RESUMO
Since its introduction comprehensive two-dimensional gas chromatography (GC × GC) has been widely applied to analyze complex samples due to its enhanced peak capacity and selectivity, thereby increasing the number of identifiable peaks and improving coelution issues. Even though it is still undergoing development, GC × GC provides many advantages in the analysis of petroleum-derived samples, whether in reservoir geochemistry applications or in environmental studies associated with spilled oils. In general, it facilitates more thorough fingerprinting and compositional evaluation. In environmental studies, it helps enhance understanding of weathering processes and the environmental behavior of hydrocarbons, as its chromatographic retention indices can robustly estimate liquid vapor pressures, aqueous solubility and other physical chemical properties. This review presents a brief history of GC × GC instrumentation, discussing recent and significant advances in petroleum applications, from data handling techniques to reservoir geochemistry and environmental forensics, as well as some specific advantages achieved and certain limitations that continue to be encountered.
RESUMO
The parasitic protozoan Leishmania (Leishmania) infantum is the etiological agent of human visceral leishmaniasis in South America, an infectious disease associated with malnutrition, anemia, and hepatosplenomegaly. In Brazil alone, around 2700 cases are reported each year. Treatment failure can occur as a result of drug, host, and/or parasite-related factors. Here, we isolated a Leishmania species from a pediatric patient with visceral leishmaniasis that did not respond to chemotherapy, experiencing a total of nine therapeutic relapses and undergoing a splenectomy. The parasite was confirmed as L. (L.) infantum after sequencing of the ribosomal DNA internal transcribed spacer, and the clinical isolate, in both promastigote and amastigote forms, was submitted to in vitro susceptibility assays with all the drugs currently used in the chemotherapy of leishmaniasis. The isolate was susceptible to meglumine antimoniate, amphotericin B, pentamidine, miltefosine, and paromomycin, similarly to another strain of this species that had previously been characterized. These findings indicate that the multiples relapses observed in this pediatric patient were not due to a decrease in the drug susceptibility of this isolate; therefore, immunophysiological aspects of the patient should be further investigated to understand the basis of treatment failure in this case.
RESUMO
BACKGROUND: Orofacial clefts are among the most common congenital craniofacial malformations and may be associated with other birth defects. However, the proportion and type of additional anomalies vary greatly between studies. This study assessed the prevalence and type of associated congenital malformations in children with orofacial clefts, who attended the largest cleft lip and palate tertiary referral center in Portugal. METHODS: Consecutive children with orofacial clefts who attended at least 1 consultation in our Clefts Unit between 1981 and 2012 were studied. Demographic and clinical data regarding the number and type of associated malformations were retrospectively collected and analyzed. RESULTS: Of the 701 patients studied, 219 (31.2%) had associated congenital malformations. These malformations were more frequent in children with cleft palate (43.4%) than in children with cleft lip and palate (27.5%) or with cleft lip only (19.4%). Within the group with associated anomalies, 73 cases (33.3%) had conditions related with known chromosomal defects, monogenic syndromes or sequences, and 146 cases (66.7%) had multiple congenital anomalies of unknown origin. From those, head and neck malformations were the most common (60.3%), followed by malformations in the cardiovascular (28.3%) and musculoskeletal systems (26%). CONCLUSIONS: The overall prevalence of associated malformations of nearly 1 in 3 children with orofacial clefts stressed the need for a comprehensive evaluation of these patients by a multidisciplinary cleft team. Moreover, one-third of the children had multiple congenital anomalies of known origins. Thus, early routine screening for other malformations and genetic counseling might be valuable for orofacial clefts management.
