Geographical characterization of the triatomine infestations in north–central Guatemala

In an entomological study in 2002, the degree of domestic and peridomestic infestation with triatomine bugs and the geographical distribution of such infestations were investigated in north-central Guatemala. The survey team searched for triatomines in houses constructed with mud walls or thatched roofs, in villages suspected of being infested. The level of infestation observed was lower than that seen in the same area and in eastern Guatemala, in a preliminary survey, 3 years earlier. Most of the infestations detected were of Triatoma dimidiata but even this species was found in <7% of the houses investigated. Infestations with Rhodnius prolixus or other potential vectors of Trypanosoma cruzi were much rarer. The generally low levels of infestation make the elimination of R. prolixus and the reduction of the domestic population of Tri. dimidiata feasible in the study area. The southern part of the study area had higher levels of domestic infestation and colonization than the north, and peridomestic infestation was highest in the south-west. Given such geographical variation in the pattern of infestation, it would seem wise to stratify the study region into areas of high, moderate and low-risk of human-triatomine contact, so that appropriate vector-control strategies can be targeted at the worst-affected areas. Regular entomological surveillance, ideally with community participation, is recommended. Analysis of the relationship between the geographical patterns of infestation and factors such as vegetation, altitude and vector migration would be useful.

Human Papillomavirus (HPV) Genotyping: Automation and Application in Routine Laboratory Testing

A large number of assays designed for genotyping human papillomaviruses (HPV) have been developed in the last years. They perform within a wide range of analytical sensitivity and specificity values for the different viral types, and are used either for diagnosis, epidemiological studies, evaluation of vaccines and implementing and monitoring of vaccination programs. Methods for specific genotyping of HPV-16 and HPV-18 are also useful for the prevention of cervical cancer in screening programs. Some commercial tests are, in addition, fully or partially automated. Automation of HPV genotyping presents advantages such as the simplicity of the testing procedure for the operator, the ability to process a large number of samples in a short time, and the reduction of human errors from manual operations, allowing a better quality assurance and a reduction of cost. The present review collects information about the current HPV genotyping tests, with special attention to practical aspects influencing their use in clinical laboratories.

Low-dose radiation hyper-radiosensitivity in multicellular tumour spheroids

OBJECTIVE

We propose and study a new model aimed at describing the low-dose hyper-radiosensitivity phenomenon appearing in the survival curves of different cell lines.

METHODS

The model uses the induced repair assumption, considering that the critical dose at which this mechanism begins to act varies from cell to cell in a given population. The model proposed is compared with the linear-quadratic model and the modified linear-quadratic model, which is commonly used in literature and in which the induced repair is taken into account in a heuristic way. The survival curve for the MCF-7 line of human breast cancer is measured at low absorbed doses and the uncertainties in these doses are estimated using thermoluminiscent dosemeters.

RESULTS

It is shown that these multicellular spheroids present low-dose hyper-radiosensitivity. The new model permits an accurate description of the data of two human cell lines (previously published) and of the multicellular spheroids of the MCF-7 line here measured.

CONCLUSION

The model shows enough flexibility to account for data with very different characteristics and considers in a faithful way the hypothesis of the repair induction.

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.

Bioequivalence of acenocoumarol in chilean volunteers: an open, randomized, double-blind, single-dose, 2-period, and 2-sequence crossover study for 2 oral formulations

The aim of this study was to compare the bioavailability of an oral formulation of the coumarin derivative-vitamine K antagonist acenocoumarol (Acebron™ 4 mg, Test) with the reference formulation (Neo-Sintrom™ 4 mg). We performed a single-dose, double-blind, fasting, 2-period, 2-sequence, crossover study design. Plasma concentrations of acenocoumarol were determined using a validated UPLC-MS/MS method. 24 healthy Chilean volunteers (11 male, 13 female) were enrolled and all of them completed the study. Adverse events were monitored throughout the study. The values of the pharmacokinetic parameters were (mean ± SD): AUC0-24 =1 364.38±499.26 ngxh/mL for the test and 1 328.39±429.20 ngxh/mL for the reference; AUC0-∞ =1 786.00±732.85 ngxh/mL for the test and 1 706.71±599.66 ngxh/mL for the reference; Cmax =180.69±35.11 ng/mL with a Tmax of 1.83±0.95 h for the test and 186.97±38.21 ng/mL with a Tmax of 2.19±0.83 h for the reference. Regarding half life measurements, the mean ± SD of t1/2 were 11.84±4.54 h for the test and 11.08±3.28 h for the reference. The 90% confidence intervals for the test/reference ratio using logarithmic transformed data were 97.89-100.87%, 98.62-101.99% and 98.64-102.38% for Cmax, AUC0-t(24) and AUC0-∞. There were no significant differences in pharmacokinetic parameters between groups.The results obtained in this study lead us to conclude, based on FDA criteria, that the test acenocoumarol formulation (Acebron™, 4 mg tablets) is bioequivalent to the reference product (Neo-Sintrom™, 4 mg tablets).

Affective style and eating disorders: a field study

Eating disorders (ED) are a heterogeneous group of problems related to restraint and/or overeating. It is proposed that individual differences in affective reactivity and moods (affective style) might be related to these behaviours. Variations in affective style are expressed by differing levels of sensitivity to the motivation systems of approach and avoidance. The present study tested whether a relation exists between ED and variations in the sensitivity of motivational systems as well as mood dispositions. A total of 2020 undergraduate students completed the Eating Disorder Diagnostic Scale (EDDS), the Behavioural Inhibition System and Behavioural Activation System Scales (BIS/BAS), and the Positive and Negative Affect Schedule (PANAS). The results showed a significant within- subject interaction of Alimentary group x Motivation (F=4.056; p<0.007). It was also observed that the Overeating group had lower levels of motivation asymmetry than the Normal (p<0.01) and Restrictive (p<0.005) groups and marginally lower levels than the Purgative group (p<0.07). The study results suggest mainly that the avoidance/inhibition motivational system is related to eating problems connected with overeating, including chronic alimentary restraint (chronic dieters). The theoretical and clinical implications of these findings are discussed.

Measurement of the depth of maximum of extensive air showers above 10{18} eV

We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

Cutaneous manifestations in renal transplant recipients of Santiago, Chile

INTRODUCTION

Renal transplant recipients have a heightened risk of developing various cutaneous manifestations, such as skin infections, skin cancer, and secondary effects of immunosuppressive drugs. These manifestations differ depending on the evaluated population. The objective of this study was to describe the prevalence of cutaneous manifestations among renal transplant recipients in Chile between 1979 and 2008.

METHODS

Patients were recruited and then evaluated using a standardized questionnaire. Dermatologic physical examination was performed in every patient describing skin lesions, immunosuppressive drug effects, and malignant diseases. All suspicious lesions were biopsied for analysis. Every patient was queried for the development of skin cancer after his or her transplantation.

RESULTS

A total of 91 patients were enrolled; ages 10-67 years. Sixty percent of the patients presented with an infection at the initial evaluation. The most common infection was onychomycosis (58%) and verruca vulgaris (25%). In this study 58% of patients developed cutaneous side effects of immunosuppressive drugs. Among the evaluated patients, 16% showed premalignant or malignant manifestations on physical examination. The most frequent manifestations were actinic keratosis (17%), basal cell carcinoma (1%), and squamous cell carcinoma (1%). On a retrospective analysis, 12% of patients developed skin cancer after transplantation, 66% squamous cell carcinoma and 34% basal cell carcinoma, with a ratio of 1.9 to 1.

DISCUSSION

Cutaneous manifestations in renal transplant recipients are generally secondary to immunosuppression. These patients show a greater risk of having human papilloma virus (HPV) infections and nonmelanoma skin cancer. Periodic dermatologic evaluation of these patients should be performed to detect early lesions and modify risk factors.