Decrease in the fatigue resistance of nickel-titanium rotary instruments after clinical use in curved root canals.

OBJECTIVE: The changes in fatigue resistance of nickel-titanium rotary ProFile instruments after clinical use for shaping 10 curved molar root canals were evaluated in this study. STUDY DESIGN: Twenty-five sets of files #20, #25, and #30 and tapers .04 and .06 were divided into 2 groups, one with 10 sets of new files that were tested in a fatigue test bench device as a control. The other, experimental group, with 15 sets of clinically used files, was tested in the same device. The Student t test was employed to compare mean values of the measured parameters. RESULTS: A statistically significant decrease in the number of cycles to failure was determined for the clinically used files, as compared with the new ones. The fracture point was the same for all files tested. CONCLUSIONS: The clinical use of ProFile instruments for shaping curved canals reduces their fatigue resistance.     

Small Conductance Ca2+-Activated K+ Channels Formed by the Expression of Rat SK1 and SK2 Genes in HEK 293 Cells

The rat SK1 gene ( rSK1 ) does not form functional Ca²⁺-activated potassium channels when expressed alone in mammalian cell lines. Using a selective antibody to the rSK1 subunit and a yellow fluorescent protein (YFP) tag we have discovered that rSK1 expression produces protein that remains largely at intracellular locations. We tested the idea that rSK1 may need an expression partner, rSK2, in order to form functional channels. When rSK1 was co-expressed with rSK2 in HEK 293 cells it increased the current magnitude by 77 ± 34 % (as compared with cells expressing rSK2 alone). Co-expression of rSK1 with rSK2 also changed the channel pharmacology. The sensitivity of SK current to block by apamin was reduced ~16-fold from an IC₅₀ of 94 p m (for SK2 alone) to 1.4 n m (for SK2 and SK1 together). The sensitivity to block by UCL 1848 (a potent small molecule blocker of SK channels) was similarly reduced, ~26-fold, from an IC₅₀ of 110 p m to 2.9 n m . These data clearly demonstrate that rSK1 and rSK2 subunits interact. The most likely explanation for this is that the subunits are able to form heteromeric assemblies.     

Colorimetric analysis of some diuretic drugs: hydrochlorothiazide and spironolactone

Two convenient spectrophotometric methods were developed for the determination of hydrochlorothiazide and spironolactone. A specific colour reaction for the determination of hydrochlorothiazide is reported. One method is based on the reaction of hydrochlorothiazide withn-butylamine and cobaltous chloride in anhydrous methanol. A blue-violet colour is produced and is measured at 570 nm. A highly selective colorimetric method was adopted for the analysis of spironolactone by reacting with isoniazid forming a coloured hydrazone derivative and subsequent measurement of the coloured product at 405 nm.From Determination of certain diuretics, M Pharm Sci thesis.The volumetric flasks were dried by rinsing them with pure acetone after draining off the water, then allowing to drain until dry or blowing air through them.     

Abdominal Aortic Aneurysms: Endovascular Options and Outcomes — Proliferating Therapy,But Effective?

Abdominal aortic aneurysm (AAA) has a reported prevalence rate of 1.4% in the US. AAA rupture accounts for an estimated 15,000 deaths per year, rendering it the 10th leading cause of death in men over the age of 55. Endovascular repair (EVR) has proliferated in the last two decades as an increasingly popular alternative to traditional open surgery, and is now the default treatment in the majority of centres worldwide. This review article outlines the evidence supporting this stance. The development of EVR is reviewed, alongside trends in utilisation of this therapy over time. The evidence for the relative short-term and long-term outcomes of EVR and open AAA repair is discussed, and ongoing controversies surrounding the use of EVR are considered.     

First experience of the use of a generic of plerixafor in peripheral blood stem cell mobilization in multiple myeloma and lymphoma patients

Mobilization failure in patients is a major therapeutic concern which makes subsequent ASCT impossible. A new growth factor called Plerixafor (Mozobil®) developed by the pharmaceutical industry (Sanofi-aventis, France), is a chemoreceptor antagonist, CXCR4 type, which disrupts the interaction of SDFI and CXCR4, thereby enhancing the effect of G-CSF mobilization and is especially indicated for mobilization failure. Currently, there is a generic of plerixafor developed by the pharmaceutical industry (Hetero Drugs Ltd, India). The brand name of this medicine is Mozifor®. The objective of this study was to evaluate if generic plerixafor has the same efficacy and safety as originator plerixafor when used with G-CSF in the mobilization of PBSCs for autologous ASCT in multiple myeloma (MM) and lymphoma failure patients. The 32 patients received plerixafor were divided in two groups. The first group concerns the 11 consecutive patients prospectively received generic plerixafor (Mozifor®) in the period between January to July 2020. These were compared with a retrospective control cohort (second group n = 21) who had been treated between 2009 and 2019 with originator plerixafor (Mozobil®). For the Mozifor® group, the mean CD34+ was 4.54x10⁶/kg(1.56-6.79), the median time to achieve an absolute neutrophil count >0.5 G/L was 13 days (range: 8–21). The median time to self-sustained platelet count >20 G/L was 15 days (range: 8–24). For the Mozobil® group, the mean CD34+ was 3.1x10⁶/kg (0.56-8.91) (p=0.86), the median time to achieve an absolute neutrophil count >0.5 G/L was 10 days (range 7–23). The median time to self-sustained platelet count >20 G/L was 13 days (range: 7–29). Our study showed that the generic of plerixafor was practically identical to that of the originator (Mozobil®) with no significant difference (p = 0.52). This study demonstrates the safety and feasibility of mobilization PBSC with generic plerixafor in ASCT in MM and lymphoma. Although these outcomes are encouraging, prospective comparison with other traditional auto-HCT regimens used for patients with MM and lymphoma is warranted.     

Single nucleotide polymorphisms identification in expressed genes of Schistosoma mansoni

Single nucleotide polymorphism (SNP) markers have been shown to be useful in genetic investigations of medically important parasites and their hosts. In this paper, we describe the prediction and validation of SNPs in ESTs of Schistosoma mansoni. We used 107,417 public sequences of S. mansoni and identified 15,614 high-quality candidate SNPs in 12,184 contigs. The presence of predicted SNPs was observed in well characterized antigens and vaccine candidates such as those coding for myosin; Sm14 and Sm23; cathepsin B and triosephosphate isomerase (TPI). Additionally, SNPs were experimentally validated for the cathepsin B. A comparative model of the S. mansoni cathepsin B was built for predicting the possible consequences of amino acid substitutions on the protein structure. An analysis of the substitutions indicated that the amino acids were mostly located on the surface of the molecule, and we found no evidence for a significant conformational change of the enzyme. However, at least one of the substitutions could result in a structural modification of an epitope.     

Ultrastructural comparison of external morphology of immature stages of Lutzomyia (Nyssomyia) intermedia and Lutzomyia (Nyssomyia) whitmani (Diptera: Psychodidae), vectors of cutaneous leishmaniasis, by scanning electron microscopy

Lutzomyia (Nyssomyia) intermedia (Lutz & Neiva 1912) and Lutzomyia (Nyssomyia) whitmani (Antunes & Coutinho 1939) (Diptera: Psychodidae) are vectors of American cutaneous leishmaniasis in several endemic regions of Brazil. We analyzed the external morphological aspects of the immature stages of these two vectors by using scanning electron microscopy. In general, the larval stages of the two species are morphologically similar, although some differences were noted. Detailed examination of the eggs of both species revealed similar exchorionic ornamentations of unconnected parallel ridges. The larval head capsules are well defined, heavily sclerotized, and bear prominent chewing mouthparts. The abdominal segments are easily recognized by the presence of prolegs on their ventral surfaces. The morphology of the anal lobe on the terminal abdominal segment differs between the two species. We found the following three types of sensillae inserted on the antennae: (1) clavate basiconic; (2) small, blunt coeloconic; and (3) multipourous clavate coleoconic. In addition; five subtypes of trichoid sensillae were found on the larval body: (1) long, (2) short, (3) curved long, (4) brush-like, and (5) weakly brush-like. The caudal filaments located on the last abdominal segment were recognized as long trichoid sensillae. We observed pores on the surface of the clavate coelonic sensillae and on the caudal filaments that presumably function as chemoreceptors. The larvae of the two species show similarities in the lobular-form antennae of L1 larvae, which changes to digitiform in second instar (L2), L3, and L4. This study demonstrated that the external surface of the eggs and larvae of Lu. intermedia and Lu. whitmani are morphologically similar, but they can be distinguished by details in the microanatomy observed by scanning electron microscopy.