Differences in Olivo-Cerebellar Circuit and Cerebellar Network Connectivity in Essential Tremor: a Resting State fMRI Study

The olivo-cerebellar circuit is thought to play a crucial role in the pathophysiology of essential tremor (ET). Whether olivo-cerebellar circuit dysfunction is also present at rest, in the absence of clinical tremor and linked voluntary movement, remains unclear. Assessing this network in detail with fMRI is challenging, considering the brainstem is close to major arteries and pulsatile cerebrospinal fluid-filled spaces obscuring signals of interest. Here, we used methods tailored to the analysis of infratentorial structures. We hypothesize that the olivo-cerebellar circuit shows altered intra-network connectivity at rest and decreased functional coupling with other parts of the motor network in ET. In 17 ET patients and 19 healthy controls, we investigated using resting state fMRI intracerebellar functional and effective connectivity on a dedicated cerebellar atlas. With independent component analysis, we investigated data-driven cerebellar motor network activations during rest. Finally, whole-brain connectivity of cerebellar motor structures was investigated using identified components. In ET, olivo-cerebellar pathways show decreased functional connectivity compared with healthy controls. Effective connectivity analysis showed an increased inhibitory influence of the dentate nucleus towards the inferior olive. Cerebellar independent component analyses showed motor resting state networks are less strongly connected to the cerebral cortex compared to controls. Our results indicate the olivo-cerebellar circuit to be affected at rest. Also, the cerebellum is "disconnected" from the rest of the motor network. Aberrant activity, generated within the olivo-cerebellar circuit could, during action, spread towards other parts of the motor circuit and potentially underlie the characteristic tremor of this patient group.

Closing the loop: Novel quantitative fMRI approach for manipulation of the sensorimotor loop in tremor

Tremor is thought to be an effect of oscillatory activity within the sensorimotor network. To date, the underlying pathological brain networks are not fully understood. Disentangling tremor activity from voluntary motor output and sensorimotor feedback systems is challenging. To better understand the intrinsic sensorimotor fingerprint underlying tremor, we aimed to disentangle the sensorimotor system into driving (motor) and feedback/compensatory (sensory) neuronal involvement, and aimed to pinpoint tremor activity in essential tremor (ET) and tremor-dominant Parkinson's disease (PD) with a novel closed-loop approach. Eighteen ET patients, 14 tremor-dominant PD patients, and 18 healthy controls were included. An MR-compatible wrist manipulator was employed during functional MRI (fMRI) while muscle activity during (in)voluntary movements was concurrently recorded using electromyography (EMG). Tremor was quantified based on EMG and correlated to brain activity. Participants performed three tasks: an active wrist motor task, a passive wrist movement task, and rest (no wrist movement). The results in healthy controls proved that our experimental paradigm activated the expected motor and sensory networks separately using the active (motor) and passive (sensory) task. ET patients showed similar patterns of activation within the motor and sensory networks. PD patients had less activity during the active motor task in the cerebellum and basal ganglia compared to ET and healthy controls. EMG showed that in ET, tremor fluctuations correlated positively with activity in the inferior olive region, and that in PD tremor fluctuations correlated positively with cerebellar activity. Our novel approach with an MR-compatible wrist manipulator, allowed to investigate the involvement of the motor and sensory networks separately, and as such to better understand tremor pathophysiology. In ET sensorimotor network function did not differ from healthy controls. PD showed less motor-related activity. Focusing on tremor, our results indicate involvement of the inferior olive in ET tremor modulation, and cerebellar involvement in PD tremor modulation.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Probiotic as an adjuvant therapy in chronic urticaria: a blinded randomized controlled clinical trial

Summary

Background. Chronic spontaneous urticaria (CSU) is a common and treatment challenging disorder which may involve about 2% of normal population and in 50% do not respond properly even to the second line therapies. We aimed to evaluate the efficacy and safety of a synbiotic (prebiotic + probiotic) named as LactoCare in treatment of CSU in the RCT for the first time. Methods. This blinded RCT conducted on 42 patients (21 patients in control antihistamine group and 21 in intervention antihistamine + probiotic group) with CSU during 8 weeks. The efficacy assessed by Urticaria Activity Score (UAS7) and quality of life measured by Persian validated Dermatology Life Quality Index (DLQI). Results. Before and after UAS7 score in control group was 35.33 ± 7.81 and 16.86 ± 13.54, respectively. There was 53% score reduction in control group. Before and after UAS7 score in intervention group was 32 ± 7.84 and 11 ± 11.41, respectively. There was 66% score reduction in intervention group. Improvement of DLQI in control and intervention group was 44% and 66%, respectively. At the end, UAS7 score reduction and DLQI improvement in both groups was statistically significant. Conclusions. Probiotics are effective, safe and satisfactory adjuvant therapy for CSU. Combination of probiotic and antihistamines had no statistically significant different efficacy than the antihistamine alone, based on UAS7 score. But Patients with combination therapy may experience higher reduction rate of itch, number of urticaria and total UAS7 score that is clinically of great value and is really practical by itself. Patients with combination therapy experienced more improvement of quality of life (DLQI).

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

Design of microresonators to minimize thermal noise below the standard quantum limit

Microfabricated resonators play a crucial role in the development of quantum measurement, including future gravitational wave detectors. We use a micro-genetic algorithm and a finite element method to design a microresonator whose geometry is optimized to maximize the sub-Standard Quantum Limit (SQL) performance including lower thermal noise (TN) below the SQL, a broader sub-SQL region, and a sub-SQL region at lower frequencies. For the proposed design, we study the effects of different geometries of the mirror pad and cantilever microresonator on sub-SQL performance. We find that the maximum ratio of SQL to TN is increased, its frequency is decreased, and the sub-SQL range is increased by increasing the length of the microresonator cantilever, increasing the radius of the mirror pad, decreasing the width of the microresonator cantilever, and shifting the laser beam location from the mirror center. We also find that there exists a trade-off between the maximum ratio of SQL to TN and the sub-SQL bandwidth. The performance of this designed microresonator will allow it to serve as a test-bed for quantum non-demolition measurements and to open new regimes of precision measurement that are relevant for many practical sensing applications, including advanced gravitational wave detectors.

Distinct cortical activity patterns in Parkinson's disease and essential tremor during a bimanual tapping task

Background

Parkinson’s disease (PD) and essential tremor (ET) are neurodegenerative diseases characterized by movement deficits. Especially in PD, maintaining cyclic movement can be significantly disturbed due to pathological changes in the basal ganglia and the cerebellum. Providing external cues improves timing of these movements in PD and also affects ET. The aim of this study is to determine differences in cortical activation patterns in PD and ET patients during externally and internally cued movements.

Methods

Eleven PD patients, twelve ET patients, OFF tremor suppressing medication, and nineteen age-matched healthy controls (HC) were included and asked to perform a bimanual tapping task at two predefined cue frequencies. The auditory cue, a metronome sound presented at 2 or 4 Hz, was alternately switched on and off every 30 s. Tapping at two different frequencies were used since it is expected that different brain networks are involved at different frequencies as has been shown in previous studies. Cortical activity was recorded using a 64-channel EEG cap. To establish the cortical activation pattern in each group, the task related power (TRP) was calculated for each subject. For inter-groups analysis, EEG electrodes for divided into 5 different areas.

Results

Inter-group analysis revealed significant differences in areas responsible for motor planning, organization and regulation and involved in initiation, maintenance, coordination and planning of complex sequences of movements. Within the area of the primary motor cortex the ET group showed a significantly lower TRP than the HC group. In the area responsible for combining somatosensory, auditory and visual information both patient groups had a higher TRP than the HC group.

Conclusions

Different neurological networks are involved during cued and non-cued movements in ET, PD and HC. Distinct cortical activation patterns were revealed using task related power calculations. Different activation patterns were revealed during the 2 and 4 Hz tapping task indicating different strategies to execute movements at these rates. The results suggest that a including a cued/non-cued tapping task during clinical decision making could be a valuable tool in an objective diagnostic protocol.

A Power Spectral Density-Based Method to Detect Tremor and Tremor Intermittency in Movement Disorders

There is no objective gold standard to detect tremors. This concerns not only the choice of the algorithm and sensors, but methods are often designed to detect tremors in one specific group of patients during the performance of a specific task. Therefore, the aim of this study is twofold. First, an objective quantitative method to detect tremor windows (TWs) in accelerometer and electromyography recordings is introduced. Second, the tremor stability index (TSI) is determined to indicate the advantage of detecting TWs prior to analysis. Ten Parkinson’s disease (PD) patients, ten essential tremor (ET) patients, and ten healthy controls (HC) performed a resting, postural and movement task. Data was split into 3-s windows, and the power spectral density was calculated for each window. The relative power around the peak frequency with respect to the power in the tremor band was used to classify the windows as either tremor or non-tremor. The method yielded a specificity of 96.45%, sensitivity of 84.84%, and accuracy of 90.80% of tremor detection. During tremors, significant differences were found between groups in all three parameters. The results suggest that the introduced method could be used to determine under which conditions and to which extent undiagnosed patients exhibit tremors.

Deficits in tapping accuracy and variability in tremor patients

Background

The basal ganglia and cerebellum are brain structures involved in movement initiation, execution and termination. They are thought to be involved in the tremor generation and movement deficits in Parkinson’s disease (PD) and essential tremor (ET). Especially in PD, maintaining cyclic movement, such as walking or tapping can be significantly disturbed. Providing external cues improves timing of these movements in PD but its effect on ET has not yet been studied in depth. The aim of this study is to evaluate the usefulness of a bimanual tapping task as a tool during clinical decision making.

Method

Hand movements and tremor was recorded using accelerometers and EMG (m. extensor carpi ulnaris) from PD and ET patients and healthy controls during a bimanual tapping task as a way to distinguish PD from ET. All subjects performed the tapping task at two different frequencies, 2 Hz and 4 Hz, with and without the presence of auditory cues.

Results

No significant intra-group differences were found in the patient groups. Acceleration data revealed significantly less accurate tapping and more variable tapping in PD than in ET and healthy controls. ET subjects tapped less accurate and with a greater variability than healthy controls during the 4 Hz tapping task. Most interestingly the tapping accuracy improved in PD patients when kinetic tremor was recorded with EMG during the task.

Conclusion

Providing ET and PD patients with an external cue results in different tapping performances between patient groups and healthy controls. Furthermore, the findings suggest that kinetic tremor in PD enables patients to perform the task with a greater accuracy. So far this has not been shown in other studies.

Familial Cortical Myoclonic Tremor and Epilepsy, an Enigmatic Disorder: From Phenotypes to Pathophysiology and Genetics. A Systematic Review

Background

Autosomal dominant familial cortical myoclonic tremor and epilepsy (FCMTE) is characterized by distal tremulous myoclonus, generalized seizures, and signs of cortical reflex myoclonus. FCMTE has been described in over 100 pedigrees worldwide, under several different names and acronyms. Pathological changes have been located in the cerebellum. This systematic review discusses the clinical spectrum, treatment, pathophysiology, and genetic findings.

Methods

We carried out a PubMed search, using a combination of the following search terms: cortical tremor, myoclonus, epilepsy, benign course, adult onset, familial, and autosomal dominant; this resulted in a total of 77 studies (761 patients; 126 pedigrees) fulfilling the inclusion and exclusion criteria.

Results

Phenotypic differences across pedigrees exist, possibly related to underlying genetic differences. A "benign" phenotype has been described in several Japanese families and pedigrees linked to 8q (FCMTE1). French patients (5p linkage; FCMTE3) exhibit more severe progression, and in Japanese/Chinese pedigrees (with unknown linkage) anticipation has been suggested. Preferred treatment is with valproate (mind teratogenicity), levetiracetam, and/or clonazepam. Several genes have been identified, which differ in potential pathogenicity.

Discussion

Based on the core features (above), the syndrome can be considered a distinct clinical entity. Clinical features may also include proximal myoclonus and mild progression with aging. Valproate or levetiracetam, with or without clonazepam, reduces symptoms. FCMTE is a heterogeneous disorder, and likely to include a variety of different conditions with mutations of different genes. Distinct phenotypic traits might reflect different genetic mutations. Genes involved in Purkinje cell outgrowth or those encoding for ion channels or neurotransmitters seem good candidate genes.

Intermittent cortical involvement in the preservation of tremor in essential tremor

Cortical involvement in essential tremor, an involuntary action tremor supposedly of subcortical origin, is uncertain. Conflicting results of corticomuscular coherence studies in essential tremor suggest an intermittent corticomuscular coupling. On the basis of the literature, we hypothesized that corticomuscular coupling is influenced by bilateral motor synchronization and "cognitive states" such as awareness of tremor. In the present study, we investigated 1) the existence of intermittent corticomuscular coherence (CMC) in essential tremor and 2) factors that influence CMC strength. In 18 essential tremor patients and 18 healthy controls, who mimicked tremor, we simultaneously recorded 64-channel EEG and 6-channel bipolar surface EMG from right and left wrist extensors and flexors. Right-sided (mimicked) hand tremor was recorded with and without a cognitive arithmetic task and with left-sided (mimicked) hand tremor. CMC values per task were compared within and between groups. Changes in CMC strength during tasks were calculated. Our main findings are 1) significant CMC around the (mimicked) tremor frequency across all tasks in both groups; 2) significant differences in CMC between unilateral tasks, with the highest values during the cognitive task only in the essential tremor group; and 3) significant fluctuations of CMC strength over time, independent of the tremor intensity, only in the essential tremor group. Our results suggest a limited role, and certainly not a continuous steering role, of sensorimotor cortical neurons in the generation of tremor. In clinical practice, these findings might help to standardize tremor registration and the interpretation of the analysis.NEW & NOTEWORTHY The part of the motor cortex involved in essential tremor is uncertain. The current electrophysiological study is the first to assess corticomuscular coherence systematically. The study shows a dynamic nature of corticomuscular coherence and a possible influence of cognitive states. The results elucidate the involvement of the motor cortex in tremor and help interpret the varying results in the literature. In clinical practice, the findings may guide in standardizing tremor registration and its interpretation.

Targeted brain activation using an MR-compatible wrist torque measurement device and isometric motor tasks during functional magnetic resonance imaging

Dedicated pairs of isometric wrist flexion tasks, with and without visual feedback of the exerted torque, were designed to target activation of the CBL and BG in healthy subjects during functional magnetic resonance imaging (fMRI). Selective activation of the cerebellum (CBL) and basal ganglia (BG), often implicated in movement disorders such as tremor and dystonia, may help identify pathological changes and expedite diagnosis. A prototyped MR-compatible wrist torque measurement device, free of magnetic and conductive materials, allowed safe execution of tasks during fMRI without causing artifacts. A significant increase of activity in CBL and BG was found in healthy volunteers during a constant torque task with visual feedback compared to a constant torque task without visual feedback. This study shows that specific pairs of motor tasks using MR-compatible equipment at the wrist allow for targeted activation of CBL and BG, paving a new way for research into the pathophysiology of movement disorders.

Motor network disruption in essential tremor: a functional and effective connectivity study

Although involvement of the cerebello-thalamo-cortical network has often been suggested in essential tremor, the source of oscillatory activity remains largely unknown. To elucidate mechanisms of tremor generation, it is of crucial importance to study the dynamics within the cerebello-thalamo-cortical network. Using a combination of electromyography and functional magnetic resonance imaging, it is possible to record the peripheral manifestation of tremor simultaneously with brain activity related to tremor generation. Our first aim was to study the intrinsic activity of regions within the cerebello-thalamo-cortical network using dynamic causal modelling to estimate effective connectivity driven by the concurrently recorded tremor signal. Our second aim was to objectify how the functional integrity of the cerebello-thalamo-cortical network is affected in essential tremor. We investigated the functional connectivity between cerebellar and cortical motor regions showing activations during a motor task. Twenty-two essential tremor patients and 22 healthy controls were analysed. For the effective connectivity analysis, a network of tremor-signal related regions was constructed, consisting of the left primary motor cortex, premotor cortex, supplementary motor area, left thalamus, and right cerebellar motor regions lobule V and lobule VIII. A measure of variation in tremor severity over time, derived from the electromyogram, was included as modulatory input on intrinsic connections and on the extrinsic cerebello-thalamic connections, giving a total of 128 models. Bayesian model selection and random effects Bayesian model averaging were used. Separate seed-based functional connectivity analyses for the left primary motor cortex, left supplementary motor area and right cerebellar lobules IV, V, VI and VIII were performed. We report two novel findings that support an important role for the cerebellar system in the pathophysiology of essential tremor. First, in the effective connectivity analysis, tremor variation during the motor task has an excitatory effect on both the extrinsic connection from cerebellar lobule V to the thalamus, and the intrinsic activity of cerebellar lobule V and thalamus. Second, the functional integrity of the motor network is affected in essential tremor, with a decrease in functional connectivity between cortical and cerebellar motor regions. This decrease in functional connectivity, related to the motor task, correlates with an increase in clinical tremor severity. Interestingly, increased functional connectivity between right cerebellar lobules I-IV and the left thalamus correlates with an increase in clinical tremor severity. In conclusion, our findings suggest that cerebello-dentato-thalamic activity and cerebello-cortical connectivity is disturbed in essential tremor, supporting previous evidence of functional cerebellar changes in essential tremor.

Assay of IL-22 and IL-25 in serum, whole blood, and peripheral blood mononuclear cell cultures of patients with severe asthma

BACKGROUND

Although some studies show that IL-22 and IL-25 play critical roles in the pathogenesis of asthma, little is known about the systemic production of these cytokines. The aim of this study was to assay IL-22 and IL-25 in serum, in mitogen-activated whole blood (WB), and in mitogen-activated peripheral blood mononuclear cell (PBMC) cultures of patients with severe asthma.

METHODS

In this cross-sectional study, a questionnaire was prepared to determine the severity of asthma. Through the questionnaire, information including clinical signs, clinical symptoms, and past medical history were acquired. Information collected allowed all patients who were active or ex-smokers to be excluded. A trained observer assessed airway reversibility, peak flowmetry, and spirometry in the remaining patients. Twenty-one patients and simultaneously, twenty age- and sex-matched healthy controls were selected. Sterile blood (10ml) was taken from each study participant. Sera were isolated and anticoagulant blood used for WB and PBMC cultures and haematological tests. Phytohaemagglutinin and lipopolysaccharide (LPS) were used to activate WB and PBMC. The data from these two groups were compared using Student's t-test.

RESULTS

Although the total white blood cell count was elevated in the asthmatic group, other haematological indices, including IL-22 and IL-25 levels in the asthmatic group were not significantly (p>0.05) different from controls.

CONCLUSIONS

The levels of IL-22 and IL-25 in patients with severe asthma are no higher than those of non-asthmatic individuals. Any major role for IL-22 and IL-25 in severe asthma is likely to be localised to the lungs and bronchial tissues.

Neuroimaging essentials in essential tremor: a systematic review

Background

Essential tremor is regarded to be a disease of the central nervous system. Neuroimaging is a rapidly growing field with potential benefits to both diagnostics and research. The exact role of imaging techniques with respect to essential tremor in research and clinical practice is not clear. A systematic review of the different imaging techniques in essential tremor is lacking in the literature.

Methods

We performed a systematic literature search combining the terms essential tremor and familial tremor with the following keywords: imaging, MRI, VBM, DWI, fMRI, PET and SPECT, both in abbreviated form as well as in full form. We summarize and discuss the quality and the external validity of each study and place the results in the context of existing knowledge regarding the pathophysiology of essential tremor.

Results

A total of 48 neuroimaging studies met our search criteria, roughly divided into 19 structural and 29 functional and metabolic studies. The quality of the studies varied, especially concerning inclusion criteria. Functional imaging studies indicated cerebellar hyperactivity during rest and during tremor. The studies also pointed to the involvement of the thalamus, the inferior olive and the red nucleus. Structural studies showed less consistent results.

Discussion and conclusion

Neuroimaging techniques in essential tremor give insight into the pathophysiology of essential tremor indicating the involvement of the cerebellum as the most consistent finding. GABAergic dysfunction might be a major premise in the pathophysiological hypotheses. Inconsistencies between studies can be partly explained by the inclusion of heterogeneous patient groups. Improvement of scientific research requires more stringent inclusion criteria and application of advanced analysis techniques. Also, the use of multimodal neuroimaging techniques is a promising development in movement disorders research. Currently, the role of imaging techniques in essential tremor in daily clinical practice is limited.

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We conducted a systematic review of neuroimaging studies in essential tremor.

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Cerebellar involvement is the most consistent finding.

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GABAergic dysfunction is worthwhile investigating more intensively.

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We encourage multimodal neuroimaging focussing on brain networks.

Chemical composition and antiprolifrative activity of Artemisia persica Boiss. and Artemisia turcomanica Gand. essential oils

Essential oils obtained from aerial parts of Artemisia persica and Artemisia turcomanica were analyzed by GC/MS. While 28 components representing 91.01 % of A. persica were identified, the identity of 50 components, constituting 81.93 % of the total oil, was confirmed in A. turcomanica. β-thujone was the main compound (75.23%) in A. persica while the major identified phytochemicals in A. turcomanica were 1,8-cineol (19.23%), camphor (15.55%) and filifolone (15.53%). Both of the essential oils were predominantly made up of monoterpenes. Time- and dose-dependent cytotoxic effects of A. persica and A. turcomanica on MCF-7 cell line evaluated by MTT assay at 24, 48 and 72 h, showed that the highest cytotoxic effect of A. persica and A. turcomanica were appeared at 72 h incubation. At that incubation period, CI50 of A. persica was found to be 0.15 μg/ml, while that of A. turcomanica was 0.1 μg/ml. Thus, cytotoxicity of A. turcomanica was slightly higher than A. persica which could be attributed to the higher content of sesquiterpene present in A. turcomanica. As a conclusion, these volatile oils could have chemotherapeutic potentials.

Familial cortical myoclonic tremor with epilepsy and cerebellar changes: description of a new pathology case and review of the literature

BACKGROUND

Over 60 Asian and European families with cortical myoclonic tremor and epilepsy have been reported under various names. Cerebellar changes may be part of the syndrome. In this study, we report the neuropathology findings in a new Dutch familial cortical myoclonic tremor with epilepsy case and review the literature on this syndrome.

METHODS

Neuropathological investigations were performed for a third case of the Dutch pedigree. In addition, we searched the literature for pedigrees meeting the criteria for benign familial myoclonic tremor and epilepsy.

RESULTS

Our third Dutch case showed cerebellar Purkinje cell changes and a normal cerebral cortex. The pedigrees described show phenotypical differences, cerebellar symptoms and cerebellar atrophy to a variable degree. Japanese pedigrees with linkage to chromosome 8q have been reported with milder disease features than members of Italian pedigrees with linkage to chromosome 2p. French pedigrees (5p) possibly show even more severe and progressive disease, including cognitive changes and cerebellar features.

DISCUSSION

Currently, familial cortical myoclonic tremor is not listed by the International League Against Epilepsy, although it can be differentiated from other epileptic syndromes. Genetic heterogeneity and phenotypical differences between pedigrees exist. Cerebellar changes seem to be part of the syndrome in at least a number of pedigrees.

Toward Automated, At-Home Assessment of Mobility Among Patients With Parkinson Disease, Using a Body-Worn Accelerometer

Objective. To develop an automated and objective method to assess mobility in Parkinson disease (PD) patients in daily-life settings and to investigate whether accelerometer-derived measures discriminate between PD and healthy controls as they walk and simulate activities of daily living (ADL). Methods. Healthy older adults (17) and patients with PD (22) wore a triaxial accelerometer on their lower back during short walks (validation study) and during a walk around the medical center to simulate daily activities (ADL simulation). The variability (consistency and rhythmicity) of stepping was assessed. The patients completed the walks before and after taking their anti-Parkinsonian medications. Frequency-based acceleration measures included dominant frequency, amplitude (strength of signal frequency), width (frequency dispersion), and slope (a combination reflecting amplitude and width) of the main frequency of the power spectral density in the 0.5- to 3.0-Hz band. A subset of the Unified Parkinson-Disease Rating Scale provided a clinical measure of gait impairment (UPDRS-Gait5). A PD patient and control wore the sensors for 3 days at home. Results. The width was larger, and the amplitude and slope were smaller in the PD patients compared to the controls in the validation study and ADL simulation ( P < .02). The width decreased, and the amplitude and slope increased when patients took anti-Parkinsonian medications ( P < .007). Significant correlations were observed between acceleration-derived measures and UPDRS-Gait5. The data obtained at home was similar to the clinic data. Conclusions. Frequency-derived measures are valid and sensitive estimates of stride-to-stride variability that can be used to assess the quality and consistency of walking in patients with PD in real-life settings.

Study on the prevalence of dairy cattle lameness and its effects of production indices in Iran. A locomotion scoring base study

In this current study, prevalence of lameness was detected and its changes during different parities, Days in Milk (DIM) and milk production were studies. In addition, effects of lameness on Open Days (OD) and Service per Conception (S/C) were studied. Three dairy farms on three scales (1: Large, approximately 900 milking cows, 2: Medium, approximately 100 milking cows and 3: Small, approximately 20 milking cows) were watched for lameness in 2005-2006. Locomotion Scoring (LS) by Sprecher method (1-5 point scale) has been done by videoing of the animals at the exit of the milking parlor. Videos were reviewed by two expert and mean of the each score used as score of the animal, cows with scores 1 and 2 recorded as non-lame and 3, 4 and 5 as lame cows. The average score of the lameness in autumn and spring recorded as 2.47 and 2.73, respectively that was higher significantly in spring. LS has been increased significantly by increasing parity and DIM, as highest scores were recorded in parity 4 and DIM 240-300. No significant differences between lame and non-lame cows were recorded in according to their milk production. The highest (percent in lame cows) scores were recorded in high producing cows. No significant difference in milk production has been recorded in different LS. However the average production of milk in lame cows were 1.08 L day(-1) less that non-lame cows. The average OD of the lame cows was significantly longer (52 days) than non-lame cows. Lame cows needed significantly higher service/conception (one) than non-lame cows. Median of OD and S/C has been increased by LS.

The relationship between KCl infusion and changes of ECG, electrolytes of plasma and K content of donkey's red blood cells

Sudden marked increases in the serum potassium concentration, up to 8 to 9 meq L(-1), are the result of transcellular movement of potassium and are associated with profound electrocardiographic abnormalities and fluid shifts. Electrocardiographic changes associated with hyperkalemia have been described in the cat, the dog, the horse and are well documented in man. Since there is no research about the effects of hyperkalemia on electrocardiogram of donkey, the purpose of this study was to induce the experimentally hyperkalemia in donkey and studying the relationship between KCl infusion and changes of ECG, electrolytes of plasma and K content of donkey's red blood cells. This research was carried out in seven clinically healthy female donkeys, injected with 0.35 molar potassium chloride solutions to jugular vein. Results indicated that potassium content of RBC at 30, 45, 60, 75 and 90 min, blood potassium level at 30, 45, 60, 75 and 90 min, blood calcium at 60, 75, 90 and 105, increased significantly and blood magnesium decreased significantly at 135 min. Electrocardiographic changes were first degree A-V block, wandering pacemaker, inversion of negative to positive T-wave, flattening of the P-wave, ventricular premature beat, sinus arrest, bradycardia and sinus tachycardia.

Study of some physiological changes in sugar beet cv. 7233 in the presence of sugar beet cyst nematode, Heterodera schachtii and an antagonistic sterile fungus StFCh1-1 in the rhizosphere condition

In this study, several physiological parameters of inoculated sugar beet plants, with the beet cyst nematode, Heterodera schachtii, were evaluated in the presence of an antagonistic sterile fungus StFCh1-1 in the rhizosphere condition. The sugar beet plant used in this bioassay was a multigerm cultivar, 7233, which is sensitive to the beet cyst nematode and has been adapted to cultivate in temperate and cool regions of the sugar beet production areas of Iran. In this regard a potent bioassay was conducted in the sterile glass tubes (20 x 3 cm phi ) containing 30 g autoclaved soil and planted with a sterile germinated seed of sugar beet, totally in 24 tubes. The seedling of sugar beet plant at four leaves stages in two treatments (nematode and nematode + fungus) was inoculated with 50 disinfected beet cyst nematodes. As a standard procedure the bioassay composed of four treatments including: fungus, nematode, nematode + fungus and untreated control. Two months after nematodes' inoculation some physiological parameters of plants were measured including: total chlorophyll, potassium and biomass. The two treated plants with nematode and nematode plus fungus showed significant decrease in biomass and chlorophyll contents but treatment with fungus alone showed no significant differences in the biomass and chlorophyll content of plants in comparison with the control. The potassium content of shoots in the invaded sugar beet plants was lowest, but it was highest in the roots. These changes might be indication of adaptive osmoregulation or acclimation responses in plants due to the nematodes as bio-stressors through the increase of metabolites and solutes. Also, these results confirmed that in plants inoculated with nematode plus fungus, a few number of female of nematodes were developed due to the antagonistic effects of sterile fungus StFCh1-1. Meanwhile, the fungus didn't have any detrimental effect on biomass, chlorophyll content and potassium in leaves of sugar beet cv. 2733 and it is safe to use as a biocontrol agent against Heterodera schachtii.

New experimental evidence about secondary processes in phenylphthalein-dimethylether and 1,1'-bis(p-methoxyphenyl)cyclohexane

The slow secondary (beta) process of 1,1'-bis (4-methoxyphenyl) cyclohexane and phenolphthalein dimethylether has been investigated by dielectric spectroscopy. New experimental results about the pressure dependence of the two processes are reported, as well as new data about the dependence of the characteristic relaxation frequency on the cooling rate used to vitrify the system in isobaric conditions. Previous investigations on these systems suggested that the first one is not a true Johari-Goldstein relaxation and both processes should originate from the flip flop motion of the phenyl ring. The results herein reported evidence that the characteristic frequency of the beta process of phenolphthalein dimethylether is more sensitive to pressure variation and to the vitrification procedure than that of 1,1'-bis (4-methoxyphenyl) cyclohexane. Such results suggest an intermolecular origin for the secondary process in phenolphthalein dimethylether and an intramolecular origin for the other one, which do not completely agree with the previous interpretation. We evidence that the microscopic mechanism at the basis of these two processes is still an open question, which should be debated on the basis of new experimental investigations.

Synthesis and characterization of novel injectable, biodegradable and in situ crosslinkable poly(hexamethylene-carbonate-fumarate), poly(hexamethylene carbonate) diacrylate and poly(ethylene glycol fumarate-co-hexamethylene carbonate-fumarate) scaffolds for bone tissue engineering

A series of novel self-crosslinkable and biodegradable polymers; poly(hexamethylene carbonate-fumarate), poly(hexamethylene carbonate) diacrylate and their amphiphilic copolymers with polyethylene glycol, poly(ethylene glycol fumarate-co-hexamethylene carbonate-fumarate) (PEGF-co-PHMCF) were developed for tissue engineering using novel synthesis approach. These novel polymers were fully characterized using nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography, differential scanning calorimetry, rheometry and shrinkage strain measurement. The cytocompatibility of macromers and their networks were evaluated by [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] MTT assay. The synthetic macromers were light colored with self-crosslinking ability via both photocrosslinking and chemical crosslinking. These polymers can be used as precursors to prepare polymer networks and scaffolds with controlled hydrophilicity, biodegradability and mechanical characteristics for application in cell delivery, tissue engineering and controlled release of biologically active agents.

Effects of tail fat on halothane biotransformation in fat-tailed sheep

1. The aim of the present study was to evaluate the effects of tail fat on halothane biotransformation following similar anaesthetic exposure in intact sheep and sheep with a ligated median sacral artery. 2. A prospective randomized experimental study was performed using 12 healthy, 10-12-month-old female sheep. 3. Sheep were randomly divided into two groups of six animals each and were anaesthetized twice at 2 weekly intervals. After mask induction with halothane in 100% oxygen, sheep were intubated and anaesthesia was maintained for 3 h using a rebreathing system. Serum fluoride concentration (SFC) was measured at 0, 1, 3, 6, 12, 24, 48 and 72 h following the induction of anaesthesia. Serum biochemistry was also evaluated at baseline and 72 h after anaesthesia. Induction and extubation times and time to sternal recumbency were also recorded during anaesthetic induction and recovery. Prior to the second anaesthesia (2 weeks later), the median sacral artery (MSA) was ligated under epidural anaesthesia in the experimental group. Sheep in the control group underwent sham operation. All sheep were anaesthetized as before. 4. Following the first halothane anaesthesia, SFC was significantly increased from 3 to 48 h compared with baseline. In the second stage of the experiment, the increases in SFC in the control group were similar to those seen in the first stage of the experiment. However, in MSA-ligated sheep, the increases in SFC were only significant between 3 and 12 h compared with baseline. The SFC was significantly higher in intact sheep from 3 to 72 h compared with the MSA-ligated group. Extubation and sternal recumbency times were significantly longer in intact sheep. 5. Ligation of the MSA in fat-tailed sheep induced a significant reduction in SFC, suggesting that the presence of tail fat substantially affects halothane metabolism during the peri-anaesthetic period in sheep. The greater extent of halothane biotransformation may be clinically important in, otherwise normal, obese patients.

Analysis of smoking behaviour among Iranian population: a cohort and period analysis

BACKGROUND

The patterns of smoking in ageing cohorts are important to public health authorities. The aim of this study is to describe the patterns of smoking among Iranian population.

METHODS

Data from cross-sectional surveys of Health and Disease Survey (HDS) in Iran were utilized. Smoking was categorized as no smoker, light smoker (less than 10 cigarettes a day), moderate smokers (10 to 20 cigarettes a day), and heavy smoker (more than 20 cigarettes a day). Age group cohorts were constructed by following each age group to the next age group in two consecutive surveys. The change in smoking behavior was express as the difference of smoking prevalence and 95% confidence interval around the difference were constructed. Three birth cohorts of 1930, 1960, and 1975 were constructed among smoker and their age at initiation of smoking were assessed for the three cohorts.

RESULTS

Smoking was more prevalent among age group 25-39 in males and age group 40-60 in females. Smoking prevalence increased in all categories of smoking behavior among male cohort of 15-25 year age-group and stayed stable afterward up to their 40's. After age 40, the prevalence of smoking decreased in heavy smokers and stayed stable in light and moderate smokers. A different pattern was seen among female smokers. Age at initiation of smoking decreased in the last decades. Among the male birth cohort of 1930, just 32.6% of smokers started smoking before age 20 compared with 48.7% in birth cohort of 1975, P value < 0.0001. Similar pattern was seen among the female smokers.

CONCLUSIONS

The pattern of smoking in Iranian population high lights the fact that smoking behavior is highly age dependent.

Modeling of supercritical extraction of mannitol from plane tree leaf

The objective of this study was to investigate the theoretical feasibility of using supercritical fluid extraction of Mannitol from plane tree leaf as an alternative technology in the pharmaceutical industry. Simulation of an extraction column using dense liquid and supercritical carbon dioxide was modeled involving partial differential equations, using orthogonal collocation on finite elements. The important solvent extraction parameters such as the partition coefficient, mass transfer coefficient, dispersion coefficient, molecular diffusion and extraction efficiency (the amount of Mannitol extracted versus the amount of solvent used) were investigated as a function of the dimensionless Reynold's and Peclet numbers in order to optimize the extraction column geometry and the carbon dioxide operating conditions. The results of this study demonstrated that supercritical extraction is a viable technique for Mannitol production and that the process conditions for a large commercial extraction system do not require a high temperature in order to obtain a high extraction efficiency. However, at low pressures, the solubility of Mannitol in carbon dioxide would limit the success of the extraction process and at very high pressures the extraction technique may not be economically feasible. To investigate the authenticity of the mathematical model, the experimental data for the desorption of hexachlorobenzene from soil was compared with the theoretical results of this research. The model is able to predict the experimental data quite well without any adjustable parameters.

Human plasma and tirilazad mesylate protect stored human erythrocytes against the oxidative damage of gamma-irradiation

Transfusion-associated graft-versus-host disease (TA-GVHD) is a serious condition that under certain circumstances can be lethal in immunosuppressed patients. The risk of TA-GVHD can be reduced in this population by gamma irradiation (gammaRad) of blood components. gammaRad results in production of reactive oxygen species which can damage red blood cells (RBC). Tirilazad mesylate (TM) is a member of the 21-aminosteroids (Lazaroids) family and is a powerful antioxidant. We investigated the ability of TM and human plasma (which contain powerful antioxidants) to protect stored human RBC against the oxidative damage of gammaRad. Fresh intact packed RBC obtained from the normal donors, with and without autologous plasma or TM (0.05 mg mL-1 RBC), were exposed to gammaRad (50 Gy) and stored for 28 days at 4 degrees C. Oxidative damage was assessed by osmotic fragility at 65 mM NaCl concentration (expressed by percentage haemolysis in 65 mM NaCl solution) and lipid peroxidation (measured by thiobarbituric acid reactive substances, TBARS). Our results showed that storage and irradiation of untreated intact RBC increased the osmotic fragility at 65 mM NaCl concentration (65.8 +/- 1.3 vs. 51.20 +/- 0.87% haemolysis; irradiated vs. controls, respectively; P = 0.002) and lipid peroxidation (TBARS = 4.47 +/- 0. 12 vs. 3.45 +/- 0.09 microM L-1 RBC; irradiated vs. controls, respectively; P = 0.001). TM protected the intact RBC against radiation-induced haemolysis (35.8 +/- 5.0 vs. 65.8 +/- 1.3% haemolysis; treated vs. untreated irradiated RBC, respectively; P = 0.02) and lipid peroxidation (TBARS = 2.91 +/- 0.2 vs. 4.47 +/- 0.12 microM L-1 RBC; treated vs. untreated irradiated RBC, respectively; P = 0.005). Addition of autologous plasma to packed RBC significantly reduced the extent of radiation-induced haemolysis by more than six-fold (12.45 +/- 0.26 vs. 65.8 +/- 2.2% haemolysis; irradiated RBC with versus without plasma, respectively; P = 0.0001). In conclusion, these results show that irradiation and storage of blood damages RBC via oxidative processes and addition of autologous plasma and/or TM protects RBC against such damage and possibly enhances their storage and survival.

Immunocytochemical staining of Kupffer and endothelial cells in fine needle aspiration cytology of hepatocellular carcinoma

OBJECTIVE

To evaluate the significance of the presence of Kupffer and endothelial cells in distinguishing hepatocellular carcinoma (HCC) and adenocarcinoma (AC) on cytologic smears.

STUDY DESIGN

Fine needle aspiration biopsies (FNABs) from 43 cases, 21 HCC and 22 AC (8 primary and 14 metastatic), were immunostained for Factor VIII and vimentin as markers for endothelial cells and Kupffer cells, respectively. Cytologic diagnosis was verified by histologic and/or clinical follow-up.

RESULTS

Eighteen of the 21 cases (86%) of HCC and 11 (5 primary and 6 metastatic) of 22 cases (50%) of AC showed positive immunostaining for Factor VIII (P = .02). Vimentin immunostaining was positive in 55% of HCCs and 41% of ACs (P = .74). Forty-five percent of cases of HCC showed immunostaining for both Factor VIII and vimentin, while 22% of cases of AC showed immunostaining for both Factor VIII and vimentin (P = .18).

CONCLUSION

Immunocytochemical identification of endothelial cells using Factor VIII may have important diagnostic value in separating HCC from adenocarcinomas in liver FNABs. The presence of Kupffer cells labeled with vimentin has no diagnostic significance in FNAB of these tumors.

Peritoneal washing cytology is unnecessary in gynecologic surgery for benign diseases

BACKGROUND

The presence of tumor cells in peritoneal washing cytology specimens taken during surgery affects the staging of many gynecologic malignancies. Peritoneal washings are often collected routinely, even in cases of presumed benign disease. This study was designed to address whether evaluation of these specimens is justified.

METHODS

We reviewed diagnostic reports from all peritoneal washings and the corresponding surgical pathology specimens from patients undergoing gynecologic surgery during a 1-year period in one institution and a 20-month period in the other. Cases were divided into benign and malignant categories based on the surgical pathology diagnosis.

RESULTS

Three hundred forty-six patients had peritoneal washings collected during the study period. The proportion of cases with malignancy was 30% in one institution and 49% in the other. Of these, 119 had an endometrial or ovarian malignancy, including 16 ovarian tumors of low malignant potential. Malignant cells were detected in 19 cases. In 10 of these 19, grossly apparent peritoneal tumor implants were present at the time of surgery. The remaining 227 were found to have benign disease, and the peritoneal washing cytology diagnosis was negative in all cases. Potential savings of $13,000 to $17,000 based on current insurance reimbursement could have been realized for these 227 patients without compromising patient care.

CONCLUSIONS

These data suggest that peritoneal washing cytology specimens collected at the time of gynecologic surgery for presumed benign disease can be held and processed later if an unsuspected malignancy is discovered. This practice can result in cost savings without compromising patient care. Cancer (Cancer Cytopathol)

Assessment of pathologic prognostic factors in breast core needle biopsies

BACKGROUND

Core needle biopsies (CNB) are being used increasingly as the initial diagnostic procedure in women with breast cancer. Many clinicians are interested in obtaining as much prognostic information as possible from these limited specimens. However, the accuracy of assessing pathologic prognostic factors in core biopsy material has not been studied in detail.

DESIGN

We studied CNB and subsequent excision specimens from 79 women with invasive breast cancer. Slides from CNB and excision specimens were reviewed in a blinded fashion and each was assessed for histologic type, tumor size, histologic grade, lymphatic vessel invasion (LVI), and the presence of an extensive intraductal component (EIC).

RESULTS

Among the 79 cancers, there were 58 invasive ductal carcinomas, six invasive lobular carcinomas, 13 invasive carcinomas with ductal and lobular features and two tubular carcinomas, based on examination of the excision specimens. Histologic type on CNB correlated with that on excision in 64 cases (81%). Although there was a significant correlation between tumor size on CNB and excision specimens (r2 = 0.30, P = 0.01), the pathologic T stage was underestimated on CNB in 79% of cases. Furthermore, T substage was underestimated on CNB in 71% of T1 lesions. There was concordance in histologic grade between CNB and excisions in 75% of cases. Among the 20 discordant cases, the grade was higher in the excision than in the CNB in 13 cases and lower in seven. However, all discrepancies were within one grade. None of the 17 cancers with LVI in the excision specimen showed LVI on the CNB. Among 14 cases with an EIC on the excision specimen, only four (29%) were scored as having an EIC on CNB.

CONCLUSION

Histologic type can be accurately determined on CNB in most cases. While there was concordance in histologic grade between CNB and excision in the majority of cases, grade was discordant in a substantial minority (25%). The ability to accurately determine tumor size (pathologic T-stage), LVI, and EIC on CNB is severely limited.

Nodular lymphoid lesion of the liver: an immune-mediated disorder mimicking low-grade malignant lymphoma

Three cases of unusual lymphoid infiltrate forming nodular macroscopic masses in the liver were studied in the authors' surgical pathology laboratory. These lesions posed difficulty in diagnosis, and their differentiation from low-grade lymphoma was not possible on histopathologic evaluation alone. The liver masses were analyzed histologically and immunohistochemically as well as for clonal immunoglobulin heavy chain (IgH) and T-cell receptor gamma (TCR-gamma) gene rearrangements. The lesions were seen as solitary grossly distinct firm nodules in all three patients, measuring 0.4, 0.7, and 1.5 cm, respectively, in their greatest dimensions. Two were found in livers removed because of end-stage primary biliary cirrhosis at the time of orthotopic liver transplantation, and the third was an incidental finding during laparotomy. Microscopically, these were nodules composed of small lymphocytes, plasma cells, and immunoblasts, with varying degrees of admixed acute inflammatory cells and scattered lymphoid follicles. By immunohistochemistry and molecular studies, these were found to be reactive lymphoid proliferations. All patients are alive and well at 2, 4, and 13 years, respectively. It is concluded that these cases represent a unique type of nodular lymphoid lesion, which is probably an immune-mediated benign reactive hyperplasia. It constitutes an entity by itself and must be distinguished from low-grade lymphoma. For a definitive diagnosis, immunohistochemistry and molecular studies are required.

Oxidation of Tris and formaldehyde to CO2 by neutrophil oxidants

The buffer substance Tris is oxidized to formaldehyde by two microbicidal neutrophil oxidants, the hydroxyl radical and sodium hypochlorite. By the intact neutrophil, Tris is converted to CO2 in a process which is enhanced by stimulation with zymosan indicating that CO2 formation reflects neutrophil function. CO2 formation is more extensive at pH 6.0 than at pH 7.5 suggesting higher microbicidal activity at the low pH of inflamed tissue. In addition to Tris, its oxidation product formaldehyde is also oxidized to CO2 by hydroxyl radicals, and the formation of CO2 from formaldehyde by intact neutrophils exhibits the same features as CO2 formation from Tris. It is suggested that CO2 formation from Tris or from formaldehyde may be suitable to test for the formation of microbicidal oxidants by neutrophils.

Rhabdomyolysis after suicidal ingestion of an overdose of caffeine, acetaminophen and phenazone as a fixed-dose combination (Spalt N)

Rhabdomyolysis without renal failure was noted after suicidal ingestion of 29 tablets of Spalt N containing 7.25 g of acetaminophen, 7.25 g of phenazone and 1.45 g of caffeine by a 29 year-old weighing 73 kg. The maximum serum creatine kinase was 1920 U/L, serum myoglobins were 49 to 167 ng/mL. Acetaminophen, phenazone and caffeine were quantified and identified in serum by gas chromatography and gas chromatography/mass spectrometry. It is suggested that rhabdomyolysis might have been caused by caffeine.

Penetration of ciprofloxacin into the cerebrospinal fluid of patients with uninflamed meninges

Nine patients with external ventriculostomy and suffering from hydrocephalus, due to non-inflammatory central nervous system diseases, were given ciprofloxacin (200 mg twice daily iv). Ciprofloxacin concentrations in serum and CSF were measured by HPLC. Single-dose pharmacokinetics were determined in three patients, and 60 and 600 min post-dose levels after repeated administration in six patients. CSF concentrations were maximal 60-120 min after the end of the infusion. The CSF elimination half-life was 260-430 min compared with 145-170 in serum. Post-dose levels at 60 min ranged from 0.042 to 0.223 mg/l (median = 0.110). Repeated administration did not lead to substantial increases in serum and CSF concentrations. With respect to MIC90 values reported for bacteria involved in CNS infections, the CSF concentrations of ciprofloxacin obtained under our experimental conditions would be considered subtherapeutic. Thus ciprofloxacin therapy of CNS infections may be inadequate when only minor impairment of the blood-CSF barrier exists.