P295 EXERCISE OXYGEN KINETIC IN HYPERTROPHIC CARDIOMYOPATHY: RESULTS FROM A MULTICENTER CARDIOPULMONARY EXERCISE TESTING STUDY

Aims

Reduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). We evaluated the cardiopulmonary exercise testing (CPET) response in HCM focusing on parameters strongly associated with stroke volume (SV) and cardiac output (CO), such as oxygen uptake (VO2) and O2–pulse, considering both their absolute values and temporal behavior during physical exercise.

Methods and Results

We enrolled 312 non–end stage HCM patients, divided according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva maneuver (72% with LVOTO<30; 10% between 30 and 49 and 18% ≥ 50mmHg). Peak VO2 (percent of predicted), O2–pulse and ventilation to carbon dioxide production (VE/VCO2) slope did not change across LVOTO groups. Ninety–six (31%) HCM patients presented an abnormal O2–pulse temporal behavior, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106±45 vs. 130±49W), VO2 (74±17 vs. 80±20%) and O2–pulse (12 [9–14] vs. 14 [11–17]ml/beat), with higher VE/VCO2 slope (28 [25–31] vs. 27 [24–31]) (p < 0.005 for all). Only 2 patients had an abnormal VO2/work slope.

Conclusion

None of CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal O2–pulse exercise behavior, which is strongly related to inadequate SV during exercise, correlates with reduced functional capacity (peak and anaerobic threshold VO2 and workload) and increased VE/VCO2 slope, helping identifying more advanced disease irrespectively of LVOTO. Adding O2–pulse kinetics evaluation to standard CPET could lead to a potential incremental benefit in terms of HCM prognostic stratification and, then, therapeutic management.

Modifications to mobile chest radiography technique during the COVID-19 pandemic - implications of X-raying through side room windows

INTRODUCTION

Modifications to common radiographic techniques have resulted from the challenges presented by the COVID-19 pandemic. Reports exist regarding the potential benefits of undertaking mobile radiography through side room windows. The aim of this study was to evaluate the impact on image quality and exposure factors when undertaking such examinations.

METHODS

A phantom based study was undertaken using a digital X-ray room. Control acquisitions, using a commercially available image quality test tool, were performed using standard mobile chest radiography acquisition factors. Image quality (physical and visual), incidence surface air kerma (ISAK), Exposure Index (EI) and Deviation Index (DI) were recorded. Image quality and radiation dose were further assessed for two additional (experimental) scenarios, where a side room window was located immediately adjacent to the exit port of the light beam diaphragm. The goal of experimental scenario one was to modify exposure factors to maintain the control ISAK. The goal of experimental scenario two was to modify exposure factors to maintain the control EI and DI. Dose and image quality data were compared between the three scenarios.

RESULTS

To maintain the pre-window (control) ISAK (76 μGy), tube output needed a three-fold increase (90 kV/4 mAs versus 90 kV/11.25 mAs). To maintain EI/DI a more modest increase in tube output was required (90 kV/8 mAs/ISAK 54 μGy). Physical and visual assessments of spatial resolution and signal-to-noise ratio were indifferent between the three scenarios. There was a slight statistically significant reduction in contrast-to-noise ratio when imaging through the glass window (2.3 versus 1.4 and 1.2; P = 0.005).

CONCLUSION

Undertaking mobile X-ray examinations through side room windows is potentially feasible but does require an increase in tube output and is likely to be limited by minor reductions in image quality.

IMPLICATIONS FOR PRACTICE

Mobile examinations performed through side room windows should only be used in limited circumstances and future clinical evaluation of this technique is warranted.

Differential expression of innate immune response genes in clinical phases of chronic hepatitis B infection

We investigated innate immune gene expression in clinical phases of chronic hepatitis B infection, including immune tolerant (IT), immune active (IA), inactive carrier (IC) and hepatitis B e antigen (HBeAg)-negative phases, as well as healthy controls. Expression levels of interferon types I, II and III, their receptor subunits, IRFs, TLRs and other IFN-induced genes in peripheral blood mononuclear cells were compared. Forty HBsAg-positive treatment-naïve subjects without co-infection with HIV, HCV or HDV were enrolled. To complement the viral load, the expression levels of 37 innate immune genes were measured by qPCR. The highest response of the innate immune system was observed in the IT and HBeAg-negative phases, and the IC phase had the lowest response; 31 of the 37 studied genes reached their maximum mRNA expression levels in the IT and HBeAg-negative phases, and the minimum expression levels of 23 genes were found in the IC phase. The highest mRNA expression levels of IFNs, IFN receptor subunits, IRFs and TLRs genes in all clinical phases were IFN-λ2 and 3, IFN-γR2, IRF7 and TLR7, and the lowest levels of mRNA expression were observed for IFN-α, IFN-λR1, IRF8 and TLR2. We conclude that innate immune response genes are expressed differentially among chronic HBV phases, and this difference may help to develop new precise and noninvasive methods to determine the progression of disease in chronic HBV patients.

Chronic obstructive pulmonary disease (COPD) exacerbation: impact of comorbidities on length and costs during hospitalization

OBJECTIVE

A retrospective cohort study was performed, using administrative database of the Local Health Unit Roma-A (LHU RM-A). The included subjects were residing in one of the four districts and were hospitalized for COPD exacerbation in healthcare facilities of the LHU during years 2010-2012.

PATIENTS AND METHODS

The aim of the present study is to evaluate the impact of comorbidities, length and costs of hospital stay in patients with COPD exacerbations. Chronic obstructive pulmonary disease (COPD) is often associated with other diseases (cardiovascular diseases, diabetes, metabolic syndrome, chronic renal failure, depression) that can increase risk of mortality and hospitalization.

RESULTS

A total of 1890 COPD patients are included in the study. The mean length of hospitalization is 12.25 days (SD ± 10.91), 11.63 days (SD ± 9.76) and 11.91 days (SD ± 9.69) with a mean cost of hospitalization amounting to euro 3683.48 (SD ± 2037.12), 3356.82 (SD ± 1674.86) and 3706.81 (SD ± 2087.72) in 2010, 2011 and 2012 respectively. The presence and number of comorbidities are positively and significantly associated to the length and cost of hospitalization. In particular, patients with cardiovascular diseases or diabetes mellitus associated with other comorbidities present the highest values of hospital stay and cost. The cost and the length of hospitalization were significantly linked to the number of comorbidities.

CONCLUSIONS

Comorbidities play an important role in the hospital management of COPD exacerbation, increasing health care costs related to this disease.

Early use of non invasive ventilation in patients with amyotrophic lateral sclerosis: what benefits?

OBJECTIVE

The aim of this study was to analyze the efficacy of an early start of NIV in ALS patients, evaluating respiratory and ventilatory parameters.

PATIENTS AND METHODS

Functional respiratory parameters and arterial blood gas analysis were evaluated in forty-six patients. All patients were informed about the benefits and possible adverse effects of therapeutic support with NIV and divided in two groups based on the compliance to early start therapy with NIV (Group A) or not (Group B).

RESULTS

Among 46 ALS patients consecutively visited in our Unit, we included 20 patients in the Group A and 16 in the Group B. We have emphasized the importance of the early use of NIV stressing the difference between two groups analyzed, particularly in terms of pulmonary function tests and arterial blood gas analysis. Significant correlation was observed between Vital Capacity (VC), Forced Expiratory volume in one second (FEV1), and maximal inspiratory pressures (PImax).

CONCLUSIONS

Our study highlights the importance of noninvasive mechanical ventilation as a treatment for ALS patients and also shows the early start of NIV as an important approach in order to postpone the functional decline and the decrease of respiratory muscle strength.

Atrial fibrillation in the acute, hypercapnic exacerbations of COPD

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) has been associated with a high frequency of arrhythmias. Atrial fibrillation (AF) is one of the most common arrhythmias and causes substantial morbidity and mortality. Emerging risk factors for the development of AF include a variety of breathing disorders like COPD. Few studies have analyzed the role of reduced lung function and respiratory acidosis in predicting AF. Aim of the current study was to investigate the role of hypercapnia, pulmonary systolic hypertension and lung function impairment in COPD patients, as risk factors for atrial fibrillation development.

PATIENTS ANDV METHODS

We evaluated a population of individuals consecutively hospitalized for COPD exacerbation and hypercapnic respiratory failure between January 2012 and January 2013; among them we selected a subgroup of patients presenting a paroxysmal episode of atrial fibrillation. All patients underwent pulmonary function tests, haemogasanalysis, electrocardiogram and transthoracic echocardiography.

RESULTS

Among the 193 subjects evaluated, 35 individuals with AF and COPD were enrolled in the study. Risk of new AF was higher in those subjects with lower FEV1 and higher PaCO2 values, also there was a significantly increased prevalence of AF in patients with higher value of Pulmonary Artery Systolic Pressure (PASP), obtained by transthoracic echocardiography. Linear correlation between variables revealed a direct relationships between hypercapnia and PASP and left and right atrial areas.

CONCLUSIONS

Impaired pulmonary function, hypercapnia and high values of PASP are independent predictors of incident AF.

ROD1 is a seedless target gene of hypoxia-induced miR-210

Most metazoan microRNA (miRNA) target sites have perfect pairing to the “seed” sequence, a highly conserved region centering on miRNA nucleotides 2–7. Thus, complementarity to this region is a necessary requirement for target prediction algorithms. However, also non-canonical miRNA binding can confer target regulation. Here, we identified a seedless target of miR-210, a master miRNA of the hypoxic response. We analyzed 20 genes that were inversely correlated to miR-210 expression and did not display any complementarity with miR-210 seed sequence. We validated ROD1 (Regulator of Differentiation 1, also named PTBP3, Polypyrimidine Tract Binding protein 3) as a miR-210 seedless transcript enriched in miR-210-containing RNA-induced silencing complexes. ROD1 was not indirectly targeted by a miR-210-induced miRNA. Conversely, we identified a “centered” miR-210 binding site in ROD1 involving 10 consecutive bases in the central portion of miR-210. Reporter assays showed that miR-210 inhibited ROD1 by the direct binding to this sequence, demonstrating that ROD1 is a bona fide seedless target of miR-210. As expected, both ROD1 mRNA and protein were down-modulated upon hypoxia in a miR-210 dependent manner. ROD1 targeting by miR-210 was biologically significant: the rescue of ROD1 inhibition significantly increased hypoxia-induced cell death. These data highlight the importance of ROD1 regulation by miR-210 for cell homeostasis.

Cross-sectional imaging of individual layers and buried interfaces of graphene-based heterostructures and superlattices

By stacking various two-dimensional (2D) atomic crystals on top of each other, it is possible to create multilayer heterostructures and devices with designed electronic properties. However, various adsorbates become trapped between layers during their assembly, and this not only affects the resulting quality but also prevents the formation of a true artificial layered crystal upheld by van der Waals interaction, creating instead a laminate glued together by contamination. Transmission electron microscopy (TEM) has shown that graphene and boron nitride monolayers, the two best characterized 2D crystals, are densely covered with hydrocarbons (even after thermal annealing in high vacuum) and exhibit only small clean patches suitable for atomic resolution imaging. This observation seems detrimental for any realistic prospect of creating van der Waals materials and heterostructures with atomically sharp interfaces. Here we employ cross sectional TEM to take a side view of several graphene-boron nitride heterostructures. We find that the trapped hydrocarbons segregate into isolated pockets, leaving the interfaces atomically clean. Moreover, we observe a clear correlation between interface roughness and the electronic quality of encapsulated graphene. This work proves the concept of heterostructures assembled with atomic layer precision and provides their first TEM images.

A nonsense mutation in the human homolog of Drosophila rogdi causes Kohlschutter-Tonz syndrome

Kohlschutter-Tonz syndrome (KTS) is a rare autosomal-recessive disorder of childhood onset, and it is characterized by global developmental delay, spasticity, epilepsy, and amelogenesis imperfecta. In 12 KTS-affected individuals from a Druze village in northern Israel, homozygosity mapping localized the gene linked to the disease to a 586,513 bp region (with a LOD score of 6.4) in chromosomal region 16p13.3. Sequencing of genes (from genomic DNA of an affected individual) in the linked region revealed chr16: 4,848,632 G>A, which corresponds to ROGDI c.469C>T (p.Arg157(∗)). The nonsense mutation was homozygous in all affected individuals, heterozygous in 10 of 100 unaffected individuals from the same Druze community, and absent from Druze controls from elsewhere. Wild-type ROGDI localizes to the nuclear envelope; ROGDI was not detectable in cells of affected individuals. All affected individuals suffered seizures, were unable to speak, and had amelogenesis imperfecta. However, age of onset and the severity of mental and motor handicaps and that of convulsions varied among affected individuals homozygous for the same nonsense allele.

Treatment of acute exacerbations with non-invasive ventilation in chronic hypercapnic COPD patients with pulmonary hypertension

BACKGROUND AND OBJECTIVES

Chronic Obstructive Pulmonary Disease (COPD) is a slowly progressive airways disorder characterized by not fully reversible airflow obstruction, often presenting exacerbations of respiratory symptoms requiring hospitalization. Non-Invasive Ventilation (NIV) has been shown to be an effective adjunct to standard medical therapy in the treatment of acute respiratory failure. Secondary pulmonary hypertension leads to a rapid progression of the disease.

AIM

To evaluate the effect of NIV treatment in patients with acute exacerbation of COPD, with or without respiratory acidosis, and its effect in patients with pulmonary hypertension.

PATIENTS AND METHODS

We enrolled 61 consecutive subjects (M 41; F 20) with COPD admitted to our respiratory ward for acute respiratory exacerbation. Patients were divided into two groups on the basis of arterial pH (group A: 26 individuals with pH <7.35; group B: 35 with pH > or =7.35) and treated with optimal medical therapy (oxygen-therapy, systemic corticosteroids, bronchodilators, antibiotics) and NIV. Moreover, we evaluated functional autonomy thought Six Minute Walking Test (6 mWT), and pulmonary arterial pressure (by transthoracic echocardiography).

RESULTS

In group A NIV treatment was associated to a total regression of uncompensated respiratory acidosis (pH 7.36 vs. 7.29). In both groups we observed a significant reduction of PaCO2 (group A: 77.14 +/- 10.4 vs. 45.1 +/- 2.8 mmHg; group B: 70.1 vs. 44 +/- 3.9 mmHg) and an improvement in PaO2 (group A: 51.2 +/- 10.3 vs 84.2 mmHg; group B: 59 +/- vs. 87 +/- 3.3 mmHg). Total average duration of NIV administration was longer in Group A than in Group B (81.14 hours vs 55.83 hours). At the end of NIV treatment, we observed improvement in the autonomy of walking (175.1 meters vs 118.4 meters) in both groups. Patients with severe pulmonary hypertension (PASP > or =55 mmHg) showed a lower reduction of PaCO2 (47.8 vs. 43.7 mmHg) and a minor improvement of arterial pH (7.37 vs. 7.41) compared to patients with a lower value of pulmonary hypertension.

CONCLUSIONS

In this study we showed that NIV is useful in patients with or without uncompensated respiratory acidosis, through the improvement of symptoms, blood gases parameters, and walking autonomy. Patients with severe pulmonary hypertension are associated with poorer response to NIV treatment.

Sequence Diversity in tRNA Gene Locus A-L among Iranian Isolates of Entamoeba dispar

BACKGROUND

A number of methods for detecting diversity in Entamoeba have been described over the years. In the present study the genetic polymorphism of noncoding locus A-L was analyzed using PCR and sequencing in order to clarify the genotypic differences among E. dispar isolates.

METHODS

A total of 28 E. dispar from patients with gastrointestinal symptoms were determined and the genomic DNA was extracted directly from stool. For genotype analysis; Locus A-L was amplified by PCR and PCR products were sequenced. The sequences obtained were edited manually and aligned using Gene Runner software.

RESULTS

With sequencing of PCR products a reliable genetic diversity in size, number and position of the repeat units were observed among the Iranian E. dispar isolates in locus A-L gene. Sequences showed variation in length from 448bp to 507bp and seven distinct types were identified.

CONCLUSION

The genetic diversity of loci like A-L shows them to be suitable for epidemiological studies such as the characterization of the routes of transmission of these parasites in Iran.

Molecular epidemiology of cryptosporidiosis in Iranian children, tehran, iran

BACKGROUND

Cryptosporidium is a worldwide protozoan parasite and one of the most common causes of infection and diarrhea in humans and cattle. The aim of the present study was determination of subtypes of Cryptosporidium among children with diarrhea in Tehran by sequence analysis of the highly polymorphic 60-kDa glycoprotein (GP60) gene.

METHODS

Fecal samples were collected from 794 diarrheic children. Initial identification of Cryptosporidium was carried out on stool samples by Ziehl-Neelsen acid-fast staining method. DNA was extracted from positive microscopically samples and Cryptosporidium genotypes and subtypes were determined, accordingly.

RESULTS

Out of 794 collected samples, 19 (2.40%) were positive for Cryptosporidium oocysts. Sequences analysis of GP60 gene showed that 17 (89.47%) of the positive isolates were Cryptosporidium parvum and 2 (10.52%) were C. hominis. All subtypes of C. parvum isolates belonged to allele families IIa (6/17) and IId (11/17). The most common allele in all 17 isolates belonged to IId A20G1a (41.18%). A22G1 (IF) subtype was detected in two C. hominis isolates of the children.

CONCLUSION

The predominancy of C. parvum species (specially, IId A20G1a subtype) in current study underlines the importance of zoonotic Cryptosporidium transmission in Iran.

HMGB1 attenuates cardiac remodelling in the failing heart via enhanced cardiac regeneration and miR-206-mediated inhibition of TIMP-3

Aims

HMGB1 injection into the mouse heart, acutely after myocardial infarction (MI), improves left ventricular (LV) function and prevents remodeling. Here, we examined the effect of HMGB1 in chronically failing hearts.

Methods and Results

Adult C57 BL16 female mice underwent coronary artery ligation; three weeks later 200 ng HMGB1 or denatured HMGB1 (control) were injected in the peri-infarcted region of mouse failing hearts. Four weeks after treatment, both echocardiography and hemodynamics demonstrated a significant improvement in LV function in HMGB1-treated mice. Further, HMGB1-treated mice exhibited a ∼23% reduction in LV volume, a ∼48% increase in infarcted wall thickness and a ∼14% reduction in collagen deposition. HMGB1 induced cardiac regeneration and, within the infarcted region, it was found a ∼2-fold increase in c-kit⁺ cell number, a ∼13-fold increase in newly formed myocytes and a ∼2-fold increase in arteriole length density. HMGB1 also enhanced MMP2 and MMP9 activity and decreased TIMP-3 levels. Importantly, miR-206 expression 3 days after HMGB1 treatment was 4-5-fold higher than in control hearts and 20–25 fold higher that in sham operated hearts. HMGB1 ability to increase miR-206 was confirmed in vitro, in cardiac fibroblasts. TIMP3 was identified as a potential miR-206 target by TargetScan prediction analysis; further, in cultured cardiac fibroblasts, miR-206 gain- and loss-of-function studies and luciferase reporter assays showed that TIMP3 is a direct target of miR-206.

Conclusions

HMGB1 injected into chronically failing hearts enhanced LV function and attenuated LV remodelling; these effects were associated with cardiac regeneration, increased collagenolytic activity, miR-206 overexpression and miR-206 -mediated inhibition of TIMP-3.

MicroRNA-155 targets the SKI gene in human melanoma cell lines

The SKI protein is a transcriptional coregulator over-expressed in melanoma. Experimentally induced down-regulation of SKI inhibits melanoma cell growth in vitro and in vivo. MicroRNAs (miRNAs) negatively modulate gene expression and have been implicated in oncogenesis. We previously showed that microRNA-155 (miR-155) is down-regulated in melanoma cells as compared with normal melanocytes and that its ectopic expression impairs proliferation and induces apoptosis. Here, we investigated whether miR-155 could mediate melanoma growth inhibition via SKI gene silencing. Luciferase reporter assays demonstrated that miR-155 interacted with SKI 3'UTR and impaired gene expression. Transfection of melanoma cells with miR-155 reduced SKI levels, while inhibition of endogenous miR-155 up-regulated SKI expression. Specifically designed small interfering RNAs reduced SKI expression and inhibited proliferation. However, melanoma cells over-expressing a 3'UTR-deleted SKI were still susceptible to the antiproliferative effect of miR-155. Our data demonstrate for the first time that SKI is a target of miR-155 in melanoma. However, impairment of SKI expression is not the leading mechanism involved in the growth-suppressive effect of miR-155 found in this malignancy.

A comparative study of the responses of lithium borate and calcium sulphate phosphors in a TL personal dosemeter

This work summarises the results of a series of experiences made on Panasonic UD-802AS, a multi-element dosemeter that is currently used in Caorso Nuclear Power Plant for personnel external monitoring. Two main topics have been considered: energy response and the influence of working place dose rate on relative readings of the elements at the end of the monitoring period. The presence of four elements of different materials and filtrations gives the possibility of evaluating radiation energy by a simple algorithm, so that an accurate estimate of the personal dose equivalent can be provided; the good results of the participation of Caorso Individual Monitoring Service (IMS) to 'EURADOS 2008 intercomparison on whole-body dosemeters' account for the reliability of the method. A study on the response in low-dose rate fields is also reported, giving in practice interesting information about operational conditions.

Liquid injection atomic layer deposition of silver nanoparticles

Silver nanoparticles are being developed for applications in plasmonics, catalysts and analytical methods, amongst others. Herein, we demonstrate the growth of silver nanoparticles using an atomic layer deposition (ALD) process for the first time. The silver was deposited from pulses of the organometallic precursor (hfac)Ag(1,5-COD) ((hexafluoroacetylacetonato)silver(I)(1,5-cyclooctadiene)) dissolved in a 0.1 M toluene solution. Catalytic oxidative dehydrogenation of the silver was achieved using intermittent pulses of propanol. The effect of substrate temperature on the size and distribution of nanoparticles has been investigated over the temperature range 110-150 degrees C. Transmission electron microscopy reveals that the nanoparticles consist of face centred cubic, facetted silver crystallites. The localized surface plasmon modes of the nanoparticles have been investigated using electron energy loss spectroscopy mapping. The distributions of plasmons within the ALD nanoparticles are comparable to those grown by solution methods. Both dipolar and quadrupolar resonant modes are observed, which is consistent with previous discrete dipole approximation models. Energy loss mapping of a loss feature at 8.1 eV reveals that it correlates with the bulk or volume region of the silver nanoparticles investigated here.

MicroRNA-210 modulates endothelial cell response to hypoxia and inhibits the receptor tyrosine kinase ligand Ephrin-A3

MicroRNAs (miRNAs) are small non-protein-coding RNAs that function as negative gene expression regulators. In the present study, we investigated miRNAs role in endothelial cell response to hypoxia. We found that the expression of miR-210 progressively increased upon exposure to hypoxia. miR-210 overexpression in normoxic endothelial cells stimulated the formation of capillary-like structures on Matrigel and vascular endothelial growth factor-driven cell migration. Conversely, miR-210 blockade via anti-miRNA transfection inhibited the formation of capillary-like structures stimulated by hypoxia and decreased cell migration in response to vascular endothelial growth factor. miR-210 overexpression did not affect endothelial cell growth in both normoxia and hypoxia. However, anti-miR-210 transfection inhibited cell growth and induced apoptosis, in both normoxia and hypoxia. We determined that one relevant target of miR-210 in hypoxia was Ephrin-A3 since miR-210 was necessary and sufficient to down-modulate its expression. Moreover, luciferase reporter assays showed that Ephrin-A3 was a direct target of miR-210. Ephrin-A3 modulation by miR-210 had significant functional consequences; indeed, the expression of an Ephrin-A3 allele that is not targeted by miR-210 prevented miR-210-mediated stimulation of both tubulogenesis and chemotaxis. We conclude that miR-210 up-regulation is a crucial element of endothelial cell response to hypoxia, affecting cell survival, migration, and differentiation.

Déficit homozygote en antithrombine de type HBS; à propos d'une famille

Congenital antithrombin (AT) deficiency is the most thrombotic genetic abnormality of haemostasis. Total quantitative deficits are lethal as early as life intra-uterine. Only homozygous mutations concerning the heparin-binding site are compatible with life. We report here the case of an 18 years old patient with recurrent deep venous thrombosis of the inferior members. Haemostasis exploration shows a decreased AT activity (11%) in the presence of heparin while AT progressive activity and AT antigen are normal. Two other homozygous sisters are identified in this family study. Molecular study of AT gene show Arg47-Cys substitution, already reported in the literature with patients of different geographic origins. Treatment of patients with homozygous AT type HBS deficiency is similar that for patients with heterozygous AT deficiency; a continuous prophylactic anticoagulant treatment is always necessary and AT concentrates infusions are required in all situations needing curative heparin treatment.

Analysis of urinary N-acetyl-S-(N-methylcarbamoyl)cysteine, the mercapturic acid derived from N,N-dimethylformamide

Human biotransformation of the industrial solvent N,N-dimethylformamide gives raise to N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) which has the longest half-life (about 23 h) among urinary metabolites of N,N-dimethylformamide. It could be used for monitoring industrial exposure over several workdays, by measuring it in urine samples collected at the end of the working week. This is consistent with the suggestions of the American Conference of Governmental Industrial Hygienists, which established a limit of 40 mg/l for the year 2000. An easy, cheap and user-friendly method has been developed for determination of urinary AMCC. Unlike currently available methods, it requires neither a time-consuming preparation phase nor gas chromatographic analysis with a nitrogen-phosphorus or mass detector. The method uses high-performance liquid chromatography (HPLC), with an UV detector at 436 nm. A 10-microl volume of urine is added to a carbonate-hydrogen carbonate buffer and mixed with a dabsyl chloride solution in acetonitrile. The reaction between AMCC and the reagent is performed at 70 degrees C for 10 min. The 'dabsylated' product is stable for at least 12 h. After brief centrifugation, the solution is ready for HPLC analysis using a C18 column (250 x 4.6 mm, 5 microm). The method is sensitive (detection limit 1.8 mg/l) and specific. It identified urinary AMCC in urine of 40 subjects not exposed to N,N-dimethylformamide with a median concentration of 3.9 mg/l. In urine samples from 20 workers exposed to N,N-dimethylformamide (5-40.8 mg/m3), AMCC concentrations ranged from 16 to 170 mg/l. Industrial toxicology laboratories with limited instrumentation will be able to use it in the biological monitoring of workers exposed to N,N-dimethylformamide.

The EGF and FGF receptors mediate neuroglian function to control growth cone decisions during sensory axon guidance in Drosophila

Cell adhesion molecules (CAMs) implement the process of axon guidance by promoting specific selection and attachment to substrates. We show that, in Drosophila, loss-of-function conditions of either the Neuroglian CAM, the FGF receptor coded by the gene heartless, or the EGF receptor coded by DER display a similar phenotype of abnormal substrate selection and axon guidance by peripheral sensory neurons. Moreover, neuroglian loss-of-function phenotype can be suppressed by the expression of gain-of-function conditions of heartless or DER. The results are consistent with a scenario where the activity of these receptor tyrosine kinases is controlled by Neuroglian at choice points where sensory axons select between alternative substrates for extension.

Autoxidation of packed almonds as affected by maillard reaction volatile compounds derived from roasting

Shelled almonds of two Italian varieties, Romana and Pizzuta, peeled and unpeeled, were roasted and packed under different conditions: air (control), vacuum, and Maillard reaction volatile compounds (MRVc) derived from the roasting process. Samples were stored for approximately 8 months at room temperature, without light, and, at regular intervals, were collected and analyzed to evaluate the progress of lipid oxidation. Peroxide values, triglyceride oligopolymers, and oxidized triglycerides were evaluated during the storage time. Results showed that, although the MRVc atmosphere did not protect the lipid fraction of almonds as well as the vacuum condition; nevertheless, it was more protective than the control atmosphere, showing an antioxidant effect. The effect of the natural coating was a strong protection against lipid oxidation; in fact, only the unpeeled samples showed peroxide values lower than the threshold of acceptability (25 milliequiv of O(2)/kg of oil). Moreover, at the end of the storage period, Pizzuta almonds showed a greater deterioration than those of the Romana variety.

Screening on the occurrence of ochratoxin A in green coffee beans of different origins and types

Since to our knowledge no data are available in the literature regarding the influence of green coffee type and origin on ochratoxin A (OTA) content, determinations were carried out in order to assess the level of OTA contamination in green coffee samples of different provenience. A total of 162 samples of green coffee beans from various countries (84 from Africa, 60 from America, and 18 from Asia) were analyzed for OTA. Both the amount and the variability of OTA levels were tested as a function of green coffee provenience. The results showed that 106 of the overall samples were positive for OTA, with concentration ranging from 0 to 48 microg/kg (ppb). In particular, it was possible to verify that African samples were more contaminated with respect to samples of other origin in terms of frequency and level of OTA; the highest concentrations observed were 18 and 48 microg/kg in two samples from The Congo.

Specific muscle identities are regulated by Kruppel during Drosophila embryogenesis

During Drosophila embryogenesis, mesodermal cells are recruited to form a complex pattern of larval muscles. The formation of the pattern is initiated by the segregation of a special class of founder myoblasts. Single founders fuse with neighbouring nonfounder myoblasts to form the precursors of individual muscles. Founders and the muscles that they give rise to have specific patterns of gene expression and it has been suggested that it is the expression of these founder cell genes that determines individual muscle attributes such as size, shape, insertion sites and innervation. We find that the segmentation gene Kruppel is expressed in a subset of founders and muscles, regulates specific patterns of gene expression in these cells and is required for the acquisition of proper muscle identity. We show that gain and loss of Kruppel expression in sibling founder cells is sufficient to switch these cells, and the muscles that they give rise to, between alternative cell fates.

Krüppel, a Drosophila segmentation gene, participates in the specification of neurons and glial cells

We report that the Drosophila segmentation gene Krüppel (Kr) is expressed in neural precursor cells, neurons and glial cells at different stages of neurogenesis and that Kr mutants develop aberrant peripheral (PNS) and central (CNS) nervous systems. Expression derived from a Kr minigene rescues the segmentation defects but these embryos continue to lack most of the neural Kr activity. Phenotypic analysis of the rescued embryos indicates that, in addition to overall effects on the PNS and CNS structure via its segmentation role, Kr expression in the nervous system is functionally required for establishing particular neural and glial fates.

[Has the role of radiology changed in the fight against pulmonary tuberculosis?]

Tuberculosis is on the increase in Italy as in other industrial countries. The key to tuberculosis control is case finding and radiology plays a major role in both active and passive tuberculosis diagnosis. Have recent advances in radiologic techniques increased the value of conventional radiology? Has the role of chest radiography changed in tuberculosis screening? To answer these questions we examined a population referred to our hospital for both screening and diagnostic purposes over a 12-month period. In a population of 31,730 inhabitants, 1,461 chest radiographs were performed, 226 (15.4%) for passive and the others for active case finding. As for active case finding, high-risk patients were screened (21 immigrants and 296 aging people), together with the general population believed to be at risk according to current national recommendations (918 chest films). While screening allowed the diagnosis of only one tuberculosis case in the high-risk group, 3 cases were found in the symptomatic group with the passive protocol. In our experience, new radiologic techniques have not made the diagnosis of tuberculosis easier. Unlike in cancers, CT was not particularly useful in identifying symptomatic tuberculosis cases. In our experience, screening yielded poor results: in fact, this attempt at preventing tuberculosis caused an unreasonable waste of time and money because when screening low-risk groups many films are needed to diagnose a single case. Thus, the reason for this failure was not a technical one. It proved to be a problem of selecting the population to be screened. Our results suggest that no major change has taken place in the role of conventional radiology in passive tuberculosis case finding and that radiology must be used differently in passive case finding, that is, for screening purposes in high-risk groups only.

Molecular characterization of the lethal of scute genetic function

The lethal of scute (l'sc) genetic function, which plays an essential role in the early development of the central nervous system of the Drosophila embryo, is localized within the achaete-scute complex (AS-C). Several lines of evidence have suggested that the AS-C T3 transcription unit corresponds to the l'sc function. We demonstrate that short fragments of DNA, containing the T3 transcribed region and a few kilobases of flanking sequences, rescue, albeit partially, the lethality and neural phenotype of l'sc deletions. Still, the complex wild-type pattern of expression of T3 is not reproduced by the transduced genes. This depends on cis-control elements scattered within the entire AS-C DNA and intermingled with regulatory elements specific for other AS-C transcription units. These elements are necessary for the initial activation of T3 in the neuroectoderm, probably mediated by axis-patterning genes. The presence of a cluster of E-boxes, upstream of the T3 transcribed region, suggests another level of control of T3 expression by basic-helix-loop-helix proteins, among them its own gene product.

[Measurement of gastric emptying with Tc 99m. Technique and reliability of the test]

Among the various methods used to measure gastric emptying time, scintigraphy is nowadays the technique of choice. Since only few data are available on the operative characteristics of the method, the authors investigated reproducibility, sensitivity, and specificity of a modified scintigraphic technique for the measurement of gastric emptying time. Three groups of subjects--healthy volunteers, patients with functional dyspepsia, and patients with upper gastrointestinal conditions--were administered liquid meals having various standard consistencies (349 tests on the whole). In both healthy volunteers and dyspeptic patients the method had high sensitivity (72%), good specificity (69%), and low intra-subject variation (25%). In all cases, the increase in meal density produced a delay in gastric emptying. Dyspeptic patients had slow gastric emptying of high-fiber meals, while in duodenal ulcer and in atrophic gastritis emptying was significantly faster. The radionuclide method proved valuable in measuring gastric emptying and was useful to confirm the pathogenesis of the various conditions. As for functional and organic pathologic conditions, it allowed treatment efficacy to be evaluated.

Molecular analysis of the asense gene, a member of the achaete-scute complex of Drosophila melanogaster, and its novel role in optic lobe development

The achaete-scute complex (AS-C) comprises five genetic regions: achaete, scute (sc) alpha, lethal of sc, sc beta and sc gamma. Each region promotes the determination and positional specification of different, but partially overlapping, subsets of neural elements of Drosophila. In this work, we report a molecular characterization of the sc gamma region. It comprises 22 kb of DNA and contains two transcription units, only one of which, named asense (ase), seems involved in neurogenesis. ase encodes a protein that shares with other three AS-C proteins a domain containing a helix--loop--helix motif characteristic of a group of DNA-binding proteins. In the embryo, ase is expressed in neural precursor cells, a pattern consistent with the known requirement of sc gamma for the development of the larval nervous system. In late third-instar larvae, the gene is expressed in developing structures of the central nervous system (CNS), namely the anlagen of the optic lobes and in many cells, including neuroblasts, of the central brain and ventral ganglia. Its removal leads to anatomical defects in the adult optic lobes. This is the first demonstration of a role for the AS-C in the development of the adult CNS.

Expression of achaete and scute genes in Drosophila imaginal discs and their function in sensory organ development

Several kinds of sensory organs (SOs) appear in stereotyped positions on the adult Drosophila cuticle. The generation of these SOs requires the activity of the achaete (ac) and scute (sc) genes. To investigate whether ac and sc also provide spatial information for the positioning of SOs, we have analyzed the patterns of expression of these genes in the wing imaginal disc around the time that SO precursors are being specified. We find that expression coincides with and is restricted to areas of the disc where these precursors are known to be located. In the loss-of-function sc mutant, sc RNA is depleted in a single area located in the region where the precursor for the suppressed macrochaeta should be found. Moreover, some, and probably all, SOs require expression of these genes to reach the earliest detectable differentiated state. These and other results presented here, together with the finding that expansion of the areas of ac and/or sc expression causes the development of ectopic SOs, indicate that ac and sc promote the determination of SO precursors and delimit the regions of the imaginal discs where they can develop.

The achaete-scute complex is expressed in neurogenic regions of Drosophila embryos

The achaete-scute gene complex (AS-C) of Drosophila melanogaster is involved in the development of the embryonic central nervous system and the cuticular sensory organs of both larva and adult. We have determined the embryonic spatial distributions of three transcripts encoded in the achaete, scute alpha and lethal of scute regions of the complex. The RNAs are present mainly between the blastoderm/early gastrula and the stage of germ band shortening. The patterns of expression are complex and evolve rapidly, affecting most or all of the known neurogenic regions. Gene expression precedes and is concomitant with the histological appearance of precursors of neural cells. These results support a role for the AS-C in determination and early differentiation of embryonic neural cells.

Synthesis of the trypsin fragment 10-25/75-88 of mouse nerve growth factor. II. The unsymmetrical double chain cystine peptide

The synthesis of the unsymmetrical double chain cystine peptide corresponding to sequence 10-25/75-88 of mouse nerve growth factor is described. The synthetic product was inactive in all bioassays examined; consequently, this portion of the NGF molecule did not represent or contain a lower molecular weight form of the neurotrophic factor.

Synthesis of the trypsin fragment 10-25/75-88 of mouse nerve growth factor. I. The protected tetradecapeptide 75-88

Cyanogen bromide cleavage followed by trypsin digestion of mouse nerve growth factor (NGF) allowed the isolation of a double chain unsymmetrical cystine peptide of high neurotrophic activity. The presence of tryptophan residues severely limits the synthetic approaches for selective disulfide bridging. The strategy applied for such a purpose as well as the preparation of the suitably protected tetradecapeptide corresponding to sequence 75-88 as key intermediate for the synthesis of the NGF fragment 10-25/75-88 are described.