Seeing our hand or a tool during visually-guided actions: Different effects on the somatosensory and visual cortices

The processing of proprioceptive information in the context of a conflict between visual and somatosensory feedbacks deteriorates motor performance. Previous studies have shown that seeing one's hand increases the weighting assigned to arm somatosensory inputs. In this light, we hypothesized that the sensory conflict, when tracing the contour of a shape with mirror-reversed vision, will be greater for participants who trace with a stylus seen in their hand (Hand group, n = 17) than for participants who trace with the tip of rod without seen their hand (Tool group, n = 15). Based on this hypothesis, we predicted that the tracing performance with mirror vision will be more deteriorated for the Hand group than for the Tool group, and we predicted a greater gating of somatosensory information for the Hand group to reduce the sensory conflict. The participants of both groups followed the outline of a shape in two visual conditions. Direct vision: the participants saw the hand or portion of a light 40 cm rod directly. Mirror Vision: the hand or the rod was seen through a mirror. We measured tracing performance using a digitizing tablet and the cortical activity with electroencephalography. Behavioral analyses revealed that the tracing performance of both groups was similarly impaired by mirror vision. However, contrasting the spectral content of the cortical oscillatory activity between the Mirror and Direct conditions, we observed that tracing with mirror vision resulted in significantly larger alpha (8-12 Hz) and beta (15-25 Hz) powers in the somatosensory cortex for participants of the Hand group. The somatosensory alpha and beta powers did not significantly differ between Mirror and Direct vision conditions for the Tool group. For both groups, tracing with mirror vision altered the activity of the visual cortex: decreased alpha power for the Hand group, decreased alpha and beta power for the Tool group. Overall, these results suggest that seeing the hand enhanced the sensory conflict when tracing with mirror vision and that the increase of alpha and beta powers in the somatosensory cortex served to reduce the weight assigned to somatosensory information. The increased activity of the visual cortex observed for both groups in the mirror vision condition suggests greater visual processing with increased task difficulty. Finally, the fact that the participants of the Tool group did not show better tracing performance than those of the Hand group suggests that tracing deterioration resulted from a sensorimotor conflict (as opposed to a visuo-proprioceptive conflict).

Fast optical recording of neuronal activity by three-dimensional custom-access serial holography

Optical recording of neuronal activity in three-dimensional (3D) brain circuits at cellular and millisecond resolution in vivo is essential for probing information flow in the brain. While random-access multiphoton microscopy permits fast optical access to neuronal targets in three dimensions, the method is challenged by motion artifacts when recording from behaving animals. Therefore, we developed three-dimensional custom-access serial holography (3D-CASH). Built on a fast acousto-optic light modulator, 3D-CASH performs serial sampling at 40 kHz from neurons at freely selectable 3D locations. Motion artifacts are eliminated by targeting each neuron with a size-optimized pattern of excitation light covering the cell body and its anticipated displacement field. Spike rates inferred from GCaMP6f recordings in visual cortex of awake mice tracked the phase of a moving bar stimulus with higher spike correlation between intra compared to interlaminar neuron pairs. 3D-CASH offers access to the millisecond correlation structure of in vivo neuronal activity in 3D microcircuits.

Ultrafast Two-Photon Imaging of a High-Gain Voltage Indicator in Awake Behaving Mice

Optical interrogation of voltage in deep brain locations with cellular resolution would be immensely useful for understanding how neuronal circuits process information. Here, we report ASAP3, a genetically encoded voltage indicator with 51% fluorescence modulation by physiological voltages, submillisecond activation kinetics, and full responsivity under two-photon excitation. We also introduce an ultrafast local volume excitation (ULoVE) method for kilohertz-rate two-photon sampling in vivo with increased stability and sensitivity. Combining a soma-targeted ASAP3 variant and ULoVE, we show single-trial tracking of spikes and subthreshold events for minutes in deep locations, with subcellular resolution and with repeated sampling over days. In the visual cortex, we use soma-targeted ASAP3 to illustrate cell-type-dependent subthreshold modulation by locomotion. Thus, ASAP3 and ULoVE enable high-speed optical recording of electrical activity in genetically defined neurons at deep locations during awake behavior.

Optogenetic stimulation of complex spatio-temporal activity patterns by acousto-optic light steering probes cerebellar granular layer integrative properties

Optogenetics provides tools to control afferent activity in brain microcircuits. However, this requires optical methods that can evoke asynchronous and coordinated activity within neuronal ensembles in a spatio-temporally precise way. Here we describe a light patterning method, which combines MHz acousto-optic beam steering and adjustable low numerical aperture Gaussian beams, to achieve fast 2D targeting in scattering tissue. Using mossy fiber afferents to the cerebellar cortex as a testbed, we demonstrate single fiber optogenetic stimulation with micron-scale lateral resolution, >100 µm depth-penetration and 0.1 ms spiking precision. Protracted spatio-temporal patterns of light delivered by our illumination system evoked sustained asynchronous mossy fiber activity with excellent repeatability. Combining optical and electrical stimulations, we show that the cerebellar granular layer performs nonlinear integration, whereby sustained mossy fiber activity provides a permissive context for the transmission of salient inputs, enriching combinatorial views on mossy fiber pattern separation.

Burst-Dependent Bidirectional Plasticity in the Cerebellum Is Driven by Presynaptic NMDA Receptors

Numerous studies have shown that cerebellar function is related to the plasticity at the synapses between parallel fibers and Purkinje cells. How specific input patterns determine plasticity outcomes, as well as the biophysics underlying plasticity of these synapses, remain unclear. Here, we characterize the patterns of activity that lead to postsynaptically expressed LTP using both in vivo and in vitro experiments. Similar to the requirements of LTD, we find that high-frequency bursts are necessary to trigger LTP and that this burst-dependent plasticity depends on presynaptic NMDA receptors and nitric oxide (NO) signaling. We provide direct evidence for calcium entry through presynaptic NMDA receptors in a subpopulation of parallel fiber varicosities. Finally, we develop and experimentally verify a mechanistic plasticity model based on NO and calcium signaling. The model reproduces plasticity outcomes from data and predicts the effect of arbitrary patterns of synaptic inputs on Purkinje cells, thereby providing a unified description of plasticity.

Fast spatial beam shaping by acousto-optic diffraction for 3D non-linear microscopy

Acousto-optic deflection (AOD) devices offer unprecedented fast control of the entire spatial structure of light beams, most notably their phase. AOD light modulation of ultra-short laser pulses, however, is not straightforward to implement because of intrinsic chromatic dispersion and non-stationarity of acousto-optic diffraction. While schemes exist to compensate chromatic dispersion, non-stationarity remains an obstacle. In this work we demonstrate an efficient AOD light modulator for stable phase modulation using time-locked generation of frequency-modulated acoustic waves at the full repetition rate of a high power laser pulse amplifier of 80 kHz. We establish the non-local relationship between the optical phase and the generating acoustic frequency function and verify the system for temporal stability, phase accuracy and generation of non-linear two-dimensional phase functions.

Ultrastructure and Membrane Traffic During Cell Division in the Marine Pennate Diatom Phaeodactylum tricornutum

The marine pennate diatom Phaeodactylum tricornutum has become a model for diatom biology, due to its ease of culture and accessibility to reverse genetics approaches. While several features underlying the molecular mechanisms of cell division have been described, morphological analyses are less advanced than they are in other diatoms. We therefore examined cell ultrastructure changes prior to and during cytokinesis. Following chloroplast division, cleavage furrows are formed at both longitudinal ends of the cell and are accompanied by significant vesicle transport. Although neither spindle nor microtubules were observed, the nucleus appeared to be split by the furrow after duplication of the Golgi apparatus. Finally, centripetal cytokinesis was completed by fusion of the furrows. Additionally, F-actin formed a ring structure and its diameter became smaller, accompanying the ingrowing furrows. To further analyse vesicular transport during cytokinesis, we generated transgenic cells expressing yellow fluorescent protein (YFP) fusions with putative diatom orthologs of small GTPase Sec4 and t-SNARE protein SyntaxinA. Time-lapse observations revealed that SyntaxinA-YFP localization expands from both cell tips toward the center, whereas Sec4-YFP was found in the Golgi and subsequently relocalizes to the future division plane. This work provides fundamental new information about cell replication processes in P. tricornutum.

Culicoides biting midges (Diptera, Ceratopogonidae) in various climatic zones of Russia and adjacent lands

Culicoides biting midges play an important role in the epidemiology of many vector-borne infections, including bluetongue virus, an internationally important virus of ruminants. The territory of the Russian Federation includes regions with diverse climatic conditions and a wide range of habitats suitable for Culicoides. This review summarizes available data on Culicoides studied in the Russian Federation covering geographically different regions, as well as findings from adjacent countries. Previous literature on species composition, ranges of dominant species, breeding sites, and host preferences is reviewed and suggestions made for future studies to elucidate vector-virus relationships.

Activity-dependent gating of calcium spikes by A-type K+ channels controls climbing fiber signaling in Purkinje cell dendrites

In cerebellar Purkinje cell dendrites, heterosynaptic calcium signaling induced by the proximal climbing fiber (CF) input controls plasticity at distal parallel fiber (PF) synapses. The substrate and regulation of this long-range dendritic calcium signaling are poorly understood. Using high-speed calcium imaging, we examine the role of active dendritic conductances. Under basal conditions, CF stimulation evokes T-type calcium signaling displaying sharp proximodistal decrement. Combined mGluR1 receptor activation and depolarization, two activity-dependent signals, unlock P/Q calcium spikes initiation and propagation, mediating efficient CF signaling at distal sites. These spikes are initiated in proximal smooth dendrites, independently from somatic sodium action potentials, and evoke high-frequency bursts of all-or-none fast-rising calcium transients in PF spines. Gradual calcium spike burst unlocking arises from increasing inactivation of mGluR1-modulated low-threshold A-type potassium channels located in distal dendrites. Evidence for graded activity-dependent CF calcium signaling at PF synapses refines current views on cerebellar supervised learning rules.

[Treatment of high myopic choroidal neovascularisation with intravitreal bevacizumab]

PURPOSE

To evaluate the safety and efficacy of intravitreal bevacizumab (IVB) in the treatment of high myopic choroidal neovascularization (CNV).

MATERIALS AND METHODS

Retrospective study of 16 eyes of 16 patients with high myopic choroidal neovascularization treated with first-line IVB (1.25mg/0.05mL) with a one-year follow-up. All patients underwent a complete baseline (M0) ophthalmologic examination, including the measurement of best corrected visual acuity (BCVA), biomicroscopic and fundus examination, fluorescein and indocyanine green angiography, and optical coherence tomography. Patients were followed monthly. Additional IVB was administered when persistent or additional retinal exudation was observed. The main study parameters were visual acuity at 1, 6 and 12 months and the progression of exudation on OCT and angiography.

RESULTS

Mean age was 63±14 years and spherical equivalent was -15.4±7.4 diopters. Baseline BCVA was 0.75±0.5 logMAR. Mean follow-up was 15±2 months. The average number of IVB was 2.4±1.2 injections. Metamorphopsia decreased in all patients and completely disappeared in fourteen eyes. Mean BCVA was 0.5±0.3 logMAR at M1 and 0.6±0.5 logMAR at M6 and M12. No adverse events related to the intravitreal injections were observed.

CONCLUSION

Our study showed that IVB (Avastin(®)) is effective in the treatment of high myopic CNV. Moreover, only a small number of intravitreal injections were required to treat this condition.

Évaluation de l’intérêt d’un Serious game chez des patients souffrant de troubles bipolaires inclus dans un programme de psychoéducation

Introduction

La psychoéducation du trouble bipolaire favorise l’adhésion thérapeutique et le maintien de l’euthymie à 2 ans [1]. Au terme d’un tel programme, les patients peuvent avoir besoin d’aide pour perpétuer la mise en place des apprentissages concernant l’observance thérapeutique, les routines de vie quotidienne, l’évitement des toxiques et le repérage des prodromes thymiques. Le Serious Game BIPOLIFE®, jeu centré sur un avatar souffrant de trouble bipolaire évoluant dans des situations de la vie courante, s’articule aussi autour de ces cibles.

Objectifs

Évaluer la qualité de l’observance thérapeutique par la Medication Adherence Rating Scale (MARS) [2], les indicateurs de routine de vie et de recours aux soins psychiatriques à 1 et 4 mois de la dernière séance de psychoéducation chez les patients utilisant BIPOLIFE® vs. suivi habituel.

Méthodologie

Étude pilote multicentrique randomisée contrôlée à 2 bras (durée : 24 mois) incluant des sujets euthymiques (score de dépression MADRS ≤ 12 et de manie YMRS ≤ 8 depuis 3 mois), bénéficiant d’un programme de psychoéducation. Les patients du groupe « intervention » se connecteront au site BIPOLIFE®, de manière hebdomadaire, pendant un mois (durée de connexion libre). À l’inclusion (dernière séance de psychoéducation), 1 et 4 mois, seront évalués l’attitude vis-à-vis du traitement, la qualité du sommeil, l’indice de masse corporelle, le périmètre ombilical, la consommation de toxiques, le fonctionnement psychosocial et le recours aux soins psychiatriques.

Perspectives

Proposer BIPOLIFE® en add-on de la psychoéducation pour renforcer les compétences acquises lors du programme et le maintien de l’euthymie.

Laboratory and field-based tests of deltamethrin insecticides against adult Culicoides biting midges

Bluetongue virus (BTV) is an economically important arbovirus of ruminants transmitted by Culicoides biting midges. Vector control using residual spraying or application to livestock is recommended by many authorities to reduce BTV transmission; however, the impact of these measures in terms of both inflicting mortality on Culicoides and subsequently upon BTV transmission is unclear. This study consisted of a standardized World Health Organization laboratory assay to determine the susceptibility of European Culicoides species to deltamethrin and a field trial based upon allowing individuals of a laboratory strain of Culicoides nubeculosus Meigen to feed upon sheep treated with Butox 7.5 pour-on (a deltamethrin-based topical formulation). Susceptibility in the laboratory trial was higher in colony C. nubeculosus (24-h LC90 = 0.00106%), than in field populations of Culicoides obsoletus Meigen (24-h LC90 = 0.00203%) or Culicoides imicola Kieffer (24-h LC90 = 0.00773%). In the field, the pour-on formulation was tested with a total of 816 C. nubeculosus specimens fed upon on the thigh of treated sheep. The study revealed a maximum mortality rate of 49% at 4 d postapplication, and duration of lethal effect was predicted to be as short as 10 d, despite testing being carried out with a highly susceptible strain. The reasons for this low efficacy are discussed with reference both to the potential for lack of spread of the active ingredient on the host and feeding patterns of the major potential vector species on the sheep host. Practical implications for vector control strategies during BTV incursions are also detailed.

[Impact of the Activity-Based Financing (11th Version) on glaucoma surgery payment in hospital resources]

AIM

In this study, the potential impact of 11(th) version of the National Health System's Activity-Based Financing on the income of a University Hospital department was evaluated for glaucoma surgeries.

PATIENTS AND METHODS

The number of glaucoma surgeries in 2008 was analyzed based on the Medicalization Program of Information Systems. Using the 11(th) version of the Activity-Based Financing for Diagnosis-Related Groups (DRG), we compared the income of these surgical procedures on both an inpatient and an outpatient setting.

RESULTS

One hundred and forty-nine patients undergoing glaucoma surgery between January and December 2008 were included, 94% of whom were treated on an outpatient basis. The lower reimbursement for outpatient surgery resulted in a loss of euro 100,000 or 64% of revenues compared to an inpatient procedure.

DISCUSSION

Ambulatory glaucoma surgery is feasible but requires rigorous organization. Nonetheless, while department incomes are related to activity, ambulatory care seems financially disadvantageous. Many departments are trying to develop an ambulatory structure, but the apparent contradiction between the objectives of public health insurance and the hospital's need to balance its budget requires further clarification.

Optical monitoring of neuronal activity at high frame rate with a digital random-access multiphoton (RAMP) microscope

Two-photon microscopy offers the promise of monitoring brain activity at multiple locations within intact tissue. However, serial sampling of voxels has been difficult to reconcile with millisecond timescales characteristic of neuronal activity. This is due to the conflicting constraints of scanning speed and signal amplitude. The recent use of acousto-optic deflector scanning to implement random-access multiphoton microscopy (RAMP) potentially allows to preserve long illumination dwell times while sampling multiple points-of-interest at high rates. However, the real-life abilities of RAMP microscopy regarding sensitivity and phototoxicity issues, which have so far impeded prolonged optical recordings at high frame rates, have not been assessed. Here, we describe the design, implementation and characterisation of an optimised RAMP microscope. We demonstrate the application of the microscope by monitoring calcium transients in Purkinje cells and cortical pyramidal cell dendrites and spines. We quantify the illumination constraints imposed by phototoxicity and show that stable continuous high-rate recordings can be obtained. During these recordings the fluorescence signal is large enough to detect spikes with a temporal resolution limited only by the calcium dye dynamics, improving upon previous techniques by at least an order of magnitude.

Phylogenetic analysis of Culicoides species from France based on nuclear ITS1-rDNA sequences

Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) play important roles in the transmission of viral diseases affecting wild and domestic ruminants and horses, including Bluetongue (BT) and African horse sickness (AHS) respectively. In southern Europe, BT has been largely transmitted by the classical Afro-Asian vector Culicoides imicola Kieffer. However, other species such as C. obsoletus Meigen, C. scoticus Downs & Kettle and C. pulicaris Linné may also be involved in BTV transmission. As a consequence of the discovery of C. imicola followed by BTV-2 outbreaks on the island of Corsica in October 2000, further studies on these biting midges have been carried out. To better characterize the evolution and phylogenetic relations of Culicoides, molecular analysis in parallel with a morphology-based taxonomic approach were performed. Phylogenetic analyses of French Culicoides species were undertaken using the ribosomal DNA (rDNA) internal transcribed spacer 1 (ITS1) as a molecular target. This region was shown to be useful in understanding evolutionary and genetic relationships between species. Construction of several trees showed that molecular phylogeny within the genus Culicoides correlates not only with morphological-based taxonomy but also with ecological patterns.

Entomological surveillance of bluetongue in France in 2002

Bluetongue (BT) is an arboviral disease that appeared in the Mediterranean in 1998. In France, the principal vector, Culicoides imicola, was detected for the first time in Corsica in October 2000, a few weeks before outbreaks of BT virus serotype 2 (BTV-2). Entomological surveillance was implemented in Corsica and on mainland France in 2002. In Corsica, the aim was to study the population dynamics of C. imicola and other potential vectors. On the coastal mainland, the objective was to survey the introduction of C. imicola. One-night catches per site were performed every three weeks at 12 sites on Corsica and every month at 19 sites on the mainland. In Corsica, 84,790 Culicoides belonging to 50 species were collected over 180 nights. C. imicola accounted for 18.3% of the total captured. On the mainland, 16,197 Culicoides (44 species over 109 nights) were collected, none of which were C. imicola. The geographic and seasonal distribution of C. imicola and other species of interest are discussed in relation with their bio-ecology and environment. These datasets are essential for a better understanding of the epidemiology of BT, and to create and validate predictive models based on remote sensing in order to identify areas at risk for BT.

[So-called spontaneous intramural dissection of the esophagus]

We report two cases of spontaneous esophageal intramural dissection in two women aged 65 and 79 years. Initial symptoms were a constrictive retrosternal thoracic pain during a meal. Minor hematemesis accompanied by dysphagia or odynophagia appeared during the following hours. After excluding a cardiovascular emergency, diagnosis was confirmed by upper GI endoscopy that found a large mucosal longitudinal dissection; the lesion extended from mid-esophagus until short above the gastro-esophageal junction. Intramural parietal dissection characteristically appeared on barium swallow as a "double-barrelled" esophagus related to a thin radiolucent mucosal membrane separating the false and true lumens. Medical treatment with total parenteral nutrition, intravenous gastric antisecretory drugs, antibiotics in 1 patient was continued until symptoms disappeared; oral feeding was then started without incident. Follow-up endoscopic examinations confirmed complete healing. Regardless of etiology which remains speculative, spontaneous intramural dissection of the esophagus probably results from an intramural hematoma in most cases.

Genotype-phenotype analysis in four families with mutations in beta-myosin heavy chain gene responsible for familial hypertrophic cardiomyopathy

Familial hypertrophic cardiomyopathy is a genetically heterogeneous disease in which one of the most frequently implicated gene is the gene encoding the beta-myosin heavy chain. To date, more than 40 distinct mutations have been found within this gene. In order to progress on the determination of genotype-phenotype relationship, we have screened the beta-myosin heavy chain gene for mutations in 18 probands from unrelated families. We identified the mutation implicated in the disease in four families. Two of them, the Glu930 codon deletion and the Ile263Thr mutation, are reported here for the first time. The two other mutations are the Arg723Cys mutation, that was previously described in a proband as a de novo mutation, and the Arg719Trp mutation. A poor prognosis was associated with the Glu930codon deletion (mean maximal wall thickness (MWT) = 19.5 mm +/- 5) and the Arg719Trp mutation (mean MWT = 15.3 mm +/- 7), whereas a good prognosis was associated with the Arg723Cys mutation (mean MWT = 20.1 mm +/- 7). The combination of clinical and genetic characteristics of each family member suggests that prognosis is related neither to the degree of left ventricular wall thickness nor to a change in the net electrical charge of the protein. Additional family studies are needed to confirm these findings and to contribute to stratify the prognosis according to the mutation involved.

Double heterozygosity for mutations in the beta-myosin heavy chain and in the cardiac myosin binding protein C genes in a family with hypertrophic cardiomyopathy

Familial hypertrophic cardiomyopathy is a genetically heterogeneous autosomal dominant disease, caused by mutations in several sarcomeric protein genes. So far, seven genes have been shown to be associated with the disease with the beta-myosin heavy chain (MYH7) and the cardiac myosin binding protein C (MYBPC3) genes being the most frequently involved. We performed electrocardiography (ECG) and echocardiography in 15 subjects with hypertrophic cardiomyopathy from a French Caribbean family. Genetic analyses were performed on genomic DNA by haplotype analysis with microsatellite markers at each locus involved and mutation screening by single strand conformation polymorphism analysis. Based on ECG and echocardiography, eight subjects were affected and presented a classical phenotype of hypertrophic cardiomyopathy. Two new mutations cosegregating with the disease were found, one located in the MYH7 gene exon 15 (Glu483Lys) and the other in the MYBPC3 gene exon 30 (Glu1096 termination codon). Four affected subjects carried the MYH7 gene mutation, two the MYBPC3 gene mutation, and two were doubly heterozygous for the two mutations. The doubly heterozygous patients exhibited marked left ventricular hypertrophy, which was significantly greater than in the other affected subjects. We report for the first time the simultaneous presence of two pathological mutations in two different genes in the context of familial hypertrophic cardiomyopathy. This double heterozygosity is not lethal but is associated with a more severe phenotype.

Allele-specific amplification for the diagnosis of autosomal recessive spinal muscular atrophy

The SMN1 gene is homozygously deleted for at least exon 7, interrupted or converted to a non-functional telomeric copy in most cases of proximal spinal muscular atrophies. The presence of a pseudogene hampers direct detection of the exon 7 deletion. We describe a method for the detection of the of exon 7 deletion, based on the amplification refractory mutation system (ARMS), in a multiplex PCR with fluorescent-labelled primers. The gene and pseudogene amplification products differ in the dye bound and in their size, which allows distinction of both products on electrophoresis. The pseudogene is used as an internal control, and this method gives a clear and specific pattern for the patients. Amplification is achieved with 30 cycles, and specificity is retained up to 40 cycles.

Impaired pressor sensitivity to noradrenaline in septic shock patients with and without impaired adrenal function reserve

AIMS

To investigate the relationship between adrenal gland function and pressor response to noradrenaline in septic shock.

METHODS

Basal cortisol level, noradrenaline--mean arterial pressure dose-response curve and cortisol response to intravenous corticotrophin bolus were obtained in nine patients fulfilling usual criteria for septic shock and in six normal volunteers. In patients with septic shock, dose-response curve to noradrenaline was determined a second time 60 min after a 50 mg intravenous hydrocortisone bolus.

RESULTS

As compared with controls, patients with septic shock had increased basal cortisol levels (mean+/-s.d.: 1564+/-818 vs 378+/-104 nmol l(-1) , P=0.002, 95% confidence interval for difference in means: [452, 1920]) and a blunted cortisol response to corticotrophin (403+/-461 vs 1132+/-195 nmol l(-1), P=0.008, [-1163, -2951). Five patients had impaired adrenal function reserve. As compared with controls, septic patients displayed a moderate and non significant decrease in pressor sensitivity to noradrenaline (P=0.112). As compared with patients with adequate adrenal response, patients with impaired adrenal function reserve showed a significant decrease in pressor sensitivity to noradrenaline (P=0.038). In septic patients, hydrocortisone improved pressor response to noradrenaline (P=0.032). This effect was more marked in patients with impaired adrenal function reserve so that, as compared with patients with adequate response, the difference was no longer significant (P=0.123).

CONCLUSIONS

In septic shock, impaired adrenal function reserve may partly be accounted for by the depressed pressor sensitivity to noradrenaline. The latter may be substantially improved by physiological doses of hydrocortisone.

Production of recombinant human monocyte/neutrophil elastase inhibitor (rM/NEI)

Recombinant human monocyte/neutrophil elastase inhibitor (rM/NEI) was expressed with a baculovirus expression system. The purified recombinant protein was shown to inhibit human neutrophil elastase by the formation of a stable equimolar complex, as had been shown for M/NEI isolated from monocyte-derived cell lines. rM/NEI was remarkably stable in aqueous buffers from pH 6 to pH 8, but not in buffers below pH 6. rM/NEI activity was stable when subjected to freeze-thaw cycles and low temperature storage in Tris or phosphate buffers. rM/NEI could also be lyophilized without significant loss of activity. A 1.6-g batch of greater than 95% purity in rM/NEI was obtained by anion exchange and size exclusion chromatography with yields of 7 to 8 mg per liter of cultured insect cells. Methods and protocols were chosen for compatibility with large-scale cGMP production and were suitable for biochemical characterization and preclinical evaluation of rM/NEI as a therapeutic agent for cystic fibrosis. The availability of large amounts of purified rM/NEI will facilitate clinical evaluation of rM/NEI for prevention of the elastase-mediated destruction of lung tissue associated with the morbidity and mortality of cystic fibrosis.

Immunoglobulin A levels in bronchial samples during mechanical ventilation and onset of nosocomial pneumonia in critically ill patients

Local immunoglobulins play a key role in host defense against lung infection. We investigated the pattern of evolution of bronchial albumin, IgA, and IgG levels in ventilated ICU patients in relation to nosocomial pneumonia. Immunocompetent, critically ill patients underwent serial blood and bronchial protein determinations on Day 1 (intubation day), and on Days 3, 7, 10, and 14. The variations in proteins levels were compared with corresponding Day 1 values in the whole population, and between patients who developed lung infections (Group A) and the remaining population (Group B). Forty-four patients were included into the study. In the whole population, when compared with the baseline value, bronchial IgA/albumin ratio increased significantly (Day 3, +58%, p = 0.04); Day 14, +171%, p < 0.01), but serum IgA/albumin and serum and bronchial IgG/albumin ratios did not change significantly. In Group A, the increase in the IgA/albumin ratio was less than in Group B (Day 3, +15% versus +87%, p = 0.04; Day 14, +29% versus +210%, p < 0.01). No significant differences were observed between the two groups for bronchial and plasma albumin and IgG levels and for bronchial polymorphonuclear elastase levels. Bronchial IgA production was enhanced in ventilated patients. A reduction in this enhanced bronchial IgA production might account for the development of nosocomial pneumonia.

Local increase of antiprotease and neutrophil elastase-alpha 1-proteinase inhibitor complexes in lung cancer

Tumour progression is dependent on many factors including antiproteases and proteases released by tumour cells or host cells infiltrating the tumour. In the present study, we evaluated the antiprotease content, namely alpha 2-macroglobulin (A2M) and alpha 1-proteinase inhibitor (A1PI) and neutrophil (PMN) elastase complexed with A1PI, in limited and extended lung cancer patients compared to a nonsmoker and smoker control population. Data showed that A2M and A1PI were increased in the involved lung from limited cancer when compared to normals. In extended lung cancer, A2M content was also increased in the uninvolved side. The concentration of PMN elastase-A1PI complex was increased on both sides in lung cancer patients (10.2 ng.ml-1 in the uninvolved side, 8.2 ng.ml-1 in the involved side) when compared to nonsmokers (1.9 ng.ml-1, p less than 0.001) and smokers (3.8 ng.ml-1, p less than 0.005). This increase was not solely due to the smoking habit. We conclude that antiproteases and PMN elastase complexed with antiprotease are increased in lung cancer area. This increase could result in extracellular changes in lung cancer.

Local increase of antiprotease and neutrophil elastase-alpha 1-proteinase inhibitor complexes in lung cancer

Tumour progression is dependent on many factors including antiproteases and proteases released by tumour cells or host cells infiltrating the tumour. In the present study, we evaluated the antiprotease content, namely alpha 2-macroglobulin (A2M) and alpha 1-proteinase inhibitor (A1PI) and neutrophil (PMN) elastase complexed with A1PI, in limited and extended lung cancer patients compared to a nonsmoker and smoker control population. Data showed that A2M and A1PI were increased in the involved lung from limited cancer when compared to normals. In extended lung cancer, A2M content was also increased in the uninvolved side. The concentration of PMN elastase-A1PI complex was increased on both sides in lung cancer patients (10.2 ng.ml-1 in the uninvolved side, 8.2 ng.ml-1 in the involved side) when compared to nonsmokers (1.9 ng.ml-1, p less than 0.001) and smokers (3.8 ng.ml-1, p less than 0.005). This increase was not solely due to the smoking habit. We conclude that antiproteases and PMN elastase complexed with antiprotease are increased in lung cancer area. This increase could result in extracellular changes in lung cancer.

Improvement of the safety systems in cell separators. The new safety concept for the cell separator AS 104 (Fresenius)

The new, extended safety requirements for cell separators call for a new generation of machines to address current safety needs. In order to ensure safe treatment, the complete safety concept is of decisive importance - this includes closed seal-less systems, continuous operation, fractions collected externally to the centrifuge, and pump tubings, connections and clamps which are color and direction coded. 'Human failure' as a cause of fault should be excluded for these highly technical appliances - for example, through the use of 'fail-safe' circuits, drip-controlled ACD flow by a separate adjustable pump, detection of damages to blood components by hemolysis control.

[Peptic esophageal strictures. Dilatation with the Eder-Puestow's olives system (author's transl)]

Esophageal dilatations under topical pharyngeal anesthesia with the Eder-Puestow's metallic olives system were performed 101 times on 30 patients presenting peptic strictures. This method uses first a metallic wire introduced into the esophagus and the stomach under endoscopic control. Then, the wire allows to guide dilatating olives through very tight strictures. Functional results were excellent 28 times out of 30; two patients only required repeated dilatations because of uncomplete treatment (stenosis on esojejunal anastomosis). Finally, surgical procedure was never indicated. The use of Eder-Puestow's material together with fiberoptic esophagoscope reduces the hazard of peroral bougienage: no complication occured in our series.

Enzyme histochemical study of fat absorption in human duodenal mucosa

In seven healthy subjects the activities of various intestinal enzymes were studied using a fasting control peroral biopsy and two other biopsies 15 minutes and 30 minutes after an intestinal infusion of emulsified corn oil. Specific histochemical methods permitted the comparison of the enzymatic activities of the absorptive cells at the top of the villi before and during fat absorption which was demonstrated with a Sudan black stain. FOUR OXYDATIVE ENZYMES WERE MODIFIED AFTER THE CORN OIL INFUSION: NADH2-tetrazolium reductase, NADPH2-tetrazolium reductase, glucose-6-phosphate dehydrogenase, and lactate dehydrogenase. In six cases, the activity of NADH2-tetrazolium reductase was increased. Two of these subjects presented a simultaneous increase of NADPH2-tetrazolium reductase and glucose-6-phosphate dehydrogenase. Two other subjects presented a decrease in lactate dehydrogenase activity.