Nano-TiO2 particles impair adhesion of airway epithelial cells to fibronectin

Titanium dioxide engineered nanoparticles (nano-TiO₂) are widely used in the manufacturing of a number of products. Due to their size (<100 nm), when inhaled they may be deposited in the distal lung regions and damage Clara cells. We investigated the mechanisms by which short-term (1-h) incubation of human airway Clara-like (H441) cells to nano-TiO₂ (6 nm in diameter) alters the ability of H441 cells to adhere to extracellular matrix. Our results show that 1 h post-incubation, there was a 3-fold increase of extracellular H₂O₂, increased intracellular oxidative stress as demonstrated by 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) oxidation, and a 5-fold increase of phosphor-ERK1/2 as measured by Western blotting. These changes were accompanied by a 25% decrease of H441 adherence to fibronectin (p < 0.05 compared to vehicle incubated H441 cells). Pretreatment with the ERK1/2 inhibitor U0126 for 3 h, partially prevented this effect. In conclusion, short-term exposure of H441 cells to nano-TiO₂ appears to reduce adherence to fibronectin due to oxidative stress and activation of ERK1/2.     

Urinary Diversion Following Cystectomy

Urinary diversion is an essential component of the surgical procedure after cystectomy. Replacement with an orthotopic ileal neobladder should be the first choice if external urethral sphincter sparing surgery is possible, offering good long-term function, quality of life and patient's acceptance with few complications.The possible use of a variety of alternative intestinal segments widen the horizon of the reconstructive surgeon, allowing him or her to be prepared for unusual cases.Contraindications for orthotopic neobladder reconstruction include tumour location, reduced renal, liver, intestinal function, intellectual ability and physical handicaps.It is therefore important to custom tailor the appropriate mode of diversion for individual patients with a variety of options available, including ureterocutaneous stomas, intestinal conduits and continent catheterizable reservoirs and orthotopic neobladders. All these techniques require detailed knowledge of the possible metabolic problems encountered by using gastrointestinal segments and how they react in contact with urine. Modern surgical techniques such as nerve sparing surgery have the ability to preserve postoperative continence with voluntarily micturition as well as sexual function. In addition, preliminary experimental data hold great promise that the “off shelf” bladder substitute may become a technique of choice in the future, avoiding common problems encountered using current technqiues.     

Use of the Crossboss catheter in coronary chronic total occlusion due to in-stent restenosis

We describe treatment of six chronic total occlusions due to in-stent restenosis with the CrossBoss catheter (BridgePoint Medical, Minneapolis, Minnesota). The CrossBoss catheter allowed successful CTO crossing in 5 of 6 lesions (83%): in 50% the catheter entered the distal true lumen, whereas in 33% a wire was required for distal true lumen crossing. No complications were observed. Use of the CrossBoss catheter can facilitate treatment of coronary chronic total occlusions due to in-stent restenosis.     

Evaluation of markers out of the steroid profile for the screening of testosterone misuse. Part II: Intramuscular administration

In the fight against doping, the introduction of alternative markers to the steroid profile can be considered as an effective approach to improve the screening capabilities for the detection of testosterone (T) misuse. The aim of this study was to evaluate the potential of several T metabolites (cysteinyl conjugated and glucuronoconjugated resistant to enzymatic hydrolysis) to detect both the transdermal and the intramuscular administration of T. In Part I of the study, we studied the potential of these metabolites for the detection of T transdermal administration. Results revealed that resistant glucuronides can be a suitable complement to the current steroid profile. In this, Part II, dedicated to the intramuscular administration, we studied the potential of cysteinyl conjugated, resistant glucuronoconjugated and 1‐cyclopentenoylglycine (1‐CPG) for the detection of a single intramuscular injection of T cypionate. Possible differences in the excretion profile of all markers were explored between individuals with low basal (n=6) and medium basal (n=6) values of the testosterone/epitestosterone ratio (T/E). The results showed that all tested markers presented low intra‐individual stability in basal conditions. Despite this, all glucuronoconjugated markers and 1‐CPG, but not the cysteinyl conjugated markers, provided detection windows that were similar or longer than those obtained by markers currently included in the steroid profile. Based on the results obtained from the 2 parts of this study and from previously reported data, the potential applicability and the limitations of including these markers in the steroid profile are discussed.     

Cytoreductive Nephrectomy in Patients with Synchronous Metastases from Renal Cell Carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium

Background

The benefit of cytoreductive nephrectomy (CN) for overall survival (OS) is unclear in patients with synchronous metastatic renal cell carcinoma (mRCC) in the era of targeted therapy.

Objective

To determine OS benefit of CN compared with no CN in mRCC patients treated with targeted therapies.

Design, setting, and participants

Retrospective data from patients with synchronous mRCC (n = 1658) from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) were used to compare 982 mRCC patients who had a CN with 676 mRCC patients who did not.

Outcome measurements and statistical analysis

OS was compared and hazard ratios (HRs) adjusted for IMDC poor prognostic criteria.

Results and limitations

Patients who had CN had better IMDC prognostic profiles versus those without (favorable, intermediate, or poor in 9%, 63%, and 28% vs 1%, 45%, and 54%, respectively). The median OS of patients with CN versus without CN was 20.6 versus 9.5 mo (p < 0.0001). When adjusted for IMDC criteria to correct for imbalances, the HR of death was 0.60 (95% confidence interval, 0.52–0.69; p < 0.0001). Patients estimated to survive <12 mo may receive marginal benefit from CN. Patients who have four or more of the IMDC prognostic criteria did not benefit from CN. Data were collected retrospectively.

Conclusions

CN is beneficial in synchronous mRCC patients treated with targeted therapy, even after adjusting for prognostic factors. Patients with estimated survival times <12 mo or four or more IMDC prognostic factors may not benefit from CN. This information may aid in patient selection as we await results from randomized controlled trials.

Patient summary

We looked at the survival outcomes of metastatic renal cell carcinoma patients who did or did not have the primary tumor removed. We found that most patients benefited from tumor removal, except for those with four or more IMDC risk factors.     

Quantification of periaortic adipose tissue in contrast-enhanced CT angiography: technical feasibility and methodological considerations

The International Journal of Cardiovascular Imaging - To examine the feasibility of the quantification of abdominal periaortic fat tissue (PaFT) (tissue within −&nbsp;45 to...     

Effects of chronic partial outlet obstruction on blood flow and oxygenation of the rat bladder

PURPOSE: Experimental partial bladder outlet obstruction in rats and rabbits drives the bladder through 3 sequential responses, referred to as hypertrophy, compensation and decompensation. The hypertrophy phase, which is a period of rapid bladder growth, has previously been shown to be accompanied by a significant increase in bladder blood flow in rats and rabbits in a manner that likely supports the bladder cell growth process. However, chronic periods of obstruction in the rabbit have been shown to reduce significantly bladder blood flow, especially to the detrusor smooth muscle, corresponding with a loss of bladder contractile function or decompensation in these animals. We determined the effects of chronic 1 to 4-week partial outlet obstruction on rat bladder blood flow and directly correlated them with hypoxia in the rat bladder. MATERIALS AND METHODS: Rats underwent surgical partial bladder outlet obstruction under anesthesia. At weekly intervals after surgery relative blood flow to the bladder and spleen was measured by a fluorescent microsphere infusion technique. Sham operated rats were also studied 2 and 4 weeks following surgery. In a second experiment groups of similarly obstructed rats were treated with Hypoxyprobe-1 (Natural Pharmacia International, Inc., Research Triangle Park, North Carolina), a chemical probe for hypoxia, 3 days, 1 and 2 weeks after partial bladder outlet obstruction. The bladders were subsequently fixed and immunostained using a monoclonal antibody that detects Hypoxyprobe-1 adducts that are selectively formed in hypoxic cells. RESULTS: Neither bladder weight nor bladder relative blood flow was affected by sham surgery. Likewise, control and sham obstructed rat bladders were found to be free of Hypoxyprobe-1 reactive areas. In contrast, obstructed rats had significantly increased bladder weight at all time points. Relative weight of the obstructed rat bladders indicates the response to mild-moderate obstruction. Bladder relative blood flow in obstructed rats was significantly elevated 1 and 2 weeks after partial bladder outlet obstruction but it returned to almost control levels by 3 and 4 weeks. Hypoxyprobe-1 staining demonstrated a sequential transition of hypoxia from bladder mucosa and submucosal regions at 3 days to muscularis and serosal fibroblasts 1 week and finally to smooth muscle cells by 2 weeks after obstruction. CONCLUSIONS: In contrast to the rabbit model, global blood flow in the mild-moderate chronically obstructed rat bladder was found to be higher or nearly equivalent to blood flow in unobstructed control rat bladders. However, even in the presence of normal or above normal blood flow focal regions of hypoxia were still observed in obstructed rat bladders and these regions changed with time. These results provide a reason to understand better why rats are more resistant to the onset of bladder decompensation than rabbits and support the concept that hypoxia is involved in bladder remodeling as well as in progressive functional impairment of the bladder after partial bladder outlet obstruction.     

Does the prostatic vascular system contribute to the development of benign prostatic hyperplasia?

Benign prostatic hyperplasia (BPH) is a disease condition characterized by abnormal prostate growth in conjunction with distinct lower urinary tract symptoms. This paper considers the extent to which the prostatic vascular system contributes to normal prostate growth control as well as whether abnormal blood flow patterns in the aging prostate gland might lead to hypoxia-stimulated prostate growth. This relationship is posited from accumulated research that suggests the prostatic vascular system is a primary androgen action target and other research demonstrating the diverse effects of hypoxia in eliciting cell death or cell growth responses. This hypothesis is further supported by the coincidental clinical finding that the presence of cardiovascular disease conditions are among the general risk factors for the development of BPH, and that cardiovascular-active drugs can be used for the treatment of BPH symptoms. This hypothesis has major implications for our understanding of the etiology of BPH, as well as for the development of new and better treatments for this extremely common condition.     

Effect of hydrogen bonding interactions on the release mechanism of felodipine from nanodispersions with polyvinylpyrrolidone.

Solid dispersion systems are widely investigated for the dissolution enhancement of poorly water soluble drugs. Nevertheless, very limited commercial use has been achieved due to the poor predictability of such systems caused by the lack of a basic understanding of the dissolution optimization mechanism. In the present study an investigation of the release mechanism is performed for solid dispersion systems composed by polyvinylpyrrolidone (PVP) and felodipine (FEL), based on a correlation of their hydrophilicity with the intensity of interactions. The existing interactions were evaluated by using NMR and UV spectroscopy while molecular simulation techniques were also enabled. It was found that the interactions that take place correspond to the creation of hydrogen bonds. The correlation between the intensity of interactions and the concentration of PVP in the matrix showed a sigmoid function. The interactions are impressively increased for polymer concentration exceeding 75% (w/w). This phenomenon was well explained by using the molecular simulation technique. A similar sigmoid pattern was found for the function between dissolution profiles and polymer concentration in the matrix, indicating that the intensity of interactions promotes the dissolution enhancement. Investigation of the solubility and the particle size distribution of FEL in the binary system appeared to have similar behaviour indicating that the interactions affect the release profile through these two factors. The hydrophilicity of PVP does not significantly affect this enhancement as the contact angle was found to be linear to PVP concentration. Microscopic observation of the dissolution behaviour showed that FEL remains in fine dispersion in aqueous solution, verifying the release mechanism.