Modification of Cellulose Acetate Microfiltration Membranes Using Graphene Oxide-Polyethyleneimine for Enhanced Dye Rejection

Pressure-based membrane processes represent excellent water resource recovery prospects from industrial waste streams. In contrast with conventional pretreatment technologies, studies have shown that membrane pretreatment applications, such as microfiltration (MF), are more cost-effective and improve the results of the overall treatment processes. Hence, enhancing rejection efficiency of MF will enhance the performance of any downstream treatment processes. In this study, 0.45 µm cellulose acetate (CA) microfiltration membranes were modified by vacuum filtration-assisted layer-by-layer deposition of bilayers composed of negatively charged graphene oxide (GO) and positively charged polyethyleneimine (PEI). The performance of 1-, 2-, and 4-bilayer GO-PEI-modified membranes were investigated for their dye-rejection of anionic eriochrome black T (EBT) dye and cationic methylene blue (MB) dye in a cross-flow membrane module. As the number of bilayers on the membrane increased, the membrane thicknesses increased, and the deionized (DI) water flux through the membranes decreased from 4877 LMH/bar for the control (no bilayer) membrane to 2890 LMH/bar for the 4-bilayer membrane. Conversely, the dye-rejection performance of the modified membranes increased as increasing bilayers of GO-PEI deposited on the membranes. The anionic EBT dye saw superior rejection (~90% rejection) compared to the cationic MB dye (~80% rejection), which can be attributable to the electrostatic repulsion between the negatively charged GO surface and anionic EBT dye. After 50% recovery of the saline and dye-laden feed water, there was an observed drop in DI water fluxes of ~40-41% and 36%, respectively. There was also a slight increase in EBT dye-rejection during the composite feed-water experiments, attributed to the precipitation of salts on the membrane feed side or pore spaces, which subsequently reduce the membrane pore sizes.

Experimental evidence that polystyrene nanoplastics cross the intestinal barrier of European seabass

Plastic pollution in marine ecosystems constitutes an important threat to marine life. For vertebrates, macro/microplastics can obstruct and/or transit into the airways and digestive tract whereas nanoplastics (NPs; < 1000 nm) have been observed in non-digestive tissues such as the liver and brain. Whether NPs cross the intestinal epithelium to gain access to the blood and internal organs remains controversial, however. Here, we show directly NP translocation across the intestinal barrier of a fish, the European seabass, Dicentrarchus labrax, ex vivo. The luminal side of median and distal segments of intestine were exposed to fluorescent polystyrene NPs (PS-NPs) of 50 nm diameter. PS-NPs that translocated to the serosal side were then detected quantitatively by fluorimetry, and qualitatively by scanning electron microscopy (SEM) and pyrolysis coupled to gas chromatography and high-resolution mass spectrometry (Py-GC-HRMS). Fluorescence intensity on the serosal side increased 15-90 min after PS-NP addition into the luminal side, suggesting that PS-NPs crossed the intestinal barrier; this was confirmed by both SEM and Py-GC-HRMS. This study thus evidenced conclusively that NPs beads translocate across the intestinal epithelium in this marine vertebrate.

Sustainable laser-based technology for insect pest control

Aphids damage directly or indirectly cultures by feeding and spreading diseases, leading to huge economical losses. So far, only the use of pesticides can mitigate their impact, causing severe health and environmental issues. Hence, innovative eco-friendly and low-cost solutions must be promoted apart from chemical control. Here, we have investigated the use of laser radiation as a reliable solution. We have analyzed the lethal dose required to kill 90% of a population for two major pest aphid species (Acyrthosiphon pisum and Rhopalosiphum padi). We showed that irradiating insects at an early stage (one-day old nymph) is crucial to lower the lethal dose without affecting plant growth and health. The laser is mostly lethal, but it can also cause insect stunting and a reduction of survivors' fecundity. Nevertheless, we did not notice any significant visible effect on the offspring of the surviving irradiated generation. The estimated energy cost and the harmless effect of laser radiation on host plants show that this physics-based strategy can be a promising alternative to chemical pesticides.

Determination of Ethoxyquin in Feeds by Liquid Chromatography: Collaborative Study

Ethoxyquin is a chemical antioxidant used in feeds, ingredients, fats, and oils. A liquid chromatographic (LC) method for determination of ethoxyquin was developed. The method involves acetonitrile extraction of the sample and isocratic Cis reversed-phase chromatography with ammonium acetate buffer-acetonitrile as mobile phase and fluorescence detection. A collaborative study of the determination of ethoxyquin in various meals and extruded pet foods was conducted by The lams Company Research Laboratory. Eleven laboratories analyzed 16 samples (including 2 blind duplicates) consisting of 7 meat meals and 9 extruded pet foods. Sample means ranged from 0.25 to 289 ppm. Repeatability standard deviations ranged from 0.08 to 3.2 ppm, and repeatability relative standard deviations ranged from 4.5 to 32%. Reproducibility standard deviations ranged from 0.12 to 13 ppm, and reproducibility relative standard deviations ranged from 4.5 to 55%. The LC method for determination of ethoxyquin in feeds has been adopted first action by AOAC INTERNATIONAL.

Plasma circulating tumor DNA as an alternative to metastatic biopsies for mutational analysis in breast cancer

BACKGROUND

Molecular screening programs use next-generation sequencing (NGS) of cancer gene panels to analyze metastatic biopsies. We interrogated whether plasma could be used as an alternative to metastatic biopsies.

PATIENTS AND METHODS

The Ion AmpliSeq™ Cancer Hotspot Panel v2 (Ion Torrent), covering 2800 COSMIC mutations from 50 cancer genes was used to analyze 69 tumor (primary/metastases) and 31 plasma samples from 17 metastatic breast cancer patients. The targeted coverage for tumor DNA was ×1000 and for plasma cell-free DNA ×25 000. Whole blood normal DNA was used to exclude germline variants. The Illumina technology was used to confirm observed mutations.

RESULTS

Evaluable NGS results were obtained for 60 tumor and 31 plasma samples from 17 patients. When tumor samples were analyzed, 12 of 17 (71%, 95% confidence interval (CI) 44% to 90%) patients had ≥1 mutation (median 1 mutation per patient, range 0-2 mutations) in either p53, PIK3CA, PTEN, AKT1 or IDH2 gene. When plasma samples were analyzed, 12 of 17 (71%, 95% CI: 44-90%) patients had ≥1 mutation (median 1 mutation per patient, range 0-2 mutations) in either p53, PIK3CA, PTEN, AKT1, IDH2 and SMAD4. All mutations were confirmed. When we focused on tumor and plasma samples collected at the same time-point, we observed that, in four patients, no mutation was identified in either tumor or plasma; in nine patients, the same mutations was identified in tumor and plasma; in two patients, a mutation was identified in tumor but not in plasma; in two patients, a mutation was identified in plasma but not in tumor. Thus, in 13 of 17 (76%, 95% CI 50% to 93%) patients, tumor and plasma provided concordant results whereas in 4 of 17 (24%, 95% CI 7% to 50%) patients, the results were discordant, providing complementary information.

CONCLUSION

Plasma can be prospectively tested as an alternative to metastatic biopsies in molecular screening programs.

Abstract P1-04-03: Genome-wide analysis of copy number variations and mutation profiles of single circulating tumour cells using massively parallel paired-end sequencing

INTRODUCTION

Recent advances in single cell isolation techniques and next generation sequencing (NGS) have paved the way for the genome-wide molecular analysis of individual circulating tumour cells (CTCs) in patients with metastatic carcinomas. Here we present the results of a pilot study evaluating the feasibility and reliability of NGS of single CTC from whole blood samples.

MATERIALS & METHODS

Single cells of the human breast cancer cell line HCC38 were harvested from spiked blood samples in a semi-automated workflow consisting of immunomagnetic enrichment using the CellSearch system and dielectrophoretic cell sorting using the DEPArray system. DNA was isolated and amplified using the Ampli1 whole genome amplification (WGA) kit and subjected to low-coverage genome-wide paired-end sequencing for copy number variation (CNV) analysis and targeted re-sequencing of 200 cancer-related genes for somatic mutation analysis.

RESULTS

Single-cell WGA products of four HCC38 cells were subjected to whole genome sequencing for CNV analysis. Average coverage depth was 0,68x. At a binning window of 50 kb, detection results of CNVs in single-cell samples were highly consistent (&gt;81% copy number concordance per bin genome wide) with CNV profiles from non-amplified multi-cell samples of the same cell line. We could demonstrate that part of the discordance was due to the acquisition of novel DNA-rearrangements in the single cells. Three of the single-cell WGA products were additionally subjected to targeted re-sequencing for mutation analysis of 200 selected genes, of which the analysis is currently ongoing.

DISCUSSION

Our study demonstrates the feasibility of a comprehensive genome-wide CNV analysis and targeted mutation analysis using NGS of single tumour cells isolated from whole blood samples in a highly automated isolation workflow. This approach provides a robust framework for the study of intercellular heterogeneity within the CTC population in blood samples of patients with (metastatic) breast cancer. In addition, our results document the extent of WGA-induced bias of a recently commercialized PCR-based WGA kit.

These authors contributed equally to the data presented in this abstract.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-04-03.

Abstract P3-05-03: Characterization of PIK3CA mutations in lobular breast cancer

Background: Invasive lobular carcinoma (ILC) is the second most common breast cancer (BC) histotype, after invasive ductal carcinoma (IDC), representing ∼10-15% of the global BC population. The vast majority of ILC are estrogen receptor (ER)-positive. PIK3CA has been reported to be the most frequently mutated gene in ER-positive BC. However, until now PIK3CA mutations have mainly been described in IDC. In this study, we sought to characterize the type, prevalence, intra-patient (pt) mutational heterogeneity, and the association with transcriptomic phenotype and clinical outcome of PIK3CA mutations in ILC.

Methods: Gene expression data (HG-U133 Plus2.0) was generated from frozen samples of 116 ILC (primary tumors). For the same series, PIK3CA mutation profiling (Sequenom) was performed on at least 2 formalin-fixed paraffin embedded (FFPE) tissue blocks of the primary tumor for 102 cases, and on the only available block for the remaining 14 cases. Matched local recurrence (LR) and multiple metastatic (M) samples were also characterized for 3 and 8 pts respectively. For the transcriptomic and survival analyses, we evaluated the association between PIK3CA mutation status and gene signatures recapitulating important biological processes, and invasive disease-free & overall survival, respectively.

Results: PIK3CA mutations were detected in the primary tumor of 40/116 (35%) ILC pts: 14 (35%) mutations in the helical domain and 25 (62.5%) in the kinase domain. PIK3CA analysis in different blocks from the same primary tumors revealed a mutational heterogeneity in 7/102 (7%) cases. There was a discordance between primary and LR samples in 1/3 patients with LR, with a mutation reported in the primary but in not the LR. In 3/8 pts for which M samples were available, we observed intra-pt heterogeneity. In the first pt, a mutation in the kinase domain was reported only in 1/2 investigated blocks from the primary tumor, and in only 1/2 liver Ms. In the second pt, a mutation in the helical domain was found in the primary tumor and in the LR but not in the pleura M. In the third pt, although no mutation was observed in the primary tumor, a mutation in the helical domain was found in the M of the epiploon, but not in the Ms from the diaphragm or the ovary. Transcriptomic analyses revealed that primary tumors with a PIK3CA mutation in the helical domain were associated with increased levels of 2 stroma signatures (Bonferroni p-val: PLAU sign -Desmedt 2008–0.042 and DCN sign- Farmer 2009 – 0.048) compared to tumors without mutation. The survival analyses did not reveal any significant difference in survival between pts with and without a PIK3CA mutation.

Conclusions: This study represents the largest series described so far which investigated PIK3CA mutations in ILC. The incidence of PIK3CA mutations reported here is similar to the one reported for IDC. The investigation of multiple tumor samples per pt revealed intra-tumor as well as primary/recurrence heterogeneity. To get a definitive answer on the prognostic role of PIK3CA mutation in ILC, we are currently performing a PIK3CA mutation profiling study (Sequenom) on a series of ∼1000 consecutive ILC with long-term follow up (Iorfida et al. 2012); results will be available by SABCS2012.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-05-03.

A case of mononeuropathy multiplex with type II cryoglobulinemia, necrotizing vasculitis and low grade B cell lymphoma

OBJECTIVE

To elucidate the cause and mechanisms of nerve fiber lesions in a case of mononeuropathy multiplex (MNM).

MATERIAL AND METHODS

A 65-year-old man had a MNM for 6 months and no previous history of peripheral nerve impairment was known. He underwent a muscle and nerve biopsy by the same skin incision on the right leg.

RESULTS

Paraffin-embedded fragments from the superficial peroneal nerve and peroneous brevis muscle disclosed characteristic lesions of necrotizing vasculitis. Complement had low levels, but a search for cryoglobulinemia was negative. Two months later a purpura appeared in the lower limbs and a mixed Type II cryoglobulinemia was disclosed, whereas a search for hepatitis C virus (HCV) remained negative. Five months later the blood contained 8,600 lymphocytes/mm3 and a low grade B cell lymphoma was disclosed in the bone marrow.

CONCLUSIONS

Although not having HCV infection, our patient had mixed Type II cryoglobulinemia, necrotizing vasculitis and B cell lymphoma. Each of these three abnormalities might be in part responsible for nerve fibers impairment, with acute axonal degeneration. Mixed cryoglobulinemia must be searched carefully in patients with vasculitic neuropathy.

[Evaluation of the health inpact of the floods in the Gard on respiratory health of disaster victims]

In 2002 the Gard was subjected to exceptional flooding, as much by their size as by the number of affected community victims, more than the Nimes floods in October 1988. No community was spared and more than 800 families had to be rapidly re-located. As the medical bibliography of the impact of the floods on respiratory heath was not conclusive we have proposed to the CHU of Nimes a hospital clinical research project undertaken by the members of RNSA, the Institute of Public Health of Brussels and the European Centre for Medical Bioclimate Research and Teaching, who have accepted to share their knowledge with the Gard. It seems to us to be indispensable, considering the certifications made by the professionals on the health on the department, to validate the study methods for the evaluation of the health impact of the floods, with regard to the development of moulds in the environment, so as to recognise the risk to health, in the very special circumstances, and so allow the mobilisabion of useful resources more rapidly than previously. The new floods to which the department was subjected in December 2003 made us regret that we had not developed this project more quickly.

[Resurgence of syphilis: a prospective study at an University Hospital, Nimes]

BACKGROUND

Since 2000, the incidence of syphilis has increased in France. The study objective was to estimate the frequency of syphilis in Languedoc Roussillon region in Southern France.

METHOD

The prospective study was conducted between January 1, 2003 and June 30, 2003 in different medical wards in a French University Hospital, Nimes. The diseased patients in this study answered to a questionnaire, providing epidemiological and socio-economic data, symptomatology and treatment-seeking behaviour. Blood specimens were tested for syphilis by the serological methods (TPHA, VDRL, FTA).

RESULTS

In 6 months, serologic evidence of syphilis infection was found in 30 patients. Men were more than twice as likely as women to be infected with syphilis. Most men (64.7%) acquired the infection homosexually. Four women acquired infection during pregnancy. The mean age of study population was 46.3 years. 40.7% were married. Out of 27 cases, 70.4% cases had an associated sexually transmitted infection (HIV, hepatitis, herpes, and gonorrhoea).

CONCLUSIONS

These data confirm the increase of syphilis in south of France and underline the importance of a permanent monitoring of sexually transmitted infection in target populations to allow a timely diagnosis and an appropriate treatment, and to plan preventive strategies.

[Ragweed pollinosis in the Gard and the Vaucluse: myth or reality? For the Associated Group of Independent Allergologues and Hospital Staff of Nimes]

Thirteen allergists reviewed 18 patients living and working in Vaucluse and Gard who suffered from ragweed from August 15 to October 15 2004. This preliminary study showed how difficult it is to realise a clinical data collection about pollinosis. It is entirely necessary to work together to build the protocol, with a clear and valid definition of inclusion and exclusion criteria.

Localisation bronchique révélatrice d’une maladie de Hodgkin

INTRODUCTION

Bronchial localisation of Hodgkins disease has been described only rarely and it is exceptional as the presenting feature. More frequently the clinical presentation is extrinsic bronchial compression.

OBSERVATION

Mr B.C., 34 years old, had a past history of cured alcoholism and abuse of cannabis and buprenorphine. In February 2001 he presented with generalised pruritus, weight loss of 8 kg in one year, a 1 cm node above the right clavicle, hypereosinophilia, and CT evidence of non-obstructive mediastinal adenopathy and interstitial lesions in the right lower lobe. Five months later he was admitted to hospital with a febrile illness. The right supraclavicular node had disappeared but there was gross mediastinal adenopathy, associated with a right perihilar soft tIssue mass encircling the upper, middle and lower lobe bronchi and multiple peripheral parenchymal nodules. Bronchoscopy revealed complete stenosis of the right upper lobe bronchus and bronchial histology confirmed Hodgkins disease.

CONCLUSIONS

Bronchoscopy is an effective investigation for the detection of endobronchial Hodgkins disease, often overlooked because parenchymal abnormalities are attributed to extrinsic compression. In order to determine the disease stage more precisely we advise immediate bronchoscopy when there is suspicion that Hodgkins disease may be the cause of clinical.

Low plasma levels of dehydroepiandrosterone sulphate in HIV-positive patients coinfected with hepatitis C virus

OBJECTIVES

To evaluate plasma levels of dehydroepiandrosterone sulphate (DHEAS) in a cohort of HIV-infected patients and to analyse factors associated with DHEAS levels.

METHODS

We conducted a cross-sectional survey in the Nîmes University Hospital cohort of HIV-infected patients in south-eastern France. All HIV-infected patients with at least one outpatient visit between 1 January and 1 September 2002 were included in the study. Sociodemographic, clinical, therapeutic, immuno-virological and plasma DHEAS level data were collected during this period. Hepatitis C virus (HCV) coinfection was defined as the presence of HCV antibody with positive RNA. To identify factors associated with plasma DHEAS levels, Spearman's rank correlation and univariate and multivariate linear regression analyses were used.

RESULTS

The DHEAS plasma level was measured in 137 patients (104 men and 33 women), 37 (27.0%) of whom were HCV coinfected. The median age of the patients was 39.1 years [interquartile range (IQR): 34.9-48.7] for women and 41.8 years (36.5-47.7) for men. The median DHEAS level was 5.5 micromol/L (IQR: 2.3-8.8) for the whole sample of 137 patients, and was lower in women (2.4 micromol/L; 1.5-6.6) than in men (6.1 micromol/L; 2.5-9.0) (P<0.01), and lower in patients coinfected with HCV (2.1 micromol/L; 0.6-6.7) than in those not coinfected (6.6 micromol/L; 3.0-9.1) (P<0.01). Of all prognostic factors studied in the variance covariance analysis, three factors were associated with DHEAS: age, gender and HCV coinfection. Subgroup analysis revealed that the age-adjusted mean of the DHEAS level was lower in HCV coinfected patients for both women (1.3+/-1.1 micromol/L) and men (4.0+/-0.7 micromol/L), compared with patients not HCV coinfected (women, 5.3+/-0.7 micromol/L; men, 7.2+/-0.4 micromol/L) (P<0.01).

CONCLUSIONS

This is the first report of the determination of DHEAS plasma levels in HIV/HCV coinfected patients. When age and sex were taken into account, the DHEAS plasma level was found to be significantly lower in HCV coinfected patients. To date, the pathophysiology of such findings is unknown.

[Usefulness of molecular genetic analysis of the PRNP gene in patients with cerebellar ataxia: a new case of fatal familial insomnia]

We report the fifth French case of fatal familial insomnia, characterized by a mutation at codon 178 of prion protein gene and by heterozygoty (Met/Val) at codon 129. The clinical picture included cerebellar ataxia, dysautonomia and frontal lobe syndrome. Prion protein gene analysis was performed in order to support a diagnosis of Creutzfeldt-Jakob disease and assert the diagnosis of fatal familial insomnia. Neuropathologic analysis showed unusual changes including severe neuronal loss in the inferior olive and the dentate nucleus, and absence of obvious lesions in the thalamus. Moreover, spongiform changes were moderate in the superior temporal cortex and the occipital cortex. There was no spongiform change in frontal cortex. Abnormal prion protein (PrP(res)) was mainly evidenced in the parietal cortex. Molecular genetic study of the PRNP gene should be performed in patients who present with a cerebellar ataxia of equivocal origin.

Using cost-analysis techniques to measure the value of nurse practitioner care

Nurse practitioners are in a unique position to deliver high-quality care to a variety of populations and are being utilized in many countries worldwide. Although certain aspects of the nurse practitioner role may differ from country to country, limited financial support and competition for access to patients make it incumbent on nurse practitioners to document the cost-effectiveness of their care. Cost analysis, a business tool that can be used by any practitioner in any health care system, was used to examine business practices of an academic-based nurse-managed centre. In order for this tool to be effective, nurse practitioners must become comfortable with using cost-analysis techniques in their practices. Linking outcome data with cost data was found to be one method for explicating the value of nurse practitioner practice. Nurse practitioners must also recognize that they are competing with primary-care physician practices and other primary health-care practices. It is vital for nurse practitioners to document both the quality and the costs of their care in order to compete with physicians and other health care providers, in order to influence policy and other health-care decision makers.

Chronic cough induced by abacavir apart from a context of hypersensitivity

We report the case of an HIV-infected woman, who presented with chronic and productive cough without sign of hypersensitivity (fever, cutaneous eruption, gastrointestinal disorders), while taking abacavir. All complementary exams being negative, the involvement of abacavir has been suspected. So the drug was stopped leading to a rapid disappearance of cough. It is the first report of chronic cough with abacavir apart of a context of hypersensitivity reaction.

Peripheral neuropathy associated with mitochondrial disorders: 8 cases and review of the literature

Forty-three cases of peripheral neuropathy (PN) have been reported in the literature with a proven mitochondria (mt) DNA mutation, and 21 had a peripheral nerve biopsy (PNB). We studied 8 patients, 1 of whom had severe sensory PN, 3 mild PN, and 4 subclinical PN. Nerve biopsy was performed in every case; all patients showed axonal degeneration and 4 showed features of primary myelin damage. In addition, there were 2 crystalline-like inclusions in the Schwann cell cytoplasm of a patient with MERRF, and 1 in a patient with multiple deletions on the mtDNA. There are 11 cases of PNB in the literature with axonal lesions, 5 with demyelination, and 4 with mixed lesions. One PNB was not modified. A few crystalline-like inclusions were seen in 1 case of MERRF. Such inclusions were first reported in the Schwann cell cytoplasm of unmyelinated fibers in a patient with Refsum disease and were considered to be modified mitochondria. However, their mitochondrial origin remains debatable.

[Inhaled corticoids and systemic secondary effects: controversies]

Studies that compare the systemic impact of inhaled corticosteroids (CI) abound in the literature often with contradictory results. Most of the studies report secondary biological effects in the suprarenal function without clinical effect due to taking high doses of inhaled corticosteroids. Surveillance of the secondary effects on bone is difficult to demonstrate. Finally, speed for recognition in asthmatic children during the first year of treatment is slowed down but the level at adult age is not affected. The variability of these results is associated with the former taking of corticosteroids by the general route. Administration of corticosteroids by the systemic route, therefore makes difficult the evaluation of secondary effects due only taking inhaled corticosteroids.

[Post-traumatic medial nerve injury due to a foreign body]

A case of delayed injury to the median nerve by glass fragment is described. A median nerve palsy developed 3 years after a minor injury, totally forgotten by patient. A 34-year-old patient presented with a painful progressive median nerve lesion, with a Tinel sign just below elbow. Surgical exploration revealed a glass fragment in close proximity to median nerve. The foreign body was removed. Improvement was noted immediately, but the patient continues to have slight paresthesiae in the fingers 1 year later.

Systemic anaphylaxis induced by intradermal testing

We report the case of a patient who was referred for suspected anaphylaxis with anesthetic drugs. Gallamine was diagnosed the responsible drug and our patient developed anaphylaxis during intradermal testing (IDT) with this compound. IDT should be monitored carefully.

[Primary orthostatic tremor]

INTRODUCTION

Tremor is frequent in neurologic practice but primary orthostatic tremor was first described in 1984. Its prevalence accounts for around 4% for tremors explored in neurophysiology; in contrast, essential and parkinsonian tremors represent respectively 28 and 22% of these cases.

EXEGESIS

Orthostatic tremor is characterized by its appearance while standing. Walking, sitting, and lying down are unaffected. Clinical examination is normal except for unsteadiness disappearing when walking. Surface electromyography in the standing position is necessary for the diagnosis and shows a regular rapid tremor (frequency around 14 to 18 Hz). Its pathophysiology is unknown.

CONCLUSION

Clonazepam is the first-line treatment for orthostatic tremor. In cases of resistance or side effects of this drug orthostatic tremor may be improved by primidone or, as in our case, gabapentin.

Optical limiting threshold in carbon suspensions and reverse saturable absorber materials

I report on the measurement of threshold energy fluence for optical limiting of nanosecond and microsecond pulses in a high-performance carbon suspension known as Defence Research Establishment Valcartier carbon black suspension (CBS)-100. Thresholds as low as 24-mJ/cm(2) (nanosecond regime) and 100-mJ/cm(2) (microsecond regime) have been obtained. The measurement technique, based on an f/20 optical system and a small analysis aperture, has been tested by measurement of reverse saturable absorber materials and other carbon suspensions whose properties can be found in the technical literature. A factor of merit has emerged from these measurements that could be used to order by limiting performance the different types of carbon suspension. In this ordering, CBS-100 appears as the best choice in the set of suspensions tested for short and long pulses.

[The allergic pregnant woman]

Drugs administrated to pregnant women must be carefully monitored. Prevention of dietary sensitization in foetus via the mother is still discussed. However, it must not induce any dietary deficiency to both the mother and the foetus. Environmental prevention is also controversial. Asthmatic pregnant women must be treated because under- or non treatment is more dangerous for both the woman and the foetus compared to eventual drug side effect. Asthma must be treated with inhaled glucocorticosteroid in order to be stabilized because giving birth is the only moment which can not be interrupted. Antihistamine-H1 which can be used during pregnancy are dexchlorpheniramine for the first and second third and cetirizine during the last third of the pregnancy.

Algal growth control by a barley straw extract

In recent years, there has been an apparent increase in the occurrence of harmful algal blooms occurring in potable waters. The potential of a simple barley straw extract to inhibit algal growth was assessed. Algal growth in lakewater was inhibited by the addition of barley straw (1% w/v), with the chlorophyll a concentration remaining below the original level (40 micrograms l-1) throughout the experiment. In contrast, in the presence of wheat straw, algal biomass increased, reaching a final chlorophyll a concentration of 1160 micrograms l-1 after 28 days. Analysis of the remaining particulate straw at the end of the experiment showed that the lignin content of barley straw had increased significantly from 10-33% (w/w). Further, a preparation of a simple aqueous extract from the decomposed-barley straw was found to inhibit the cyanobacteria Microcystis sp. and the algal species Scenedesmus, with chlorophyll a levels some 10-fold lower than in untreated flasks. This study shows that a decomposed-barley extract, even in a very dilute concentration (0.005%) was capable of inhibiting the growth of Microcystis sp., a commonly occurring cyanobacterium which produces the toxin microcystin and has been responsible for some of the most serious pernicious algal blooms in the UK.

Molecular discrimination of lactobacilli used as starter and probiotic cultures by amplified ribosomal DNA restriction analysis

Lactic acid bacteria such as Lactobacillus helveticus, L. delbrueckii subsp. delbrueckii, L. delbrueckii subsp. lactis, L. delbrueckii subsp. bulgaricus, L. acidophilus, and L. casei related taxa which are widely used as starter or probiotic cultures can be identified by amplified ribosomal DNA restriction analysis (ARDRA). The genetic discrimination of the related species belonging to these groups was first obtained by PCR amplifications by using group-specific or species-specific 16S rDNA primers. The numerical analysis of the ARDRA patterns obtained by using CfoI, HinfI, Tru9I, and ScrFI was an efficient typing tool for identification of species of the L. acidophilus and L. casei complex. ARDRA by using CfoI was a reliable method for differentiation of L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis. Finally, strains ATCC 393 and ATCC 15820 exhibited unique ARDRA patterns with CfoI and Tru9I restriction enzymes as compared with the other strains of L. casei, L. paracasei, and L. rhamnosus.

[Treatment of cluster headache]

INTRODUCTION

The cluster headache (CH) is one of the most severe types of head pain. It is a typical example of a periodic disease and the International Headache Society classification recognizes two forms of this disease: episodic and chronic CH. Its prevalence is about 0.1 to 0.4% in the general population.

CURRENT KNOWLEDGE AND KEY POINTS

PATHOPHYSIOLOGY

A global hypothesis is still lacking to explain the pain, the vasodilation, the autonomic features (ipsilateral lacrimation, conjunctiva injection, rhinorrhea, partial Horner syndrome, etc.) and the periodicity of the CH. Pain and vasodilation seem secondary to an activation of the trigeminal vascular system and the periodicity of the attacks is thought to be due to a dysfunction of hypothalamic biologic clock mechanisms. Treatment of acute CH attacks. The most effective agents are oxygen inhalation and subcutaneous sumatriptan, a 5HT1B and D receptor agonist which has vasoconstrictor and anti-neurogenic inflammation properties by blocking the release from the trigeminal-sensitive fibers of neuropeptides such as CGRP and substance P. With subcutaneous sumatriptan, headache relief is very rapid, within 5 to 10 min. Prophylactic treatment of CH: The number of attacks per day varies from one to three, but some patients can have four to eight per day and acute treatments fail to provide sufficient relief or give rise to side-effects. Several different regimens have been proven effective.

FUTURE PROSPECTS AND PROJECTS

Contraindications and side-effects of the drugs limit the choice of the prophylactic treatment: corticosteroids in a tapering course, verapamil and methysergide are the most useful treatments of the episodic form. Lithium carbonate is more effective for the chronic stage of CH, but side-effects are often troublesome. Numerous other medications have been used for prophylaxis: valproate, capsaicin, beta-blockers. Unfortunately, double-blind studies are often lacking and are difficult to realize due to spontaneous variable remission of episodic CH. When adequate trials of drug therapies show a total resistance to the treatments, surgery may be considered. Radiofrequency trigeminal rhizotomy is the treatment of choice with 70% of beneficial effects. Risks and complications have to be discussed in balance with the benefit of the different surgical procedures.

Identification of the platelet ADP receptor targeted by antithrombotic drugs

Platelets have a crucial role in the maintenance of normal haemostasis, and perturbations of this system can lead to pathological thrombus formation and vascular occlusion, resulting in stroke, myocardial infarction and unstable angina. ADP released from damaged vessels and red blood cells induces platelet aggregation through activation of the integrin GPIIb-IIIa and subsequent binding of fibrinogen. ADP is also secreted from platelets on activation, providing positive feedback that potentiates the actions of many platelet activators. ADP mediates platelet aggregation through its action on two G-protein-coupled receptor subtypes. The P2Y1 receptor couples to Gq and mobilizes intracellular calcium ions to mediate platelet shape change and aggregation. The second ADP receptor required for aggregation (variously called P2Y(ADP), P2Y(AC), P2Ycyc or P2T(AC)) is coupled to the inhibition of adenylyl cyclase through Gi. The molecular identity of the Gi-linked receptor is still elusive, even though it is the target of efficacious antithrombotic agents, such as ticlopidine and clopidogrel and AR-C66096 (ref. 9). Here we describe the cloning of this receptor, designated P2Y12, and provide evidence that a patient with a bleeding disorder has a defect in this gene. Cloning of the P2Y12 receptor should facilitate the development of better antiplatelet agents to treat cardiovascular diseases.