Cone-beam computed tomography analysis of cemento-osseous dysplasia-induced changes in adjacent structures in a Brazilian population

Clinical Oral Investigations - To describe the effects of cemento-osseous dysplasia (COD) on anatomical structures. CBCT scans were retrospectively selected from a database of individuals who...     

Light–dependent effects of zinc protoporphyrin IX on endothelium–dependent relaxation resistant to NoM–nitro–L–arginine

Acetylcholine (ACh) induces an Nω–nitro–L–arginine (L–NOARG)–resistant relaxation and hyperpolarization in the rat isolated hepatic artery. The possibility that carbon monoxide (CO) produced by haem oxygenase (HO) is an endogenous mediator of this response was investigated. Exogenously applied CO evoked a concentration–dependent relaxation, and the CO ‘scavenger’ oxyhaemoglobin (10μM) reduced the maximum ACh–induced relaxation by 25%. The HO inhibitor zinc protoporphyrin IX (ZnPP, 10 μM virtually abolished the ACh–induced relaxation in experiments carried out under ordinary light conditions. However, ZnPP did not affect the ACh–induced relaxation under dark conditions, even after exposure of ZnPP to intense light before the preincubation period. Biliverdin (0.1 mM), a feedback inhibitor of HO, was also inactive under dark conditions, and the HO substrate haematin (0.1 mM) did not facilitate the ACh–induced relaxation. The relaxation induced by the nitric oxide (NO) donor 3–morpholino–sydnonimin was not affected by ZnPP in the presence of light. However, ZnPP inhibited the relaxation evoked by the potassium channel opener levcromakalim and the tonic component of the contractile response to 60 mM potassium, indicating that ZnPP has effects distinct from HO inhibition in the presence of light. ZnPP should therefore be protected from light when used to inhibit HO–mediated CO formation. The results do not suggest that CO generated by HO mediates the endothelium–dependent, L–NOARG–resistant relaxation induced by ACh in the rat hepatic artery.     

A rapid and simple preparation of amphotericin B-loaded bacterial magnetite nanoparticles

Magnetotactic bacteria, which synthesize biological magnetite nanoparticles (BMs), are the main microbial source of magnetic nanomaterials. Although the use of BMs has been explored in vitro and in vivo for new anticancer formulations, targeted treatments of fungal and parasitic diseases would also benefit from biogenic magnetic nanoformulations. Due to the necessity of new formulations of amphotericin B, we developed a magnetic-nanoparticle based conjugate of this drug using bacterial magnetosomes. Different amphotericin B preparations were obtained using BMs extracted from Magnetovibrio blakemorei strain MV-1^T as well as glutaraldehyde and poly-l-lysine as linking reagents. The highest capture efficiencies and drug loadings were achieved using 0.1‰ poly-l-lysine as the only linking agent (52.7 ± 2.1%, and 25.3 ± 1.9 μg per 100 μg, respectively) and 0.1‰ poly-l-lysine and glutaraldehyde 12.5% (45.0 ± 5.4%, and 21.6 ± 4.9 μg per 100 μg, respectively). Transmission electron microscopy and infrared spectroscopy analyses confirmed the association of amphotericin B to the BM surface. Moreover, controlled drug release from these nanoparticles was achieved by applying an alternating magnetic field. In this condition the release of amphotericin B in PBS increased approximately four-fold as compared to the release under standard conditions with no applied magnetic fields. Hence, the functionalization of BMs with amphotericin B produces stable nanoformulations with a controllable drug release profile, thus, enabling its potential in the treatment of fungal and parasitic diseases.

Three-dimensional representation of amphotericin B molecules bound to magnetosomes derived from Magnetovibrio blakemorei strain MV-1^T. Drug molecules are electrostatically adsorbed onto nanoparticles coated with positively charged poly-l-lysine.     

Associations between ventilator settings during extracorporeal membrane oxygenation for refractory hypoxemia and outcome in patients with acute respiratory distress syndrome: a pooled individual patient data analysis

Purpose

Extracorporeal membrane oxygenation (ECMO) is a rescue therapy for patients with acute respiratory distress syndrome (ARDS). The aim of this study was to evaluate associations between ventilatory settings during ECMO for refractory hypoxemia and outcome in ARDS patients.

Methods

In this individual patient data meta-analysis of observational studies in adult ARDS patients receiving ECMO for refractory hypoxemia, a time-dependent frailty model was used to determine which ventilator settings in the first 3 days of ECMO had an independent association with in-hospital mortality.

Results

Nine studies including 545 patients were included. Initiation of ECMO was accompanied by significant decreases in tidal volume size, positive end-expiratory pressure (PEEP), plateau pressure, and driving pressure (plateau pressure ? PEEP) levels, and respiratory rate and minute ventilation, and resulted in higher PaO₂/FiO₂, higher arterial pH and lower PaCO₂ levels. Higher age, male gender and lower body mass index were independently associated with mortality. Driving pressure was the only ventilatory parameter during ECMO that showed an independent association with in-hospital mortality [adjusted HR, 1.06 (95 % CI, 1.03–1.10)].

Conclusion

In this series of ARDS patients receiving ECMO for refractory hypoxemia, driving pressure during ECMO was the only ventilator setting that showed an independent association with in-hospital mortality.

     

Pulmonary artery rupture induced by a pulmonary artery catheter: a case report and review of the literature

Placement and use of pulmonary artery catheters (PACs) carry potential risks. The authors describe a case of a patient who developed massive hemoptysis after placement of a PAC that caused a rupture of the pulmonary artery with pseudoaneurysm formation. Treatment was successfully achieved with transcatheter coil embolization. Pulmonary artery rupture and pseudoaneurysm formation are among the most serious complications of PAC use because of the associated risk of mortality. Patients with this complication may be asymptomatic or may present with variable amounts of hemoptysis immediately or days after using a PAC. The gold standard diagnostic test is pulmonary angiography, and the treatment of choice for most patients is transcatheter embolization. Physicians and other health care personnel handling these catheters should be familiar with the specific PAC balloon's inflation limits to avoid complications that may injure the patient.     

Analysis of postural control and muscular performance in young and elderly women in different age groups

BACKGROUND:

muscle strength and power are two factors affecting balance. The impact of muscle strength and power on postural control has not been fully explored among different age strata over sixty.

OBJECTIVES:

the aim of the present study was to assess the muscle strength and power of elderly women in different age groups and determine their correlation with postural control.

METHOD:

eighty women were divided into four groups: the young 18-30 age group (n=20); the 60-64 age group (n=20); the 65-69 age group (n=20); and the 70-74 age group (n=20). The participants underwent maximum strength (one repetition maximum or 1-RM) and muscle power tests to assess the knee extensor and flexor muscles at 40%, 70%, and 90% 1-RM intensity. The time required by participants to recover their balance after disturbing their base of support was also assessed.

RESULTS:

the elderly women in the 60-64, 65-69, and 70-74 age groups exhibited similar muscle strength, power, and postural control (p>0.05); however, these values were lower than those of the young group (p<0.05) as expected. There was a correlation between muscle strength and power and the postural control performance (p<0.05).

CONCLUSION:

despite the age difference, elderly women aged 60 to 74 years exhibited similar abilities to generate strength and power with their lower limbs, and this ability could be one factor that explains the similar postural control shown by these women.     

Hamstrings‐to‐quadriceps strength and size ratios of male professional soccer players with muscle imbalance

The aim of this study was to determine the correlation between the concentric hamstrings/quadriceps muscle strength (H_con:Q_con) and cross‐sectional area ratios (H_csa:Q_csa) in professional soccer players with H_con:Q_con imbalance. Nine male professional soccer players (25·3 ± 4·1 years) performed five maximal concentric contractions of the knee extensors (KE) and flexors (KF) at 60 s^?1 to assess H_con:Q_con. The test was performed using the dominant (preferred kicking), and non‐dominant limb with a 5‐min recovery period was allowed between them. Only players with H_con:Q_con < 0·60 (range: 0·45–0·59) in both limbs were included in this study. The muscle cross‐sectional area (CSA) of KE and KF was determined by magnetic resonance imaging. The correlations between H_con:Q_con and H_csa:Q_csa in the dominant leg (r = ?0·33), non‐dominant leg (r = 0·19) and in the both legs combined (r = 0·28) were not statistically significant (P>0·05). Thus, the H_con:Q_con seems not to be determined by H_csa:Q_csa in professional soccer players with H_con:Q_con imbalance.     

Preservation of urine samples for metabolic evaluation of stone-forming patients

Metabolic evaluation of stone-forming (SF) patients is based on the determination of calcium, oxalate, citrate, uric acid and other parameters in 24-h urine samples under a random diet. A reliable measurement of urinary oxalate requires the collection of urine in a receptacle containing acid preservative. However, urinary uric acid cannot be determined in the same sample under this condition. Therefore, we tested the hypothesis that the addition of preservatives (acid or alkali) after urine collection would not modify the results of those lithogenic parameters. Thirty-four healthy subjects (HS) were submitted to two non-consecutive collections of 24-h urine. The first sample was collected in a receptacle containing hydrochloric acid (HCl 6 N) and the second in a dry plastic container, with HCl being added as soon as the urine sample was received at the laboratory. Additionally, 34 HS and 34 SF patients collected a spot urine sample that was divided into four aliquots, one containing HCl, another containing sodium bicarbonate (NaHCO₃ 5 g/l), and two others in which these two preservative agents were added 24 h later. Urinary oxalate, calcium, magnesium, citrate, creatinine and uric acid were determined. Urinary parameters were also evaluated in the presence of calcium oxalate or uric acid crystals. Mean values of all urinary parameters obtained from previously acidified 24-h urine samples did not differ from those where acid was added after urine collection. The same was true for spot urine samples, with the exception of urinary citrate that presented a slight albeit significant change of 5.9% between samples in HS and 3.1% in SF. Uric acid was also not different between pre- and post-alkalinized spot urine samples. The presence of crystals did not alter these results. We concluded that post-delivery acidification or alkalinization of urine samples does not modify the measured levels of urinary oxalate, calcium, magnesium, creatinine and uric acid, and that the change on citrate was not relevant, hence allowing all parameters to be determined in a single urine sample, thus avoiding the inconvenience and cost of multiple 24-h urine sample collections.