Infrared to terahertz identification of chemical substances used for the production of IEDs

In our modern times, improvised explosive devices (IEDs) have become more sophisticated than ever, capable of causing destruction and loss of life. The creative use of homemade substances for IEDs manufactures has led to efforts in developing sensitive detection methods that can anticipate, identify and protect against improvised attacks. Laser-based spectroscopic techniques provide rapid and accurate detection of chemicals in improvised explosives, but no single method can detect all components of all explosives. In this study, two spectroscopic methods are used for the sensitive identification of 8 explosive chemical substances in the form of powders and vapors. Absorption spectra of benzene, toluene, acetone and ethylene glycol were examined with CO2 laser photoacoustic spectroscopy. The photoacoustic signals of the samples were recorded in the CO2 laser emission range from 9.2 to 10.8 µm and a different spectral behavior was observed for each analyzed substance. Time-domain spectroscopy with THz radiation was used to analyze ammonium nitrate, potassium chlorate, dinitrobenzene, hexamethylenetetramine transmission spectra in the 0.1-3 THz range, and it was observed that they have characteristic THz fingerprint spectra. CO2 laser photoacoustic spectroscopy and THz time domain spectroscopy have met the criterion of proven effectiveness in identifying explosive components. The combination of these spectroscopic methods is innovative, giving a promising new approach for detection of a large number of IED components.

Abstract 374: Gpr68 Senses Blood Flow and is Essential for Vascular Physiology

Mechanotransduction plays a crucial role in vascular biology. One example of this is local regulation of vascular resistance via flow-mediated vasodilation (FMD). Impairment of this process is a hallmark of endothelial dysfunction, and a precursor to a wide array of vascular diseases such as hypertension and atherosclerosis. And yet, the molecules responsible for sensing flow (shear stress) within endothelial cells remain largely unknown. We designed a 384-well screening system that applies shear stress on cultured cells. We identified a mechanosensitive cell line that exhibits shear stress-activated calcium transients, screened a focused RNAi library, and identified GPR68 as necessary and sufficient for shear stress responses. GPR68 is expressed in endothelial cells of small diameter (resistance) arteries. Importantly, Gpr68-deficient mice display markedly impaired acute FMD and chronic flow-mediated outward remodeling in mesenteric arterioles. Therefore, GPR68 is an essential flow sensor in arteriolar endothelium, and is a critical signaling component in cardiovascular pathophysiology.

Piezo2 is the major transducer of mechanical forces for touch sensation in mice

The sense of touch provides critical information about our physical environment by transforming mechanical energy into electrical signals. It is postulated that mechanically activated cation channels initiate touch sensation, but the identity of these molecules in mammals has been elusive. Piezo2 is a rapidly adapting, mechanically activated ion channel expressed in a subset of sensory neurons of the dorsal root ganglion and in cutaneous mechanoreceptors known as Merkel-cell-neurite complexes. It has been demonstrated that Merkel cells have a role in vertebrate mechanosensation using Piezo2, particularly in shaping the type of current sent by the innervating sensory neuron; however, major aspects of touch sensation remain intact without Merkel cell activity. Here we show that mice lacking Piezo2 in both adult sensory neurons and Merkel cells exhibit a profound loss of touch sensation. We precisely localize Piezo2 to the peripheral endings of a broad range of low-threshold mechanoreceptors that innervate both hairy and glabrous skin. Most rapidly adapting, mechanically activated currents in dorsal root ganglion neuronal cultures are absent in Piezo2 conditional knockout mice, and ex vivo skin nerve preparation studies show that the mechanosensitivity of low-threshold mechanoreceptors strongly depends on Piezo2. This cellular phenotype correlates with an unprecedented behavioural phenotype: an almost complete deficit in light-touch sensation in multiple behavioural assays, without affecting other somatosensory functions. Our results highlight that a single ion channel that displays rapidly adapting, mechanically activated currents in vitro is responsible for the mechanosensitivity of most low-threshold mechanoreceptor subtypes involved in innocuous touch sensation. Notably, we find that touch and pain sensation are separable, suggesting that as-yet-unknown mechanically activated ion channel(s) must account for noxious (painful) mechanosensation.

Temperature-induced opening of TRPV1 ion channel is stabilized by the pore domain

TRPV1 is the founding and best-studied member of the family of temperature-activated transient receptor potential ion channels (thermoTRPs). Voltage, chemicals, and heat amongst other agonists allosterically gate TRPV1. Molecular determinants for TRPV1 activation by capsaicin, allicin, acid, ammonia, and voltage have been identified. However, the structures and mechanisms mediating its pronounced temperature-sensitivity remain unclear. Recent studies of the related channel TRPV3 identified residues within the pore region required for heat activation. Here we use both random and targeted mutagenesis screens of TRPV1 and identify point mutations in the outer pore region that specifically impair temperature-activation. Single channel analysis shows that TRPV1 mutations disrupt heat-sensitivity by ablating long channel openings, that are part of the temperature-gating pathway. We propose that sequential occupancy of short and long open states upon activation provides a mechanism to enhance temperature-sensitivity. Our study suggests that the outer pore plays a general role in heat-sensitivity of thermoTRPs.

A role of TRPA1 in mechanical hyperalgesia is revealed by pharmacological inhibition

Mechanical hyperalgesia is a clinically-relevant form of pain sensitization that develops through largely unknown mechanisms. TRPA1, a Transient Receptor Potential ion channel, is a sensor of pungent chemicals that may play a role in acute noxious mechanosensation and cold thermosensation. We have developed a specific small molecule TRPA1 inhibitor (AP18) that can reduce cinnameldehyde-induced nociception in vivo. Interestingly, AP18 is capable of reversing CFA-induced mechanical hyperalgesia in mice. Although TRPA1-deficient mice develop normal CFA-induced hyperalgeisa, AP18 is ineffective in the knockout mice, consistent with an on-target mechanism. Therefore, TRPA1 plays a role in sensitization of nociception, and that compensation in TRPA1-deficient mice masks this requirement.

[Cellular response one year after extracapsular cataract extraction--comparison of regular and heparin surface modified PMMA intraocular lenses]

PURPOSE

To compare the heparin-surface-modified and the regular polymethylmethacrylate posterior chamber intraocular lenses regarding cellular reactions one year after extracapsular cataract extraction.

MATERIAL AND METHODS

62 patients of either sex, with senile cataract, without diabetes and any preoperative pathology of the eye, were included in the study. 30 patients received HSM PMMA PC IOL and 32 patients received unmodified PMMA PC IOL. All patients had a standard extracapsular cataract extraction. At the examination after one year the best corrected visual acuity was defined, anterior segment of the eye was evaluated biomicroscopically, cell deposits were assessed and the state of posterior capsule was noticed.

RESULTS

One year postoperatively all patients in both groups had the best corrected visual acuity better than 0.5. Significantly fewer eyes with the HSM PMMA PC IOLs had cell deposits on the anterior surface of the lens (20% vs. 37.5%). The amount of cell deposits per patients was small. Irregularity of the pupil with presence of posterior synechias did not differ significantly between the groups. The percentage of patients with clear posterior capsule was greater in the group with implanted heparin-modified artificial lenses.

CONCLUSION

The study suggests that heparin-surface-modified posterior intraocular lenses result in less postoperative cellular response observed one year after extracapsular cataract extraction.

[Cellular reactions after intraocular lens implantation]

The surgical trauma and the presence of the artificial lens in the eye causes inflammatory reactions. The cellular response is a result of 1) the breakdown of the blood-aqueous barrier, 2) foreign body reaction induced by lens material. The presence of cellular deposits (small, fibroblast-like, epithelioid, giant cells) on the surface of intraocular lenses is related to many factors such as surgical technique, risk factors of inflammation, postoperative treatment and the kind of lens material. The aim of this paper is to present contemporary knowledge about cytopathology of intraocular lenses and chances to improve the surface characteristic to avoid the adhesion of cells.

[Allergy to squid and acari in a child]

Anaphylactic reactions after consumption of squid by patients sensitized to house dust mites have been reported several times.

CASE REPORT

A child allergic to dust mites developed an angioneurotic edema after eating squid. An immunoallergological assessment, including the prick test, labial test and IgE RAST revealed an allergy associated to both dust mites and squid.

CONCLUSIONS

In light of the potential seriousness of anaphylactic reactions, parents of children allergic to dust mites and these children should be made aware of the increased risk of allergies to squid that they may face.

[Allergy to snails and mites in children]

BACKGROUND

Anaphylactic reactions after consumption of snails by patients sensitized to house-dust mites have been reported several times.

CASE REPORT

Two 8- and 10-year old children sensitized to house-dust mites developed Quincke's oedema after eating snails. Immunoallergologic investigations including pricks-test, labial test, IgE Rast confirmed associated allergy between snails and house dust mites.

CONCLUSION

Considering the potential severity of anaphylactic reactions, it is necessary to warn children allergic to house dust mites and their parents about the high risk of associated allergy with snails.

[Asthma and intolerance to benzoates]

BACKGROUND

Some foods and drug additives may induce allergic reactions.

CASE REPORT

A girl with a family history of asthma in both parents developed asthma in her early life. She was successfully given continuous bronchodilator therapy until the age of 7 years. At that time, she had more frequent and severe exacerbations (8 within 10 months) despite reinforced continuous treatment. Oral challenges with bisulfite and sodium benzoate, both additives abundantly ingested by the patient, revealed heightened sensitivity to administration of sodium benzoate. Avoidance of this additive was followed by complete and prolonged disappearance of episodes of coughing and wheezing.

CONCLUSION

Adverse reactions to benzoate in this patient required avoidance of some drugs, some of those classically prescribed under the form of syrups in asthma.

[Turner's syndrome and isoforms of LH and FSH. Value of polyclonal enzymatic techniques]

BACKGROUND

The glycoproteic hormones, LH and FSH, circulate under heterogenous molecular forms, the isoforms. The more acidic isoforms of FSH are found in hypogonadic patients and a displacement towards the basic forms is observed during substitutive treatment.

CASE REPORT

A 13 year-old girl with Turner syndrome was examined for pubertal delay. Ultrasonography failed to see both ovaries and endocrine investigations showed a type P1 response (LH-RH test using immunological method). Control of hormonal levels by a polyclonal immunoenzymatic method confirmed primary hypogonadism.

CONCLUSIONS

Radioimmunological methods using monoclonal antibodies can underevaluate FSH and LH levels under circumstances in which the distribution of isoforms may vary. Discrepancy must lead to the measure of gonadotrophins using polyclonal immunoenzymatic methods.

[Association of Moebius syndrome and hypopituitarism due to a midline anomaly. A case report]

A 14 year old patient had both Moebius anomalad with arthrogryposis and growth hormone deficiency due to a midline defect. This combination suggests an abnormality in the organization of the neural crest and homologous neural tube segment.

[Early neurotoxicity of high-dose of methotrexate and tetrahydrobiopterin deficiency]

Transient neurologic dysfunction associated with high-dose methotrexate and citrovorum factor rescue (MTX-CF) has been previously reported. At the biochemical level, there are at least two important pathways in central nervous system metabolism which might be disturbed by MTX: MTX may deplete the cell of the de novo synthesis of purine nucleotides and thymidylate through its action on dihydrofolate reductase (DHFR), and also inhibit dihydropteridine reductase (DHPR), an enzyme maintaining the cofactor of phenylalanine-hydroxylase in its active tetrahydrogenated form (tetrahydrobiopterin), and hence interfere with the supply of the neurotransmitters derived from tyrosine and tryptophan. We describe such a neurologic disease in a patient with acute lymphoblastic leukemia (ALL) receiving chemotherapy. Significant increase in cerebrospinal fluid biopterins supports the hypothesis of an inhibition of dihydropteridine reductase by MTX, and provides additional suggestions in terms of etiology, diagnosis and treatment.

[Cervical spondylodiscitis caused by Kingella kingae. Apropos of a case]

We report a new case of spondylodiscitis due to Kingella kingae in a 19-month-old infant who had torticollis as the first manifestation. The main characteristics of Kingella kingae infections are reviewed: frequency of ENT and joint localizations, slow course, difficult clinical and bacteriological diagnosis, and satisfactory susceptibility to antimicrobial agents.

[Delayed severe decompensation of leucinosis. Significance of emergency blood exchange transfusion. Apropos of 2 cases]

The observations of two gypsy cousins born to consanguineous parents and exhibiting classical leucinemia are reminders that severe, life-threatening ketotic decompensations may occur at any time. Emergency exchange-transfusions in these two children aged 3 and 5 years reversed the course of extremely severe attacks. Medium term evaluations showed very satisfactory neuropsychologic development in both children. Pathogenesis and prevention of such episodes are discussed.

[Iatrogenic Cushing syndrome in infants. Report of a case with dwarfism]

We report a case of iatrogenic Cushing syndrome with dwarfism (-6 SD) in an eight-month-old infant. The respective role of exposure to corticosteroids in utero (the mother took 30 mg prednisolone per day throughout pregnancy) and postnatally (oral prednisolone, prednisolone in breast milk, and betamethasone cream) is discussed. Two other features are pointed out, i.e. presence of a food allergy and favorable outcome under hydrocortisone therapy.

[Rescue from sudden death syndrome and allergy to milk proteins (apropos of a case)]

Allergy to milk proteins may be responsible for the syndrome of unexplained, sudden death of infants, but well-documented cases are rare. The authors report an observation where clinical history and complementary investigations support the incrimination of this factor.

[Rod myopathy. A fatal neonatal case]

A new lethal case of nemaline myopathy is reported. Muscle biopsy at 20 days of age permitted the diagnosis but this boy died at the 35th day of life. In a review of the literature (15 similar cases) the authors analyse the diagnostic, histopathogenic, genetic and evolutive aspects of this heterogeneous disorder, apparently less "benign" than previously thought.

[The succession of precocious puberty and Stein-Leventhal syndrome]

The authors relate the observation of a girl with precocious puberty diagnosed at 4 years, treated for 7 years with medroxyprogesterone and who presents now a Stein-Leventhal syndrome. They emphasize the unique character of this association and discuss the different pathogenetic hypotheses: hypothalamo-pituitary disorder, effect of medroxyprogesterone acetate, hyperinsulinism, casual association.

[Echography in gonadal dysgenesis and ovarian dystrophy (author's transl)]

Pelvic ultrasound examination was performed in 28 patients presenting with disorder in the onset of puberty (13 suggesting gonadal dysgenesis and 15, ovarian hyperandrogenism). Results of this investigation were compared with those of coelioscopy, in order to establish the respective value of each technique in the diagnosis of disorders of puberty in girls. In patients with gonadal dysgenesis, echography may show 'residual gonads but coelioscopy remains necessary when results of radiologic investigation are negative, when clinical or hormonal data suggest that ovarian function is present. Ultrasound examination showed one or two enlarged ovaries in all but one patients in whom coelioscopy had shown this abnormality. Pelvic echography is now the first test to be performed in girls with disorders of puberty as it often permits to avoid coelioscopy.

[Somatostatin in a case of nesidioblastosis (author's transl)]

The authors report the case of a three-month-old infant presenting with hypoglycaemia. The etiology, i.e. nesidioblastosis, was asserted by simultaneous dosage of insulin and glucose and by histologic study of the pancreas. Initial therapy was a combination of diazoxide, continuous enteral alimentation and glucose injections. It's ineffectiveness led to an operative decision and 4/5 ths of the pancreas were removed. After a transitory improvement symptoms recurred. Data provided by studies of baseline levels and response to exogenous somatostatin then allowed to determine the correct dosage for treatment with long-acting somatostatin. The authors also discuss the importance of somatostatin in pathogenesis as well as for diagnosis and therapy of nesidioblasosis.

[Antenatal screening for neural tube defect by measuring alphafetoprotein in dried blood eluates (author's transl)]

Alphafetoprotein (AFP) was measured during pregnancy in dried blood eluates. Normal values (50th percentile) were established from 5,000 women throughout their pregnancies. AFP levels progressively increase from the 6th week (3.0 ng/ml whole blood) to the 32 week (124.0), then decrease slowly (70.1). Correlations between serum AFP and AFP from eluates is highly significant (p less than 0.001). Preservation of blood samples on blotting paper is good. An experimental screening of more than 1,500 pregnant women detected one case of anencephaly.

[Epidemiology of passive smoking of children from 0 to 6 years (author's transl)]

An epidemiologic survey was carried out in the South of France, concerning 892 children less than 6 years of age who were examined or hospitalized for various reasons. Smoking is significantly more important in parents of coughing children than in children who do not cough. The percentage of coughing children increases with the amount of smoking of their parents. A statistically significant relationship is found between the annual incidence of bronchopneumopathies and the total number of cigarettes smoked inside the house. A respiratory index expressed as the sum of 6 parameters representative of the respiratory infectious status of the children is correlated with parental smoking. This study also shows the enhancing effect of day care centers and nursery schools and of collective heating, difficult to adjust. This emphasizes the role of environmental factors and the multifactorial character of respiratory diseases in pre-school children.

[The Stein-Leventhal syndrome. Clinical, biological and anatomic study of 6 cases in adolescent girls (author's transl)]

Clinical, biological and anatomic studies were performed in 6 adolescent girls with the Stein-Leventhal syndrome. The rare occurrence of this syndrome in pediatrics is emphasized. The main clinical signs consist of obesity, hirsutism and menstrual irregularities. Basic LH and plasma testosterone are useful diagnostic means, as well as -- in children -- the suppression-stimulation and LH-RH tests. However, coelioscopy is necessary to allow a correct diagnosis. Histological examination might not be absolutely necessary since a large biopsy could be responsible for untimely ovulation. Estrogens and anti-androgens are the only logical treatment at the time of puberty.

[Association of male XX with Pierre Robin syndrome in a child whose father has a balanced 46XY, t (16; 17) (p13;q21) translocation]

The authors relate the association XX male and syndrome of Pierre Robin in a child whose father presents a reciprocal equilibrated translocation 46,XY t (16;17) (p13;q21). They discuss the possible relation between these different anomalies and notably the possibility of a genic effect.