Leishmanicidal activity of the venoms of the Scorpions Brotheas amazonicus and Tityus metuendus.

Leishmaniasis is a vector-transmitted zoonosis caused by different species of the genus Leishmania, with a wide clinical spectrum. It is a public health problem aggravated by a series of limitations regarding treatment. In the search for new therapeutic alternatives, scorpion venoms are a source of multifunctional molecules that act against the natural resistance of pathogens. This work evaluated the antileishmanial potential of Brotheas amazonicus and Tityus metuendus venoms against the promastigote forms of Leishmania amazonensis e Leishmania guyanensis. The venoms of B. amazonicus and T. metuendus were evaluated for their constituents using Fourier Transform Infrared (FTIR). Growth inhibition and death of promastigotes were evaluated in the presence of diferente crude venom concentrations (100 µg/mL, 50 µg/mL, 10 µg/mL, 1 µg/mL) after one hour of incubation at 25 °C. The FTIR spectra of both venoms exhibited bands in approximate regions, revealing that both exhibit similar functional groups. Crude venom from both scorpion species showed similar or superior leishmanicidal effects to the standart drug N-methylglucamine antimoniate. At the highest concentration of 100 µg/mL, cultures of L. guyanensis treated with the venom of B. amazonicus showed the highest mortality percentages, above 28%, while T. metuendus venom showed the highest activity against L. amazonensis, with mortality above 7%. This preliminar study demonstrates that B. amazonicus and T. metuendus venoms can be important tools in the search for new drugs Against leishmaniasis. Next step involves evaluating the activity against the amastigote forms and purifying the venom proteins in order to identify the best anti-leishmania candidates.

Influence of maternal body mass index on interobserver variability of fetal ultrasound biometry and amniotic-fluid assessment in late pregnancy.

OBJECTIVE: To determine the interobserver reproducibility of fetal ultrasound biometric and amniotic-fluid measurements in the third trimester of pregnancy, according to maternal body mass index (BMI) category. METHODS: This was a prospective cohort study of women with a singleton gestation beyond 34 weeks, recruited into four groups according to BMI category: normal (18.0-24.9 kg/m2 ), overweight (25.0-29.9 kg/m2) , obese (30.0-39.9 kg/m2 ) and morbidly obese (≥ 40 kg/m2 ). Multiple pregnancies, women with diabetes and pregnancies with a fetal growth, structural or genetic abnormality were excluded. In each woman, fetal biometric (biparietal diameter (BPD), head circumference, abdominal circumference (AC), femur length (FL) and estimated fetal weight) and amniotic-fluid (amniotic-fluid index (AFI) and maximum vertical pocket (MVP)) measurements were obtained by two experienced sonographers or physicians, blinded to gestational age and each other's measurements. Differences in measurements between observers were expressed as gestational age-specific Z-scores. The interobserver intraclass correlation coefficient (ICC) and Cronbach's reliability coefficient (CRC) were calculated. Bland-Altman analysis was used to assess the degree of reproducibility. RESULTS: In total, 110 women were enrolled prospectively (including 1320 measurements obtained by 17 sonographers or physicians). Twenty (18.2%) women had normal BMI, 30 (27.3%) women were overweight, 30 (27.3%) women were obese and 30 (27.3%) women were morbidly obese. Except for AFI (ICC, 0.65; CRC, 0.78) and MVP (ICC, 0.49; CRC, 0.66), all parameters had a very high level of interobserver reproducibility (ICC, 0.72-0.87; CRC, 0.84-0.93). When assessing reproducibility according to BMI category, BPD measurements had a very high level of reproducibility (ICC ≥ 0.85; CRC > 0.90) in all groups. The reproducibility of AC and FL measurements increased with increasing BMI, while the reproducibility of MVP measurements decreased. Among the biometric parameters, the difference between the BMI categories in measurement-difference Z-score was significant only for FL. Interobserver differences for biometric measurements fell within the 95% limits of agreement. CONCLUSION: Obesity does not seem to impact negatively on the reproducibility of ultrasound measurements of fetal biometric parameters when undertaken by experienced sonographers or physicians who commonly assess overweight, obese and morbidly obese women. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Venom characterization of the Amazonian scorpion Tityus metuendus.

The soluble venom from the scorpion Tityus metuendus was characterized by various methods. In vivo experiments with mice showed that it is lethal. Extended electrophysiological recordings using seven sub-types of human voltage gated sodium channels (hNav1.1 to 1.7) showed that it contains both α- and ß-scorpion toxin types. Fingerprint analysis by mass spectrometry identified over 200 distinct molecular mass components. At least 60 sub-fractions were recovered from HPLC separation. Five purified peptides were sequenced by Edman degradation, and their complete primary structures were determined. Additionally, three other peptides have had their N-terminal amino acid sequences determined by Edman degradation and reported. Mass spectrometry analysis of tryptic digestion of the soluble venom permitted the identification of the amino acid sequence of 111 different peptides. Search for similarities of the sequences found indicated that they probably are: sodium and potassium channel toxins, metalloproteinases, hyaluronidases, endothelin and angiotensin-converting enzymes, bradykinin-potentiating peptide, hypothetical proteins, allergens, other enzymes, other proteins and peptides.

Protective effect of locally applied carvacrol gel on ligature-induced periodontitis in rats: a tapping mode AFM study.

The aims of this study were to test a locally applied carvacrol gel and determine its efficacy preventing alveolar bone loss in experimental periodontitis in rats by regular methodology to validate applicability the atomic force microscopy (AFM) as a novel morphology method on this model. Wistar rats were subjected to ligature around second, upper-left molars. Animals were treated carvacrol gel topically (CAG), immediately after Experimental Periodontitis Disease induction for 1' three-times/day for 11 days. A vehicle gel was utilized as control. The periodontium and the surrounding gingivae were examined at regular histopathology and by AFM method; the neutrophil influx into the gingivae was also assayed using myeloperoxidase activity. The bacterial flora was assessed through culture of the gingival tissue. Alveolar bone loss was significantly inhibited by CAG group compared to the Vehicle (V) group, the carvacrol gel treatment reduced tissue lesion at histopathology, with preservation of the periodontium, coupled to decreased myeloperoxidase activity in gingival tissue and also prevented the proliferation of periodontal microorganisms and the weight loss. The GAC treatment preserved alveolar bone resorption and showed anti-inflammatory and antibacterial activities in experimental periodontitis. Topographical changes in histological sections were seen bringing into high relief the periodontal structures, being a simple and cost-effective method for periodontal evaluation with ultrastructural resolution.

Assessment of air pollution sources in an industrial atmosphere using principal component and multilinear regression analysis.

Aerosol samples collected in the industrial area of Estarreja, Portugal, were used to assess the source classes responsible for the particulate levels observed in the local atmosphere. Principal Component Analysis was applied separately to the concentrations of aerosol constituents and meteorological variables to obtain the number of Principal Components and to verify the influence of weather conditions on ambient air quality. The technique led to the conclusion that soil and transport emissions represent important aerosol sources even in this industrial environment. The quantitative contribution of each source class was calculated using Multilinear Regression Analysis; 37% of the aerosol mass had a soil origin, 8% was from sea spray, 18% resulted from transport emissions and 24% contained ammonium salts. Twelve percent of total suspended particle (TSP) mass could not be explained by any of the six Principal Components retained. Ammonium salts and two other minor Principal Components seem to result mainly from industrial emissions. More specific information about the contribution of each particular source was not possible with this technique.

Prevalence of bone loss in a group of Brazilian teenagers assessed on bite-wing radiographs.

Bite-wing radiographs were used to assess periodontal disease in 304 Brazilian 15-year-old schoolchildren from a population with a low socioeconomic status. The criterion for destructive periodontitis was a distance from the cementoenamel junction to the alveolar crest greater than 2 mm. 90 subjects were excluded, mainly due to missing first molars. Bone loss was diagnosed in 28% of the subjects. More males than females were affected. 50% of all lesions were observed adjacent to first molars. The juvenile periodontitis type of lesion was found in 8 subjects. It was concluded that in young populations bite-wing X-rays seem to be valuable in screening for individuals with incipient bone loss as well as for identification of subjects with juvenile periodontitis. In community programs regular use of this kind of roentgen examination is therefore recommended.