Molecular imaging of neuroinflammation in patients after mild traumatic brain injury: a longitudinal 123 I-CLINDE single photon emission computed tomography study

BACKGROUND AND PURPOSE

Neuroinflammation has been proposed as part of the pathogenesis of post-concussion symptoms (PCS), but the inflammatory response of the human brain to mild traumatic brain injury (mTBI) remains unknown. We hypothesized that a neuroinflammatory response is present in mTBI at 1-2 weeks post-injury and persists in patients with PCS.

METHODS

We scanned 14 patients with mTBI without signs of structural damage at 1-2 weeks and 3-4 months post-injury and 22 healthy controls once using the single photon emission computed tomography tracer ¹²³ I-CLINDE, which visualizes translocator protein (TSPO), a protein upregulated in active immune cells. PCS was defined as three or more persisting symptoms from the Rivermead Post Concussion Symptoms Questionnaire at 3 months post-injury.

RESULTS

Across brain regions, patients had significantly higher ¹²³ I-CLINDE binding to TSPO than healthy controls, both at 1-2 weeks after the injury in all patients (P = 0.011) and at 3-4 months in the seven patients with PCS (P = 0.006) and in the six patients with good recovery (P = 0.018). When the nine brain regions were tested separately and results were corrected for multiple comparisons, no individual region differed significantly, but all estimated parameters indicated increased ¹²³ I-CLINDE binding to TSPO, ranging from 2% to 19% in all patients at 1-2 weeks, 13% to 27% in patients with PCS at 3-4 months and -9% to 17% in patients with good recovery at 3-4 months.

CONCLUSIONS

Neuroinflammation was present in mTBI at 1-2 weeks post-injury and persisted at 3-4 months post-injury with a tendency to be most pronounced in patients with PCS.

No correlation between body mass index and striatal dopamine transporter availability in healthy volunteers using SPECT and [123I]PE2I

OBJECTIVE

Dopamine plays an important role in both the rewarding and conditioning effects of food. These effects involve mesolimbic, mesocortical, and nigrostriatal pathways. In humans, the most consistent finding has been reduced striatal dopamine D2/3 receptor availability. In striatum, dopamine is inactivated by reuptake via the dopamine transporter (DAT). The aim of the study was to test the hypothesis of lower DAT availability in obese healthy subjects using a selective DAT radiotracer in a sample of subjects with a wide range of BMI values.

DESIGN AND METHODS

Thirty-three healthy subjects with a mean age of 48.4 ± 13.3 (range, 21-71) years and a mean BMI of 29.6 ± 7.8 kg/m2 (range, 21.0-49.5) were included in the study. We used [123I]PE2I and SPECT to measure DAT availability.

RESULTS

Using multiple linear regression analyses with striatal DAT as the dependent variable and BMI, age and gender as predictors was performed. We found no correlation between BMI and striatal DAT availability in striatum (P = 0.99), caudate nucleus (P = 0.61), and putamen (P = 0.30). Furthermore, we found no group difference between obese/severely obese (BMI > 30 kg/m2) and normal weight controls (BMI ≤ 25 kg/m2).

CONCLUSIONS

We did not find any correlation between BMI and DAT availability in healthy volunteers.

A case-control study of the relation between plasma selenium and asthma in European populations: a GAL2EN project

BACKGROUND

There is evidence that selenium levels are relatively low in Europe and may be falling. Low levels of selenium or low activity of some of the enzymes dependent on selenium have been associated with asthma.

METHODS

The GA(2)LEN network has organized a multicentre case-control study in Europe to assess the relation of plasma selenium to asthma. The network compared 569 cases in 14 European centres with a diagnosis of asthma and reporting asthma symptoms in the last 12 months with 576 controls from the same centres with no diagnosis of asthma and no asthmatic symptoms in the last 12 months.

RESULTS

All cases and controls were selected from the same population defined by age and place of residence. Mean plasma selenium concentrations among the controls ranged from 116.3 microg/l in Palermo to 67.7 microg/l in Vienna and 56.1 microg/l among the children in Oslo. Random effects meta-analysis of the results from the centres showed no overall association between asthma and plasma selenium [odds ratio (OR)/10 microg/l increase in plasma selenium: 1.04; 95% confidence interval (CI): 0.89-1.21] though there was a significantly protective effect in Lodz (OR: 0.48; 95% CI: 0.29-0.78) and a marginally significant adverse effect in Amsterdam (OR: 1.68; 95% CI: 0.98-2.90) and Ghent (OR: 1.35; 95% CI: 1.03-1.77).

CONCLUSION

This study does not support a role for selenium in protection against asthma, but effect modification and confounding cannot be ruled out.

The relation between paracetamol use and asthma: a GA2LEN European case-control study

Studies from the UK and USA suggest that frequent use of paracetamol (acetaminophen) may increase the risk of asthma, but data across Europe are lacking. As part of a multicentric case-control study organised by the Global Allergy and Asthma European Network (GA(2)LEN), it was examined whether or not frequent paracetamol use is associated with adult asthma across Europe. The network compared 521 cases with a diagnosis of asthma and reporting of asthma symptoms within the last 12 months with 507 controls with no diagnosis of asthma and no asthmatic symptoms within the last 12 months across 12 European centres. All cases and controls were selected from the same population, defined by age (20-45 yrs) and place of residence. In a random effects meta-analysis, weekly use of paracetamol, compared with less frequent use, was strongly positively associated with asthma after controlling for confounders. There was no evidence for heterogeneity across centres. No association was seen between use of other analgesics and asthma. These data add to the increasing and consistent epidemiological evidence implicating frequent paracetamol use in asthma in diverse populations.

The relation between paracetamol use and asthma: a GA2LEN European case-control study

Studies from the UK and USA suggest that frequent use of paracetamol (acetaminophen) may increase the risk of asthma, but data across Europe are lacking. As part of a multicentric case-control study organised by the Global Allergy and Asthma European Network (GA(2)LEN), it was examined whether or not frequent paracetamol use is associated with adult asthma across Europe. The network compared 521 cases with a diagnosis of asthma and reporting of asthma symptoms within the last 12 months with 507 controls with no diagnosis of asthma and no asthmatic symptoms within the last 12 months across 12 European centres. All cases and controls were selected from the same population, defined by age (20-45 yrs) and place of residence. In a random effects meta-analysis, weekly use of paracetamol, compared with less frequent use, was strongly positively associated with asthma after controlling for confounders. There was no evidence for heterogeneity across centres. No association was seen between use of other analgesics and asthma. These data add to the increasing and consistent epidemiological evidence implicating frequent paracetamol use in asthma in diverse populations.

Can long-term antibiotic treatment prevent progression of peripheral arterial occlusive disease? A large, randomized, double-blinded, placebo-controlled trial

PURPOSE

The purpose was to investigate in a large, randomized, double-blinded, placebo-controlled trial, whether antibiotic treatment can prevent progression of peripheral arterial disease (PAD).

MATERIAL AND METHODS

Five hundred and seven patients were included; all patients had an established diagnosis of PAD. Their mean age was 66 years (36-85), and 59% were males. Patients were randomized to Roxithromycin 300 mg daily for 28 days. Baseline investigations were ankle blood pressure, ankle-brachial blood pressure index (ABPI), walking distance, C. pneumoniae serology, cholesterol and medical history. Follow-up was performed every 6 months. Primary events were defined as death, peripheral revascularization and major lower limb amputation. Secondary events were thrombosis, stroke, transient cerebral ischaemic attack and myocardial infarction. Change in ABPI was also investigated. Data were analyzed mainly by Cox regression and linear regression.

RESULTS

Included patients with PAD were randomized. Two patients withdrew. Of the remaining, 248 received roxithromycin and 257 placebo. In the treatment group 55% were seropositive and 53% in the placebo group. Mean follow-up was 2.1 years (range 0.06-5.1 years). In the placebo group, 26 died and 80 primary events occurred in total. In the treatment group, 28 died and 74 primary events were observed. The hazard ratio of death was 1.13 (95% CI: 0.68; 1.90), and of primary events 0.92 (95% CI: 0.67; 1.26). Also on secondary events and ABPI changes, no significant differences were found.

CONCLUSION

Long-term treatment with roxithromycin is ineffective in preventing death, amputation, peripheral revascularization, myocardial infarction, stroke, transient cerebral ischaemic attack, thrombosis and decline in ABPI in patients with an established diagnosis of PAD.

Imaging of dopamine transporters and D2 receptors in patients with Parkinson's disease and multiple system atrophy

PURPOSE

The aim of this study was to ascertain whether combined presynaptic and postsynaptic dopaminergic single-photon emission computed tomography (SPECT) scanning is useful for differentiation between patients with idiopathic Parkinson's disease (IPD), patients with multiple system atrophy of the striatonigral type (MSA) and healthy subjects.

METHODS

SPECT measurements of the dopamine transporter (DAT) were done with 123I-beta-CIT, while for determination of the dopamine D2-like receptors (D2), 123I-epidepride was used. Clinical evaluation and SPECT scans were carried out in 14 patients with IPD, eight patients with MSA and 11 healthy age-matched control subjects.

RESULTS

Putaminal DAT binding was reduced to 32% of control values in IPD and to 19% of control values in MSA . Significantly higher striatal asymmetry in DAT binding was found in MSA than in controls, but IPD patients had significantly higher asymmetry than MSA patients. Striatal D2 binding did not differ significantly between patients and healthy controls but the ratio between caudate DAT and D2 binding was significantly higher in patients with IPD than in those with MSA, even when disease severity was taken into account.

CONCLUSION

Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference greater than 15% are likely to suffer from IPD. Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference of between 5% and 15% are more likely to have MSA. 123I-epidepride SPECT measurements may add further diagnostic information, since the ratio between DAT and D2 receptor binding is significantly higher in IPD than in MSA.

Prognosis of shoulder tendonitis in repetitive work: a follow up study in a cohort of Danish industrial and service workers

BACKGROUND

The physical and psychosocial work environment is expected to modify recovery from shoulder disorders, but knowledge is limited.

METHODS

In a follow up study of musculoskeletal disorders in industrial and service workers, 113 employees were identified with a history of shoulder pain combined with clinical signs of shoulder tendonitis. The workers had yearly re-examinations up to three times. Quantitative estimates of duration, repetitiveness, and forcefulness of current tasks were obtained from video recordings. Perception of job demands, decision latitude, and social support was recorded by a job content questionnaire. Recovery of shoulder tendonitis was analysed by Kaplan-Meier survival technique and by logistic regression on exposure variables and individual characteristics in models, allowing for time varying exposures.

RESULTS

Some 50% of workers recovered within 10 months (95% CI 6 to 14 months). Higher age was strongly related to slow recovery, while physical job exposures were not. Perception of demands, control, and social support at the time when the shoulder disorder was diagnosed, were associated with delayed recovery, but these psychosocial factors did not predict slow recovery in incident cases identified during follow up.

CONCLUSION

The median duration of shoulder tendonitis in a cross sectional sample of industrial and service workers was in the order of 10 months. This estimate is most likely biased towards too high a value. Recovery was strongly reduced in higher age. Physical workplace exposures and perceived psychosocial job characteristics during the period preceding diagnosis seem not to be important prognostic factors.

Cerebral blood flow, oxidative metabolism and cerebrovascular carbon dioxide reactivity in patients with acute bacterial meningitis

BACKGROUND

The optimal arterial carbon dioxide tension (P(a)CO(2)) in patients with acute bacterial meningitis (ABM) is unknown and controversial. The objective of this study was to measure global cerebral blood flow (CBF), cerebrovascular CO(2) reactivity (CO(2)R), and cerebral metabolic rates (CMR) of oxygen (O(2)), glucose (glu), and lactate (lac), in patients with ABM and compare the results to those obtained in healthy volunteers.

METHODS

We studied 19 patients (17 of whom were sedated) with ABM and eight healthy volunteers (controls). CBF was measured during baseline ventilation and hyperventilation with single-photon emission computed tomography (SPECT) (14 patients) and/or the Kety-Schmidt technique (KS) (11 patients and all controls). In KS studies, CMR was measured by multiplying the arterial to jugular venous concentration difference (a-v D) by CBF.

RESULTS

CBF did not differ significantly among groups, although a larger variation was seen in patients than in controls. CO(2)R was not significantly different among groups. At baseline, patients had significantly lower a-v DO(2), CMR(O(2)), CMR(glu), and CMR(lac) than controls. CMR(O(2)) did not change between hyperventilation compared to baseline ventilation, whereas CMR(glu) increased.

CONCLUSION

In patients with acute bacterial meningitis, we found variable levels of CBF and cerebrovascular CO(2) reactivity, a low a-v DO(2), low cerebral metabolic rates of oxygen and glucose, and a cerebral lactate efflux. In these patients, a ventilation strategy guided by jugular bulb oximetry and/or repeated CBF measurements may be more optimal in terms of cerebral oxygenation than a strategy aiming at identical levels of P(a)CO(2) for all patients.

Cerebral blood flow in patients with chronic heart failure before and after heart transplantation

BACKGROUND AND PURPOSE

Arterial blood pressure and cardiac output are often reduced in patients with chronic heart failure (CHF). Counterregulatory mechanisms with increased neurohormonal activation and changes in the distribution of cardiac output are assumed to secure vital organ perfusion. However, clinical examination of patients with CHF frequently reveals neurological symptoms with dizziness and memory problems, suggesting altered brain perfusion. In this study we determined whether cerebral blood flow (CBF) is reduced in patients with New York Heart Association (NYHA) functional class III and IV (n=12) compared with healthy control subjects (n=12). Furthermore, we examined whether heart transplantation (n=5) could restore CBF.

METHODS

CBF was estimated by single-photon emission computed tomography and (133)Xe as tracer, and middle cerebral artery velocity was measured by transcranial Doppler ultrasound.

RESULTS

In the CHF patients, CBF was 36+/-1 mL/min per 100 g, corresponding to a 31% reduction compared with the control group (52+/-5 mL/min per 100 g) (P<0.05). After heart transplantation, CBF increased from 35+/-3 mL/min per 100 g before transplantation to 50+/-3 mL/min per 100 g within the first postoperative month (P<0.05).

CONCLUSIONS

We conclude that CBF is substantially, but reversibly, reduced in patients with NYHA class III/IV heart failure. This phenomenon suggests that redistribution of cardiac output inadequately secures brain perfusion in patients with severe CHF.

Transport of DNA into the nuclei of xenopus oocytes by a modified VirE2 protein of Agrobacterium

We used Agrobacterium T-DNA nuclear transport to examine the specificity of nuclear targeting between plants and animals and the nuclear import of DNA by a specialized transport protein. Two karyophilic Agrobacterium virulence (Vir) proteins, VirD2 and VirE2, which presumably associate with the transported T-DNA and function in many plant species, were microinjected into Drosophila embryos and Xenopus oocytes. In both animal systems, VirD2 localized to the cell nuclei and VirE2 remained exclusively cytoplasmic, suggesting that VirE2 nuclear localization signals may be plant specific. Repositioning one amino acid residue within VirE2 nuclear localization signals enabled them to function in animal cells. The modified VirE2 protein bound DNA and actively transported it into the nuclei of Xenopus oocytes. These observations suggest a functional difference in nuclear import between animals and plants and show that DNA can be transported into the cell nucleus via a protein-specific pathway.

VentPlan: a ventilator-management advisor

VentPlan assists physicians, nurses, and respiratory therapists in the management of artificial respiration for critically ill patients in the intensive-care unit (ICU). VentPlan interprets clinical observations, monitored data, and arterial-blood-gas analyses to make recommendations for setting the ventilator. The VentPlan interface allows users to examine the physiologic model, to inspect details of the data on which the model is based, and to exercise the model to try out different ventilator settings before they implement a new setting. We also report here a preliminary evaluation of VentPlan's ability to predict the arterial oxygen and carbon-dioxide tensions following adjustments to the ventilator. We conclude that VentPlan's physiologic models are acceptably accurate for predicting the effects of small adjustments of the ventilator.

Activins are expressed early in Xenopus embryogenesis and can induce axial mesoderm and anterior structures

We show that mammalian and Xenopus activins induce dorsal axial mesoderm and anterior structures in explants of Xenopus blastula cells that would otherwise form epidermis. The induced explants of animal cap cells can form notochord, muscle, neural tissue, and eyes all arranged in a rudimentary axial pattern. Activin A shares inductive properties and antigenic determinants with PIF, an inducing factor recently isolated from mouse macrophage culture supernatants. Genes encoding Xenopus activin beta A and beta B chains were cloned. Activin beta B transcripts are first detected in Xenopus blastula, whereas activin beta A transcripts do not appear until the late gastrula stage. Recombinant Xenopus activin beta B protein induces mesodermal and neural tissues similar to those induced by mammalian activin A and PIF. Furthermore, ectopic expression of Xenopus activin beta B produces a second body axis in embryos injected with synthetic mRNA. Our results suggest that early induction and axial patterning are accomplished by endogenous activin B, not activin A, in Xenopus.

Activin can induce the formation of axial structures and is expressed in the hypoblast of the chick

We show that PIF/activin can induce the formation of axial structures including a full-length notochord, segmented somites, and a neural tube in isolated epiblasts from chick blastulae. Using degenerate PCR primers, we have cloned a fragment of the activin beta B chain from chick hypoblast cDNA, and a fragment of the activin beta A chain from chick genomic DNA. Furthermore, we show that in the chick, activin is transcribed precisely when axial mesoderm is being induced. Since exogenous PIF/activin can induce the formation of axial structures and since activin beta B is transcribed at the time and place where the mesodermal axial structures are being induced, we propose that in the chick, activin B is the endogenous inducer of the body axis.

Reversibility of skeletal fluorosis

At two x ray examinations in 1957 and 1967, 17 cases of skeletal fluorosis were identified among long term cryolite workers in Copenhagen. In 1982 four of these patients were alive, eight to 15 years after exposure had ended. Radiographs were obtained, and the urinary fluoride excretion was measured. A similar picture emerged in all four cases: extensive fading of the sclerosis of trabecular bone in ribs, vertebral bodies, and pelvis, whereas cortical bone thickening and calcification of muscle insertions and ligaments remained virtually unchanged. The fluoride excretion was increased in three cases (with the shortest exposure free period). These findings indicate that with continuous remodelling of bone tissue trabecular sclerosis is slowly reversible and the excess fluoride is excreted in the urine.