Household food insecurity before and during the COVID-19 pandemic in Chile.

OBJECTIVES: To compare food insecurity (FI) in Chile before and during the COVID-19 pandemic according to different household types and vulnerability indicators. STUDY DESIGN: Longitudinal study based on two population-based surveys in Chile (CASEN 2017 and COVID 2020). METHODS: Descriptive analysis and multinomial regression models for FI through the Food Insecurity Experience Scale (FIES). RESULTS: FI levels increased significantly (P < 0.001) between 2017 (30%) and 2020 (49%). There was increased FI in all households, but especially in those with economically dependent persons (i.e. children, adolescents and older adults). Household vulnerability indicators showed a statistically significant relationship with FI both before and during the pandemic. The pandemic has resulted in new population groups experiencing FI. CONCLUSIONS: The COVID-19 pandemic has led to a significant increase in FI, which has also been seen in new population groups.

Sociodemographic, Socio-economic, Clinical and Behavioural Factors Modifying Experience and Prevalence of Dental Caries in the Permanent Dentition.

OBJECTIVE: To identify the sociodemographic, socio-economic, clinical and behavioural factors that modify the experience of decayed, missing and filled teeth (DMFT) and caries prevalence in Nicaraguan children 9-12 years old. SUBJECTS AND METHODS: We conducted a cross-sectional study in 800 school children 9-12 years old in the city of León, Nicaragua. The clinical oral examinations to identify caries experience were undertaken by two trained and certified examiners. Sociodemographic, socio-economic and behavioural data were collected using questionnaires. Negative binomial regression (NBR) and binary logistic regression (BLR) models were used to model caries experience and caries prevalence, respectively. RESULTS: Mean DMFT index was 0.98 ± 1.74 and caries prevalence (DMFT > 0) was 37.9%. In the NBR model, the categories that increase the expected DMFT mean were: older age, female gender, presence of plaque, and if the school children received curative and curative/preventive dental care in the last year. In the BLR model, the odds of presenting with caries in the permanent dentition were increased in older children, those from large families, mothers with a positive dental attitude, and those school children who received curative and curative/preventive dental care in the last year. CONCLUSIONS: Using different models, we identified several sociodemographic, socio-economic, clinical and behavioural factors that modify the experience (NBR) and prevalence (BLR) of dental caries.

Present status of accelerator-based BNCT: Focus on developments in Argentina.

In this work we provide some information on the present status of accelerator-based BNCT (AB-BNCT) worldwide and subsequently concentrate on the recent accelerator technology developments in Argentina.

Immunochemical quantitation of human submandibular-sublingual lysozyme.

A method for quantitating lysozyme by using carbamylated antiserum (commercially available) to human lysozyme in a electroimmunodiffusion technique has been developed. The method measures specific protein not lytic activity as the lyso-plate method does. We have applied this method to tears, parotid saliva, submandibular-sublingual saliva, nasal secretions, serum, and minor salivary gland secretions. We specifically selected submandibular-sublingual saliva for a comparison test with the lyso-plate method because of the known mucin content of the submandibular-sublingual saliva. Our findings indicate that no pretreatment is necessary for the electroimmunodiffusion technique. The lyso-plate method, on the other hand, requires pretreatment with Tris-acetate pH 4.5 to dissociate the mucin-lysozyme complex and give accurate values.

Lysozyme and lactoferrin quantitation in the crevicular fluid.

This study was designed to determine if quantitation of lysosomal products in crevicular fluid may be useful as a diagnostic test to evaluate clinical status in periodontal disease. Levels of lysozyme and lactoferrin were quantitated in crevicular fluid from patients with gingivitis, generalized adult periodontitis, localized juvenile periodontitis and normals. Crevicular fluid (CF) was collected from each patient by standardized filter paper strips and evaluated for lysozyme and lactoferrin by rocket immunoelectrophoresis. Levels of lysozyme (micrograms of protein per microliter of CF) were significantly higher in localized juvenile periodontitis patients as compared to gingivitis and adult periodontitis. On the other hand, levels of lactoferrin (micrograms of protein per microliter of CF) did not show significant differences between gingivitis, adult periodontitis and localized juvenile periodontitis. These results indicate that a lysozyme to lactoferrin ratio could be of value as a diagnostic test for localized juvenile periodontitis patients.

Host proteins in dental plaques of caries-resistant versus caries-susceptible human groups.

The level of host proteins in 3-day supragingival plaque extracts was compared in caries-resistant (CR) and caries-susceptible (CS) adults with little or no gingival inflammation to minimize the contribution of gingival crevicular fluid ( GCF ). Except for IgA, all the host proteins examined were present at similar levels in both groups of subjects. Although the IgA exhibited fragmentation on sodium dodecylsulphate gradient-polyacrylamide gel electrophoresis (SDS-PAGE) and transfer electrophoresis in both groups, the amount of binding to a standard antisecretory IgA antiserum was higher in CR than in CS subjects. This could be a reflection of the trend towards a higher concentration of IgA in saliva of CR subjects or the result of less proteolytic activity in CR plaque. Even in 3-day plaque in the absence of gingival inflammation, GCF contributes a significant share of the host proteins to plaque extracts. Salivary proteins in plaque do not parallel their relative concentration in saliva.

Immunochemical study of host proteins in human supragingival compared with denture plaque.

The contribution of proteins from saliva and gingival crevicular fluid (GCF) to plaque was determined by comparing extracts of supragingival plaque of unknown age formed on normal teeth with plaque formed on artificial teeth in complete or partial dentures where crevicular fluid is absent. There was a total absence of albumin and a virtual absence of IgG from denture plaque samples, confirming their crevicular origin. The concentration of lactoferrin was much higher than that of lysozyme in all supragingival but not in the denture plaque samples, suggesting that GCF provided more lactoferrin than lysozyme to plaque. Amylase was a component in both denture and supragingival plaque, present in similar amounts in both deposits. Cysteine-containing phosphoproteins from saliva were in low concentration but present in all plaque samples; proline-rich proteins were virtually absent, reflecting the high vulnerability to proteolysis of these proteins. Salivary proteins in plaque extracts do not correspond with their relative concentrations in saliva.

Constraints on dairy cattle productivity at the smallholder level in the Philippines.

Survey data on dairy cattle production were gathered in two sites [Site I (three-year survey) and Site II (two-year survey)] in Southern Luzon, Philippines. Crossbred (Holstein-Friesian x Sahiwal) dairy cows (n = 122) managed by smallholder farmers belonging to five primary cooperatives under the federation of dairy farmers, were monitored monthly for milk production, feed intake and availability, and reproduction and health status. The purpose of the survey was to identify constraints to productivity. The reproductive status of the cows was monitored by measuring milk and plasma progesterone concentrations by radioimmunoassay and rectal palpation of the ovaries. Plasma concentrations of selected metabolites [beta-hydroxybutyrate (BHB), inorganic phosphorus, albumin, globulin, urea] were also measured at one month before calving and at one month and 2-3 months postpartum, to determine if these could serve as biochemical indicators of nutritional stress. A long calving interval (CI = > 400 days) was identified as the major constraint to productivity of dairy cattle on smallholder farms. The three main problems related to this reproductive constraint were: (1) poor breeding management, in particular lack of accurate estrus detection; (2) repeat breeding, i.e. three or more services were required before conception; and (3) poor ovarian function, shown by some cows with lose progesterone levels. An important cause of these problems was undernutrition, particularly at critical periods of the cow's reproductive life, reflected in the slow recovery from loss in body weight and condition score during the early postpartum period and the increased plasma BHB values at peripartum period in some cows, indicative of negative energy balance, and the flat lactation profile. These findings are useful and relevant as a database in the development of an appropriate management scheme aimed toward improving dairy cattle production and productivity at smallholder level. It highlights the importance of estrus detection, good breeding management and the use of a practical strategic nutritional supplementation, particularly during stressful periods in the cows's reproductive life.

[The Peutz-Jeghers syndrome and intestinal invagination]. / El síndrome de Peutz-Jeghers e invaginación intestinal.

Peutz-Jeghers syndrome is a autosomal dominant disorder characterized by hamartomatous polyposis of the gastrointestinal tract and mucocutaneous melanin pigmentation. This condition can occur and cause symptoms at any age, but intestinal obstruction due to intussusception is a frequent complication. Two cases of this syndrome associated to intussusception are reported. Both patients were girls, 2 and 8 years old respectively and underwent surgical treatment.

(9)Be(d,n)(10)B-based neutron sources for BNCT.

In the frame of accelerator-based BNCT, the (9)Be(d,n)(10)B reaction was investigated as a possible source of epithermal neutrons. In order to determine the configuration in terms of bombarding energy, target thickness and Beam Shaping Assembly (BSA) design that results in the best possible beam quality, a systematic optimization study was carried out. From this study, the optimal configuration resulted in tumor doses ≥40Gy-Eq, with a maximum value of 51Gy-Eq at a depth of about 2.7cm, in a 60min treatment. The optimal configuration was considered for the treatment planning assessment of a real Glioblastoma Multiforme case. From this, the resulted dose performances were comparable to those obtained with an optimized (7)Li(p,n)-based neutron source, under identical conditions and subjected to the same clinical protocol.

Accelerator-based BNCT.

The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. In particular, the present status and recent progress of the Argentine project will be reviewed. The topics will cover: intense ion sources, accelerator tubes, transport of intense beams, beam diagnostics, the (9)Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases.

Evaluation of performance of an accelerator-based BNCT facility for the treatment of different tumor targets.

PURPOSE: Encouraging Boron Neutron Capture Therapy (BNCT) clinical results obtained in recent years have stimulated intense research to develop accelerator-based neutron sources to be installed in clinical facilities. In this work an assessment of an accelerator-based BNCT facility for the treatment of different tumor targets was performed, comparing the accelerator-derived results with reported reactor-based trials under similar conditions and subjected to the same clinical protocols. MATERIALS AND METHODS: A set of real image studies was used to cover clinical-like cases of brain and head-and-neck tumors. In addition, two clinical cases of malignant nodular melanoma treated at the RA-6 BNCT facility in Argentina were used to thoroughly compare the clinical dosimetry with the accelerator-derived results. RESULTS: The minimum weighted dose delivered to the clinical target volume was higher than 30 Gy and 14 Gy for the brain tumor and head-and-neck cases, respectively, in agreement with those achieved in clinical applications. For the melanoma cases, the minimum tumor doses were equal or higher than those achieved with the RA-6 reactor for identical field orientation and protocol. The whole-body dose assessment showed that the maximum photon-equivalent doses for those normal organs close to the beam direction were below the upper limits considered in the protocols used in the present work. CONCLUSIONS: The obtained results indicate not only the good performance of the proposed beam shaping assembly design associated to the facility but also the potential applicability of accelerator-based BNCT in the treatment of both superficial and deep-seated tumors.

Computational dosimetry of a simulated combined standard X-rays and BNCT treatment.

There has been increasing interest in combining Boron Neutron Capture Therapy (BNCT) with standard radiotherapy, either concomitantly or as a BNCT treatment of a recurrent tumor that was previously irradiated with a medical electron linear accelerator (LINAC). In this work we report the simulated dosimetry of treatments combining X-rays and BNCT.

Treatment planning capability assessment of a beam shaping assembly for accelerator-based BNCT.

Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT) a theoretical study was performed to assess the treatment planning capability of different configurations of an optimized beam shaping assembly for such a facility. In particular this study aims at evaluating treatment plans for a clinical case of Glioblastoma.