable information that significantly improves the selection of patients for surgical or non-surgical treatment.
Percutaneous Radiofrequency Ablation of Colorectal Hepatic Metastases – Initial Experience
Authors: White T.J. , Roy-Choudhury S.H. , Breen D.J. , Cast J. , Maraveyas A. , Smyth E.F. , Hartley J.E. , Monson J.R.T.
Published: September 2004

Background and Aim: Most patients with hepatic metastases from colorectal carcinoma are unsuitable for resection. Radiofrequency ablation (RFA) has been applied to such lesions at laparotomy. This study aimed to evaluate the less invasive approach of percutaneous RFA. Method: Patients with unresectable liver metastases identified on cross-sectional imaging were considered for percutaneous RFA either alone or in combination with systemic chemotherapy. Subjects with >6 lesions or lesions of maximum size >70 mm were excluded. Percutaneous RFA was applied under sedation and radiological guidance (CT/US). Treatment effect was determined by follow-up imaging. Actuarial survival was calculated by the Kaplan-Meier analysis. Results: Thirty patients (21 males), median age 74.5 years (range 44–85 years), underwent percutaneous RFA to 56 lesions during 54 treatment sessions. The median size of lesion was 30 mm (range 8–70 mm). Fifteen lesions were treated more than once because of recurrence or incomplete ablation. The median ablation time per lesion was 12 min (range 4.5–36 min). Eleven patients had pre-procedural chemotherapy and 15 patients received chemotherapy after treatment. There was minimal associated morbidity (5.6% of treatments). Median hospital stay per treatment was 1 day (range 1–7). Median actuarial survival from the date of first percutaneous RFA was 22 months (95% CI 12.9–31.1 months). Eleven patients were alive at the time of data collection. Conclusion: Percutaneous RFA is a safe, well-tolerated intervention for unresectable hepatic metastases which can be repeated, if required. The technique may be associated with prolonged survival in this selected group of subjects. Future studies should consider the role of percutaneous RFA either in place of or as an adjunct to palliative chemotherapy.
Oestrogen Deficiency and Growth Hormone Treatment in Childhood Are Not Associated with Hearing in Adults with Turner Syndrome
Authors: Ostberg Julia E. , Beckman Adam , Cadge Barbara , Conway Gerard S.
Published: September 2004

Background/Aims: Women with Turner syndrome (TS) have an increased prevalence of hearing loss, with conductive (CHL) and sensorineural (SNHL) components. The association between hearing loss and clinical parameters, particularly oestrogen and previous growth hormone (GH) treatment, was investigated. Methods: A cross-sectional study of pure tone audiometry tests in an adult TS population. Previous ENT history, karyotype, anthropomorphic measurements and the impact of oestrogen and childhood GH therapy were assessed. One hundred and thirty-eight women (median age 29, range 16–67 years) completed the study. Results: Normal hearing was found in 20.3% of women, CHL in 18.8%, SNHL in 57.2% and confounding factors in 3.6%. Neither CHL nor SNHL were associated with oestrogen deficiency or GH treatment independent of age. CHL but not SNHL was more common in those with a history of recurrent otitis media (p < 0.01) and monosomy 45,X (p < 0.01). Conclusions: Current regimens of oestrogen and GH therapy have no impact on adult hearing loss in TS, independent of age. The prevalence of SNHL increases with age. CHL but not SNHL is associated with ENT history and karyotype. According to present evidence, the only possible intervention to reduce hearing loss in women with TS remains assiduous treatment of ENT problems in childhood.
Rat Abdominal Aorta Stenting: A New and Reliable Small Animal Model for In-Stent Restenosis
Authors: Langeveld Bas , Roks Anton J.M. , Tio René A. , van Boven Ad J. , van der Want Johannes J.L. , Henning Rob H. , van Beusekom Heleen M.M. , van der Giessen Willem J. , Zijlstra Felix , van Gilst Wiek H.
Published: September 2004

Background: A high throughput animal model may enhance pathophysiological studies to mechanisms of in-stent restenosis (ISR). More and appropriate antibodies and transgenic and knockout strains are available in rats. Consequently, a model for ISR in the rat would be convenient for pathobiological studies. Here we present the full characteristics of a rat ISR model suitable for high throughput stent research. Methods: The abdominal aorta of rats was separated from surrounding tissue and a BeStent™ 2 or a Cypher™ sirolimus-eluting stent was locally inserted. After 1, 3, 7, 28 and 56 days, the aortas were harvested, fixed, embedded and cut. Morphometric analysis was performed and inflammation scored. Results: The neointimal area increased to a maximum after 28 days (0.55 ± 0.08 mm2). Subsequently, the neointimal area slightly decreased. The injury score and the neointimal area were linearly correlated (r = 0.85, p < 0.01). Thrombus formation was present after 1 day. Leukocyte adherence was evident after 1 day, maximal after 3 days (93 ± 21 cells/section) and decreased thereafter. The inflammation score increased after 3 days to a maximum after 7 days (1.37 ± 0.06) and declined thereafter. After 28 days the Cypher sirolimus-eluting stent decreased the stenosis in comparison to the BeStent 2 (10.2 ± 0.85 vs. 18.0 ± 2.0%, respectively, p < 0.01). Conclusions: Stent deployment in the rat abdominal aorta results in thrombus formation, inflammation and neointimal formation. Moreover, there is a linear correlation between the injury score and the neointimal area. These responses resemble ISR events as seen in other animal models. Moreover, a known anti-restenotic stent also reduces neointimal formation in this model. Rat abdominal aorta stenting is a promising animal model for ISR, it is suitable for testing commercially manufactured stents and studying the pathophysiology of ISR.
The Effect of Phonological Repetition on Cortical Magnetic Responses Evoked by Visually Presented Words
Authors: Sekiguchi Takahiro , Koyama Sachiko , Kakigi Ryusuke
Published: September 2004

Neuroimaging studies have reported that the left superior temporal cortical area is activated by visually presented words. In the present study, we recorded cortical magnetic responses evoked by visual words and examined the effect of phonological repetition (e.g., hair–hare) on left superior temporal cortical activity, using pairs of homophonic Japanese words as stimuli. Unlike English, Japanese has a large number of homophone pairs with a totally different orthography. By taking advantage of this feature of the Japanese writing system, the effect of phonological repetition can be solely examined without being confounded by the effect of orthographic similarity. Magnetic responses were recorded over the bilateral temporal sites of the brain while subjects silently read words. The words were presented one by one; a quarter of them was immediately followed by a homophonic word. Clear magnetic responses in the latency range of 300–600 msec were observed in the left hemisphere, and the responses to the homophones were smaller than those to the first presented words. In the right hemisphere, clear responses were not consistently recorded in the same latency range, and no effect of phonological repetition was observed. The sources of the responses recorded over the left hemisphere were estimated to be in the left superior temporal cortical area adjacent to the auditory cortex and the source strength as well as the magnetic responses showed a reduction by phonological repetition. This result suggests that the activity in the left superior temporal cortical area is associated with access to the phonological representation of words.
Maturation of White Matter is Associated with the Development of Cognitive Functions during Childhood
Authors: Nagy Zoltan , Westerberg Helena , Klingberg Torkel
Published: September 2004

In the human brain, myelination of axons continues until early adulthood and is thought to be important for the development of cognitive functions during childhood. We used diffusion tensor MR imaging and calculated fractional anisotropy, an indicator of myelination and axonal thickness, in children aged between 8 and 18 years. Development of working memory capacity was positively correlated with fractional anisotropy in two regions in the left frontal lobe, including a region between the superior frontal and parietal cortices.

Reading ability, on the other hand, was only correlated with fractional anisotropy in the left temporal lobe, in the same white matter region where adults with reading disability are known to have lower fractional anisotropy. Both the temporal and the frontal regions were also correlated with age. These results show that maturation of white matter is an important part of brain maturation during childhood, and that maturation of relatively restricted regions of white matter is correlated with development of specific cognitive functions.
Neural Correlates of Retrieval Orientation: Effects of Study–Test Similarity
Authors: Hornberger Michael , Morcom Alexa M. , Rugg Michael D.
Published: September 2004

ERPs elicited by correctly classified unstudied items in tests of yes/no recognition memory were used to investigate the neural correlates of retrieval cue processing. Items in Experiment 1 consisted of pictures and their corresponding names, allowing study and test material to be factorially crossed in four separate study–test cycles. The ERPs elicited by unstudied pictures and words were, in each case, more negative-going when the study material belonged to the alternative rather than the same class of items. These findings demonstrate that previously reported ERP “retrieval orientation effects” depend on differences in similarity between study and test items, and not on the form of the sought for material. In Experiments 2a and 2b, study materials were auditory words and pictures, and the test items were visual words. In both experiments, ERPs elicited by unstudied test words were more negative-going when pictures rather than auditory words were the study material. Thus, ERP retrieval orientation effects do not depend on the employment of a copy cue condition. It is proposed that the effects reflect differences in the processing necessary to maximize over lap between cue and memory representations.
Context-dependent Deactivation of the Amygdala during Pain
Authors: Petrovic Predrag , Carlsson Katrina , Petersson Karl Magnus , Hansson Per , Ingvar Martin
Published: September 2004

The amygdala has been implicated in fundamental functions for the survival of the organism, such as fear and pain. In accord with this, several studies have shown increased amygdala activity during fear conditioning and the processing of fear-relevant material in human subjects. In contrast, functional neuroimaging studies of pain have shown a decreased amygdala activity. It has previously been proposed that the observed deactivations of the amygdala in these studies indicate a cognitive strategy to adapt to a distressful but in the experimental setting unavoidable painful event. In this positron emission tomography study, we show that a simple contextual manipulation, immediately preceding a painful stimulation, that increases the anticipated duration of the painful event leads to a decrease in amygdala activity and modulates the autonomic response during the noxious stimulation. On a behavioral level, 7 of the 10 subjects reported that they used coping strategies more intensely in this context. We suggest that the altered activity in the amygdala may be part of a mechanism to attenuate pain-related stress responses in a context that is perceived as being more aversive. The study also showed an increased activity in the rostral part of anterior cingulate cortex in the same context in which the amygdala activity decreased, further supporting the idea that this part of the cingulate cortex is involved in the modulation of emotional and pain networks.
Judging Time Intervals Using a Model of Perceptuo-Motor Control
Authors: Grealy Madeleine A. , Craig Cathy M. , Bourdin Christophe , Coleman Simon G.
Published: September 2004

Estimating a time interval and temporally coordinating movements in space are fundamental skills, but the relationships between these different forms of timing, and the neural processes that they incur, are not well understood. While different theories have been proposed to account for time perception, time estimation, and the temporal patterns of coordination, there are no general mechanisms which unify these various timing skills. This study considers whether a model of perceptuo-motor timing, the τGUIDE, can also describe how certain judgements of elapsed time are made.

To evaluate this, an equation for determining interval estimates was derived from the τGUIDE model and tested in a task where participants had to throw a ball and estimate when it would hit the floor. The results showed that in accordance with the model, very accurate judgements could be made without vision (mean timing error 19.24 msec), and the model was a good predictor of skilled participants' estimate timing. It was concluded that since the τGUIDE principle provides temporal information in a generic form, it could be a unitary process that links different forms of timing.
Development of Brain Mechanisms for Processing Orthographic and Phonologic Representations
Authors: Booth James R. , Burman Douglas D. , Meyer Joel R. , Gitelman Darren R. , Parrish Todd B. , Mesulam M. Marsel
Published: September 2004

Developmental differences in the neurocognitive networks for lexical processing were examined in 15 adults and 15 children (9-to 12-year-olds) using functional magnetic resonance imaging (fMRI). The lexical tasks involved spelling and rhyming judgments in either the visual or auditory modality. These lexical tasks were compared with nonlinguistic control tasks involving judgments of line patterns or tone sequences. The first main finding was that adults showed greater activation than children during the cross-modal lexical tasks in a region proposed to be involved in mapping between orthographic and phonologic representations. The visual rhyming task, which required conversion from orthography to phonology, produced greater activation for adults in the angular gyrus. The auditory spelling task, which required the conversion from phonology to orthography, also produced greater activation for adults in the angular gyrus. The greater activation for adults suggests they may have a more elaborated posterior heteromodal system for mapping between representational systems. The second main finding was that adults showed greater activation than children during the intra-modal lexical tasks in the angular gyrus. The visual spelling and auditory rhyming did not require conversion between orthography and phonology for correct performance but the adults showed greater activation in a system implicated for this mapping. The greater activation for adults suggests that they have more interactive convergence between representational systems during lexical processing.
Brain Signatures of Syntactic and Semantic Processes during Children's Language Development
Authors: Hahne Anja , Eckstein Korinna , Friederici Angela D.
Published: September 2004

Developmental aspects of language comprehension were investigated using event-related brain potentials. Children between the ages of 6 and 13 listened to passive sentences that were correct, semantically incorrect, or syntactically incorrect, and data in each condition were compared with those of adults. For semantic violations, adults demonstrated a negativity (N400), as did children, but the latency decreased with age. For syntactic violations, adults displayed an early left anterior negativity (ELAN) and a late centro-parietal positivity (P600). A syntactic negativity and a late positivity were also present for children between 7 and 13 years, again with latency decreasing with age. Six-year-olds, in contrast, did not demonstrate an ELAN effect, but a late, reduced P600 pattern for the syntactic violation condition. In the early time window, the 6-year-olds displayed a widely distributed negativity that was larger for the correct than for the syntactically incorrect condition. These data indicate that the neurophysiological basis for semantic processes during auditory sentence comprehension does not change dramatically between early childhood and adulthood. Syntactic processes for passive sentences appear to differ between early and late childhood, at least with respect to those processes reflected in the ELAN component. As there is evidence that the ELAN reflects highly automatic structure building processes, we conclude that these processes are not yet established at age 7, but gradually develop toward adult-like processing during late childhood.
The Cerebellum and English Grammatical Morphology: Evidence from Production, Comprehension, and Grammaticality Judgments
Authors: Justus Timothy
Published: September 2004

Three neuropsychological experiments on a group of 16 cerebellar patients and 16 age-and education-matched controls investigated the effects of damage to the cerebellum on English grammatical morphology across production, comprehension, and grammaticality judgment tasks. In Experiment 1, participants described a series of pictures previously used in studies of cortical aphasic patients. The cerebellar patients did not differ significantly from the controls in the total number of words produced or in the proportion of closed-class words. They did differ to a marginally significant extent in the production of required articles. In Experiment 2, participants identified the agent in a series of aurally presented sentences in which three agency cues (subject–verb agreement, word order, and noun animacy) were manipulated. The cerebellar patients were less affected than the controls were by the manipulation of subject–verb agreement to a marginally significant extent. In Experiment 3, participants performed a grammaticality judgment task on a series of aurally presented sentences. The cerebellar patients were significantly less able to discriminate grammatical and ungrammatical sentences than the controls were, particularly when the error was of subject– verb agreement as opposed to word order. The results suggest that damage to the cerebellum can result in subtle impairments in the use of grammatical morphology, and are discussed in light of hypothesized roles for the cerebellum in language.
Neural Bases of Talker Normalization
Authors: Wong Patrick C. M. , Nusbaum Howard C. , Small Steven L.
Published: September 2004

To recognize phonemes across variation in talkers, listeners can use information about vocal characteristics, a process referred to as “talker normalization.” The present study investigates the cortical mechanisms underlying talker normalization using fMRI. Listeners recognized target words presented in either a spoken list produced by a single talker or a mix of different talkers. It was found that both conditions activate an extensive cortical network. However, recognizing words in the mixed-talker condition, relative to the blocked-talker condition, activated middle/superior temporal and superior parietal regions to a greater degree. This temporal– parietal network is possibly associated with selectively attending and processing spectral and spatial acoustic cues required in recognizing speech in a mixed-talker condition.