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.

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.

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.

Task-dependent oscillations during unimanual and bimanual movements in the human primary motor cortex and SMA studied with magnetoencephalography.

The neural mechanisms subserving uni- and bimanual control of movements are not well understood. Nevertheless, recent studies indicate a functional role of oscillatory activity in movement control and point towards a hemispheric asymmetry in motor control. This study specifically addresses the issues of (i) task-relatedness, (ii) hemispheric symmetry, and (iii) frequency specificity of the measures power, cerebro-muscular coherence, and cerebro-cerebral coherence in bilateral primary motor cortex and supplementary motor area (SMA). We have studied 10 right-handed subjects with simultaneous recordings of magnetoencephalography and surface electromyography during different unimanual and bimanual tasks. Using the analysis technique Dynamic Imaging of Coherent Sources (DICS), left and right primary motor cortex and SMA were functionally localized. Power, cerebro-musclar coherence, and cerebro-cerebral coherence between these areas were computed for four frequency bands in each condition and subjected to ANOVA. Results show a task-specific modulation of power and coherence, and further indicate a hemispheric asymmetry in the control of unimanual and bimanual movements. In addition, different frequency bands showed different task-dependent variations. The gamma band (26-40 Hz) showed strongest modulation for cerebro-muscular coherence and was strongest for the isometric contraction conditions. In contrast, the beta band (13-24 Hz) showed the strongest variations between static and dynamic conditions, and seems to play a particular role in movement control. In summary, our results indicate a differential functional role of oscillatory activity and coupling in the motor system.

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.

The neural basis of intermittent motor control in humans.

The basic question of whether the human brain controls continuous movements intermittently is still under debate. Here we show that 6- to 9-Hz pulsatile velocity changes of slow finger movements are directly correlated to oscillatory activity in the motor cortex, which is sustained by cerebellar drive through thalamus and premotor cortex. Our findings suggest that coupling of 6- to 9-Hz oscillatory activity in the cerebello-thalamo-cortical loop represents the neural mechanism for the intermittent control of continuous movements.

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.

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 versus prednisolone versus combination therapy in the treatment of acute pseudophakic cystoid macular edema.

OBJECTIVE: To evaluate the efficacy of ketorolac tromethamine 0.5% ophthalmic solution, prednisolone acetate 1.0% ophthalmic solution, and ketorolac and prednisolone combination therapy in the treatment of acute, visually significant, cystoid macular edema (CME) occurring after cataract extraction surgery. DESIGN: Randomized, double-masked, prospective trial. PARTICIPANTS: Twenty-eight patients who had undergone cataract extraction and in whom clinical CME developed within 21 to 90 days after cataract surgery. METHODS: Patients were randomized to topical therapy with ketorolac (group K), prednisolone (group P), or ketorolac and prednisolone combination therapy (group C) four times daily. Treatment was continued until CME resolved or for 3 months, whichever occurred first. Treatment was then tapered over 3 weeks. Examinations were monthly and included Snellen visual acuity, contrast sensitivity, Amsler grid, slit-lamp examination, dilated fundus examination, and fluorescein angiography. RESULTS: Twenty-six of 28 patients completed the study. Patients were enrolled an average of 48 days after surgery. The average improvements in Snellen visual acuity were as follows: 1.6 lines in group K, 1.1 lines in group P, and 3.8 lines in group C. This reached statistical significance for all visits when group C was compared with group P, and for visits 4 and 5 when group C was compared with group K. Group C reached a mean change of two lines or more by visit 2; at no time did either group K or P reach a mean two-line improvement. At no time was a significant difference detected between group K and P with regard to visual acuity or change from baseline. A two-line or more improvement in Snellen acuity was achieved in 16 of 26 patients (61%). Analysis by group revealed four of eight patients (50%) in group P, six of nine patients (67%) in group K, and eight of nine patients (89%) in group C who had achieved a two-line or more improvement. In patients who did improve two lines or more, improvement occurred an average of 2.75 months after initiating therapy in group P, 1.43 months in group K, and 1.33 months in group C. Improvements in contrast sensitivity and leakage on fluorescein angiography tended to mirror improvements in Snellen acuity. CONCLUSIONS: Treatment of acute, visually significant pseudophakic CME with ketorolac and prednisolone combination therapy appears to offer benefits over monotherapy with either agent alone. Patients were more likely to experience recovery of two lines or more of visual acuity. Patients treated with combination therapy or ketorolac monotherapy responded more quickly than did patients treated with prednisolone alone.

Control of intraocular pressure elevations after argon laser trabeculoplasty: comparison of brimonidine 0.2% to apraclonidine 1.0%.

OBJECTIVE: To determine whether brimonidine 0.2% can control intraocular pressure (IOP) spikes as well as apraclonidine 1.0% can in those patients undergoing argon laser trabeculoplasty (ALT). DESIGN: Prospective, randomized, double-masked, clinical trial. PARTICIPANTS: A total of 56 eyes of 41 patients with open-angle glaucoma or ocular hypertension were entered in the study; 46 eyes of 41 patients were eventually used for the final analysis. INTERVENTION: Patients were randomized to receive either brimonidine 0.2% or apraclonidine 1.0% before and after 360 degrees ALT. Both patient and physician were masked as to which agent each patient received. MAIN OUTCOME MEASURES: Intraocular pressure measurements were recorded before surgery and at 1, 2, and 4 hours after surgery. The difference between the preoperative IOP (baseline) and the highest recorded postoperative IOP was recorded as the maximum IOP change. The mean of the maximum IOP change for each group was analyzed using a two-sample, one-tailed t test. RESULTS: The mean of the maximum IOP change in the brimonidine 0.2% group was -2.6+/-3.6 mmHg, and the mean for the apraclonidine 1.0% group was -2.3+/-3.7 mmHg (P = 0.8). No patient had a pressure spike greater than 10 mmHg. CONCLUSIONS: Brimonidine 0.2% appears to be as effective as apraclonidine 1.0% in preventing IOP spikes after argon laser trabeculoplasty.

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.