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A method for the polarographic determination of cyanide as contaminant in pralidoxime mesylate (PM) formulations was developed. The volatile cyanide formed in the formulations was stabilized as tetracyanonickelate (TCN) anion complex after reaction with ammoniacal Ni(II) solution. The stable TCN anion complex (Kstb=1031) was determined by anodic stripping voltammetry at the hanging mercury drop electrode (HMDE). The polarographic signal was proportional to the cyanide concentration and the high concentration of PM did not interfere. The linear range of calibration was from 1.2 to 16 μg cyanide with r=0.998. The RSD was 1.3% (n=5) for 2.4 μg cyanide and a detection limit of 0.8 μg cyanide was calculated. The proposed method is adequate as a quality control of PM formulations.

Los objetivos de este estudio fueron evaluar y comparar la influencia de la polimerización adicional con calor y presión de vapor o calor y nitrógeno presurizado en la resistencia a la compresión, módulo de elasticidad y microdureza Vickers de una resina compuesta Ormocer®;. Para esto, se confeccionaron 45 muestras cilíndricas con 3 mm de diámetro y 6 mm de altura en una matriz de PTFE. La resina compuesta Admira (Voco, Cuxhaven, Germany) fue introducida gradualmente y fotopolimerizada por 40 s con el aparato XL-1500 (3M ESPE, St. Paul, MN, EUA). Seguidamente, las muestras fueron almacenadas en un horno a 37ºC por 24 horas y divididas aleatoriamente en tres grupos. Las muestras del grupo I (control) fueron testadas inmediatamente después del período de almacenamiento. En el grupo II, las muestras fueron sometidas a 120ºC bajo presión de vapor de agua por 20 min y, en el grupo III, las muestras fueron polimerizadas adicionalmente a 140°C con presión de 60 lbs. de nitrógeno durante 10 minutos. Inmediatamente, las muestras fueron testadas en una máquina de ensayo universal (Emic DL 2000, São José dos Pinhais, Paraná, Brazil) a 0,5 mm/min hasta que se fracturaron. Los valores de resistencia a la compresión (MPa), módulo de elasticidad (GPa) y microdureza Vickers (VHN) fueron tratados estadísticamente con ANOVA/Tukey (p < 0,05). Los valores de resistencia (MPa, DP) fueron: grupo I (control) 114,25b (±34,74); grupo II 127,64b (±33,27); grupo III 167,97ª (±40,15). Módulo de elasticidad (GPa, DP): grupo I (control) 6,11b (±0,35); grupo II 8,45ab (±0,33); grupo III 11,31a (±0,47). Microdureza Vickers (VHN, DP): grupo I (control) 47,26b (6,32); grupo II 58,63ª (13,92); grupo III 63,69ª (8,86). Se puede concluir entonces, que el método de polimerización adicional a 140°C bajo presión de 60 lbs de nitrógeno aumentó significativamente la resistencia a la compresión, y ambos métodos adicionales de cura aumentaron significativamente el módulo de elasticidad y microdureza Vickers de la resina compuesta Admira (p < 0,05). The purposes of this study were evaluate and compare the influence of post-curing with heat and steam pressure or heat and nitrogen pressure in the compressive strength, elastic modulus and Vickers microhardness of an Ormocer®; composite resin. Forty-five cylindrical samples with 3 mm diameter and 6 mm high were manufacture using a PTFE mould. The composite resin Admira (Voco, Cuxhaven, Germany) was inserted incrementally and cured for 40 s with XL-1500 (3M ESPE, St. Paul, MN, EUA). After that, the samples were stored in a stove at 37ºC for 24 hours and randomly divided in three groups. The samples of group I (control) were tested just after the stored period. In group II, the samples were submitted to 120ºC with water steam for 20 min, and for group III, the samples was post-cured at 140°C under 60 lbs of nitrogen for 10 min. The samples were tested with universal testing machine (Emic DL 2000, São José dos Pinhais, Paraná, Brazil) at 0.5 mm/min until fracture. Data of compressive strength (MPa), elastic modulus (GPa), and Vickers microhardness (VHN) were statistically evaluated with ANOVA/Tukey (p < 0.05). The mean values of compressive strength (SD) were: group I (control) 114.25b (±34.74); group II 127.64b (±33.27); group III 167.97a (±40.15); elastic modulus (SD): group I (control) 6.11b(±3.5); group II 8.45ab (±3.34); group III 11.31a(±4.7); Vickers microhardness (SD): group I (control) 47.26b (2.7); group II 58.63a (2.3) and group III 63.69a (3.5). It is possible to conclude that the post-curing method at 140°C under 60 lbs of nitrogen improved significantly the compressive strength, and both methods improved the elastic modulus and microhardness (p < 0.05).

Los objetivos de este estudio fueron evaluar y comparar la influencia de la polimerización adicional con calor y presión de vapor o calor y nitrógeno presurizado en la resistencia a la compresión, módulo de elasticidad y microdureza Vickers de una resina compuesta Ormocer®;. Para esto, se confeccionaron 45 muestras cilíndricas con 3 mm de diámetro y 6 mm de altura en una matriz de PTFE. La resina compuesta Admira (Voco, Cuxhaven, Germany) fue introducida gradualmente y fotopolimerizada por 40 s con el aparato XL-1500 (3M ESPE, St. Paul, MN, EUA). Seguidamente, las muestras fueron almacenadas en un horno a 37ºC por 24 horas y divididas aleatoriamente en tres grupos. Las muestras del grupo I (control) fueron testadas inmediatamente después del período de almacenamiento. En el grupo II, las muestras fueron sometidas a 120ºC bajo presión de vapor de agua por 20 min y, en el grupo III, las muestras fueron polimerizadas adicionalmente a 140°C con presión de 60 lbs. de nitrógeno durante 10 minutos. Inmediatamente, las muestras fueron testadas en una máquina de ensayo universal (Emic DL 2000, São José dos Pinhais, Paraná, Brazil) a 0,5 mm/min hasta que se fracturaron. Los valores de resistencia a la compresión (MPa), módulo de elasticidad (GPa) y microdureza Vickers (VHN) fueron tratados estadísticamente con ANOVA/Tukey (p < 0,05). Los valores de resistencia (MPa, DP) fueron: grupo I (control) 114,25b (±34,74); grupo II 127,64b (±33,27); grupo III 167,97ª (±40,15). Módulo de elasticidad (GPa, DP): grupo I (control) 6,11b (±0,35); grupo II 8,45ab (±0,33); grupo III 11,31a (±0,47). Microdureza Vickers (VHN, DP): grupo I (control) 47,26b (6,32); grupo II 58,63ª (13,92); grupo III 63,69ª (8,86). Se puede concluir entonces, que el método de polimerización adicional a 140°C bajo presión de 60 lbs de nitrógeno aumentó significativamente la resistencia a la compresión, y ambos métodos adicionales de cura aumentaron significativamente el módulo de elasticidad y microdureza Vickers de la resina compuesta Admira (p < 0,05).

The authors describe a case of neonatal osteoarthritis of the hip due to group B streptococcus and discuss the importance of recognizing this bacteria in the late focal infections of the newborn.

Vertebral osteomyelitis is an uncommon disease in children, presenting with signs and symptoms that, at least initially, make a correct diagnosis difficult to be achieved. The authors report five cases of vertebral osteomyelitis in children, describing its clinical and laboratory peculiarities. The usefulness of the different radiologic studies for the diagnosis and follow up of these patients is discussed. We confirm previous reports according to which, with adequate clinical and therapeutic management, the prognosis is good for most patients.

$\textbf{BACKGROUND}$: Investigations of the relationships between the gut microbiota and gastrointestinal parasitic nematodes are attracting growing interest by the scientific community, driven by the need to better understand the contribution of parasite-associated changes in the composition of the gut flora to both host malnutrition and immune modulation. These studies have however been carried out mainly in humans and experimental animals, while knowledge of the make-up of the gut commensal flora in presence or absence of infection by parasitic nematodes in domestic animals is limited. In this study, we investigate the qualitative and quantitative impact that infections by a widespread parasite of cats (i.e. $\textit{Toxocara cati}$) exert on the gut microbiota of feline hosts. $\textbf{METHODS}$: The faecal microbiota of cats with patent infection by $\textit{T. cati}$ (= $\textit{Tc+}$), as well as that of negative controls (= $\textit{Tc-}$) was examined via high-throughput sequencing of the V3-V4 hypervariable region of the bacterial 16S rRNA gene, followed by bioinformatics and biostatistical analyses of sequence data. $\textbf{RESULTS}$: A total of 2,325,366 useable high-quality sequences were generated from the faecal samples analysed in this study and subjected to further bioinformatics analyses, which led to the identification of 128 OTUs and nine bacterial phyla, respectively. The phylum Firmicutes was predominant in all samples analysed (mean of 53.0%), followed by the phyla Proteobacteria (13.8%), Actinobacteria (13.7%) and Bacteroidetes (10.1%). Among others, bacteria of the order Lactobacillales, the family $\textit{Enterococcaceae}$ and genera $\textit{Enterococcus}$ and $\textit{Dorea}$ showed a trend towards increased abundance in $\textit{Tc+}$ compared with $\textit{Tc-}$ samples, while no significant differences in OTU richness and diversity were recorded between $\textit{Tc+}$ and $\textit{Tc-}$ samples ($\textit{P}$=0.485 and $\textit{P}$=0.581, respectively). However, Canonical Correlation and Redundancy Analyses were able to separate samples by infection status ($\textit{P}$=0.030 and $\textit{P}$=0.015, respectively), which suggests a correlation between the latter and the composition of the feline faecal microbiota. $\textbf{CONCLUSIONS}$: In spite of the relatively small number of samples analysed, subtle differences in the composition of the gut microbiota of $\textit{Tc+}$ vs $\textit{Tc-}$ cats could be identified, some of which in accordance with current data from humans and laboratory animal hosts. Nevertheless, the findings from this study contribute valuable knowledge to the yet little explored area of parasite-microbiota interactions in domestic animals.