Volatile sulfur compounds in asthmatic children and adolescents: A cross-sectional study in breath and saliva.

BACKGROUND: Halitosis in children implies psychosocial repercussions. Risk factors associated with this condition are unclear, and detection methods are inaccurate. AIM: To quantify the levels of sulfur-like compounds in children with asthma and healthy children from a novel validated assay, and to establish the risk factors related to halitosis. DESIGN: One hundred and twenty-eight individuals (63 healthy and 65 asthmatic) from 3 to 17 years of age were tested using a passive colorimetric sensor to measure the levels of sulfur-like compounds in breath and saliva. Information was collected on oral hygiene habits, gingival and dental health, breathing type, and dental malocclusion. RESULTS: The mean values of hydrogen sulfide were 4.0 ± 6.8 and 19.7 ± 12.2 ppbv (parts per billion in volume) in the control and asthmatic groups, respectively (p < .001). The presence of higher concentrations of sulfur compounds was significantly associated (p < .05) with the presence of gingival inflammation, tongue coating, dental plaque, mouth breathing, hypomineralization, age, tongue brushing, and the use of dental floss. CONCLUSION: The level of sulfur in breath and saliva was significantly higher in patients with asthma. These results can serve as a precedent to raise awareness among paediatricians and parents about oral hygiene care in children and adolescents.

Trends in pediatric CNS tumors in Armenia: a multicenter retrospective study.

PURPOSE: Central nervous system (CNS) tumors are the most common solid malignancies in children worldwide, including in Armenia. The current study aims to analyze epidemiological data, treatment, and outcomes of children and young adults (≤25 years) with CNS tumors in Armenia during the last 26 years. METHODS: We collected data from pediatric and young adult patients treated in selected sites in Armenia from 1st January 1995 to 31st December 2020. Incidence by sex, age at diagnosis, time from first complaints to diagnosis, histopathology results, treatment strategies, complications, and overall survival (OS) rates were calculated. RESULTS: The multicenter data analysis revealed 149 patients with diagnosed primary CNS tumors over 26 years. Among them, 84 (56.4%) were male. The median age at diagnosis was 7 years (range, 3 months to 25 years), and the median time from the first complaints to diagnosis was 2 months (range, 1 week to 70 months). Medulloblastomas and other embryonal tumors (47), low-grade gliomas (32), and high-grade gliomas (22) were the most commonly diagnosed malignancies. Ependymomas, craniopharyngiomas, germ cell tumors, and other malignancies were observed in 22 patients. For 26 patients, no histopathological or radiological diagnosis was available. Follow-up information was available for 98 (65.8%) patients. The 5-year OS rate for the whole study group was 67.7%. CONCLUSION: Consistent with international data, embryonal tumors, and gliomas were the most commonly diagnosed CNS malignancies in Armenia. Multimodal treatment was often not available in Armenia during the study period, especially for early cases.

Reliable assessment of carbon black nanomaterial of a variety of cell culture media for in vitro toxicity assays by asymmetrical flow field-flow fractionation.

Carbon black nanomaterial (CB-NM), as an industrial product with a large number of applications, poses a high risk of exposure, and its impact on health needs to be assessed. The most common testing platform for engineered (E)NMs is in vitro toxicity assessment, which requires prior ENM dispersion, stabilization, and characterization in cell culture media. Here, asymmetric flow field-flow fractionation (AF4) coupled to UV-Vis and dynamic light scattering (DLS) detectors in series was used for the study of CB dispersions in cell culture media, optimizing instrumental variables and working conditions. It was possible to disperse CB in a non-ionic surfactant aqueous solution due to the steric effect provided by surfactant molecules attached on the CB surface which prevented agglomeration. The protection provided by the surfactant or by culture media alone was insufficient to ensure good dispersion stability needed for carrying out in vitro toxicity studies. On the other hand, cell culture media in combination with the surfactant improved dispersion stability considerably, enabling the generation of shorter particles and a more favourable zeta potential magnitude, leading to greater stability due to electrostatic repulsion. It was demonstrated that the presence of amino acids in the culture media improved the monodisperse nature and stability of the CB dispersions, and resulted in a turn towards more negative zeta potential values when the pH was above the amino acid isoelectric point (IEP). Culture media used in real cell culture scenarios were also tested, and in vitro toxicity assays were developed optimizing the compatible amount of surfactant.

Improving Sustainability of the Griess Reaction by Reagent Stabilization on PDMS Membranes and ZnNPs as Reductor of Nitrates: Application to Different Water Samples.

A new approach based on the use of polydimethylsiloxane (PDMS) membranes doped with Griess reagents for in situ determination of NO2- and NO3-- in real samples is proposed. The influence of some doping compounds, on the properties of the PDMS membranes, such as tetraethyl orthosilicate (TEOS), or/and ionic liquids (OMIM PF6) has been studied. Membrane characterization was performed. To apply the procedure to NO3- determination, dispersed Zn nanoparticles (ZnNPs) were employed. The analytical responses were the absorbance or the RGB components from digital images. Good precision (RSD < 8%) and detection limit of 0.01 and 0.5 mgL-1 for NO2- and NO3-, respectively, were achieved. The approach was satisfactory when applied to the determination of NO2- and NO3- in drinking waters, irrigation and river waters, and waters from canned and fresh vegetables. The results obtained were statistically comparable with those by using nitrate ISE or UV measurement. This approach was transferred satisfactory to 96 wells for multianalysis. This study enables the improvement in the on-site determination of NO2- and NO3- in several matrices. It is a sustainable alternative over the reagent derivatizations in solution and presents several advantages such as being versatile, simplicity, low analysis time, cost, and energy efficiency. The response can be detected visually or by portable instruments such as smartphone.

Treating rare tumors with the assistance of the expert virtual consultation system: two cases of juvenile granulosa cell tumors.

BACKGROUND: The lack of internationally recognized guidelines for very rare tumors, such as juvenile granulosa cell tumors (JGCTs), which are nonepithelial, unusual ovarian tumors, is a challenge for pediatric oncologists, especially in developing countries with limited resources and experience in treating rare tumors. METHODS: We report clinical data of 2 girls with JGCTs treated at the Pediatric Cancer and Blood Disorders Center of Armenia with the assistance of the EXPeRT (European Cooperative Study Group for Pediatric Rare Tumors) international cooperation panel. CASE PRESENTATION: Two girls (16 and 15 years old) with JGCTs of the ovaries, stage Ic, underwent surgery and, with consultation through an online advisory board (http://vrt.cineca.it/), received 4 cycles of chemotherapy according to the PEI regimen (cisplatin, etoposide, ifosfamide). CONCLUSION: Very rare tumors, especially in advanced stages, have limited data and a low survival rate. International collaboration with the EXPeRT group is beneficial for physicians with limited experience and facilitates research in pediatric oncology.

NQS-Doped PDMS Solid Sensor: From Water Matrix to Urine Enzymatic Application.

The development of in situ analytical devices has gained outstanding scientific interest. A solid sensing membrane composed of 1,2-naphthoquinone-4-sulfonate (NQS) derivatizing reagent embedded into a polymeric polydimethylsiloxane (PDMS) composite was proposed for in situ ammonium (NH4+) and urea (NH2CONH2) analysis in water and urine samples, respectively. Satisfactory strategies were also applied for urease-catalyzed hydrolysis of urea, either in solution or glass-supported urease immobilization. Using diffuse reflectance measurements combined with digital image processing of color intensity (RGB coordinates), qualitative and quantitative analyte detection was assessed after the colorimetric reaction took place inside the sensing membrane. A suitable linear relationship was found between the sensor response and analyte concentration, and the results were validated by a thymol-PDMS-based sensor based on the Berthelot reaction. The suggested sensing device offers advantages such as rapidity, versatility, portability, and employment of non-toxic reagents that facilitate in situ analysis in an energy-efficient manner.

Nylon-Supported Plasmonic Assay Based on the Aggregation of Silver Nanoparticles: In Situ Determination of Hydrogen Sulfide-like Compounds in Breath Samples as a Proof of Concept.

A procedure for supporting silver nanoparticles (AgNPs) on nylon is proposed. Besides, the membrane has been developed as a solid-phase colorimetric plasmonic sensor for volatile sulfide compounds (VSCs) like H2S, CH3SH, and (CH3)2S. AgNP behavior in the membrane has been studied by UV-vis diffuse reflectance spectrometry, Raman spectrometry, High-resolution transmission electron microscopy (HR-TEM), and Scanning electron microscopy (SEM). The sensor responded by changing its color from yellow in absence of VSCs to several orange/brown colors in the function of VSC concentration as occurs in solution; an increase in the hydrodynamic diameter, estimated by both asymmetrical flow field-flow fractionation (AF4) coupled on line to Dynamic light scattering (DLS) detector and batch DLS, is achieved when sulfide is added to the citrate-capped AgNPs. Diffuse reflectance spectrometry and processed digital images obtained with a smartphone have been used as measurements and several transformations for quantitation are proposed; a linear concentration range of hydrogen sulfide from 150 to 1000 ppbv and a detection limit (LOD) of 45 ppbv were achieved, measuring after 10 min of the sensor exposition to the hydrogen sulfide atmosphere (2 L) for humidity percentages between 50 and 96% and room temperature. Satisfactory results in terms of precision (<10%) and selectivity were obtained. The new sensor reported was stable, sensitive, inexpensive, disposable, safe, and user-friendly. Furthermore, it has successfully been applied to determine VSCs expressed as hydrogen sulfide in breath samples (2 L and 250 mL) as a proof of concept. The limit of detection can be improved by increasing the exposition time, if necessary.

Younger age and previous exposure to radiation therapy are correlated with the severity of chemotherapy-induced thrombocytopenia.

BACKGROUND: Chemotherapy-induced thrombocytopenia (CIT) is a significant complication of cancer therapy. Data on the optimal management approaches of this morbidity in children and young adults are still limited. AIM: The aim of the study is to estimate the frequency and severity of CIT and associated clinically significant bleeding in children and young adults with solid tumours and haematologic malignancies. METHODS: For this retrospective, hospital-based study, children (0-18 y) and young adults (19-40 y) with different types of solid tumours and haematologic malignancies who received chemotherapy at the Muratsan Hospital Complex of Yerevan State Medical University were identified from the patients' database and included in the study (overall 122 patients). Thrombocytopenia was defined as a decrease of platelet count below <100 × 109/L. For assessing bleeding, WHO scale had been used. RESULTS: Overall, the whole group of patients received 430 chemotherapy cycles. During 131 (31.6%) chemotherapy cycles, patients developed CIT. The study revealed a statistically significant inversely proportional correlation between the age and the severity of CIT. Another important finding of the study was that the patients, who previously were exposed to radiation therapy, were more likely to develop CIT, than those who have not received radiation therapy (68% and 28.7%, p = 0.001). From 430 cycles of chemotherapy, 31 (7.2%) cycles reported to have bleeding events. CONCLUSION: Our study showed that clinically significant thrombocytopenia and bleeding are quite rare among children and young adults. Younger age and previous exposure to radiation therapy are positively correlated with the severity of thrombocytopenia. Larger studies are needed to investigate these findings.

Characterization of light-dependent hydrogen production by new green microalga Parachlorella kessleri in various conditions.

Nowadays, hydrogen (H2) production by green microalgae seems to be a very perspective, as stocks of water and solar energy are practically inexhaustible and renewable. The aim of this study was the optimization of conditions (organic carbon sources and lighting regime), which can provide light-dependent H2 production by green microalga Parachlorella kessleri RA-002 newly isolated in Armenia. The results indicated that carbon sources and lighting regimes affected H2 production. In the presence of used carbon sources H2 production was observed, but the highest yield of H2 was obtained in the presence of acetate. It was 2-fold higher than the H2 yield determined in the presence of glucose. The increase of H2 production might be connected with the stimulation of H2-producing enzyme - [Fe]-hydrogenase synthesis. The data obtained show that acetate can be used as an effective carbon source in H2 production. H2 production by microalga (in the presence of acetate and glucose) was enhanced by 1.5-2.5-fold in comparison with continuously illuminated algal cells, when P. kessleri was illuminated during 24h, and then was moved in the darkness. H2 yield increase is possible due to hydrogenase activation and the creation of anaerobic conditions. This study was significant to find out available effective substrates and optimal lighting regime to provide with light-dependent H2 production by microalgae.

Denosumab treatment for progressive skull base giant cell tumor of bone in a 14 year old female - a case report and literature review.

BACKGROUND: Giant cell tumor of bone (GCT) is a rare primary bone tumor, which can metastasize and undergo malignant transformation. The standard treatment of GCT is surgery. In patients with unresectable or metastatic disease, additional therapeutic options are available. These include blocking of the receptor activator of NF-kappa B ligand (RANKL) signaling pathway, which plays a role in the pathogenesis of GCT of bone, via the anti-RANKL monoclonal antibody denosumab. CASE PRESENTATION: Herein we report on a female teenager who presented in a very poor clinical condition (cachexia, diplopia, strabismus, dysphonia with palsy of cranial nerves V, VI, VIII, IX, X, XI and XII) due to progressive disease, after incomplete resection and adjuvant radiotherapy, of a GCT which affected the cervical spine (C1 and C2) as well as the skull base; and who had an impressive clinical response to denosumab therapy. To the best of our knowledge, this is the youngest patient ever reported with a skull base tumor treated with denosumab. CONCLUSION: In situations when surgery can be postponed and local aggressiveness of the tumor does not urge for acute surgical intervention, upfront use of denosumab in order to reduce the tumor size might be considered. Principally, the goal of denosumab therapy is to reduce tumor size as much as possible, with the ultimate goal to make local surgery (or as in our case re-surgery) amenable. However, improvement in quality of life, as demonstrated in our patient, is also an important aspect of such targeted therapies.

Treating Adults with Hodgkin Lymphoma in the Developing World: a Hospital-Based Cohort Study from Armenia.

BACKGROUND: With advances in diagnostics and treatment approaches, patients with Hodgkin's lymphoma (HL) in developed countries can nowadays expect to have excellent outcomes. However, information about the characteristics and outcomes in the developing world is very scarce, and this is important given the fact that there are several reports about differences of disease characteristics depending on geographic location and the development level of the country. MATERIALS AND METHODS: In this retrospective study we assessed the features of 36 adult (≥18 years old) patients with HL and their diagnosis and treatment and outcomes in the Clinic of Chemotherapy of Muratsan University Hospital of Yerevan State Medical University, Armenia, between 2008- 2014. RESULTS: All patients had classic HL and among them 19 (53%) had nodular sclerosis subtype, 8 (22%) mixed cellularity and 9 (25%) lymphocyte-rich. 16 (44.5%) patients were at stage II, 13 (36%) stage III and 7 (19.5%) stage IV. Median follow-up time was 24.5 months (range 1-71 months) and during the whole follow- up period only two relapses (early) were documented and there were no deaths. Twenty-three (64%) patients received a BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) regimen, and 13 (36%) ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine) regimen. A total of 25 (69.5%) patients received radiation in addition to chemotherapy. CONCLUSIONS: Although the number of patients involved in the study is small and the median follow-up time was just two years, this retrospective study shows that treatment of HL can be successfully organized in a resource-limited setting.