An evaluation of the present status of quality assurance program implementation in digital mammography facilities in a developing country

Quality assurance program (QAP) implementation in mammography is a key aspect to guarantee the acquisition of -quality images and, thus, an opportune diagnosis of breast cancer. A QAP involves planned and systematic actions, such as quality control (QC) tests that will produce consistently high-quality images, while considering low radiation exposure for stakeholders. Currently, there is poor evidence of the current QAP implementation status in developing countries, particularly in Latin America. In this work, 47 Mexican digital mammography facilities were evaluated in terms of their QAP implementation's current status during the period October 2021 to April 2022. A survey of three key indicators of compliance/non-compliance with QAPs was carried out. Also, 17 QC test parameters were assessed in all mammography units according to an international framework. The Kruskal-Wallis test, McNemar test, and Spearman correlation were used to identify the significant correlation between the QC tests and QAP indicators. Statistical analysis showed a significant positive correlation between the QAP indicators and QC parameters that were evaluated, especially associated with an increase in image quality. Almost 90% of the facilities evaluated failed in some QAP indicators, and only 44.68% of the facilities had an updated and current QAP implemented. Successful QAP implementation directly impacted on the QC mammography test results, particularly in terms of image quality, thus conditioning a successful mammography acquisition chain. The results obtained in this work suggest that better regulations need to be implemented to guarantee QAP surveillance, which could mean an increase in opportune diagnosis and management of breast cancer, with improved radiological safety for patients and occupational exposure personnel.

[Self-reported prevalence of fructan food hypersensitivity in university students from the State of Mexico]

OBJECTIVE

To determine the self-reported prevalence of fructans food hypersensitivity in a sample of Mexican university students and to investigate the most frequent symptoms, the related foods involved, risk factors and gastrointestinal function status.

METHODS

A cross-sectional, descriptive study was conducted in a convenience sample of 412 university students aged from 18 to 35 years. Data were collected about their personal and family history of gastrointestinal diseases, the presence of symptoms after consumption of certain foods, and the severity of their symptoms.

RESULTS

The prevalence of fructans food hypersensitivity was 31.1 %; it was higher in women than in men. The most frequent gastrointestinal symptoms were bloating and flatulence. The most frequent extra-intestinal symptoms were fatigue and stress. The food groups related to the occurrence of symptoms were legumes, vegetables, and fruits. Significant association was found between female sex, personal and family history of gastrointestinal diseases and the presence of fructans food hypersensitivity (p < 0.05). Most individuals with fructans food hypersensitivity had mild gastrointestinal dysfunction (67.2 %).

CONCLUSIONS

FFH is a common condition, it was found in one third of university students and occurs mainly in women. More research and diffusion about this pathology is required.

Herbal extracts and essential oils microencapsulation studies for different applications

Studies on bioactivities of numerous essential oils (EOs) and herbal extracts compounds against diseases are crucial. Microencapsulation methods development might be an alternative to obtain bioactive compounds for cosmetics and pharmaceutical uses. In this study, we carried out a literature review of 219 503 data articles using ScienceDirect, Redalyc, Web of Science, Scopus, SciELO, and Google Scholar databases in English and Spanish, after with inclusion (original articles, book chapters, and theoretical references) and exclusion criteria (frameworks description), we found 1854 restricting the publication years between 2004 and August 2020 and 35 relevant articles with our scope research. References found contained a collection of methods that could be utilized to create microcapsules, including coacervation, extrusion, polymerization, and spray drying. This article analyzed the most recent and advanced microencapsulation techniques and their applications in the food, cosmetic, and pharmaceutical industries. Herbal extracts and EOs have many applications, depending on the wall materials and microencapsulation methods that could help know about selective release and efficacy to ensure optimal dosing and other advantages; thus, improving the profitability of these product manufacturers.

Photoprotective Activity of Buddleja cordata Cell Culture Methanolic Extract on UVB-irradiated 3T3-Swiss Albino Fibroblasts

The research on compounds exhibiting photoprotection against ultraviolet radiation (UVR) is a matter of increasing interest. The methanolic extract of a cell culture of Buddleja cordata has potential photoprotective effects as these cells produce phenolic secondary metabolites (SMs). These metabolites are attributed with biological activities capable of counteracting the harmful effects caused by UVR on skin. In the present work, the methanolic extract (310–2500 µg/mL) of B. cordata cell culture showed a photoprotective effect on UVB-irradiated 3T3-Swiss albino fibroblasts with a significant increase in cell viability. The greatest photoprotective effect (75%) of the extract was observed at 2500 µg/mL, which was statistically comparable with that of 250 µg/mL verbascoside, used as positive control. In addition, concentrations of the extract higher than 2500 µg/mL resulted in decreased cell viability (≤83%) after 24 h of exposure. Phytochemical analysis of the extract allowed us to determine that it was characterized by high concentrations of total phenol and total phenolic acid contents (138 ± 4.7 mg gallic acid equivalents and 44.01 ± 1.33 mg verbascoside equivalents per gram of extract, respectively) as well as absorption of UV light (first and second bands peaking at 294 and 330 nm, respectively). Some phenylethanoid glycosides were identified from the extract.

Metropolitan age-specific mortality trends at borough and neighborhood level: The case of Mexico City

Understanding the spatial and temporal patterns of mortality rates in a highly heterogeneous metropolis, is a matter of public policy interest. In this context, there is no, to the best of our knowledge, previous studies that correlate both spatio-temporal and age-specific mortality rates in Mexico City. Spatio-temporal Kriging modeling was used over five age-specific mortality rates (from the years 2000 to 2016 in Mexico City), to gain both spatial (borough and neighborhood) and temporal (year and trimester) data level description. Mortality age-specific patterns have been modeled using multilevel modeling for longitudinal data. Posterior tests were carried out to compare mortality averages between geo-spatial locations. Mortality correlation extends in all study groups for as long as 12 years and as far as 13.27 km. The highest mortality rate takes place in the Cuauhtémoc borough, the commercial, touristic and cultural core downtown of Mexico City. On the contrary, Tlalpan borough is the one with the lowest mortality rates in all the study groups. Post-productive mortality is the first age-specific cause of death, followed by infant, productive, pre-school and scholar groups. The combinations of spatio-temporal Kriging estimation and time-evolution linear mixed-effect models, allowed us to unveil relevant time and location trends that may be useful for public policy planning in Mexico City.

Spatio-Temporal Representativeness of Air Quality Monitoring Stations in Mexico City: Implications for Public Health

Assessment of the air quality in metropolitan areas is a major challenge in environmental sciences. Issues related include the distribution of monitoring stations, their spatial range, or missing information. In Mexico City, stations have been located spanning the entire Metropolitan zone for pollutants, such as CO, NO2, O3, SO2, PM2.5, PM10, NO, NO x , and PM CO . A fundamental question is whether the number and location of such stations are adequate to optimally cover the city. By analyzing spatio-temporal correlations for pollutant measurements, we evaluated the distribution and performance of monitoring stations in Mexico City from 2009 to 2018. Based on our analysis, air quality evaluation of those contaminants is adequate to cover the 16 boroughs of Mexico City, with the exception of SO2, since its spatial range is shorter than the one needed to cover the whole surface of the city. We observed that NO and NO x concentrations must be taken into account since their long-range dispersion may have relevant consequences for public health. With this approach, we may be able to propose policy based on systematic criteria to locate new monitoring stations.

Lyophilized Polyvinylpyrrolidone Hydrogel for Culture of Human Oral Mucosa Stem Cells

This work shows the synthesis of a polyvinylpyrrolidone (PVP) hydrogel by heat-activated polymerization and explores the production of hydrogels with an open porous network by lyophilisation to allow the three-dimensional culture of human oral mucosa stem cells (hOMSCs). The swollen hydrogel showed a storage modulus similar to oral mucosa and elastic solid rheological behaviour without sol transition. A comprehensive characterization of porosity by scanning electron microscopy, mercury intrusion porosimetry and nano-computed tomography (with spatial resolution below 1 μm) showed that lyophilisation resulted in the heterogeneous incorporation of closed oval-like pores in the hydrogel with broad size distribution (5 to 180 μm, d₅₀ = 65 μm). Human oral mucosa biopsies were used to isolate hOMSCs, expressing typical markers of mesenchymal stem cells in more than 95% of the cell population. Direct contact cytotoxicity assay demonstrated that PVP hydrogel have no negative effect on cell metabolic activity, allowing the culture of hOMSCs with normal fusiform morphology. Pore connectivity should be improved in future to allow cell growth in the bulk of the PVP hydrogel.

[Allergy to cow's milk protein, or lactose intolerance: a cross-sectional study in university students]

BACKGROUND

Factors like ethnic origin and geographical area affect the frequency of cow's milk protein allergy (CMPA) and lactose intolerance (LI). Epidemiological information about the non-pediatric population is still missing.

OBJECTIVE

To determine the prevalence of CMPA and LI in university students.

METHODS

A cross-sectional study of 1200 students of 18 to 25-year-old. A structured questionnaire was applied in order to identify the clinical manifestations triggered by the intake of cow's milk (CM), and these were categorized as linked to CMPA or linked to LI.

RESULTS

Thirty students met the criteria for CMPA (prevalence of 2.5 %; CI 95 % = 1.7-3.6 %) and 128 for LI (prevalence of 10.7 %, CI 95 % = : 9.0 % - 12.5 %). The frequency of personal history of food allergy and dust mite allergy was higher in students with CMPA than in students with LI. Oral pruritus, skin and respiratory discomforts were predominant in CMPA. Abdominal cramps and flatulence were predominant in LI.

CONCLUSIONS

IL is more frequent than CMPA; which frequency was one in every 10 students; and the frequency of CMPA was one in 400.

Synthesis and characterization of a polymeric network made of polyethylene glycol and chitosan as a treatment with antibacterial properties for skin wounds

Polyethylene glycol has been widely investigated for wound healing and dressing applications. Despite its advantages (i.e. great biocompatibility), polyethylene glycol lacks antibacterial activity. For this reason, semi-interpenetrated polymeric networks were prepared by combining a chemically cross-linked polyethylene glycol network with chitosan. The aim of this work was to identify the best amount of chitosan able to improve the antibacterial properties against Staphylococcus aureus. Briefly, the networks were synthesized by a sequential method, adding chitosan in different proportion to the polyethylene glycol. The antibacterial activity was tested following the MGA 0100 of the Pharmacopeia of the United States of Mexico. Fourier-transform infrared with attenuated total reflection spectroscopy, scanning electron microscopy and swelling behavior PBS at 37° C and room temperature were also performed to characterize the polymeric networks. The results showed that PC-2% was able to inhibit the bacterial growth of Staphylococcus aureus even more than Fosfomycin antibiotic. The networks showed cylindrical pores of different sizes (50-100 µm). The maximum swelling of all the networks was achieved in PBS at 37°C (>315%). Free hemoglobin and hemolysis assays were also evaluated to know the compatibility with erythrocytes. Human dermal fibroblasts were used to evaluate direct cytotoxicity. Therefore, the produced gels exerted interesting antibacterial activity and showed good biocompatibility properties.

Self-reported prevalence of clinical features of allergy to nuts and seeds, and seafood in university students

Background

In developing countries, there is a lack of epidemiological information related to food hypersensitivity, including nuts and seafood.

Objective

The aim was to determine the prevalence of allergic reactions and clinical manifestations associated with the consumption of nuts and seeds or seafood in university students.

Methods

We designed an observational cross-sectional study. A structured questionnaire was applied to Mexican university students to identify allergic reactions associated with the consumption of nuts and seeds, and seafood.

Results

A sample of 1,200 students was included; mean age of 19.7 ± 1.7 years. Prevalence of symptoms associated with the consumption of nuts and seeds, and seafood were 2.8% (33 of 1,200) and 3.5% (42 of 1,200) respectively. The main clinical manifestations were abdominal pain (63.6% in nuts and seeds), flushing (50% in seafood), and pharyngeal oppression (19% in seafood). Prevalence of perceived, probable and systemic allergy to nuts and seeds was 2.8% (95% confidence interval [CI], 2.5%–3.0%), 0.8% (95% CI, 0.3%–1.3%) and 0.2% (95% CI, 0%–0.4%) respectively. On the other hand, the prevalence (perceived, probable, and systemic) associated with seafood consumption was 3.5% (95% CI, 2.5%–4.5%), 1.8% (95% CI, 1.0%–2.5%), and 0.5% (95% CI, 0.1%–0.9%). Walnut and shrimp were the most frequently reported foods.

Conclusion

For every 100 Mexican university students, approximately 3 or 4 perceived to have allergy attributed to the consumption of some nuts and seeds or seafood, while 1 or 2 students would have a probable reaction to this same type of food. Walnut and shrimp would be causing the higher quantity of food allergic reactions.

Self-report prevalence and associated factors to drug hypersensitivity in Mexican young adults

Background

Drug hypersensitivity is defined as any unfavorable reaction that occurs after the administration of any drug. It may or may not be mediated by the involvement of the immune system. Epidemiological data related to drug hypersensitivity reactions in our country are scarce.

Objective

To determine the prevalence of drug hypersensitivity in a group of young adults, as well as to identify associated factors.

Methods

A structured questionnaire was applied to young people aged 18 to 25 years. The instrument was oriented to identify reactions of drug hypersensitivity, as well as the most prevalent drugs involved. In addition, a personal and family history of atopic diseases was included. Analysis for associations between variables was been done through logistic regression.

Results

The prevalence of drug hypersensitivity reactions was 12% (144 of 1,200). The antibiotics were the agents most related to hypersensitivity reactions (9.8%) followed by nonsteroidal anti-inflammatory drugs (1.6%). Factors associated with drug hypersensitivity were a personal history of asthma, odds ratio (OR) 3.15 (95% confidence interval [CI], 1.44–6.91), maternal and paternal history of drug hypersensitivity, OR 2.33 (95% CI, 1.21–4.48) and OR 3.11 (95% CI, 1.22–7.92), respectively.

Conclusion

The results of this research show that drug hypersensitivity in young adults is a highly prevalent event and it is associated with personal history of asthma and history of drug hypersensitivity in parents.

Preparation of Quantum Dots Hydrogel Nanocomposites with Improved Cytotoxicity

Nanocomposites are materials with unique properties and a wide range of applications. The combination of different nanostructures with traditional materials gives a variety of possibilities that should be analyzed. Especially, functional fluorescent semiconductor quantum dots (QDs) embedded in polymeric matrices have shown promising fluorescence and biocompatibility properties. These hybrid materials can be used in medical applications such as biodiagnostic and bioimaging. In this study, two hydrogels, one of polyethylene glycol diacrylate (PEGDA) and other of polyacrylamide (PAAm), were prepared with quantum dots of CdTe (4 nm of diameter) and characterized. The aim of this research was to analyze the optical properties of the nanocomposites and their cell viability. QDs nanocomposites were fabricated by a free radical polymerization process. The optical studies showed that the nanocomposites have well defined properties of fluorescence. To study the biocompatibility of the nanocomposites, metastatic B16f10 cell line were used and MTT assay was performed. The nanocomposites had a significant improved cell viability compared with QDs solutions.

Hydrogels based on poly(ethylene glycol) as scaffolds for tissue engineering application: biocompatibility assessment and effect of the sterilization process

Hydrogels are suitable materials to promote cell proliferation and tissue support because of their hydrophilic nature, porous structure and sticky properties. However, hydrogel synthesis involves the addition of additives that can increase the risk of inducing cytotoxicity. Sterilization is a critical process for hydrogel clinical use as a proper scaffold for tissue engineering. In this study, poly(ethylene glycol) (PEG), poly(ethylene glycol)-chitosan (PEG-CH) and multi-arm PEG hydrogels were synthesized by free radical polymerization and sterilized by gamma irradiation or disinfected using 70 % ethanol. The biocompatibility assessment in human fibroblasts and hemocompatibility studies (hemolysis, platelet aggregation, morphology of mononuclear cells and viability) in peripheral blood from healthy volunteers (ex vivo), were performed. The sterilization or disinfection effect on hydrogel structures was evaluated by FT-IR spectroscopy. Results indicated that hydrogels do not induce any damage to fibroblasts, erythrocytes, platelets or mononuclear cells. Moreover, there was no significant difference in the biocompatibility after the sterilization or disinfection treatment. However, after gamma irradiation, several IR spectroscopic bands were shifted to higher or lower energies with different intensity in all hydrogels. In particular, several bands associated to carboxyl or hydroxyl groups were slightly shifted, possibly associated to scission reactions. The disinfection treatment (70 % ethanol) and γ-irradiation at 13.83 ± 0.7 kGy did not induce morphological damages and yielded sterile and biocompatible PEG hydrogels potentially useful for clinical applications.

In vitro evaluation of the mutagenic and cytostatic effect of Tamaron, Lannate and Manzate alone and in mixture

Pesticides are often used in agriculture, especially in floriculture. They are frequently applied in binary or ternary mixtures. Nevertheless, their impact on the genetic material has been scarcely explored. In this study, the mutagenic and cytostatic effect of three widely used pesticides, alone and combined, were analyzed. Briefly, lymphocytes cultures were obtained from peripheral blood samples of five healthy donors to determine the sister chromatid exchange and the replicative index (RI). Then, lymphocytes were exposed to Tamaron (100 ppm), Lannate (200 ppm) and Manzate (300 ppm) alone and combined. For the binary mixtures, the concentrations used were 50 ppm of Tamaron, 100 ppm of Lannate and 150 ppm of Manzate. For the ternary mixtures the following concentrations were used: Tamaron (33 ppm), Lannate (70 ppm) and Manzate (100 ppm). Finally, differential staining was performed. It was found that the frequency of SCE/cell showed a significant difference (P ≤ 0.05) between the control (2.66) and the individual treatments of Tamaron (4.87), Lannate: (5.12) and Manzate (4.23). Also, the values of the SCE in the binary mixture of Tamaron+Lannate (5.57), Tamaron+Manzate (6.06) and Lannate+Manzate (6.22) and the ternary mixture (6.63) were statistically different compared to the control. In the RI there was a significant difference between the control (1.98) and the Manzate (1.87). RI differences were also statistically significant (P ≤ 0.05) in mixtures of Tamaron+Lannate (1.64), Tamaron+Manzate (1.63), Lannate+Manzate (1.69) and total mixture (1.53). Therefore, it is suggested that these pesticides alone and in mixtures have both mutagenic and cytostatic synergistic effect in human lymphocytes in vitro.

Peripheral Pathways in the Food-Intake Control towards the Adipose-Intestinal Missing Link

In the physiological state a multitude of gut hormones are released into the circulation at the same time depending on the quality and quantity of the diet. These hormones interact with receptors at various points in the "gut-brain axis" to affect short-term and intermediate-term feelings of hunger and satiety. The combined effects of macronutrients on the predominant gut hormone secretion are still poorly understood. Besides, adipokines form an important part of an "adipoinsular axis" dysregulation which may contribute to β -cell failure and hence to type 2 diabetes mellitus (T2DM). Even more, gestational diabetes mellitus (GDM) and T2DM seem to share a genetic basis. In susceptible individuals, chronic exaggerated stimulation of the proximal gut with fat and carbohydrates may induce overproduction of an unknown factor that causes impairment of incretin production and/or action, leading to insufficient or untimely production of insulin, so that glucose intolerance develops. The bypass of the duodenum and jejunum might avoid a putative hormone overproduction in the proximal foregut in diabetic patients that might counteract the action of insulin, while the early presentation of undigested or incompletely digested food to the ileum may anticipate the production of hormones such as GLP1, further improving insulin action.

Abstract 3279: Effects of the isoforms of the angiogenic growth factor VEGF on neo-vascularization and tumor response to the tyrosine kinase inhibitor cediranib

Functional vasculature is required to supply tissues with oxygen and metabolic needs. A complex network of angiogenic growth factors directs blood vessel growth and maturation. This work investigated the role of VEGF-A isoforms in the mechanism of action of the pan-VEGF receptor inhibitor cediranib, currently in clinical trials.

Recombinant VEGF-A isoforms (VEGF120, 164, 189) were encapsulated in polyvinylpyrrolidone (PVP) hydrogel and effects on blood vessel development were determined using dorsal skin-fold window chambers surgically implanted into SCID mice. Intravital microscopy was used to monitor vasculature in vivo. In separate experiments, mouse fibrosarcoma cell lines expressing individual mouse VEGF-A isoforms (120, 164, 188) or all three isoforms (WT) were implanted into window chambers, and mice treated with cediranib (6 mg/kg/day p.o.) or vehicle for 4 days. Mice bearing single VEGF-A isoform-expressing subcutaneous tumors were treated with cediranib/vehicle once daily, as above, but continuing until tumors reached 15mm diameter in one dimension or a mean of 12.5mm. Pericyte (α-SMA, PDGFRβ) and endothelial cell (PECAM) marker expression were determined by real time PCR.

A reversible vascular ‘blurriness’ (VEGF189&lt;VEGF164&lt;VEGF120), indicative of edema, occurred 1 day after hydrogel implant. VEGF164 increased neovascular development immediately adjacent to implants whilst VEGF120 stimulated vascular extension/widening at a distance from hydrogels within the window chamber tissue area. VEGF120 and VEGF189 tended to increase vessel tortuosity. In the fibrosarcoma window chamber experiments, cediranib had little effect on VEGF188-driven tumor vasculature except a transient reduction in vessel width up to 6 h after the first dose. PCR data showed VEGF188-induced vasculature was associated with higher levels of pericyte marker expression than vessels from VEGF120-driven tumors although pericyte marker expression increased in both tumor types with cediranib treatment. WT and VEGF120-induced vessels appeared smoother and wider after cediranib treatment in the window chamber with the greatest growth-inhibition being seen with VEGF120-expressing subcutaneous tumors.

Our preliminary results support the hypothesis that VEGF188/9 promotes development of more mature vessels insensitive to vascular pruning by VEGFR signalling inhibition, whereas VEGF120 promotes the formation of more immature vessels susceptible to vascular pruning. Our data suggest that vascular responsiveness to cediranib treatment may decrease as pericyte coverage increases.

Funding: BBSRC/AstraZeneca

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3279. doi:10.1158/1538-7445.AM2011-3279

Nanoscopic mechanical anisotropy in hydrogel surfaces

The bulk mechanical properties of soft materials have been studied widely, but it is unclear to what extent macroscopic behavior is reflected in nanomechanics. Using an atomic force microscopy (AFM) imaging method called force spectroscopy mapping (FSM), it is possible to map the nanoscopic spatial distribution of Young's modulus, i.e. "stiffness," and determine if soft or stiff polymer domains exist to correlate nano- and macro-mechanics. Two model hydrogel systems typically used in cell culture and polymerized by a free radical polymerization process, i.e. poly (vinyl pyrrolidone) (PVP) and poly(acrylamide) (PAam) hydrogels, were found to have significantly different nanomechanical behavior despite relatively similar bulk stiffness and roughness. PVP gels contained a large number of soft and stiff nanodomains, and their size was inversely related to crosslinking density and changes in crosslinking efficiency within the hydrogel. In contrast, PAam gels displayed small nanodomains occuring at low frequency, indicating relatively uniform polymerization. Given the responsiveness of cells to changes in gel stiffness, inhomogeneities found in the PVP network indicate that careful nanomechanical characterization of polymer substrates is necessary to appreciate complex cell behavior.