Genome-wide association analyses identify 95 risk loci and provide insights into the neurobiology of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) genetics are characterized by lower discoverability than most other psychiatric disorders. The contribution to biological understanding from previous genetic studies has thus been limited. We performed a multi-ancestry meta-analysis of genome-wide association studies across 1,222,882 individuals of European ancestry (137,136 cases) and 58,051 admixed individuals with African and Native American ancestry (13,624 cases). We identified 95 genome-wide significant loci (80 new). Convergent multi-omic approaches identified 43 potential causal genes, broadly classified as neurotransmitter and ion channel synaptic modulators (for example, GRIA1, GRM8 and CACNA1E), developmental, axon guidance and transcription factors (for example, FOXP2, EFNA5 and DCC), synaptic structure and function genes (for example, PCLO, NCAM1 and PDE4B) and endocrine or immune regulators (for example, ESR1, TRAF3 and TANK). Additional top genes influence stress, immune, fear and threat-related processes, previously hypothesized to underlie PTSD neurobiology. These findings strengthen our understanding of neurobiological systems relevant to PTSD pathophysiology, while also opening new areas for investigation.

Discovery of 95 PTSD loci provides insight into genetic architecture and neurobiology of trauma and stress-related disorders

Posttraumatic stress disorder (PTSD) genetics are characterized by lower discoverability than most other psychiatric disorders. The contribution to biological understanding from previous genetic studies has thus been limited. We performed a multi-ancestry meta-analysis of genome-wide association studies across 1,222,882 individuals of European ancestry (137,136 cases) and 58,051 admixed individuals with African and Native American ancestry (13,624 cases). We identified 95 genome-wide significant loci (80 novel). Convergent multi-omic approaches identified 43 potential causal genes, broadly classified as neurotransmitter and ion channel synaptic modulators (e.g., GRIA1, GRM8, CACNA1E ), developmental, axon guidance, and transcription factors (e.g., FOXP2, EFNA5, DCC ), synaptic structure and function genes (e.g., PCLO, NCAM1, PDE4B ), and endocrine or immune regulators (e.g., ESR1, TRAF3, TANK ). Additional top genes influence stress, immune, fear, and threat-related processes, previously hypothesized to underlie PTSD neurobiology. These findings strengthen our understanding of neurobiological systems relevant to PTSD pathophysiology, while also opening new areas for investigation.

Trauma Matters: Integrating Genetic and Environmental Components of PTSD

Trauma is ubiquitous, but only a subset of those who experience trauma will develop posttraumatic stress disorder (PTSD). In this review, it is argued that to determine who is at risk of developing PTSD, it is critical to examine the genetic etiology of the disorder and individual trauma profiles of those who are susceptible. First, the state of current PTSD genetic research is described, with a particular focus on studies that present evidence for trauma type specificity, or for differential genetic etiology according to gender or race. Next, approaches that leverage non-traditional phenotyping approaches are reviewed to identify PTSD-associated variants and biology, and the relative advantages and limitations inherent in these studies are reflected on. Finally, it is discussed how trauma might influence the heritability of PTSD, through type, risk factors, genetics, and associations with PTSD symptomology.

Integrating genetics and transcriptomics to study major depressive disorder: a conceptual framework, bioinformatic approaches, and recent findings

Major depressive disorder (MDD) is a complex and heterogeneous psychiatric syndrome with genetic and environmental influences. In addition to neuroanatomical and circuit-level disturbances, dysregulation of the brain transcriptome is a key phenotypic signature of MDD. Postmortem brain gene expression data are uniquely valuable resources for identifying this signature and key genomic drivers in human depression; however, the scarcity of brain tissue limits our capacity to observe the dynamic transcriptional landscape of MDD. It is therefore crucial to explore and integrate depression and stress transcriptomic data from numerous, complementary perspectives to construct a richer understanding of the pathophysiology of depression. In this review, we discuss multiple approaches for exploring the brain transcriptome reflecting dynamic stages of MDD: predisposition, onset, and illness. We next highlight bioinformatic approaches for hypothesis-free, genome-wide analyses of genomic and transcriptomic data and their integration. Last, we summarize the findings of recent genetic and transcriptomic studies within this conceptual framework.

Altered gene expression and PTSD symptom dimensions in World Trade Center responders

Despite experiencing a significant trauma, only a subset of World Trade Center (WTC) rescue and recovery workers developed posttraumatic stress disorder (PTSD). Identification of biomarkers is critical to the development of targeted interventions for treating disaster responders and potentially preventing the development of PTSD in this population. Analysis of gene expression from these individuals can help in identifying biomarkers of PTSD. We established a well-phenotyped sample of 371 WTC responders, recruited from a longitudinal WTC responder cohort using stratified random sampling, by obtaining blood, self-reported and clinical interview data. Using bulk RNA-sequencing from whole blood, we examined the association between gene expression and WTC-related PTSD symptom severity on (i) highest lifetime Clinician-Administered PTSD Scale (CAPS) score, (ii) past-month CAPS score, and (iii) PTSD symptom dimensions using a 5-factor model of re-experiencing, avoidance, emotional numbing, dysphoric arousal and anxious arousal symptoms. We corrected for sex, age, genotype-derived principal components and surrogate variables. Finally, we performed a meta-analysis with existing PTSD studies (total N = 1016), using case/control status as the predictor and correcting for these variables. We identified 66 genes significantly associated with total highest lifetime CAPS score (FDR-corrected p < 0.05), and 31 genes associated with total past-month CAPS score. Our more granular analyses of PTSD symptom dimensions identified additional genes that did not reach statistical significance in our analyses with total CAPS scores. In particular, we identified 82 genes significantly associated with lifetime anxious arousal symptoms. Several genes significantly associated with multiple PTSD symptom dimensions and total lifetime CAPS score (SERPINA1, RPS6KA1, and STAT3) have been previously associated with PTSD. Geneset enrichment of these findings has identified pathways significant in metabolism, immune signaling, other psychiatric disorders, neurological signaling, and cellular structure. Our meta-analysis revealed 10 genes that reached genome-wide significance, all of which were downregulated in cases compared to controls (CIRBP, TMSB10, FCGRT, CLIC1, RPS6KB2, HNRNPUL1, ALDOA, NACA, ZNF429 and COPE). Additionally, cellular deconvolution highlighted an enrichment in CD4 T cells and eosinophils in responders with PTSD compared to controls. The distinction in significant genes between total lifetime CAPS score and the anxious arousal symptom dimension of PTSD highlights a potential biological difference in the mechanism underlying the heterogeneity of the PTSD phenotype. Future studies should be clear about methods used to analyze PTSD status, as phenotypes based on PTSD symptom dimensions may yield different gene sets than combined CAPS score analysis. Potential biomarkers implicated from our meta-analysis may help improve therapeutic target development for PTSD.

An unusual case of mammary Paget’s disease in a woman with psoriasis

Mammary Paget’s disease (MPD) is a malignant breast tumor, which is characterized by intraepidermal infiltration from malignant glandular epithelial cells. Often it may include an underlying ductal carcinoma in situ or an invasive ductal carcinoma. Clinically it appears as an erythematous patch, moist or crusted, with or without desquamation that in some cases becomes ulcerated, causing infiltration and inversion of the nipple. We report the clinical case of a 60-year-old woman, treated in our department for psoriasis, presenting with erythema of nipple and areola with nipple erosion, ulceration and poor secretion. Suspecting Paget’s disease of the nipple, radiological exams (mammography and breast MRI) were performed. A biopsy for histological examination was carried out and confirmed the diagnosis of mammary Paget’s disease. MPD is sometimes difficult to diagnose both clinically and radiologically, therefore it is important to distinguish from other conditions: in literature MPD is reported in differential diagnosis with psoriasis given its similar clinical features, and in some cases MPD has been treated with topical and systemic steroids due to a wrong diagnosis. However, the concomitance, in the same individual, of mammary Paget’s disease and psoriasis has never been described.

Subcutaneous cervical emphysema and pneumomediastinum due to a diastatic rupture of the cecum

Pneumomediastinum usually occurs after esophageal or chest trauma. Subcutaneous cervical emphysema as a presentation of non-traumatic colonic perforation following colorectal cancer or diverticulitis, is very rare. We report a case of a patient with rectal cancer who developed a diastatic cecum retroperitoneal perforation with a secondary pneumomediastinum and cervical emphysema. The patient was in treatment with a neoadjuvant chemo-radiotherapy for a low rectal cancer. Treatment consisted in an emergency right hemi-colectomy with ileostomy and performance of distal colonic fistula. The Authors discuss the occurrence of pneumomediastinum and cervical emphysema complicating rectal cancer, pointing out ethiopathogenesis, clinical presentation, diagnosis and treatment. The importance of performing a diverting colostomy when neoadjuvant chemotherapy is scheduled in patients with stenotic rectal cancer, although not clinically occluded.

A rare case of myeloid sarcoma presenting as anal fissure

Myeloid sarcoma is a tumor composed of myeloblasts occurring at an extramedullary site. It may develop in patients with acute myeloid leukemia, myeloproliferative or myelodysplastic syndrome, sometimes preceding onset of the systemic disease. Frequent sites of myeloid sarcoma are bones or various soft tissues. Gastrointestinal involvement is very rare. We report a unique case of myeloid sarcoma presenting as a painful anal fissure, in a patient with a history of acute myeloid leukemia. The diagnosis was achieved by a surgical excisional biopsy and immunoistochemical staining.

Secretion of dengue virus envelope protein ectodomain from mammalian cells is dependent on domain II serotype and affects the immune response upon DNA vaccination

Dengue virus (DENV) is currently among the most important human pathogens and affects millions of people throughout the tropical and subtropical regions of the world. Although it has been a World Health Organization priority for several years, there is still no efficient vaccine available to prevent infection. The envelope glycoprotein (E), exposed on the surface on infective viral particles, is the main target of neutralizing antibodies. For this reason it has been used as the antigen of choice for vaccine development efforts. Here we show a detailed analysis of factors involved in the expression, secretion and folding of E ectodomain from all four DENV serotypes in mammalian cells, and how this affects their ability to induce neutralizing antibody responses in DNA-vaccinated mice. Proper folding of E domain II (DII) is essential for efficient E ectodomain secretion, with DIII playing a significant role in stabilizing soluble dimers. We also show that the level of protein secreted from transfected cells determines the strength and efficiency of antibody responses in the context of DNA vaccination and should be considered a pivotal feature for the development of E-based DNA vaccines against DENV.

Short-term spatial and temporal variability in greenhouse gas fluxes in riparian zones

Recent research indicates that riparian zones have the potential to contribute significant amounts of greenhouse gases (GHG: N2O, CO2, CH4) to the atmosphere. Yet, the short-term spatial and temporal variability in GHG emission in these systems is poorly understood. Using two transects of three static chambers at two North Carolina agricultural riparian zones (one restored, one unrestored), we show that estimates of the average GHG flux at the site scale can vary by one order of magnitude depending on whether the mean or the median is used as a measure of central tendency. Because the median tends to mute the effect of outlier points (hot spots and hot moments), we propose that both must be reported or that other more advanced spatial averaging techniques (e.g., kriging, area-weighted average) should be used to estimate GHG fluxes at the site scale. Results also indicate that short-term temporal variability in GHG fluxes (a few days) under seemingly constant temperature and hydrological conditions can be as large as spatial variability at the site scale, suggesting that the scientific community should rethink sampling protocols for GHG at the soil-atmosphere interface to include repeated measures over short periods of time at select chambers to estimate GHG emissions in the field. Although recent advances in technology provide tools to address these challenges, their cost is often too high for widespread implementation. Until technology improves, sampling design strategies will need to be carefully considered to balance cost, time, and spatial and temporal representativeness of measurements.

RECTAL IMPACTION DUE TO PRICKLY PEAR SEEDS BEZOAR: A CASE REPORT

Fecal impaction is the third cause of lower gastrointestinal tract obstruction after strictures for colon cancer and postoperative adhesions. A rapid diagnosis is necessary to avoid complications due to intestinal obstruction. Rectal phytobezoar due to prickly pear fruit seeds are an extremely rare entity, in the literature about twenty similar cases are described. Prickly pears are common in many countries, even in the Mediterranean area. When the ingestion of their fruit is excessive, this can be harmful, leading to the formation of phytobezoar causing fecal impaction. We describe the first case of phytobezoar due to prickly pear fruit seeds in continental Europe: a 76-year-old Italian female who ingested almost 40 prickly pear fruit leading to the composition of a large rectal phytobezoar. The patient presented clinically with fecal impaction, diagnosed by imaging and successfully treated by rectal irrigation and manual disimpaction. Our aim is to remind the physicians of these risks in evaluating patients with intestinal obstruction, when there is positive anamnesis for provenience from some areas in which these fruits are eaten. We also want to underline the role of Imaging Multi Detector Computed Tomography (MDCT) in the diagnosis of these very uncommon entities.

Treatment of permagna incisional hernia with skin necrosis and abscess: case report

Ventral incisional hernia rate is decreasing due to the introduction of new clinical and surgery method. As a result, the complex incisional hernias, are less often described and rarely treated. We describe our experience in emergency case. We present the case of permagna incisional hernia with skin necrosis, subcutaneous abscess and bowel perforation which cause a long-lasting bedding. The successful management includes an emergency surgery applying hernia reduction, bowel resection and abdominal wall reconstruction through a biological mesh and positioning of VAC System. There is not a gold standard treatment that obtained an unanimous consensus, however we recommend the following procedure in that, in our patient, it shows no recurrences, infections and other post-operative complications.

Laparoscopic-endoscopic rendez-vous resection of iuxta-cardial gastric GIST

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and they often require a surgical removal. Gastrointestinal stromal tumors can originate from any part of the gastrointestinal tract but gastric location is the most common. In the past the risk of rupture of pseudocapsula and peritoneal dissemination have discouraged surgeons from making a minimally invasive surgical treatment. Recently laparoscopic wedge resection has been proposed. Performance of this mini-invasive technique is however difficult in some gastric location of gastrointestinal stromal tumors, such as iuxta-cardial region. The Authors report and discuss a new technique they used to remove a gastrointestinal stromal tumor located just below the cardia, using a rendez-vous endoscopic and laparoscopic technique.

Abdominal emergency in elderly: a case of small bowel obstruction and ischemia caused by bulky IA ovarian cancer

Bowel obstruction resulting from colorectal and ovarian cancer is a serious and distressing complication of these malignancies. This may be caused by diffuse peritoneal carcinomatosis, bulky masses filling the pelvis and abdomen or postoperative adhesions, and should be carefully worked out by pre-operative imaging. We report the case of a small bowel obstruction and intestinal ischemia caused by a bulky (20x40 cm in diameter) cystic ovarian neoplasm that was found to be a stage IA G2 cystadenocarcinoma, successfully managed by uterus-sparing surgery.

Polyp of the cecum. Laparoscopic-assisted polypectomy

The Authors discuss on a laparoscopic-assisted approach for excision of a sessile villous adenomatous polyp of the cecum, unresectable by endoscopy. Because of the large implant of the polyp, endoscopic polypectomy was considered at high risk and a surgical laparoscopic procedure was scheduled for removal of the lesion. After right colon mobilization, an intraoperative endoscopy confirmed the location of th polyp in the posterior wall of the cecum, closed to the ileo-cecal valve. A small 10 cm laparotomy, through which the cecum was pulled out the abdominal cavity, was performed. Then, a minimal colotomy along the intestinal taenia was carried out to allow a safe and complete excision of the polyp. This laparoscopic approach differs from the other laparoscopic-assisted methods reported in the Literature since it provides at the same time the postoperative advantages associated with minimal access surgery and a safe oncological removal of the polyp with low risks of complications.

Laparoscopic treatment of mucinous adenocarcinoma of jejunum associated with celiac disease. Case report

Mucinous adenocarcinoma of the small bowel is very rare, and only few cases have been described in the literature. Association of this tumor with celiac disease has never been published. The authors report a unique case of jejunal mucinous adenocarcinoma in which a concomitant celiac disease has been histologically recognized. The difficult diagnosis, the role of laparoscopic surgery and the relationship between small bowel tumors and celiac disease are discussed. A 49-year-old man presented with recurrent melena, nausea, vomiting and anemia. A stenosis of the jejunum was documented by means of CT scan and video capsule enteroscopy. A laparoscopy was scheduled. A tumor, found in the first jejunal loop, was removed by laparoscopic surgery. Histopathology revealed a rare mucinous adenocarcinoma associated with epithelial changes secondary to celiac disease. Although small bowel tumors are rare entity, in patients with celiac disease complaining of symptoms related to altered intestinal transit or occult bleeding, an appropriate work-up should be planned for diagnosis. Mucinous type intestinal adenocarcinoma, even if never published before, could be observed. Laparoscopic surgery is often essential for the diagnosis and treatment.

Laparoscopic splenectomy in patients under the age of eighteen. Experience in 18 cases

BACKGROUND

Pediatric surgery is now in the forefront of minimal access procedures. Although pediatric surgeons have been skeptic about laparoscopic splenectomy, recently minimally invasive approach for spleen removal has been revaluated also in young patients. Purpose of this study was to report Authors' personal experience in patients under eighteen who underwent laparoscopic splenectomy. Results of the procedure were evaluated.

PATIENTS AND METHODS

A retrospective review was undertaken in 18 splenectomised patients under the age of eighteen. Indications were hereditary spherocytosis in 10 patients, β-thalassemia in 4, idiopathic thrombocytopenic purpura in 3 and a splenic cyst in 1 child.

RESULTS

No intra-operative complications occurred. No conversion to open surgery was reported. During the follow-up one case of portal vein thrombosis, treated by medical therapy, was encountered and no other postoperative complications were observed.

CONCLUSIONS

Laparoscopic approach has to be preferable for all those children undergoing spleen surgery. In experienced hands, it is of beneficial effects with a very reasonable rate of complications.

Laparoscopic left colectomy: from the perfect knowledge of surgical anatomy to the proper surgical technique

Laparoscopic colo-rectal surgery has been increasingly accepted and performed in several surgical centres. However, there are still concerns about the intra-operative risks and therefore on the safety of the procedure especially during the learning curve. As a matter of fact, in approximately one third of laparoscopic colo-rectal procedures, an intra-operative complication, mainly bleeding or iatrogenic injuries, may occur. In this paper, according to our experience, we analyse step by step the surgical technique of the laparoscopic left colectomy and evaluate the technical difficulties and complications in order to avoid them.

Noninvasive positive-pressure ventilation in ALS: Predictors of tolerance and survival

OBJECTIVE

To identify factors associated with tolerance and survival after noninvasive positive-pressure ventilation (NIPPV) and to investigate the influence of NIPPV on lung function in patients with ALS.

METHODS

NIPPV was offered to 71 patients with ALS in accordance with currently published guidelines. Effects of NIPPV on lung function and factors influencing tolerance and survival after NIPPV were studied.

RESULTS

Forty-four patients (61.9%; 95% CI: 50.6 to 73.2) tolerated NIPPV (NIPPV use >or=4 h/day) and 27 (38.1%; 95% CI: 26.8 to 49.4) were intolerant (NIPPV use <4 h/day). Patients with mild or moderate bulbar symptoms were more likely to tolerate NIPPV than those with severe impairment (odds ratio = 6.09, 95% CI: 1.18 to 31.52, p = 0.031). After NIPPV introduction, a slower decline in forced vital capacity (FVC) was observed in tolerant vs intolerant patients (p = 0.002). The slope of FVC decline after NIPPV initiation (risk ratio [RR]: 0.78, 95% CI: 0.65 to 0.94, p = 0.01) together with NIPPV tolerance (RR: 0.32, 95% CI: 0.13 to 0.78, p = 0.013) were the only independent predictors of survival in the overall group of patients. In multivariate analysis, body mass index was the most powerful predictor of longer survival after NIPPV in tolerant patients (RR: 0.77, 95% CI: 0.61 to 0.96, p = 0.022).

CONCLUSION

Survival after noninvasive ventilation was independently related to ventilatory use (>or=4 h/day) and to the modifications of forced vital capacity decline after treatment initiation. The severity of bulbar impairment and the nutritional status of the ALS patients at the introduction of ventilation may predict tolerance and survival.

A chart of failure risk for noninvasive ventilation in patients with COPD exacerbation

Knowing the likelihood of failure of noninvasive positive pressure ventilation (NPPV) in patients with exacerbation of chronic obstructive pulmonary disease (COPD) could indicate the best choice between NPPV and endotracheal intubation instituted earlier. For this purpose, two risk charts were designed (at admission and after 2 h of NPPV) that included all relevant measurable clinical prognostic indicators derived from a population representing the patients seen routinely in clinical practice. Risk stratification of NPPV failure was assessed in 1,033 consecutive patients admitted to experienced hospital units, including two intensive care units, six respiratory intermediate care units, and five general wards. NPPV was successful in 797 patients. Patients with a Glasgow Coma Score <11, acute physiology and chronic health evaluation (APACHE) II > or =29, respiratory rate > or =30 breaths x min(-1) and pH at admission <7.25 have a predicted risk of failure >70%. A pH <7.25 after 2 h greatly increases the risk (>90%). The risk charts were validated on an independent group of 145 consecutive COPD patients treated with NPPV due to an acute ventilatory failure episode. To identify patients with a probability of failure >50%, the sensitivity and specificity were 33% and 96.7% on admission and 52.9% and 94.1% after 2 h of NPPV, respectively. The prediction chart, based on data from the current study, can function as a simple tool to predict the risk of failure of noninvasive positive pressure ventilation and thus improve clinical management of patients tailoring medical intervention.

Liquid chromatographic/mass spectrometric determination of desmedipham and phenmedipham and their metabolites in soil

A simple method is described for the simultaneous determination of residues of 2 carbamate herbicides (phenmedipham and desmedipham) and related metabolites (m-aminophenol, aniline, and m-toluidine) in soil. The analytes are extracted from spiked soils with methanol. The solvent/soil suspension is centrifuged, and the supernatant is directly injected, without any further cleanup, into a reversed-phase liquid chromatography/mass spectrometry apparatus equipped with a TurbolonSpray interface. The method was tested on 5 soils having different physicochemical properties. Recoveries from the soil types, spiked over the range of 50-200 ppb, were essentially quantitative for each analyte. The detection limits of the method are < or = 25 ng/g.

Bacterial expression and conformational analysis of a chemosensory protein from Schistocerca gregaria

Chemosensory proteins (CSPs) are a class of small, soluble proteins present at high concentrations in chemosensory organs of different insect species. Several pieces of evidence suggest their involvement in carrying chemical messages from the environment to chemosensory receptors. However, a structural description of the mechanism of delivery has not been reported. In order to provide the first detailed conformational characterization of these molecules, we cloned a specific isoform (CSP-sg4) from Schistocerca gregaria and expressed it in Escherichia coli. The product was obtained with yields of more than 20 mg per L of culture, all in its soluble form. The recombinant protein was identical to the native one with respect to pairing of the disulfide bridges, aggregative state and secondary structure elements. Structural investigations revealed a significantly stable polypeptide with respect to variations in temperature and acidity. CD analysis, preliminary NMR data and secondary structure prediction pointed to a correctly folded structure where helical regions and loops are alternated in a similar fashion as that observed for other classes of odorant- and pheromone-binding proteins presenting no sequence similarity to CSPs.

Purification, cloning and characterisation of odorant- and pheromone-binding proteins from pig nasal epithelium

Two distinct classes of lipocalin isoforms (OBP-IIs and OBP-IIIs) were purified and identified from porcine nasal mucosa of male and female individuals. Using primers designed on their N-terminal sequence, the complete primary structures of the mature polypeptides were determined. Mass spectrometry analysis confirmed the identity of the cDNA-derived sequences and provided information regarding their post-translational modifications. These species strongly resemble a lipocalin expressed by von Ebner's gland and salivary lipocalins carrying sex-specific pheromones secreted only by the boar's submaxillary glands. Both OBP-IIs and OBP-IIIs present two cysteines paired in a disulphide bond; the remaining residues occur in a reduced form. In addition, OBP-IIIs are heavily glycosylated and markedly different in their glycan moiety from the salivary lipocalins. A three-dimensional model is proposed based on protein species with known structure. Like salivary lipocalins, OBP-IIIs bind a number of odorant molecules, with highest affinity for the specific pheromone 5alpha-androst-16-en-3-one. The high similarity between OBPs from the nasal area and lipocalins from secretory glands suggests a common function in binding the same pheromonal ligands, the latter carrying chemical messages into the environment the former delivering them to specific receptors.

Development of a method based on accelerated solvent extraction and liquid chromatography/mass spectrometry for determination of arylphenoxypropionic herbicides in soil

A sensitive and specific analytical procedure for determining arylphenoxypropionic herbicides in soil samples, using Ionspray ionization (ISI) liquid chromatography/mass spectrometry (LC/MS), is presented. Arylphenoxypropionic acids are a new class of herbicides used for selective removal of most grass species from any non-grass crop, commercialized as herbicide esters. Previous studies have shown that the esters undergo fast hydrolysis in the presence of vegetable tissues and soil bacteria, yelding the corresponding free acid. The feasibility of rapidly extracting arylphenoxypropionic herbicides from soil by accelerated solvent extraction (ASE) techniques was evaluated. Four different soil samples were fortified with target compounds at levels of 5 and 20 ng/g by following a procedure able to mimic weathered soils. Herbicides were extracted by a methanol/water (80:20 v/v) solution (0.12 M) of NaCl at 90 degrees C. After clean-up using graphitized carbon black (GCB) as absorbent, the extract was analyzed by HPLC/ISI-MS. The effect of concentration of acid in the mobile phase on the response of ISI-MS was investigated. The effects of varying the orifice plate voltage on the production of diagnostic fragment ions, and on the response of the MS detector, were also investigated. The ISI-MS response was linearly related to the amounts of analytes injected between 1 and 200 ng. The limit of detection (signal-to-noise ratio = 3) of the method for the pesticides in soil samples was estimated to be less than 1 ng/g.

Soluble proteins from chemosensory organs of Eurycantha calcarata (Insects, Phasmatodea)

Three related nucleotide sequences, encoding mature proteins of 108-113 amino acids, have been obtained from antennal cDNA of the Phasmid Eurycantha calcarata. Among these, one is also expressed in the tarsi as demonstrated by N-terminal sequence and mass spectrometric analyses of protein samples isolated from both organs. PCR experiments performed with specific primers, showed that this species is also expressed in the mouth organs and in the cuticle, while the other two are antennal specific. All three isoforms are similar to Drosophila OS-D and other proteins reported in several insect orders, but one of them is significantly different from the other two. The best conserved elements are the N-terminal region and the four cysteine residues. Accurate ESMS measurements indicated that all cysteines are involved in two disulphide bonds and ruled out the occurrence of additional post-translational modifications. Polyclonal antibodies, raised against the purified protein, did not react with proteins of the same class expressed in another Phasmid species, Carausius morosus, and in the orthopteran Schistocerca gregaria, nor did antibodies against these proteins recognise those of E. calcarata.

Solid-phase extraction followed by high-performance liquid chromatography-ionspray interface-mass spectrometry for monitoring of herbicides in environmental water

In this work we developed a sensitive and specific multiresidue method, based on reversed-phase liquid chromatography-mass spectrometry, with an ionspray interface (LC-ISI-MS), for determining 52 of most representative compounds of herbicides in water samples. The procedure used involved passing 0.5 l of surface water, 2 l of ground water and 4 l of drinking water samples, respectively, through a 0.5 g graphitized carbon black (GCB) extraction cartridge. Base-neutral and acid herbicides were differential eluted from GCB cartridge and follow analyzed by HPLC-ISI-MS apparatus. A conventional 4.6-mm-ID reversed-phase LC C18 column, operating with a mobile phase flow-rate of 1 ml/min, was used to chromatograph the analytes. A flow of 100 microl/min of the column effluent was diverted to the ISI source. The study demonstrates the sensitivity of the technique, with detection limit under 10 ng/l in drinking water samples. Performance data for the method such as recovery and precision are also reported.

Amino acid sequence, post-translational modifications, binding and labelling of porcine odorant-binding protein

An odorant-binding protein, migrating in SDS-PAGE with an apparent molecular weight of 22 kDa and an isoelectric point of 4.2, has been purified from pig nasal mucosa. Its complete amino acid sequence was determined by a combination of mass spectrometry and Edman degradation procedures. The protein consists of a single polypeptide chain of 157 amino acids, presenting at the N-terminus a pyroglutamic acid residue. The two cysteine residues, occurring in the primary structure at positions 63 and 155, are involved in an intramolecular disulphide bridge. Sequence comparison with other lipocalins revealed a good similarity with bovine odorant-binding protein, the only member of this class which does not contain disulphide bonds and of which the three-dimensional structure recently has been resolved. Nine out of the 1 6 residues lining the binding pocket in bovine OBP are conserved in the porcine protein, suggesting structural similarities in this region of the molecule. The synthesis of a fluorescent photoaffinity labelling agent and of two tin-containing thymol analogues is also described. These compounds together with other ligands were able to bind the protein as revealed by competitive binding experiments.

Determination of arylphenoxypropionic herbicides in water by liquid chromatography-electrospray mass spectrometry

A very sensitive and specific analytical procedure for determining arylphenoxypropionic herbicides in aqueous environmental samples, using pneumatically assisted electrospray (ESI) liquid chromatography-mass spectrometry (LC-MS) is presented. Arylphenoxypropionic acids are a new class of herbicides used for the selective removal of most grass species from any nongrass crop. These herbicides are commercialized as herbicide esters. It has been shown that the ester derivatives undergo fast hydrolysis in the presence of vegetable tissues and soil bacteria, yielding the corresponding free acid. The analytical procedure involves passing 1l of surface or ground water and 2l of drinking-water samples, through a 0.5-g graphitized carbon black (GCB) extraction cartridge. A conventional 4.6-mm I.D. reversed-phase LC C18, operating with a 1 ml/min mobile phase flow-rate, was used for chromatographing the analytes. A flow of 200 microliters/min of the column effluent was diverted to the ESI source. The ESI source was operated in positive-ion mode for neutral pesticides and in negative-ion mode for acid pesticides. For ion-signal optimization, the effect of the concentration of the acid in the mobile phase on the response of the ESI-MS detector was investigated. By evaluating the specificity and sensitivity of the method, the effects of varying the orifice plate voltage on the production of the diagnostic fragment and the response of the MS detector were also investigated. For the analyte considered, the response of the mass detector was linearly related to the amount of the analyte injected between 1 and 200 ng. In all cases, recoveries of the analytes were better than 91%. The limit of detection (signal-to-noise ratio = 3) of the method for the pesticides considered in drinking water samples was estimated to be about 3-10 ng/l.

Subtypes of odorant-binding proteins--heterologous expression and ligand binding

Odorant-binding proteins (OBP) in the mucus of the olfactory epithelium are thought to transfer the hydrophobic odorous compounds through the aqueous barrier towards the chemo-sensory cells. To evaluate their binding properties, two distinct OBP subtypes of the rat were expressed as N-terminal His-tagged fusion proteins in Escherichia coli, thus allowing an efficient purification. Based on gel chromatography and CD spectroscopy analysis the recombinant OBP subtypes seem to share several structural features with other members of the lipocalin family. Approaches to elucidate whether heterologous expressed OBPs interact with odorous compounds revealed that OBP1 specifically binds 2-[3H]-isobutyl-3-methoxypyrazine whereas OBP2 did not shown any specific binding to this compound. In contrast, the chromophore 1-anilinonaphthalene 8-sulfonic acid (1,8-ANS) specifically interacted with OBP2 but not with OBP1. Displacement experiments monitored by the relative fluorescence intensity revealed that fatty acids with appropriate chain length act as efficient competitors. Some odorous compounds, notably lilial (p-tert-butyl-alpha-methyl dihydrocinnamic aldehyde) and citralva (3,7-dimethyl-2,6-octadienenitrile), also displaced efficiently the chromophore, whereas pyrazine derivatives including 2-isobutyl-3-methoxypyrazine and other odorants did not. These results indicate that rat OBPs have distinct ligand specificities.

Development of a method based on liquid chromatography-electrospray mass spectrometry for analyzing imidazolinone herbicides in environmental water at part-per-trillion levels

An evaluation was made of the feasibility of using reversed-phase liquid chromatography-mass spectrometry with an electrospray interface (LC-ESI-MS) to measure traces of imidazolinone herbicides in different natural water samples. The imidazolinones are a significant new class of low-use-rate, reduced-environmental-risk herbicides for the protection of a wide variety of agricultural commodities. The procedure used involved passing 0.5, 1, 2 1 of river, ground and drinking water samples, respectively, through a 0.5 g graphitized carbon black (GCB) extraction cartridge. Analytes were eluted from the GCB surface by 8 ml of a methylene chloride-methanol (80:20, v/v) solution acidified with formic acid, 25 mM. Recovery was higher than 89% irrespective of the aqueous matrix in which the analytes were dissolved. A conventional 4.6 mm I.D. reversed-phase LC C18 column operating with a mobile phase flow-rate of 1 ml/min was used to chromatograph the analytes. A flow of 50 microliters/min of the column effluent was diverted to the ESI source. The effects of acid concentration on ESI-MS detector response in the mobile phase were investigated. The effects on the production of diagnostic fragments produced by varying the orifice plate voltage and the response of the MS detector were also evaluated. For the analyte considered, the response of the mass detector was linearly related to the amount of analyte injected between 1 and 50 ng. The limit of detection (signal-to-noise ratio = 3) of the method for the pesticides considered in drinking water samples was estimated to be about 2-5 ng/l.

Lipocalins of boar salivary glands binding odours and pheromones

Large amounts of an odorant-binding protein have been isolated from submaxillary glands of mature male pig. This polypeptide molecule is sex-specific, being absent in females. On electrophoretic gels under denaturing conditions it migrated as a broad band with an apparent molecular mass of around 20 kDa. Electrospray mass spectrometry revealed the presence of three main components, whose mass differences are not interpretable as result of any common post-translational modifications, indicating the presence of distinct polypeptide chains. N-terminal Edman degradation yielded a single sequence of 29 amino acids. It includes the lipocalin signature (-G-X-W-) and shows clear homology with a subclass of odorant-binding proteins present in mouse saliva, nasal mucus and urine. The purified protein still retained small ligands tightly bound; among them 5alpha-androst-16-en-3-one and 5alpha-androst-16-en-3alpha-ol, both known sex pheromones for the pig, were identified. The protein also binds 2-isobutyl-3-methoxypyrazine, a good ligand for most odorant-binding proteins, with a dissociation constant of 5 microM.

Identification of HHV-8 DNA in the skin lesions of Kaposi's sarcoma in an immunosuppressed patient with bullous pemphigoid

Kaposi's sarcoma rarely occurs as an opportunistic tumor in iatrogenically immunosuppressed patients. We describe the clinical presentation, treatment of Kaposi's sarcoma skin lesions in an immunosuppressed patient with bullous pemphigoid. Using the polymerase chain reaction, HHV-8 DNA was detected in two separate Kaposi's sarcoma lesions but not in control tissues. The amplified DNA fragments derived from our patient's Kaposi's sarcoma skin lesions contained unique point mutations that distinguished the virus isolated from Kaposi's sarcoma lesions derived from other patients. This is the first demonstration that HHV-8 DNA is associated with Kaposi's sarcoma skin lesions in an HIV-negative, immunosuppressed patient with bullous pemphigoid. HHV-8 is probably a common latent herpesvirus that is activated by immunosuppressive therapy in genetically predisposed patients and may be involved in the pathogenesis of Kaposi's sarcoma.

Neuropeptide Y release from cultured hippocampal neurons: stimulation by glutamate acting at N-methyl-D-aspartate and AMPA receptors

L-Glutamate, N-methyl-D-aspartate, DL-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and kainate increased the release of neuropeptide Y-like immunoreactivity from primary cultures of rat hippocampal neurons incubated in Mg2+(1.2 mM)-containing medium. The neuropeptide Y-like immunoreactivity released by 100 microM glutamate was mainly accounted for by neuropeptide Y (1-36), but consisted in part (about 20%) of peptide YY. The effect of 100 microM glutamate on neuropeptide Y-like immunoreactivity release was largely (about 70%) prevented by the N-methyl-D-aspartate receptor antagonist dizocilpine maleate (10 microM), while the remainder (about 30%) was sensitive to the AMPA/ kainate receptor antagonist 6-nitro-7-sulphamoylbenzo(f)quinoxaline-2-3-dione (10 microM). The AMPA(100 microM)-evoked release of neuropeptide Y-like immunoreactivity was strongly antagonized by 6-nitro-7-sulphamoylbenzo(f)quinoxaline-2-3-dione and by 1-aminophenyl-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine, but it was in part (15-20%) sensitive to dizocilpine. The releases of neuropeptide Y-like immunoreactivity elicited by glutamate, N-methyl-D-aspartate, AMPA and kainate were all strongly Ca(2+)-dependent. Tetrodotoxin (1 microM) abrogated the N-methyl-D-aspartate-evoked release and partly inhibited the release caused by glutamate, but did not modify significantly AMPA- or kainate-evoked release. Removal of Mg2+ from the medium caused increase of neuropeptide Y-like immunoreactivity release, an effect prevented by dizocilpine maleate or 7-Cl-kynurenate. Cyclothiazide (10 microM), a drug known to prevent AMPA receptor desensitization, enhanced the neuropeptide Y-like immunoreactivity release elicited by 100 microM AMPA, but not that caused by 100 microM kainate. However, when used at a lower concentration (50 microM), kainate elicited a response that was potentiated significantly by cyclothiazide. It is concluded that glutamate can stimulate Ca(2+)-dependent release of neuropeptide Y from hippocampal neurons mainly through N-methyl-D-aspartate receptors and, less so, by activating cyclothiazide-sensitive receptors of the AMPA-preferring type.

Treatment of acute respiratory failure secondary to pulmonary oedema with bi-level positive airway pressure by nasal mask

We report the successful outcome of first-line intervention of noninvasive positive pressure ventilation (NPPV) in four patients, three of whom had hypercapnic acute respiratory failure (ARF) and one hypoxaemic ARF, secondary to pulmonary oedema. The clinical condition showed rapid improvement and the NPPV, performed together with aggressive medical treatment, was effective in decreasing the respiratory frequency, and in correcting gas exchange abnormalities within the first 3 h. The average duration of nasal mask ventilation was 11 h (range 6-15 h). The patients were weaned, following ARF, by removing the ventilator whenever inspiratory positive airway pressure (IPAP) was 5 cmH2O. NPPV was applied, by nasal mask, using a bi-level positive airway pressure (BiPAP) delivering pressure support ventilation (PSV). We conclude that application of noninvasive positive pressure ventilation may be effective in correcting gas exchange abnormalities, in relieving respiratory distress and, perhaps, in avoiding endotracheal intubation in selected patients with acute respiratory failure secondary to reversible medical condition such as pulmonary oedema.

[Bio-imaging for the study of organic changes in the C.N.S.: comparison between computerized tomography and magnetic resonance]

Several comparative studies have been carried out in order to evaluate the possible diagnostic superiority of Computed Tomography (C.T.) vs. Magnetic Resonance Imaging (M.R.I.) in different diseases of the Central Nervous System. The present investigation is aimed at critically revising this problem also including the study of patients clinical data as a criterion of choice. A sample of 69 subjects was examined. It was seen that in demyelinative as well as in chronic cerebrovascular diseases M.R.I. should be preferred because of its higher sensitivity and specificity. Concerning specifically chronic cerebrovascular diseases, clinical data can have a more significant role in justifying the choice of M.R.I. C.T., and M.R.I. should be considered as complementary rather than competitive in studying cerebral tumors and spinal cord pathology; the planning of surgical operations, needing a complete evaluation of data, which in these cases are very variable, requires the use of both methods.