CSOs: tools for assessing their operation in our systems

In recent years, regulations have been introduced under European legislation to govern wastewater discharge into natural environments, with particular provisions for combined sewer overflows. It has therefore become indispensable to control the hydraulic behaviour of these constructions. This article addresses the issue of 1D and 3D hydraulic modelling of CSOs. In the case of 1D modelling, a computational tool that is adapted to the hydraulic complexity of side weirs has been designed. For 3D modelling, the Fluent calculation code has been tested. The two modelling approaches have been validated by the data collected from the small-scale model in Obernai (French).

Use of 3D modelling and several ultrasound sensors to assess overflow rate

A new instrumentation mode has been put in place in order to determine the overflow rate of five complex CSOs of the system in Sélestat (French), which are subject to self monitoring. 3D and 1D models have made it possible to predict the shapes of the water lines and suggest a location for the ultrasound sensors. In order to validate the instrumentation principle, three overhead sensors were placed on a weir. The overflow laws suggested are of the type Q(overflow) = a1h1b1 + a2h2b2 + a3h3b3. Early results of the overflow rate that have been obtained by applying the law are close to 10 % of the flow measured in the physical test bench. On the actual site, the ultrasound sensors were assembled on a rail covering the entire weir in order to be able to change their position in future after models calibration.

Candidiasis in the Intensive Care Unit

In the last 2 decades, Candida species have progressed from infrequent pathogens to among the most important and frequent opportunistic microorganisms causing nosocomial infection in intensive care unit (ICU) patients. Medical and surgical ICUs have become the epicenter of the Candida epidemic. Superficial infections causing oropharyngeal and esophageal candidiasis are common, and, although non-life threatening, may be refractory to conventional antifungals. In contrast, invasive candidiasis, candidemia, and hematogenous disseminated infections are associated with considerable attributable mortality. Although blood isolates of C. albicans remain susceptible to fluconazole, the increasing incidence of non- albicans Candida species with intrinsic reduced susceptibility to azoles creates new therapeutic challenges. Fortunately, lipid formulations of amphotericin B and the recently introduced echinocandin group represent new and strategic treatment responses to the challenge of invasive candidiasis.

Successful medical treatment of two patients with eosinophilic oesophagitis

BACKGROUND/PURPOSE

Significant oesophageal eosinophilia is associated with oesophagitis and gastroesophageal reflux (GER). Eosinophilic oesophagitis is a rare disease that causes thickening of the oesophageal wall, narrowing of the oesophageal lumen, and severe motor disturbance.

METHODS AND RESULTS

Two 12 yr-old patients with eosinophilic oesophagitis were studied prospectively. Clinical and investigation details are presented. Elemental formula was administered until complete remission of disease. Final outcome was assessed after 3 months on regular diet with exclusion of specific allergic components. Both patients responded to the dietary manipulation.

CONCLUSIONS

Eosinophilic oesophagitis must be included in the differential diagnosis when dealing with oesophageal strictures of unknown or unclear aetiology. Elimination diet therapy plays a crucial role in ameliorating the course of the illness. Blood eosinophilia correlates with therapeutic response and with improvement of the disease.

Trypanosoma cruzi mitochondrial malate dehydrogenase triggers polyclonal B-cell activation

It has been proposed that Trypanosoma cruzi, the aetiologic agent of Chagas' disease, produces mitogenic substances responsible for the polyclonal B-cell activation observed during the acute phase of the infection. Isolation and characterization of the molecules involved in the induction of polyclonal activation observed during infectious diseases have posed a great challenge for the immunologist over the last decade. In this work we report that a 33 kD protein obtained from an alkaline fraction of T. cruzi epimastigotes (FI) stimulates proliferation and promotes differentiation into antibody-secreting cells of normal murine B cells in a T-cell independent manner. By flow cytometry we also found that the 33 kDa protein induces an increase in the expression of MHC class II and B7.2 but not B7.1 molecules on the B-cell surface. Sequencing by mass spectrometry identified the T. cruzi 33 kD protein as hypothetical oxidoreductase, a member of the aldo/ketoreductase family. In this report we demonstrate that this protein is also present in the infective bloodstream trypomastigote form of the parasite and was identified as T. cruzi mitochondrial malate dehydrogenase (mMDH) by enzyme activity and by Western blotting using a specific mMDH polyclonal antiserum. The biologic relevance of mMDH-induced polyclonal activation concerning T. cruzi infection is discussed.

Major histocompatibility complex class I molecules bind natural peptide ligands lacking the amino-terminal binding residue in vivo

Major histocompatibility complex (MHC) class I-peptide complexes are stabilized by multiple interactions, including those of the peptidic NH(2)-terminal group in the A pocket of the MHC molecule. In this study, the characterization of four natural HLA-B39 ligands lacking the amino-terminal binding residue is reported. These peptides were found in the endogenous peptide pool of one or more of the B*3901, B*3905, and B*3909 allotypes and sequenced by nanoelectrospray mass spectrometry. Control experiments ruled out that they resulted from exopeptidase trimming of their NH(2)-terminally extended counterparts: NAc-SHVAVENAL, EHGPNPIL, IHEPEPHIL, and EHAGVISVL, also present in the same peptide pools, during purification. HAGVISVL and HVAVENAL behaved similarly to the corresponding NH(2)-terminally extended peptides in their binding to B*3901 and B*3909 at the cell surface in vitro, and in cell surface stabilization of B*3901. This is, to our knowledge, the first demonstration that peptides lacking the amino-terminal binding residue bind in vivo to classical MHC class I molecules. The results indicate that canonical MHC-peptide interactions in the A pocket are not always necessary for endogenous peptide presentation.

Multiple regimes of constrained chromosome motion are regulated in the interphase Drosophila nucleus

BACKGROUND

Increasing evidence indicates specific changes in the three-dimensional organization of chromosomes in the cell nucleus during the cell cycle and development. These changes may be linked to changes in both the coordinated regulation of gene transcription and the timing of chromosome replication. While there is cytological evidence for short-range diffusive motion of chromosomes during interphase, the mechanisms for large-scale chromosome remodeling inside the nucleus remain unknown.

RESULTS

Chromosome motion was tracked in Drosophila spermatocyte nuclei by 3D fluorescence microscopy. The Lac repressor/lac operator system was used to label specific chromosomal sites in live tissues, allowing extended observation of chromatin motion in different cell cycle stages. Our results reveal a highly dynamic chromosome organization governed by two types of motion: a fast, short-range component over a 1-2 s time scale and a slower component related to long-range chromosome motion within the nucleus. The motion patterns are consistent with a random walk. In early G2, short-range motion occurs within a small, approximately 0.5 microm radius domain, while long-range motion is confined to a much larger, chromosome-sized domain. Progression through G2 as cells approach meiotic prophase is accompanied by a complete arrest of long-range chromosome motion.

CONCLUSIONS

Our analysis provides direct evidence for cell cycle-regulated changes in interphase chromatin motion. These changes are consistent with changes in local and long-range constraints on chromosome motility. We propose that dynamic interactions between chromosomes and internal nuclear structures modulate the range and rate of interphase chromatin diffusion and thereby regulate large-scale nuclear chromosome organization.

Sensory input directs spatial and temporal plasticity in primary auditory cortex

The cortical representation of the sensory environment is continuously modified by experience. Changes in spatial (receptive field) and temporal response properties of cortical neurons underlie many forms of natural learning. The scale and direction of these changes appear to be determined by specific features of the behavioral tasks that evoke cortical plasticity. The neural mechanisms responsible for this differential plasticity remain unclear partly because important sensory and cognitive parameters differ among these tasks. In this report, we demonstrate that differential sensory experience directs differential plasticity using a single paradigm that eliminates the task-specific variables that have confounded direct comparison of previous studies. Electrical activation of the basal forebrain (BF) was used to gate cortical plasticity mechanisms. The auditory stimulus paired with BF stimulation was systematically varied to determine how several basic features of the sensory input direct plasticity in primary auditory cortex (A1) of adult rats. The distributed cortical response was reconstructed from a dense sampling of A1 neurons after 4 wk of BF-sound pairing. We have previously used this method to show that when a tone is paired with BF activation, the region of the cortical map responding to that tone frequency is specifically expanded. In this report, we demonstrate that receptive-field size is determined by features of the stimulus paired with BF activation. Specifically, receptive fields were narrowed or broadened as a systematic function of both carrier-frequency variability and the temporal modulation rate of paired acoustic stimuli. For example, the mean bandwidth of A1 neurons was increased (+60%) after pairing BF stimulation with a rapid train of tones and decreased (-25%) after pairing unmodulated tones of different frequencies. These effects are consistent with previous reports of receptive-field plasticity evoked by natural learning. The maximum cortical following rate and minimum response latency were also modified as a function of stimulus modulation rate and carrier-frequency variability. The cortical response to a rapid train of tones was nearly doubled if BF stimulation was paired with rapid trains of random carrier frequency, while no following rate plasticity was observed if a single carrier frequency was used. Finally, we observed significant increases in response strength and total area of functionally defined A1 following BF activation paired with certain classes of stimuli and not others. These results indicate that the degree and direction of cortical plasticity of temporal and receptive-field selectivity are specified by the structure and schedule of inputs that co-occur with basal forebrain activation and suggest that the rules of cortical plasticity do not operate on each elemental stimulus feature independently of others.

Cellular immune response and Th1/Th2 cytokines in human neurocysticercosis: lack of immune suppression

Some reports have suggested that human neurocysticercosis (NCC) induces immunosuppression. To test this hypothesis, we performed a study on active cases of NCC who had not received cestocidal or immunosuppressive treatments. We examined blood counts and specific T cell markers (CD3, CD4, and CD8) by flow cytometry and found no differences between patients with NCC and healthy individuals. Both groups responded to concanavalin A (Con A), and patients with NCC responded more to a parasite crude antigen than uninfected individuals. Peripheral blood mononuclear cells were examined for interleukin (IL)-2, interferon-gamma, IL-10, and IL-4 mRNA. Regardless of infection status, more than 60% of individuals synthesized IL-2 mRNA and, less frequently, the other cytokines. These data suggest that immunosuppression does not occur in NCC patients.

Surgical approach to funnel-shaped congenital tracheal stenosis

PURPOSE

The aim of this study was to evaluate the results obtained by 2 different techniques of tracheoplasty in the treatment of long-segment, funnel-shaped congenital tracheal stenosis (CTS) in 2 tertiary paediatric hospitals.

METHODS

The clinical records of patients with long segment congenital tracheal stenosis during the period January 1990 to June 1999 were reviewed retrospectively. Age, gender, symptoms, imaging (x-ray, computed tomography, magnetic resonance imaging, or bronchography), endoscopic findings, associated anomalies, treatment, intubation time, postoperative treatment, intensive care unit stay, complications, hospital stay, evolution, and follow-up time were analyzed. Short congenital tracheal stenosis treated by resection and end-to-end anastomosis are not included. Results are given as mean +/- SEM.

RESULTS

Ten (7 boys, 4 girls) of 14 patients with CTS had a funnel-shaped CTS. Mean age at treatment was 9.7 +/- 4.8 months (range, 3 days to 4.7 years). All of the patients presented with CTS affecting the distal third of the trachea and 4 of them extension to 1 main stem bronchus. They were treated by 2 different types of tracheoplasty: anterior costal cartilage graft (ACGT, 6 patients) and slide tracheoplasty (ST, 4 patients). All the patients treated by ACGT failed: 4 died and 2 required further surgery for restenosis. Causes of death were acute respiratory failure during surgery (2 cases) and anastomotic dehiscence (2 cases). The patients treated with ST are asymptomatic and doing well. Mean postoperative intubation time of the ACGT group was 35 +/- 25 days (10 to 60 days), whereas in the ST group it was 14 +/- 12 days (0 to 51 days). Mean hospital stays were 292 +/- 271 days (21 to 563 days) and 24 +/- 13 days (7 to 63 days), respectively. Mean follow-up time is 28 +/- 14 months (3 to 94 months).

CONCLUSIONS

Surgery of long-segment congenital tracheal stenosis has a high failure and complication rate with vital implications in prognosis. Treatment should be done in a multidisciplinary basis by a highly trained and motivated team. Slide tracheoplasty seems to be the better option, although further multicentre studies should be conducted.

Basal forebrain acetylcholine release during REM sleep is significantly greater than during waking

Cholinergic neurons of the basal forebrain supply the neocortex with ACh and play a major role in regulating behavioral arousal and cortical electroencephalographic activation. Cortical ACh release is greatest during waking and rapid eye movement (REM) sleep and reduced during non-REM (NREM) sleep. Loss of basal forebrain cholinergic neurons contributes to sleep disruption and to the cognitive deficits of many neurological disorders. ACh release within the basal forebrain previously has not been quantified during sleep. This study used in vivo microdialysis to test the hypothesis that basal forebrain ACh release varies as a function of sleep and waking. Cats were trained to sleep in a head-stable position, and dialysis samples were collected during polygraphically defined states of waking, NREM sleep, and REM sleep. Results from 22 experiments in four animals demonstrated that means +/- SE ACh release (pmol/10 min) was greatest during REM sleep (0.77 +/- 0.07), intermediate during waking (0.58 +/- 0.03), and lowest during NREM sleep (0.34 +/- 0.01). The finding that, during REM sleep, basal forebrain ACh release is significantly elevated over waking levels suggests a differential role for basal forebrain ACh during REM sleep and waking.

Results of the Azizkhan procedure for long-term suprastomal tracheomalacia

One of the reasons of failure to decannulate patients after airway surgery or long-term tracheostomy is suprastomal tracheomalacia. We present 7 cases with long-term tracheostomies treated by an anterior cricoid suspension described by Azizkhan in 1993. Prior to surgery, other causes of airway obstruction, as well as the presence of gastroesophageal reflux disease should be ruled out. All of them are decannulated. This procedure is a safe surgical technique, easily reproducible and with low costs.

Surgery of subglottic stenosis in neonates and children

The excellent management of patients in the different Intensive Care Units has decreased mortality but, as a side effect, we have to treat an increasing number of patients with airway problems secondary to prolonged intubation. The clinical records of patients diagnosed of acquired or congenital subglottic stenosis (SE) between 1990 and 1995 were retrospectively reviewed. Types of treatment included conservative, endoscopic, and open surgery: anterior cricoid split (ACS), anterior laryngotracheoplasty (ALTP) and anteroposterior laryngotracheoplasty (APLTP). 46 patients had SE: 7 congenital and 39 acquired. According to Cotton's classification 13 had grade I, 16 grade II, 12 grade III and none grade IV. Eleven of twelve cases treated conservatively did well (92%); one out of six patients managed endoscopically required further surgery (7%); good results were obtained in 5 of 7 cases treated by ACS (71 %); 8 out of 9 patients treated by ALTP did well (89%) and 7 out of 8 managed by APLTP had good results (87.5%). One iatrogenic suture dehiscence required further surgery. There is no statistical difference in the complication rate between patients treated conservatively and those treated by open surgery, while the mean hospital stay was higher in the latter (p < 0.05). An appropriate surgical technique should be offered to those patients with SE who do not do well with conservative management, since these techniques have yielded good results with a low rate of complications. Long-term follow-up shows the absence of recurrence.

Deletion of an insulator element by the mutation facet-strawberry in Drosophila melanogaster

Eukaryotic chromosomes are thought to be subdivided into a series of structurally and functionally independent units. Critical to this hypothesis is the identification of insulator or boundary elements that delimit chromosomal domains. The properties of a Notch mutation, facet-strawberry (fa(swb)), suggest that this small deletion disrupts such a boundary element. fa(swb) is located in the interband separating polytene band 3C7, which contains Notch, from the distal band 3C6. The fa(swb) mutation alters the structural organization of the chromosome by deleting the interband and fusing 3C7 with 3C6. Genetic studies also suggest that fa(swb) compromises the functional autonomy of Notch by allowing the locus to become sensitive to chromosomal position effects emanating from distal sequences. In the studies reported here, we show that a DNA fragment spanning the fa(swb) region can insulate reporter transgenes against chromosomal position effects and can block enhancer-promoter interactions. Moreover, we find that insulating activity is dependent on sequences deleted in fa(swb). These results provide evidence that the element defined by the fa(swb) mutation corresponds to an insulator.

The clinical effectiveness of a dentifrice containing triclosan and a copolymer for providing long-term control of breath odor measured chromatographically

The objective of this double-blind clinical study was to investigate the effectiveness of a commercially available dentifrice containing triclosan and a copolymer (Colgate Total Toothpaste) for controlling long-term, i.e., seven-hour and overnight breath odor. In particular, a comparison was made between the level of control of breath odor provided by the test dentifrice, and that provided by a placebo dentifrice which did not contain triclosan or a copolymer. This study followed a two-treatment, two-period crossover design. Prospective subjects were provided with a supply of a commercially available fluoride dentifrice, which was used for a one-week period prior to the two seven-day treatment periods. During each treatment period, subjects were instructed to brush their teeth twice a day, morning and evening, for sixty seconds with their assigned study dentifrice, using the soft-bristled toothbrush which had been provided. On the morning following the seventh day of each treatment period, subjects reported to the clinical facility for overnight breath odor assessments. Directly following this, subjects brushed their teeth, ate and drank normally, and reported once again to the clinical facility at seven hours post-toothbrushing for another breath odor assessment. Prior to the overnight breath odor assessments, subjects refrained from brushing their teeth, rinsing their mouths or using breath mints, and from eating or drinking anything on the morning of the evaluation. Subjects refrained from the use of tobacco products, and from eating onions, garlic, or strong spices throughout the entire study. Breath odor was instrumentally evaluated by measuring the level of volatile sulfur compounds in the mouth air using a 565 Tracor gas chromatograph equipped with a flame photometric detector. Measurements were taken in duplicate, and then averaged. Levels of volatile sulfur compounds were expressed in nanograms per milliliter (ng/ml) of mouth air. The two dentifrices exhibited statistically significant differences (p < 0.05) with respect to both overnight breath odor and seven-hour post-toothbrushing breath odor. The mean overnight breath odor scores were 9.63 ng/ml for Colgate Total Toothpaste, and 12.64 ng/ml for the placebo dentifrice. For seven-hour breath odor, the mean scores were 5.62 ng/ml for Colgate Total Toothpaste, and 7.10 ng/ml for the placebo dentifrice. Thus, the results of this double-blind clinical study on 19 subjects support the conclusion that Colgate Total Toothpaste provides effective seven-hour and overnight control of breath odor.

alpha-Alkyl-alpha-Amino-beta-Lactam Peptides: Design, Synthesis, and Conformational Features

Remarkable asymmetric induction is achieved in the alkylation of the lithium enolate of the beta-lactam 1. This allows the first time access to a new family of peptidomimetics 2 with predictable conformational constraints.

The Zw5 protein, a component of the scs chromatin domain boundary, is able to block enhancer-promoter interaction

The scs and scs' elements were proposed to function as chromatin domain boundaries for the 87A7 heat shock locus in Drosophila melanogaster. Here we report the identification and characterization of SBP (scs binding protein), a component of the scs nucleoprotein complex. SBP binds specifically to a 24-bp region of scs in vitro and is associated with scs in vivo. Multiple copies of an oligonucleotide containing the SBP recognition sequence are capable of blocking enhancer-promoter interactions in transgene assays. Mutations in the oligonucleotide that disrupt SBP binding in vitro also eliminate enhancer-blocking activity in vivo. We show that SBP is encoded by the zeste-white 5 gene and that mutations in zeste-white 5 reduce the enhancer-blocking activity of the multimerized oligonucleotides.

Lung transplantation from ventilated non-heart-beating donors: experimental study in a neonatal swine model

BACKGROUND/PURPOSE

A shortage of transplantable lungs is a constant and frustrating reality. The use of organs retrieved from ventilated non-heart-beating donors (VNHBD) may alleviate this problem. The purpose of this work was to assess lung function of donor grafts subjected to different time lengths of in situ warm ischemia (WIT).

METHODS

Twenty piglets weighing between 6 and 8 kg were allocated randomly to the following study groups: Sham (n = 5), heart-beating donors, non warm ischemia; I-30 (n = 5), I-60 (n = 5) and I-90 (n = 5), VNHBD-WIT of 30, 60, and 90 minutes, respectively. Recipients were rendered dependent on the single left transplanted lung by clamping right pulmonary artery and bronchus 1 hour after transplantation. Assessment of pulmonary function was monitored hourly by hemodynamic, oxygenation, and pulmonary mechanic measurements during a period of 6 hours after reperfusion. Lung grafts were weighed pre- and posttransplantation.

RESULTS

Final mean lung weight was significantly greater in VNHBD (92.5+/-3.1 v Sham values 75.6 g+/-2.4; P < .01). Cold ischemic time averaged 80.1+/-2.7 minutes. After right lung exclusion, hemodynamic changes consisted of a sustained increase in pulmonary vascular resistance and a reduction in cardiac output. Lung mechanics also deteriorated with a gradual rise in airway resistance and a fall in compliance.

CONCLUSIONS

These data suggest that posttransplantation lung graft function from VNHBD with up to 90 minutes of WIT, is preserved and equivalent to those achieved by grafts harvested after heart-beating donation.