Nano-topography: Quicksand for cell cycle progression?

The 3-D spatial and mechanical features of nano-topography can create alternative environments, which influence cellular response. In this paper, murine fibroblast cells were grown on surfaces characterized by protruding nanotubes. Cells cultured on such nano-structured surface exhibit stronger cellular adhesion compared to control groups, but despite the fact that stronger adhesion is generally believed to promote cell cycle progression, the time cells spend in G1 phase is doubled. This apparent contradiction is solved by confocal microscopy analysis, which shows that the nano-topography inhibits actin stress fiber formation. In turn, this impairs RhoA activation, which is required to suppress the inhibition of cell cycle progression imposed by p21/p27. This finding suggests that the generation of stress fibers, required to impose the homeostatic intracellular tension, rather than cell adhesion/spreading is the limiting factor for cell cycle progression. Indeed, nano-topography could represent a unique tool to inhibit proliferation in adherent well-spread cells.     

Caspofungin in vitro and in vivo activity against Brazilian Pythium insidiosum strains isolated from animals

OBJECTIVES: The present study evaluated the susceptibility of 27 clinical isolates of Pythium insidiosum to caspofungin in vitro and correlated the results with the therapeutic response in vivo in rabbits with experimental pythiosis. METHODS: The macrodilution method was performed in accordance with the CLSI document M38-A technique. Three reading criteria for MICs were adopted: MIC0, MIC1 and MIC2 (100%, 90% and 50% growth inhibition, respectively). The minimum fungicidal concentration was also determined. Ten rabbits inoculated with viable P. insidiosum zoospores were divided into two groups: group 1 (control) and group 2 (treated with caspofungin at a dosage of 1 mg/kg/day for 20 consecutive days). RESULTS: Of the isolates 51.8% had an MIC0 of 64 mg/L, 88.8% of isolates had an MIC1 between 8 and 64 mg/L and 62.9% of isolates had a minimum fungicidal concentration of 64 mg/L. In the in vivo assay, growth of subcutaneous lesions reduced during treatment, but rapidly resumed when treatment was stopped. CONCLUSIONS: The results showed that caspofungin has limited fungistatic activity against P. insidiosum. This work is the first study to analyse the susceptibility of this oomycete to inhibitors of beta-glucans of the cellular wall.     

Incidence of tacrolimus-induced gingival overgrowth in the absence of calcium channel blockers: a short-term study

AIM: The aim of this study was to determine the incidence and severity of gingival overgrowth (GO) induced by tacrolimus (Tcr) compared with ciclosporin A (CiA) in the absence of calcium channel blockers (CCB) in renal transplant recipients. METHODS: Forty patients (20 Tcr and 20 CiA) were evaluated before and 30 and 90 days after kidney transplantation. Demographic (age, gender) and periodontal parameters were recorded for all patients. Patients taking CCB at any time during the study were excluded from the investigation. RESULTS: The mean GO score was significantly lower (p=0.014) in the Tcr group (6.4%) compared with the CiA group (17.9%) after 90 days of immunosuppressive therapy. At 90 days post-transplant, clinically significant GO was observed in four patients of the CiA group and in two of the Tcr group. This difference was not statistically significant (0.66). CONCLUSION: No significant difference in the incidence of clinically significant GO was observed between the CiA and Tcr groups up to 90 days of immunosuppressive therapy.     

The effect of a single irradiation of low-level laser on nipple pain in breastfeeding women: a randomized controlled trial

Lasers in Medical Science - Photobiomodulation with low-level laser therapy (PBM-LLLT) has been introduced as a new tool to relieve nipple pain and repair nipple damage in breastfeeding women;...     

Milestone Achievement and Neurodevelopment of Rural Amazonian Toddlers (12 to 24 Months) with Different Methylmercury and Ethylmercury Exposure

Neurological outcomes (Gesell development schedules [GDS]), age of walking, and age of talking were studied in 299 toddlers (12 to 24 mo) in relation to environmental (fish consumption and tin mining) exposure. Exposure to fish methylmercury (MeHg) consumption and iatrogenic ethylmercury (EtHg) in Thimerosal-containing vaccines (TCV) was quantified in toddlers from two rural villages (n?=?91, Itapuã; n?=?218, Bom Futuro) respectively populated by fishers and cassiterite miners. Median total hair Hg (HHg) concentrations of infants from Itapuã (3.5 μg/g) were significantly higher than those of infants from Bom Futuro (2.2 μg/g). Median EtHg exposure from TCV was also significantly higher in toddlers from Itapuã (137.5 μg) than in those from Bom Futuro (112.5 μg). There were no significant differences between groups for any of the Gesell schedules; however, there were proportionally more compromised toddlers (GDS < 70) in Itapuã than Bom Futuro. Median age of talking was not statistically different but median age of walking was significantly higher in Bom Futuro. In toddlers from both villages, of fishers and miners, HHg concentrations were significantly correlated with family fish consumption. A logistic regression model was applied to all infants after classification into two groups: above or below the median Gesell schedules. Overall, there was no distinctive pattern of neurodevelopment associated with either HHg or EtHg exposure; however, nutritional status was significantly associated with GDS. In conclusion, milestone achievement was delayed in toddlers from tin-ore mining communities. Despite significantly higher exposure to both forms of organic Hg (MeHg from maternal fish consumption, and EtHg from TCV) in toddlers from the fishing village, significant differences were seen only among the proportions of most severely affected toddlers (GDS < 70).     

UPPER ESOPHAGEAL SPHINCTER RESTING PRESSURE VARIES DURING ESOPHAGEAL MANOMETRY

Background

The upper esophageal sphincter is composed of striated muscle. The stress of intubation and the need to inhibit dry swallows during an esophageal manometry test may lead to variations in basal pressure of this sphincter. Upper esophageal sphincter is usually only studied at the final part of the test. Was observed during the performance of high resolution manometry that sphincter pressure may vary significantly over the course of the test.

Aim

To evaluate the variation of the resting pressure of the upper esophageal sphincter during high resolution manometry.

Methods

Was evaluated the variation of the basal pressure of the upper esophageal sphincter during high resolution manometry. Were reviewed the high resolution manometry tests of 36 healthy volunteers (mean age 31 years, 55% females). The basal pressure of the upper esophageal sphincter was measured at the beginning and at the end of a standard test.

Results

The mean time of the test was eight minutes. The basal pressure of the upper esophageal sphincter was 100 mmHg at the beginning of the test and 70 mmHg at the end (p<0.001). At the beginning, one patient had hypotonic upper esophageal sphincter and 14 hypertonic. At the end of the test, one patient had hypotonic upper esophageal sphincter (same patient as the beginning) and seven hypertonic upper esophageal sphincter.

Conclusion

A significant variation of the basal pressure of the upper esophageal sphincter was observed in the course of high resolution manometry. Probably, the value obtained at the end of the test may be more clinically relevant.     

Effectiveness of the endotracheal tube cuff on the trachea: physical and mechanical aspects

Introduction

The inflation pressure of the endotracheal tube cuff can cause ischemia of the tracheal mucosa at high pressures; thus, it can cause important tracheal morbidity and tracheal microaspiration of the oropharyngeal secretion, or it can even cause pneumonia associated with mechanical ventilation if the pressure of the cuff is insufficient.

Objective

In order to investigate the effectiveness of the RUSCH® 7.5 mm endotracheal tube cuff, this study was designed to investigate the physical and mechanical aspects of the cuff in contact with the trachea.

Methods

For this end, we developed an in vitro experimental model to assess the flow of dye (methylene blue) by the inflated cuff on the wall of the artificial material. We also designed an in vivo study with 12 Large White pigs under endotracheal intubation. We instilled the same dye in the oral cavity of the animals, and we analyzed the presence or not of leakage in the trachea after the region of the cuff after their deaths (animal sacrifice). All cuffs were inflated at the pressure of 30 cmH₂O.

Results

We observed the passage of fluids through the cuff in all in vitro and in vivo experimental models.

Conclusion

We conclude that, as well as several other cuff models in the literature, the RUSCH® 7.5 mm tube cuffs are also not able to completely seal the trachea and thus prevent aspiration of oropharyngeal secretions. Other prevention measures should be taken.