MR scanning, tattoo inks, and risk of thermal burn: An experimental study of iron oxide and organic pigments: Effect on temperature and magnetic behavior referenced to chemical analysis.

BACKGROUND: Tattooed persons examined with magnetic resonance imaging (MRI) can develop burning sensation suggested in the literature to be thermal burn from the procedure. MRI-induced thermal effect and magnetic behavior of known tattoo pigments were examined ex vivo. MATERIALS AND METHODS: Magnetic resonance imaging effects on 3 commonly used commercial ink stock products marketed for cosmetic tattooing was studied. A main study tested 22 formulations based on 11 pigment raw materials, for example, one line of 11 called pastes and another called dispersions. Samples were spread in petri dishes and tested with a 0.97 T neodymium solid magnet to observe visual magnetic behavior. Before MRI, the surface temperature of the ink was measured using an infrared probe. Samples were placed in a clinical 3T scanner. Two scans were performed, that is, one in the isocenter and one 30 cm away from the center. After scanning, the surface temperature was measured again. Chemical analysis of samples was performed by mass spectroscopy. RESULTS: Mean temperature increase measured in the isocenter ranged between 0.14 and 0.26°C (P < .01) and in the off-center position from -0.16 to 0.21°C (P < .01). Such low increase of temperature is clinically irrelevant. Chemical analysis showed high concentrations of iron, but also nickel and chrome were found as contaminants. High concentration of iron was not associated with any increase of temperature or any physical draw or move of ink. CONCLUSION: The study could not confirm any clinically relevant temperature increase of tattoo pigments after MRI.

Persistent neuropsychiatric impairment in HCV patients despite clearance of the virus?!

One of the most disabling symptoms of hepatitis C virus (HCV) infection is chronic fatigue. While this is accepted for HCV polymerase chain reaction (PCR)-positive patients, a relationship between HCV infection and chronic fatigue is questioned after successful virus eradication. As fatigue is a subjective criterion, we aimed to evaluate in addition mood alterations and cognitive function in HCV-exposed patients with only mild liver disease and to assess a) possible interrelationships between these factors and health-related quality of life and b) the impact of viremia and former interferon treatment. One hundred and fifty-nine anti-HCV-positive individuals without advanced liver disease answered health-related quality of life (HRQoL), fatigue and depression questionnaires and underwent a battery of attention and memory tests. Accompanying diseases which could distort the results of the study such as HIV co-infection or drug addiction were exclusion criteria. The patients were subdivided into four groups according to their viremia status and interferon treatment history. Patients' data were evaluated with respect to norms given in the respective test manuals and in addition compared to those of 33 age-matched healthy controls. Eighty-five per cent of the patients had chronic fatigue, 50-60% mild depression or anxiety, 45% memory deficits and 30% attention deficits, irrespective of their HCV viremia status or treatment history. HRQoL correlated negatively with chronic fatigue (P<.001), while cognitive deficits-especially memory function-were independent from fatigue and depression. HCV infection may cause long-standing cerebral dysfunction that significantly impairs HRQoL and may even persist after clearance of the virus.

Cerebral microglia activation in hepatitis C virus infection correlates to cognitive dysfunction.

Hepatitis C virus (HCV) infection may induce chronic fatigue and cognitive dysfunction. Virus replication was proven within the brain and HCV-positive cells were identified as microglia and astrocytes. We hypothesized that cerebral dysfunction in HCV-afflicted patients is associated with microglia activation. Microglia activation was assessed in vivo in 22 patients with chronic HCV infection compared to six healthy controls using [(11) C]-PK11195 Positron Emission Tomography (PET) combined with magnetic resonance tomography for anatomical localization. Patients were subdivided with regard to their PCR status, Fatigue Impact Scale score (FIS) and attention test sum score (ATS). A total of 12 patients (54.5%) were HCV PCR positive [of which 7 (58.3%) had an abnormal FIS and 7 (58.3%) an abnormal ATS], 10 patients (45.5%) were HCV PCR negative (5 (50%) each with an abnormal FIS or ATS). Patients without attention deficits showed a significantly higher accumulation of [(11) C]-PK11195 in the putamen (P = 0.05), caudate nucleus (P = 0.03) and thalamus (P = 0.04) compared to controls. Patients with and without fatigue did not differ significantly with regard to their specific tracer binding in positron emission tomography. Preserved cognitive function was associated with significantly increased microglia activation with predominance in the basal ganglia. This indicates a probably neuroprotective effect of microglia activation in HCV-infected patients.

Apolipoprotein E-ε4 deficiency and cognitive function in hepatitis C virus-infected patients.

Hepatitis C virus (HCV) causes not only liver damage in certain patients but can also lead to neuropsychiatric symptoms. Previous studies have shown that the type 4 allele of the gene for apolipoprotein E (APOE) is strongly protective against HCV-induced damage in liver. In this study, we have investigated the possibility that APOE genotype is involved in the action of HCV in brain. One hundred HCV-infected patients with mild liver disease underwent a neurological examination and a comprehensive psychometric testing of attention and memory function. In addition, patients completed questionnaires for the assessment of fatigue, health-related quality of life and mood disturbances. Apolipoprotein E gene genotyping was carried out on saliva using buccal swabs. The APOE-ε4 allele frequency was significantly lower in patients with an impairment of working memory, compared to those with a normal working memory test result (P = 0.003). A lower APOE-ε4 allele frequency was also observed in patients with definitely altered attention ability (P = 0.008), but here, the P-value missed the level of significance after application of the Bonferroni correction. Our data suggest that the APOE-ε4 allele is protective against attention deficit and especially against poor working memory in HCV-infected subjects with mild liver disease. Considering the role of apolipoprotein E in the life cycle of the virus, the findings shed interesting new light upon possible pathomechanisms behind the development of neuropsychiatric symptoms in hepatitis C infection.

Successful videocapsule endoscopy in patients with an abdominal cardiac pacemaker.

Pacemaker location in the abdominal wall is considered a contraindication to videocapsule endoscopy (VCE). The aim of this study was to review our experience on the use of VCE in patients with a pacemaker located in the abdominal wall. VCE was carried out with monitoring of cardiac rhythm. This was a retrospective review of VCE case studies performed at two tertiary care university medical centers (pediatric and adult). The main outcome measures were adverse events and quality of VCE images. No adverse events were experienced in any of the five patients with implanted cardiac pacemakers, including the two with abdominal pacemaker. No interference with the VCE recording was observed during the studies, although the capsule was observed to be briefly inactivated by the pacemaker in one case. The present study, though small, suggests that VCE is safe in adult and pediatric patients who are fitted with cardiac pacemakers, even when implanted in the abdominal wall. The VCE exam can be carried out successfully under close supervision. Dysfunction of the capsule appears to be more likely than problems with cardiac pacing.

Efficacy and safety of bimatoprost in patients with elevated intraocular pressure: a 30-day comparison with latanoprost.

PURPOSE: To compare the safety and efficacy of bimatoprost and latanoprost in patients with primary open-angle glaucoma or ocular hypertension. METHODS: This was a 30-day, multicenter, double-masked, randomized, clinical trial. Patients (n = 64) diagnosed with primary open-angle glaucoma or ocular hypertension were randomly assigned to receive bimatoprost 0.03%, latanoprost 0.005%, or vehicle topically in both eyes once daily, in the evening, for 29 days. The primary endpoint was the reduction in IOP from baseline on day 14 and day 29. Secondary outcome measures included eye examinations and safety parameters. RESULTS: Bimatoprost and latanoprost significantly lowered IOP from baseline (p <.001). Bimatoprost lowered IOP more than latanoprost at every timepoint measured (bimatoprost: 25-34% reduction, 5.9-8.9 mm Hg; latanoprost: 20-31% reduction, 4.4-7.9 mm Hg), although the between-group differences did not reach statistical significance. Over the 12-hour course of IOP measurements on day 29, bimatoprost provided better diurnal IOP control than latanoprost (p =.0378, area under the curve of diurnal IOP reductions, 1-way ANOVA with pairwise t-test). Both treatment regimens were safe and well tolerated, with no significant between-group differences in reports of specific adverse events. The most common side effect was conjunctival hyperemia, which was similarly apparent in the bimatoprost and latanoprost treatment groups. CONCLUSIONS: At the end of this 30-day trial, once-daily bimatoprost 0.03% provided better diurnal IOP control than latanoprost and was safe and well tolerated in patients with ocular hypertension and glaucoma.

Microtiter enzyme-linked immunosorbent assay using recombinant derived antigens versus western blot in the confirmation of presence of antibodies against the human immunodeficiency virus type 1.

A microtiter enzyme-linked immunosorbent assay using recombinant derived antigens was compared with the Western blot (Dupont) in the confirmation of the presence of antibodies against the human immunodeficiency virus type 1 (HIV-1). Of 104 sera (104 individuals) that were negative by a screening ELISA, 91 were also negative by both confirmation assays. In three sera only the microtiter assay was found to be indeterminate, and in nine other sera only Western blot. The only microtiter assay positive serum was from a male patient at risk for infection with HIV. 279 sera from 83 patients were found positive by screening. Of these, 223 sera were positive in both confirmation assays, and no serum was negative. Only one serum was indeterminate by the microtiter ELISA in contrast to 55 sera, including follow-up samples from 25 patients, most of whom had AIDS, by Western blot (Dupont criteria). However, the number of Western blot indeterminate sera decreased substantially applying less stringent criteria for interpretation. In conclusion, the microtiter ELISA performed well as a confirmation test for the presence of antibodies against HIV-1. In addition, the results demonstrate that in the microtiter assay the envelope peptide kp41 is highly discriminative in detecting anti-HIV-1 negative and anti-HIV-1 positive sera.

A comparison of the efficacy and tolerability of brimonidine and latanoprost in adults with open-angle glaucoma or ocular hypertension: a three-month, multicenter, randomized, double-masked, parallel-group trial.

BACKGROUND: Many physicians recommend either brimonidine or latanoprost as firstline therapy for chronic open-angle glaucoma or ocular hypertension. However, a search of MEDLINE indicates that there have been few head-to-head comparisons of the 2 monotherapies in a clinical setting. OBJECTIVE: This study compared the clinical efficacy and tolerability of brimonidine 0.2% twice daily with those of latanoprost 0.005% once daily as monotherapy in patients with open-angle glaucoma or ocular hypertension. METHODS: In this 3-month, multicenter, double-masked, parallel-group, 4-visit study, treatment-naive and previously treated patients with open-angle glaucoma or ocular hypertension and bilateral intraocular pressure (IOP) after washout of between 22 and 34 mm Hg were randomized to receive either brimonidine or latanoprost. Patients who had received previous treatment with either study drug were excluded from the study. The primary outcome measure was response rate, defined as the percentage of patients achieving > or = 20% reduction in IOP from baseline to month 3. Secondary outcome measures were mean IOP reduction from baseline to month 3 and clinical success, defined as the investigator's recommendation that the patient continue using the assigned study medication. RESULTS: A total of 127 patients (55 treatment naive) were enrolled, 66 in the brimonidine group and 61 in the latanoprost group. After 3 months of treatment, 80% of patients in the brimonidine group and 74% of patients in the latanoprost group had achieved > or = 20% reduction in IOP from baseline. The mean reduction in IOP from baseline at month 3 was 6.8 mm Hg with brimonidine and 6.5 mm Hg with latanoprost (27.8% vs 27.0%, respectively). Among treatment-naive patients, a significantly higher percentage of brimonidine-treated patients achieved > or = 20% decrease in IOP compared with latanoprost-treated patients (88% vs 59%, respectively; P = 0.01). In previously treated patients, a higher percentage of the latanoprost group achieved > or = 20% reduction in IOP compared with the brimonidine group (88% vs 74%, respectively); however, the difference was not statistically significant. Significantly more patients in the brimonidine group achieved clinical success at month 3 compared with patients in the latanoprost group (91% vs 74%; P = 0.01). CONCLUSIONS: At peak effect, brimonidine twice daily was as effective as latanoprost once daily in lowering IOP. In treatment-naive patients, latanoprost was associated with a significantly higher rate of nonresponse after 3 months of treatment compared with brimonidine. This suggests that brimonidine may be the more reliable choice for first-line therapy of newly diagnosed open-angle glaucoma or ocular hypertension. In previously treated patients, however, latanoprost provided greater mean IOP reduction than did brimonidine. Significantly more patients achieved clinical success with brimonidine monotherapy than with latanoprost monotherapy.

Ketorolac tromethamine 0.5% ophthalmic solution in the treatment of moderate to severe ocular inflammation after cataract surgery: a randomized, vehicle-controlled clinical trial.

PURPOSE: To investigate the efficacy and safety of ketorolac tromethamine 0.5% ophthalmic solution (Acular; Allergan, Inc, Irvine, California) in the treatment of moderate to severe anterior segment inflammation developing after unilateral cataract surgery with intraocular lens implantation. METHODS: Only patients who exhibited moderate or greater levels of cells and flare 1 day after surgery were included in this multicenter, double-masked, randomly assigned, parallel-group study. Topical ketorolac or vehicle solution (Allergan, Inc) was administered to the treated eye four times daily, starting the day after surgery and continuing for 14 days. RESULTS: Ketorolac was significantly more effective than the vehicle solution in reducing anterior chamber cells (P < or = .030) and flare (P < or = .025), conjunctival erythema (P < or = .046), ciliary flush (P < or = .006), tearing (P < or = .012), photophobia (P < or = .014), and pain (P < or = .049). Half as many patients from the ketorolac group (14/51) were discontinued from the study for lack of efficacy, compared with the vehicle group (28/51; P = .005). There was no significant difference between ketorolac and the vehicle solution in changes in visual acuity, intraocular pressure, biomicroscopic or ophthalmoscopic variables, or adverse events. CONCLUSIONS: Ketorolac tromethamine 0.5% ophthalmic solution is safe and provides substantial anti-inflammatory activity in the treatment of moderate to severe anterior segment inflammation developing after cataract surgery and intraocular lens implantation.

Putting order into the development of sensitivity to global motion.

We studied differences in the development of sensitivity to first-versus second-order global motion by comparing the motion coherence thresholds of 5-year-olds and adults tested at three speeds (1.5, 6, and 9 degrees s(-1)). We used Random Gabor Kinematograms (RGKs) formed with luminance-modulated (first-order) or contrast-modulated (second-order) concentric Gabor patterns with a sinusoidal spatial frequency of 3c deg(-1). To achieve equal visibility, modulation depth was set at 30% for first-order Gabors and at 100%, for second-order Gabors. Subjects were 24 adults and 24 5-year-olds. For both first- and second-order global motion, the motion coherence threshold of 5-year-olds was less mature for the slowest speed (1.5 degrees s(-1)) than for the two faster speeds (6 and 9 degrees s(-1)). In addition, at the slowest speed, the immaturity was greater for second-order than for first-order global motion. The findings suggest that the extrastriate mechanisms underlying the perception of global motion are different, at least in part, for first- versus second-order signals and for slower versus faster speeds. They also suggest that those separate mechanisms mature at different rates during middle childhood.

Changes in social behavior and brain catecholamines during the development of ascorbate deficiency in Guinea pigs.

Behavioral patterns of pairs of guinea pigs were recorded in 15-min observation sessions on alternate days during a 6-day baseline phase and a 21- to 25-day period following the introduction of an ascorbate-free diet. Ascorbate-deficient animals were compared to two pair-fed control groups. During the last 5 days of the experiment, marked reductions in frequency and/or cumulative duration of active behaviors (e.g. locomotion, rearing, social grooming) were observed in the ascorbate- deficient group, while duration of inactivity in proximity to the test partner increased greatly. The decline in probability of locomotion was greater at long temporal lags (> 15 sec) after locomotion of the test partner than at short lags. Evidence of behavioral changes began to appear after 9-13 days on the ascorbate-free diet. Assays of brain tissue after sacrifice on the last day of the experiment revealed significant reductions in concentrations of ascorbate and norepinephrine. Some behavioral measures were highly correlated with brain ascorbate but not with brain norepinephrine, suggesting that other transmitter systems are involved in mediating the behavioral changes. The results also suggest the value of measurement of social behavior in assessing the behavioral effects of dietary or other treatments.

Comparison of the pharmacokinetics of intravenously administered rac-baclofen and its (-)-(R)- and (+)-(S)-enantiomers in dogs.

Baclofen is a centrally acting muscle relaxant marketed as the racemate. Since only the (-)-(R)-enantiomer is pharmacologically active, the pharmacokinetics of rac-baclofen and its enantiomers were studied individually in the same group of dogs to determine if there was any stereospecificity in the drug's kinetics after a single intravenous dose. High-pressure liquid chromatography was used to determine concentrations in plasma and urine. A major difference was found in the urinary recovery of the unchanged drug. Only about 50% of the dose of the clinically used racemate appeared as unchanged drug in the urine; whereas the active (-)-(R)-isomer was for the most part renally excreted (85%). Irrespective of isomeric composition, the renal clearance was dependent upon the creatinine clearance. Differences in non-renal clearance could not be explained by stereoselective formation of the gamma-hydroxymetabolite. It is concluded that in the dog, the active enantiomer is also pharmacokinetically preferred.

Mercury excretion and intravenous ascorbic acid.

We tested the hypothesis that intravenous ascorbic acid increases urinary excretion of mercury in subjects with low mercury levels from dental amalgam, food, and other sources. From 89 adult volunteers we selected 28 subjects with the highest mercury excretions (2 to 14 micrograms/24 h). We administered intravenous infusions of 500 ml lactated Ringer's solution with and without addition of 750 mg of ascorbic acid/kg body weight, up to 60 g ascorbic acid. Average mercury excretion during the 24 h after infusion of ascorbic acid was 4.0 +/- 0.5 micrograms (mean +/- SEM), which was not significantly more than after infusion of Ringer's solution alone (3.7 +/- 0.5 micrograms). Lead excretion was similarly unaffected. If ascorbic acid administered intravenously benefits some persons with suspected adverse reactions to mercury, the benefit in subjects similar to ours appears unrelated to short-term enhanced excretion of mercury or lead.

Neuromuscular electrical stimulation prevents muscle disuse atrophy during leg immobilization in humans.

AIM: Short periods of muscle disuse, due to illness or injury, result in substantial skeletal muscle atrophy. Recently, we have shown that a single session of neuromuscular electrical stimulation (NMES) increases muscle protein synthesis rates. The aim was to investigate the capacity for daily NMES to attenuate muscle atrophy during short-term muscle disuse. METHODS: Twenty-four healthy, young (23 ± 1 year) males participated in the present study. Volunteers were subjected to 5 days of one-legged knee immobilization with (NMES; n = 12) or without (CON; n = 12) supervised NMES sessions (40-min sessions, twice daily). Two days prior to and immediately after the immobilization period, CT scans and single-leg one-repetition maximum (1RM) strength tests were performed to assess quadriceps muscle cross-sectional area (CSA) and leg muscle strength respectively. Furthermore, muscle biopsies were taken to assess muscle fibre CSA, satellite cell content and mRNA and protein expression of selected genes. RESULTS: In CON, immobilization reduced quadriceps CSA by 3.5 ± 0.5% (P < 0.0001) and muscle strength by 9 ± 2% (P < 0.05). In contrast, no significant muscle loss was detected following immobilization in NMES although strength declined by 7 ± 3% (P < 0.05). Muscle MAFbx and MuRF1 mRNA expression increased following immobilization in CON (P < 0.001 and P = 0.07 respectively), whereas levels either declined (P < 0.01) or did not change in NMES, respectively. Immobilization led to an increase in muscle myostatin mRNA expression in CON (P < 0.05), but remained unchanged in NMES. CONCLUSION: During short-term disuse, NMES represents an effective interventional strategy to prevent the loss of muscle mass, but it does not allow preservation of muscle strength. NMES during disuse may be of important clinical relevance in both health and disease.

Substantial skeletal muscle loss occurs during only 5 days of disuse.

AIM: The impact of disuse on the loss of skeletal muscle mass and strength has been well documented. Given that most studies have investigated muscle atrophy after more than 2 weeks of disuse, few data are available on the impact of shorter periods of disuse. We assessed the impact of 5 and 14 days of disuse on skeletal muscle mass, strength and associated intramuscular molecular signalling responses. METHODS: Twenty-four healthy, young (23 ± 1 year) males were subjected to either 5 (n = 12) or 14 (n = 12) days of one-legged knee immobilization using a full leg cast. Before and immediately after the immobilization period, quadriceps muscle cross-sectional area (CSA), leg lean mass and muscle strength were assessed, and biopsies were collected from the vastus lateralis. RESULTS: Quadriceps muscle CSA declined from baseline by 3.5 ± 0.5 (P < 0.0001) and 8.4 ± 2.8% (P < 0.001), leg lean mass was reduced by 1.4 ± 0.7 (P = 0.07) and 3.1 ± 0.7% (P < 0.01) and strength was decreased by 9.0 ± 2.3 (P < 0.0001) and 22.9 ± 2.6% (P < 0.001) following 5 and 14 days of immobilization respectively. Muscle myostatin mRNA expression doubled following immobilization (P < 0.05) in both groups, while the myostatin precursor isoform protein content decreased after 14 days only (P < 0.05). Muscle MAFBx mRNA expression increased from baseline by a similar magnitude following either 5 or 14 days of disuse, whereas MuRF1 mRNA expression had increased significantly only after 5 days. CONCLUSION: We conclude that even short periods of muscle disuse can cause substantial loss of skeletal muscle mass and strength and are accompanied by an early catabolic molecular signalling response.

Do centres with well-developed protocols, training and infrastructure have higher rates of thrombolysis for acute ischaemic stroke?

BACKGROUND: The introduction of intravenous thrombolysis with recombinant tissue Plasminogen Activator (rt-PA) has greatly improved the effectiveness of acute ischaemic stroke care. However, in most hospitals only 2-10% of all admitted stroke patients are treated with thrombolysis. AIM: The purpose of this study is to identify if available protocols, training and infrastructure influence the thrombolysis rate. DESIGN: Cohort study of 12 hospitals in the Netherlands. METHODS: In a cohort of patients admitted with acute stroke within 24 h from onset of symptoms, data were obtained. Stroke service characteristics of 12 hospitals were acquired through structured interviews with intra- and extramural representatives, in order to asses (i) protocols, (ii) training and (iii) complexity of infrastructure. Data were analysed with multi-level logistic regression to relate the likelihood of treatment with thrombolysis to availability and completeness of protocols, training and infrastructure both outside (extramural) and inside (intramural) each centre. RESULTS: Overall 5515 patients were included in the study. Thrombolysis rates varied from 5.7% to 21.7%. An association was observed between thrombolysis rates and extramural training [odds ratio (OR): 1.11; 95% confidence interval (CI): 0.99-1.25] and availability of intramural protocols (OR: 1.46; 95% CI: 1.12-1.91). After adjustment for hospital size and teaching vs. nonteaching hospital, these associations became stronger; extramural training [adjusted OR (aOR): 1.14; 95% CI: 1.01-1.30] and availability of intramural protocols (aOR: 1.77; 95% CI: 1.30-2.39). CONCLUSIONS: Extramural training and intramural protocols are important tools to increase thrombolysis rates for acute ischaemic stroke in hospitals. Intramural protocols and extramural training should be aimed at all relevant professionals.