Imaging diagnosis--Conventional and functional magnetic resonance imaging of a brain abscess in a goat

A 2-month-old female goat was presented for depressed mental status and multifocal central neurologic signs 3 weeks after hot-iron disbudding. Conventional magnetic resonance imaging (MRI) findings included a large intra axial mass in the left frontal lobe that was T2 hyperintense and T1 hypointense centrally with a contrast-enhancing peripheral capsule and perilesional T2 hyperintensity. A restrictive pattern was present in diffusion-weighted imaging. Magnetic resonance spectroscopy demonstrated an increased amount of succinate, acetate, amino acids, lipids; minimal amounts of lactate; and decreased amounts of N-acetyl aspartate and choline. A cerebral abscess due to Trueperella pyogenes was confirmed from necropsy and tissue culture.

Reports of patients and relatives from the CogniCIS study about cognition in clinically isolated syndrome: what are our patients telling us?

OBJECTIVE

To assess the Multiple Sclerosis Neuropsychological Questionnaire (MSNQ) in patients with clinically isolated syndrome (CIS).

METHODS

130 European CIS patients and 60 relatives completed the MSNQ.

RESULTS

The mean (SD) MSNQ score for CIS patients was 15.5 (10.8) and for their informants 11.3 (9.6). Neither the CIS patient nor relative MSNQ report scores correlated with any of the cognitive test scores in the Brief Repeatable Battery of Neuropsychological Tests, but they were significantly related to psychosocial scales including depression.

CONCLUSIONS

In CIS, patient and relative MSNQ scores are influenced by psychosocial variables rather than actual objective cognitive status. Formal cognitive test assessment is recommended for CIS patients.

Experimental evaluation of the nitrite sensitivity coefficient in granular anammox biomass

Nitrite is widely reported to inhibit anammox activity and growth. One modeling approach for nitrite impairment of anammox growth is the use of a nitrite sensitivity coefficient which increases the endogenous decay coefficient of anammox bacteria proportionally to nitrite concentration. The objective of this study was to measure nitrite concentration profiles within active anammox granules incubated at fixed bulk nitrite concentrations and to compare these with nitrite concentration profiles predicted by a biofilm model that incorporates the nitrite sensitivity coefficient. We developed an apparatus for the repeated measurement of nitrite concentration profiles along the radius of granular anammox biomass over a period of 6 days at fixed bulk nitrite concentrations. Granular anammox biomass was obtained from a two-stage bench-scale partial nitritation/anammox reactor system. There was no apparent effect of nitrite concentration on nitrite utilization kinetics after 6 days at exposures up to 90 mg NO(2)(-)-N/L. These findings suggest that anammox bacteria tolerate extended exposures to elevated nitrite concentrations, and in its present form, the nitrite sensitivity coefficient is not applicable for anammox growth modeling.

Survival in MS: a randomized cohort study 21 years after the start of the pivotal IFNβ-1b trial

OBJECTIVE

To examine the effects of interferon beta (IFNβ)-1b on all-cause mortality over 21 years in the cohort of 372 patients who participated in the pivotal randomized clinical trial (RCT), retaining (in the analysis) the original randomized treatment-assignments.

METHODS

For this randomized long-term cohort study, the primary outcome, defined before data collection, was the comparison of all-cause mortality between the IFNβ-1b 250 μg and placebo groups from the time of randomization through the entire 21-year follow-up interval (intention-to-treat, log-rank test for Kaplan-Meier survival curves). All other survival outcomes were secondary.

RESULTS

After a median of 21.1 years from RCT enrollment, 98.4%(366 of 372) of patients were identified, and, of these, 81 deaths were recorded (22.1% [81 of 366]). Patients originally randomly assigned to IFNβ-1b 250 μg showed a significant reduction in all-cause mortality over the 21-year period compared with placebo (p = 0.0173), with a hazard ratio of 0.532 (95% confidence interval 0.314-0.902). The hazard rate of death at long-term follow-up by Kaplan-Meier estimates was reduced by 46.8% among IFNβ-1b 250 μg-treated patients (46.0% among IFNβ-1b 50 μg-treated patients) compared with placebo. Baseline variables did not influence the observed treatment effect.

CONCLUSIONS

There was a significant survival advantage in this cohort of patients receiving early IFNβ-1b treatment at either dose compared with placebo. Near-complete ascertainment, together with confirmatory findings from both active treatment groups, strengthens the evidence for an IFNβ-1b benefit on all-cause mortality.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that early treatment with IFNβ-1b is associated with prolonged survival in initially treatment-naive patients with relapsing-remitting multiple sclerosis.

Critical modeling parameters identified for 3D CFD modeling of rectangular final settling tanks for New York City wastewater treatment plants

New York City Environmental Protection is in the process of incorporating biological nitrogen removal (BNR) in its wastewater treatment plants (WWTPs) which entails operating the aeration tanks with higher levels of mixed liquor suspended solids (MLSS) than a conventional activated sludge process. The objective of this paper is to discuss two of the important parameters introduced in the 3D CFD model that has been developed by the City College of New York (CCNY) group: (a) the development of the 'discrete particle' measurement technique to carry out the fractionation of the solids in the final settling tank (FST) which has critical implications in the prediction of the effluent quality; and (b) the modification of the floc aggregation (K(A)) and floc break-up (K(B)) coefficients that are found in Parker's flocculation equation (Parker et al. 1970, 1971) used in the CFD model. The dependence of these parameters on the predictions of the CFD model will be illustrated with simulation results on one of the FSTs at the 26th Ward WWTP in Brooklyn, NY.

Can the functional assessment of multiple sclerosis adapt to changing needs? A psychometric validation in patients with clinically isolated syndrome and early relapsing–remitting multiple sclerosis

Background: The Functional Assessment of Multiple Sclerosis (FAMS) is widely used in clinical trial programmes; however, it was developed before the rise in trials targeted at early stage multiple sclerosis (MS) and clinically isolated syndrome (CIS).

Objective: The aim of this study was to assess the psychometric properties of the FAMS within two clinically distinct populations, CIS and early relapsing–remitting MS (RRMS), and discern the appropriateness of the FAMS within these populations.

Methods: Secondary analysis was conducted on FAMS data from two clinical trials assessing interferon beta–1b in early RRMS and CIS. The statistical analysis assessed the scale acceptability, reliability, validity and responsiveness of the FAMS. Item response theory (IRT) was also conducted on the early RRMS sample in order to assess how well the FAMS discriminated amongst individuals with less severe MS.

Results: Results from both trials demonstrated an improvement in the FAMS psychometric properties with increased baseline disease severity. However, high ceiling effects were evident amongst less severe patients, and there was an overall lack of responsiveness to improvement and poor construct validity. IRT also demonstrated its lack of discrimination/sensitivity in early RRMS.

Conclusions: In trials involving patients with early stage RRMS and CIS, modifications to the FAMS based on a qualitative assessment of its content validity in these populations would be required in order to potentially improve the FAMS psychometric properties and sensitivity.

Interferon β-1b and glatiramer acetate effects on permanent black hole evolution

OBJECTIVE

To compare interferon β-1b (IFNβ-1b) and glatiramer acetate (GA) on new lesion (NL) (gadolinium-enhancing, new T2) evolution into permanent black holes (PBH)--a marker of irreversible tissue damage--in patients with relapsing-remitting multiple sclerosis (RRMS).

METHODS

BEYOND was a large, phase III, clinical trial comparing IFNβ-1b 250 μg, IFNβ-1b 500 μg, and GA (2:2:1). Patient scans were reexamined post hoc for PBH in a rater-blinded manner. Two predefined coprimary endpoints compared IFNβ-1b 250 μg with GA: first, number of PBH per patient at year 2 evolving from year 1 NL, then proportion of year 1 NL evolving into PBH at year 2. IFNβ-1b 500 μg and GA were compared in an exploratory fashion.

RESULTS

Approximately 90% (1,957/2,244) of patients had NL at year 1 with follow-up at year 2. Mean numbers of PBH per patient at year 2 evolving from year 1 NL were lower for IFNβ-1b 250 μg than GA (0.30 vs 0.43; p = 0.0451). The proportion of NL evolving into PBH was similar (IFNβ-1b 250 μg vs GA: 21.6% vs 23.5%; p > 0.20). For IFNβ-1b 500 μg, both the mean PBH number per patient at year 2 evolving from year 1 NL (0.26 vs 0.43; p = 0.0037) and proportion of NL evolving into PBH (16.3% vs 23.5%; p = 0.0409) were lower relative to GA.

CONCLUSION

IFNβ-1b affected PBH development to a similar or better extent than GA. IFNβ-1b favorably influences an MRI outcome indicative of permanent tissue destruction in the brains of patients with multiple sclerosis.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that IFNβ-1b is associated with a reduction in MRI PBH formation and evolution compared with GA between years 1 and 2 of treatment.

Development of a flocculation sub-model for a 3-D CFD model based on rectangular settling tanks

To assess performance and evaluate alternatives to improve the efficiency of rectangular Gould II type final settling tanks (FSTs), New York City Department of Environmental Protection and City College of NY developed a 3D computer model depicting the actual structural configuration of the tanks and the current and proposed hydraulic and solids loading rates. Fluent 6.3.26™ was the base platform for the computational fluid dynamics (CFD) model, for which sub-models of the SS settling characteristics, turbulence, flocculation and rheology were incorporated. This was supplemented by field and bench scale experiments to quantify the coefficients integral to the sub-models. The 3D model developed can be used to consider different baffle arrangements, sludge withdrawal mechanisms and loading alternatives to the FSTs. Flocculation in the front half of the rectangular tank especially in the region before and after the inlet baffle is one of the vital parameters that influences the capture efficiency of SS. Flocculation could be further improved by capturing medium and small size particles by creating an additional zone with an in-tank baffle. This was one of the methods that was adopted in optimizing the performance of the tank where the CCNY 3D CFD model was used to locate the in-tank baffle position. This paper describes the development of the flocculation sub-model and the relationship of the flocculation coefficients in the known Parker equation to the initial mixed liquor suspended solids (MLSS) concentration X0. A new modified equation is proposed removing the dependency of the breakup coefficient to the initial value of X0 based on preliminary data using normal and low concentration mixed liquor suspended solids values in flocculation experiments performed.

Analysis of clinical outcomes according to original treatment groups 16 years after the pivotal IFNB-1b trial

BACKGROUND

Evidence for efficacy of disease-modifying drugs in multiple sclerosis (MS) comes from trials of short duration. We report results from a 16 y, retrospective follow-up of the pivotal interferon beta-1b (IFNB-1b) study.

METHODS

The 372 trial patients were randomly assigned to placebo (n=123), IFNB-1b 50 microg (n=125) or IFNB-1b 250 microg (n=124) subcutaneously every other day for at least 2 y. Some remained randomised for up to 5 y but, subsequently, patients received treatment according to physicians' discretion. Patients were re-contacted and asked to participate. Efficacy related measures included MRI parameters, relapse rate, the Expanded Disability Status Scale, the Multiple Sclerosis Functional Composite Measure and conversion to secondary progressive MS.

RESULTS

Of the 88.2% (328/372) of patients who were identified, 69.9% (260/372) had available case report forms. No differences in outcome between original randomisation groups could be discerned using standard disability and MRI measures. However, mortality rates among patients originally treated with IFNB-1b were lower than in the original placebo group (18.3% (20/109) for placebo versus 8.3% (9/108) for IFNB-1b 50 microg and 5.4% (6/111) for IFNB-1b 250 microg).

CONCLUSIONS

The original treatment assignment could not be shown to influence standard assessments of long-term efficacy. On-study behaviour of patients was influenced by factors that could not be controlled with the sacrifice of randomisation and blinding. Mortality was higher in patients originally assigned to placebo than those who had received IFNB-1b 50 microg or 250 microg. The dataset provides important resources to explore early predictors of long-term outcome.

Cross-sectional study assessing long-term safety of interferon-beta-1b for relapsing-remitting MS

OBJECTIVE

The 16-Year Long-Term Follow-Up (LTF) to the pivotal interferon-beta-1b (IFNbeta-1b) trial explored clinical, MRI, cognitive, and patient-reported outcomes. Here, we report the safety assessments.

METHODS

In the pivotal study, 372 patients were randomized to placebo (n = 123), IFNbeta-1b 50 microg (n = 125), or IFNbeta-1b 250 microg (n = 124) subcutaneously every other day for up to 5 years. Sixteen years later, patients were asked to participate in this cross-sectional follow-up study. No particular therapy was stipulated during follow-up. Adverse events experienced since the pivotal trial were recorded. Neutralizing antibodies (NAbs) to IFNbeta-1b were measured using the myxovirus protein A induction assay. Statistical analyses were descriptive.

RESULTS

In total, 88.2% of patients (328/372) were identified. Some centers achieved 100% ascertainment, obviating selection bias. Treatment-related adverse events (e.g., leukopenia and liver and thyroid dysfunction) reported by LTF participants were in keeping with those previously established. Based on a follow-up period that includes 2,000 patient-years of IFNbeta-1b treatment, no new adverse events were observed that were associated with long-term IFNbeta-1b exposure. By LTF, NAbs to IFNbeta-1b disappeared in the majority (76%) of NAb-positive patients. NAb status during the pivotal study appeared to have no impact on long-term clinical and MRI outcomes. There were more deaths among patients assigned to placebo in the pivotal study (20/109 [18.3%]) compared with patients who received IFNbeta-1b 50 microg (9/108 [8.3%]) or IFNbeta-1b 250 microg (6/111 [5.4%]).

CONCLUSION

The results from the 16-Year Long-Term Follow-Up study support the long-term safety of interferon-beta-1b therapy in multiple sclerosis.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that patients with relapsing-remitting MS taking IFNbeta-1b 50 microg or 250 microg subcutaneously every other day for up to 5 years, with subsequent unspecified treatment, have fewer deaths after 16 years of follow-up than similar patients on placebo for up to 5 years, with subsequent unspecified treatment (risk difference 11.5%, 95% confidence interval 4-19).

Efficacy and tolerability of a new formulation of pancrelipase delayed-release capsules in children aged 7 to 11 years with exocrine pancreatic insufficiency and cystic fibrosis: a multicenter, randomized, double-blind, placebo-controlled, two-period crossover, superiority study

BACKGROUND

Pancreatic enzyme replacement therapy (PERT) is essential for maintaining adequate nutrition in children with exocrine pancreatic insufficiency (EPI) due to cystic fibrosis (CF). The US Food and Drug Administration regulations now require all PERT products to undergo clinical efficacy and safety studies before they can be considered for marketing approval.

OBJECTIVE

This study was conducted to compare the efficacy of a new formulation of pancrelipase (pancreatin) delayed-release 12,000-lipase unit capsules with placebo in children with EPI due to CF.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled, 2-period crossover, superiority study of the new formulation of pancrelipase delayed-release 12,000-lipase unit capsules in children aged 7 to 11 years with CF and EPI. In each period, pancrelipase or identical placebo capsules were taken for 5 days. The primary outcome measure was the coefficient of fat absorption (CFA); secondary outcome measures were the coefficient of nitrogen absorption (CNA) and clinical symptoms. The latter were assessed based on patient-reported daily stool frequency, stool consistency (hard, formed/normal, soft, or watery), flatulence (none, mild, moderate, or severe), and abdominal pain (none, mild, moderate, or severe). Safety measures included vital signs, physical examinations, standard laboratory safety tests (hematology and biochemistry), and adverse events.

RESULTS

Seventeen patients were randomized to treatment and 16 completed the study; 1 patient withdrew consent during the first treatment period and was not included in the efficacy analysis. Patients' median age was 8.0 years (range, 7-11 years); 12 patients (70.6%) were male. CFA values were significantly greater for pancrelipase compared with placebo, with least squares mean (SE) values of 82.8% (2.7%) and 47.4% (2.7%), respectively (P < 0.001). The results were similar for CNA, with mean values of 80.3% (3.2%) and 45.0% (3.2%) (P < 0.001). Pancrelipase treatment had significantly greater effects on CFA and CNA in patients with a placebo CFA <50% than in those with a placebo CFA >50% (both parameters, P < 0.001 and P = 0.008, respectively). Significant improvements in stool fat, weight, and nitrogen and a significant reduction in daily stool frequency were observed with pancrelipase compared with placebo (all, P < 0.001). Symptoms of EPI were less severe and remained relatively stable during pancrelipase treatment, but worsened slightly during receipt of placebo. Treatment-emergent adverse events were reported in 5 patients (29.4%) during receipt of pancrelipase and in 9 patients (56.3%) during receipt of placebo; these were predominantly gastrointestinal events. There were no discontinuations due to treatment-emergent adverse events and no serious adverse events.

CONCLUSIONS

In this study in children with EPI due to CF, the new formulation of pancrelipase delayedrelease capsules was associated with improvements in CFA, CNA, stool properties, and EPI symptoms compared with placebo. Pancrelipase delayed-release capsules appeared to be well tolerated. ClinicalTrials.gov identifier: NCT00690820. (Clin Ther.

On-line mass spectrometry: membrane inlet sampling

Significant insights into plant photosynthesis and respiration have been achieved using membrane inlet mass spectrometry (MIMS) for the analysis of stable isotope distribution of gases. The MIMS approach is based on using a gas permeable membrane to enable the entry of gas molecules into the mass spectrometer source. This is a simple yet durable approach for the analysis of volatile gases, particularly atmospheric gases. The MIMS technique strongly lends itself to the study of reaction flux where isotopic labeling is employed to differentiate two competing processes; i.e., O(2) evolution versus O(2) uptake reactions from PSII or terminal oxidase/rubisco reactions. Such investigations have been used for in vitro studies of whole leaves and isolated cells. The MIMS approach is also able to follow rates of isotopic exchange, which is useful for obtaining chemical exchange rates. These types of measurements have been employed for oxygen ligand exchange in PSII and to discern reaction rates of the carbonic anhydrase reactions. Recent developments have also engaged MIMS for online isotopic fractionation and for the study of reactions in inorganic systems that are capable of water splitting or H(2) generation. The simplicity of the sampling approach coupled to the high sensitivity of modern instrumentation is a reason for the growing applicability of this technique for a range of problems in plant photosynthesis and respiration. This review offers some insights into the sampling approaches and and the experiments that have been conducted with MIMS.

Efficacy and safety of Creon 24,000 in subjects with exocrine pancreatic insufficiency due to cystic fibrosis

BACKGROUND

Pancreatic enzyme replacement therapy is critical for adequate nutrition in cystic fibrosis (CF) patients with exocrine pancreatic insufficiency (EPI).

METHODS

This was a double-blind, randomised, placebo-controlled, two-period crossover study assessing efficacy and safety of Creon 24,000-unit capsules in CF subjects > or =12 years with EPI. Patients were randomised to one of two 5-day sequences, Creon/placebo or placebo/Creon (target dose, 4000 lipase units/g fat). Primary outcome was the coefficient of fat absorption (CFA); secondary outcomes were coefficient of nitrogen absorption (CNA), symptoms, and safety.

RESULTS

Thirty-two subjects were randomised. Mean CFA and CNA were significantly greater with Creon than placebo (CFA, 88.6% vs. 49.6%; CNA, 85.1% vs. 49.9%; p<0.001 for both). Symptoms were improved and fewer treatment-emergent adverse events were reported with Creon than placebo. One patient discontinued for weight loss unrelated to study drug.

CONCLUSIONS

This study demonstrated Creon was effective in treating EPI due to CF and was safe and well tolerated.

Variations in care for operable breast cancer and outcomes between rural and metropolitan centers in Australia

e11517

Background: The causes of variation in breast cancer survival remain uncertain. Care provided to women with breast cancer may vary in relation to both the care setting and characteristics of the clinicians. Methods: To compare the outcomes of management of breast cancer treated in rural and metropolitan centers, a prospective audit of breast cancer in a region of Australia was undertaken. Over a nine-year observation period 2102 women with invasive breast cancer underwent potentially curative surgery. Treatments received, including systemic adjuvant therapy, were compared to contemporary guideline-based indicators. Breast cancer specific mortality was analyzed using Cox proportional hazards models. Results: Overall agreement of received treatment with the indicators was high. Women treated within rural centers were, however, much less likely to receive post operative radiotherapy after breast conserving surgery (86.4% vs. 97.0%; p<0.001). The overall recurrence rate, including distant metastases, for all women was 11.6%. Local or regional recurrence was more frequent in rural centers compared with metropolitan centers (4.1% versus 2.1%; p=0.05). Breast cancer mortality was increased in women with large tumors, high grade disease, and positive axillary lymph nodes. Non-compliance with treatment guidelines was associated with a trend towards increased breast cancer mortality (HR=1.55; p=0.056). After adjustment for these factors and patient age, undergoing surgery in rural centers was associated with increased breast cancer mortality (HR=1.84; p<0.001). Although women treated in rural centers were older, their cancer stage and tumour characteristics were similar to those of women treated in metropolitan centers. Non-cancer related mortality was elevated in women treated in rural centers compared with women travelling to a city for surgery (HR=2.08; p=0.005). Conclusions: Increased non-cancer related mortality in rural treated women suggests increased medical co-morbidity in this group, which may have influenced treatment choices and outcomes. Low rates of adjuvant radiotherapy were noted for women treated in rural centers. In addition, clinically significant differences in outcome, including breast cancer mortality, were observed.

No significant financial relationships to disclose.

Nitrogen removal process optimization in New York City WPCPS: a case study of Wards Island WPCP

The New York City Department of Environmental Protection has been engaged in a continuous process to develop a nitrogen removal program to reduce the nitrogen mass discharge from its water pollution control plants, (WPCPs), from 49,158 kg/d to 20,105 kg/d by the year 2017 as recommended by the Long Island Sound Study. As part of the process, a comprehensive research effort was undertaken involving bench, pilot and full scale studies to identify the most effective way to upgrade and optimize the existing WPCPs. Aeration tank 13 (AT-13) at the Wards Island WPCP was particularly attractive as a full-scale research facility because its aeration tank with its dedicated final settling tanks and RAS pumps could be isolated from the remaining treatment facilities. The nitrogen removal performance of AT-13, which, at the time, was operated as a "basic step feed BNR Facility", was evaluated and concurrently nitrification kinetic parameters were measured using in-situ bench scale experiments. Additional bench scale experiments provided denitrification rates using different sources of carbon and measurement of the maximum specific growth rate of nitrifying bacteria. The combined findings were then used to upgrade AT-13 to a "full" BNR facility with carbon and alkalinity addition. This paper will focus on the combined bench and full scale results that were the basis for the consequent upgrade.

Sample sizes for brain atrophy outcomes in trials for secondary progressive multiple sclerosis

BACKGROUND

Progressive brain atrophy in multiple sclerosis (MS) may reflect neuroaxonal and myelin loss and MRI measures of brain tissue loss are used as outcome measures in MS treatment trials. This study investigated sample sizes required to demonstrate reduction of brain atrophy using three outcome measures in a parallel group, placebo-controlled trial for secondary progressive MS (SPMS).

METHODS

Data were taken from a cohort of 43 patients with SPMS who had been followed up with 6-monthly T1-weighted MRI for up to 3 years within the placebo arm of a therapeutic trial. Central cerebral volumes (CCVs) were measured using a semiautomated segmentation approach, and brain volume normalized for skull size (NBV) was measured using automated segmentation (SIENAX). Change in CCV and NBV was measured by subtraction of baseline from serial CCV and SIENAX images; in addition, percentage brain volume change relative to baseline was measured directly using a registration-based method (SIENA). Sample sizes for given treatment effects and power were calculated for standard analyses using parameters estimated from the sample.

RESULTS

For a 2-year trial duration, minimum sample sizes per arm required to detect a 50% treatment effect at 80% power were 32 for SIENA, 69 for CCV, and 273 for SIENAX. Two-year minimum sample sizes were smaller than 1-year by 71% for SIENAX, 55% for CCV, and 44% for SIENA.

CONCLUSION

SIENA and central cerebral volume are feasible outcome measures for inclusion in placebo-controlled trials in secondary progressive multiple sclerosis.

Persistent T1 hypointensity as an MRI marker for treatment efficacy in multiple sclerosis

BACKGROUND

MRI is often used as primary outcome measure in phase II clinical trials in multiple sclerosis (MS). Since persistent T1 hypointense lesions are a surrogate parameter for axonal damage and demyelination, they may serve as a marker for monitoring the efficacy of neuroprotective drugs. At present, a power analysis using black hole (BH) evolution as primary outcome measure has not been performed.

OBJECTIVE

To assess the feasibility of using BH evolution on serial brain MR images as primary outcome measure in proof of concept studies in MS.

METHODS

MRI-data obtained from 169 active RRMS patients were analysed for BH evolution by determining the cumulative number of contrast enhancing lesions (CEL) evolving into a persistent black hole (PBH) after 3 months. With a parametric simulation procedure, based on a statistical distribution fitting the data, sample sizes were calculated.

RESULTS

21.2% of the total number of CELs observed during the study period evolved into a PBH. Ring enhancing lesions evolved most frequently into a PBH (59.4%), followed by lesions larger than 10 mm (57.4%) and periventricular CELs (30.6%). The simulation procedure, based on the statistical negative binomial (NB) model resulted in a sample sizes between 200 subjects and 30 subjects per arm, for treatment effects ranging from 50% to 90% reduction of the number of CELs evolving into a PBH, respectively.

CONCLUSION

To perform a MRI monitored phase II clinical trial with a feasible sample size, using the evolution of CELs into PBHs as primary outcome parameter, a potent drug is required to obtain sufficient power.

[Case report: equine arteritis virus (EAV) as the cause of abortion in alpacas?]

Here we report a case of a late abortion of a primiparous alpaca where genome fragments of the equine viral arteritis virus (EAV) could be detected in fetal tissues using reverse transcription polymerase chain reaction (RT-PCR). All five alpacas of the herd had virus neutralizing antibodies against EAV. EAV thus must be regarded as a potential agent for abortions in alpacas. Possible routes of introduction of the virus are discussed.

Sensorimotor gating and habituation of the startle response in schizophrenic patients randomly treated with amisulpride or olanzapine

BACKGROUND

Schizophrenic patients exhibit impairments in prepulse inhibition (PPI) and habituation of the acoustic startle response (ASR). Recent studies suggested that PPI deficits and habituation deficits are normalized after antipsychotic treatment. Despite clear evidence of gating and habituation mechanisms in animal models, it is still unknown which neurotransmitter systems are involved in schizophrenic patients. Thus, we compared the effects of a combined 5-HT2A/D2 and a pure D2/D3 antagonist on PPI and habituation of ASR in patients with schizophrenia.

METHODS

The ASR was measured in 37 acute schizophrenic patients who were randomized and double-blinded as to treatment with amisulpride or olanzapine. Patients were assessed during the first week and after four and eight weeks of treatment. Twenty healthy matched control subjects were examined likewise.

RESULTS

Schizophrenic patients showed a significant PPI deficit and significantly decreased startle amplitude at baseline. The gating deficit disappeared after antipsychotic treatment in both treatment groups. Amisulpride sensitized the startle amplitude, whereas startle amplitude was not changed by olanzapine. After correcting for startle amplitude, patients did not show a habituation deficit; however, amisulpride accelerated habituation, whereas olanzapine had no effect.

CONCLUSIONS

Our findings suggest that the PPI-restoring effect of antipsychotics is probably attributed to a dopamine D2 receptor blockade.

Evidence that bicarbonate is not the substrate in photosynthetic oxygen evolution

It is widely accepted that the oxygen produced by photosystem II of cyanobacteria, algae, and plants is derived from water. Earlier proposals that bicarbonate may serve as substrate or catalytic intermediate are almost forgotten, though not rigorously disproved. These latter proposals imply that CO2 is an intermediate product of oxygen production in addition to O2. In this work, we investigated this possible role of exchangeable HCO3- in oxygen evolution in two independent ways. (1) We studied a possible product inhibition of the electron transfer into the catalytic Mn4Ca complex during the oxygen-evolving reaction by greatly increasing the pressure of CO2. This was monitored by absorption transients in the near UV. We found that a 3,000-fold increase of the CO2 pressure over ambient conditions did not affect the UV transient, whereas the S(3) --> S(4) --> S(0) transition was half-inhibited by raising the O2 pressure only 10-fold over ambient, as previously established. (2) The flash-induced O2 and CO2 production by photosystem II was followed simultaneously with membrane inlet mass spectrometry under approximately 15% H2(18)O enrichment. Light flashes that revealed the known oscillatory O2 release failed to produce any oscillatory CO2 signal. Both types of results exclude that exchangeable bicarbonate is the substrate for (and CO2 an intermediate product of) oxygen evolution by photosynthesis. The possibility that a tightly bound carbonate or bicarbonate is a cofactor of photosynthetic water oxidation has remained.

Interferon beta-1b in secondary progressive MS: a combined analysis of the two trials

BACKGROUND

A European (EU) and a North American (NA) placebo-controlled study with interferon beta-1b (IFNB-1b) in secondary progressive multiple sclerosis (SPMS) showed divergent results with regard to their primary outcome of sustained Expanded Disability Status Scale (EDSS) progression, while effects were similar on relapse and MRI-related endpoints. Reasons for this discrepancy were explored in the combined dataset.

METHODS

Baseline characteristics and variability in EDSS assessments were compared. Retrospective combined analyses for time to confirmed progression were performed to assess treatment effects overall and in subgroups defined by pre-study disease activity criteria and other key baseline variables.

RESULTS

The variance of EDSS measurements was 6.5% higher in the NA-SPMS study. The EU study included patients in an earlier phase of SPMS and with more active disease both pre-study (relapses, MRI) as well as on study (EDSS, relapses, and MRI variables as assessed in the placebo groups). The pooled analysis showed an overall risk reduction by about 20% in patients treated with 8 MIU (250 mcg) IFNB-1b for EDSS progression confirmed at 6 months (p = 0.008). Risk reduction by 30% to 40% was found for patients with at least one relapse or change in EDSS by >1 in the 2 years prior to study entry. No other consistent across-studies relation of clinical and MRI variables at baseline to potential treatment response was found.

CONCLUSIONS

Although post hoc, this combined analysis of the two large studies with IFNB-1b in secondary progressive multiple sclerosis suggests that both pronounced disability progression and continuing relapse activity might help in identifying those patients in the secondary progressive phase of the disease who are more likely to benefit from treatment.

Attenuation of the prepulse inhibition of the acoustic startle response within and between sessions

Prepulse inhibition (PPI) and habituation of the acoustic startle response (ASR) are widely used biological markers in the study of psychiatric disorders and have been shown to be homologous across species. Previous studies in humans suggested that PPI is a stable and reliable measure between test sessions, but that PPI decreases within sessions. The purpose of this study was to explore the short- and long-term decrease in PPI as a potential confound in the measurement and interpretation of PPI. We investigated the progression of PPI and habituation of ASR in three test sessions spaced 4 weeks apart in a group of 20 healthy participants. Analysis revealed a significant decrease in the percent PPI within and between the test sessions. Nevertheless, PPI was reliable across three test sessions, indicating that the significant attenuation of PPI over time was a consistent phenomenon. These results suggest that PPI exhibits short- and long-term attenuation.

Soluble vascular cell adhesion molecule (VCAM) is associated with treatment effects of Interferon beta-1b in patients with Secondary Progressive Multiple Sclerosis

BACKGROUND

Subcutaneous IFNbeta-1b (Betaferon) is an established immunomodulatory treatment for relapsing remitting MS and active secondary progressive multiple sclerosis (SPMS). It modulates cytokine and adhesion molecule expression but long term in vivo effects of IFNbeta-1b on the immune system are not known in multiple sclerosis.

OBJECTIVE

To address the effects of IFNbeta-1b on serum levels for soluble adhesion molecules and cytokine receptors from MS patients.

METHODS

Serial blood samples were obtained from 40 patients of the frequent MRI subgroup (20 patients each from the placebo and the IFNbeta-1b treatment group), participating in the European multi-center clinical trial with IFNbeta-1b for secondary progressive MS, at regular intervals for up to 36 months. Soluble adhesion molecules (sVCAM, sICAM-1, sL-Selectin) as well as TNF-receptor I and II were analysed in the serum of patients by enzyme linked immunosorbent assays (ELISAs). Monthly brain MRI was performed in 34 of these patients (16 patients from the placebo and 18 from the IFNbeta-1b group) during months 1-6 and 19-24 to monitor disease activity as assessed by newly occurring gadolinium (Gd) enhancing lesions.

RESULTS

An early and significant increase in sVCAM and sTNF-RII serum levels was detected in 16 out of 20 patients (80 %) treated with subcutaneous IFNbeta-1b already at month 1 but was absent in all but one patient during placebo treatment (p < 0.01). Raised sVCAM and TNF RII serum levels during months 1-6 inversely correlated with less MRI activity in the 19-24 months treatment interval in the IFNa-1b treatment group ( p = 0.0093 for TNF-RII; p = 0.047 for VCAM).

CONCLUSIONS

sVCAM and sTNF RII levels in the serum of SPMS patients are increased during IFNbeta-1b therapy and may at least in part explain some of the treatment effects, like reduced immune cell transmigration.

Interferon beta-1b treatment does not induce autoantibodies

BACKGROUND

There is little information regarding the potential of interferon beta (IFNbeta) to induce or exacerbate autoimmune disease. Existing data from uncontrolled studies are contradictory and do not differentiate between autoimmune dysfunction, which is frequent in patients with multiple sclerosis (MS), and untoward drug effects.

OBJECTIVE

To evaluate the impact of IFNbeta on hepatic, thyroid, and other markers of autoimmunity using data from the European placebo-controlled double-blind, multicenter study of IFNbeta-1b in patients with secondary progressive MS (SPMS).

METHODS

Serum samples obtained at baseline and at 6-month intervals for 24 months were analyzed for the following autoantibodies (AAbs): antinuclear (ANA), antimitochondrial (AMA), smooth muscle (SMA), liver kidney microsome (LKM), thyroid microsome (TPO), and human thyroglobulin (TG). AAb status at baseline and during treatment was related to respective laboratory and clinical deviations.

RESULTS

The analysis of AAb data included 355 patients receiving IFNbeta-1b and 353 receiving placebo. There was no difference between treatment groups in de novo AAb positivity. A greater proportion of women were AAb positive at baseline and during treatment. No association was found between liver enzyme elevations and ANA, AMA, or SMA antibody formation in either treatment group. Laboratory-based thyroid alterations during the study were significantly related to TG/TPO status at baseline but were not associated with IFNbeta-1b treatment. Adverse events possibly indicative of other diseases with autoimmune links were not associated with respective AAb status.

CONCLUSION

Interferon beta-1b treatment did not induce autoantibody formation in this population of patients with secondary progressive multiple sclerosis.

A novel approach to treatment of hypertension in diabetic patients - a multicenter, double-blind, randomized study comparing the efficacy of combination therapy of Eprosartan versus Ramipril with low-dose Hydrochlorothiazide and Moxonidine on blood pressure levels in patients with hypertension and associated diabetes mellitus type 2 - rationale and design [ISRCTN55725285]

Hypertension and diabetes mellitus are closely interrelated and coexist in as many as two-thirds of patients with type 2 diabetes. The consequent risk of such an association is an accelerated development of atherosclerotic cardiovascular disease and nephropathy complications.In choosing an antihypertensive agent, effectiveness needs to be accompanied by favourable metabolic, cardioprotective, and nephroprotective properties. Given the multifactorial nature of hypertension, the approach that has gained widespread agreement is treatment with more than one agent. Agents with different mechanisms of action increase antihypertensive efficacy because of synergistic impacts on the cardiovascular system. Combination therapy allows the use of lower doses of each antihypertensive agent which accounts for the excellent tolerability of combination products.The aim of the present study is to quantify the efficacy of combination therapy of Eprosartan 600 mg respectively Ramipril 5 mg with low-dose Hydrochlorothiazide and Moxonidine on blood pressure levels in patients with essential hypertension and associated diabetes mellitus type 2.The use of monotherapy (Eprosartan or Ramipril) followed by addition of low-dose Hydrochlorothiazide as second agent and of Moxonidine as a third agent will be individualized to the severity of hypertension in the particular patient and to his/her degree of response to current treatment.

Safety and efficacy of intravenously administered tedisamil for rapid conversion of recent-onset atrial fibrillation or atrial flutter

OBJECTIVES

The goal of the present study was to assess the efficacy and safety of intravenous tedisamil, a new antiarrhythmic compound, for conversion of recent-onset atrial fibrillation (AF) or atrial flutter (AFL) to normal sinus rhythm (NSR).

BACKGROUND

Tedisamil is a novel antiarrhythmic drug with predominantly class III activity. Its efficacy and safety for conversion of recent onset AF or AFL to NSR is not known.

METHODS

This was a multicenter, double-blind, randomized, placebo-controlled, sequential ascending dose-group trial. A total of 201 patients with symptomatic AF or AFL of 3 to 48 h duration were enrolled in a two-stage study. During stage 1, patients were randomized to receive tedisamil at 0.4 mg/kg body weight or matching placebo; during stage 2, patients received tedisamil at 0.6 mg/kg body weight or matching placebo. Treatments were given as single intravenous infusions. The primary study end point consisted of the percentage of patients converting to NSR for at least 60 s within 2.5 h.

RESULTS

Of 175 patients representing the intention-to-treat sample, conversion to NSR was observed in 41% (25/61) of the tedisamil 0.4 mg/kg group, 51% (27 of 53) of the tedisamil 0.6 mg/kg group, and 7% (4/59) of the placebo group (p < 0.001 for both tedisamil groups vs. placebo). Average time to conversion was 35 min in patients receiving tedisamil. There were two instances of self-terminating ventricular tachycardia: one episode of torsade de pointes and one of monomorphic ventricular tachycardia, both in patients receiving 0.6 mg/kg tedisamil.

CONCLUSIONS

Tedisamil at dosages of 0.4 and 0.6 mg/kg was superior to placebo in converting AF or AFL. Tedisamil has a rapid onset of action leading to conversion within 30 to 40 min in the majority of responders.

MRI metrics as surrogate endpoints for EDSS progression in SPMS patients treated with IFN beta-1b

BACKGROUND

Although metrics derived from conventional MRI (cMRI) are widely used as outcome measures in clinical trials of MS, no formal study has been performed to validate cMRI metrics as surrogate endpoints for disability progression in MS.

METHODS

A validation procedure was applied to the clinical and MRI data collected in the context of the European randomized, double-blind, placebo-controlled trial of interferon beta-1b (IFNbeta-1b) in patients with secondary progressive MS. The Prentice operational criteria were used to assess surrogacy for the number of active lesions seen on the first year T2-weighted MRI scans and the percentage T2 lesion volume change between the baseline and the first year MRI scans. The primary clinical outcome was disability at study exit (3 years), adjusted for the baseline disability.

RESULTS

The number of active T2 lesions and the T2 lesion volume percentage change over the first year of the study accounted for 57% of the treatment effect on disability progression over the entire study duration. On the contrary, the same cMRI metrics accounted for 79% of the treatment effect on the relapse rate.

CONCLUSIONS

This study shows that the beneficial effect of IFNbeta-1b on disability accumulation in patients with secondary progressive MS is, to a large extent, independent of the changes detected using cMRI. As a consequence, cMRI metrics should not be used as a stand-alone measure of outcome in phase III trials of IFNbeta in secondary progressive MS.

The effect of interferon beta-1b on quantities derived from MT MRI in secondary progressive MS

BACKGROUND

Magnetization transfer (MT) MRI can provide in vivo markers reflecting the severity of irreversible, MS-related brain damage occurring within and outside T2-visible lesions.

OBJECTIVE

To assess the effect of interferon (IFN) beta-1b treatment on the accumulation of brain damage in patients with secondary progressive (SP) MS, measured using MT MRI.

METHODS

Eighty-two patients with SPMS from five centers participating in a European, multicenter, double-blind, placebo-controlled trial of IFNbeta-1b in SPMS underwent brain T2-weighted and MT MRI at baseline. Evaluable follow-up data were available for 75 patients at 12 months, 54 at 24 months, and 47 at 36 months. MT MRI scans were postprocessed and analyzed to obtain histograms of MT ratio (MTR) values from the whole brain. A region of interest-based analysis of MTR values from the normal-appearing white matter (NAWM) was also performed.

RESULTS

In both the treatment arms, there was a decrease of average brain MTR values from baseline to month 24 (mean change -4.9%) and month 36 (mean change -4.3%). These changes were significant for the placebo group at both timepoints and for the IFNbeta-1b group at month 24 only, with no significant treatment effect. A decrease of NAWM MTR was also observed, with no significant difference between the two treatment arms.

CONCLUSION

In this cohort of patients with secondary progressive MS, interferon beta-1b did not show an overall effect on the worsening of magnetization transfer MRI measures, when compared with placebo. The data show that change in magnetization transfer ratio is a promising tool for monitoring disease evolution in secondary progressive MS and that the information obtained from magnetization transfer MRI complements that obtained from MRI measures of lesion load and inflammation.

Neutralizing antibodies during treatment of secondary progressive MS with interferon beta-1b

OBJECTIVE

To investigate the relationship between neutralizing antibodies (NAB) and disease progression, relapses, and MR measures of MS.

METHODS

Sequential serum samples from all 718 patients of the European Study Group in Interferon beta-1b in Secondary Progressive MS were analyzed to investigate relations between NAB and disease progression, relapses, and MR measures.

RESULTS

This study showed no attenuating effect of NAB development on progression in disability. The effects of NAB on relapse rate showed substantial variation, depending on the statistical approach and definition of positivity, though analyses comparing low- and high-NAB+ periods with NAB- periods suggested a titer-related effect. MR T2 lesion volume changes from baseline were significantly higher for NAB+ patients but remained lower than for placebo patients. A substantial proportion of NAB+ patients became NAB-. No untoward effect of NAB development on safety was observed.

CONCLUSION

These results support the conclusion that even though high NAB titers appear to have impact on treatment efficacy with respect to relapses, treatment decisions should be based primarily on clinical grounds.