Oxidative stress‐induced alterations in seminal plasma antioxidants: Is there any association with keap1 gene methylation in human spermatozoa?

Kelch‐like ECH‐associated protein 1 (keap1)‐nuclear factor‐erythroid 2‐related factor 2 (Nrf2) pathway is one of the master regulators of cellular defence against oxidative stress. Epigenetic alterations like hypermethylation of keap1 gene impair keap1‐Nrf2 system in several oxidative stress–associated diseases. The objective of this study was to evaluate the epigenetic status of keap1 in sperm DNA of normozoospermic subjects, having different levels of reactive oxygen species (ROS) in seminal plasma. Semen samples were obtained from 151 apparently healthy male partners of couples who attended the Avicenna infertility clinic. Samples were categorised into four groups according to their ROS levels: group A (n = 39, ROS < 20 RLU/s per 10⁶ spermatozoa), group B (n = 38, 20 ≤ ROS < 40 RLU/s per 10⁶ spermatozoa), group C (n = 31, 40 ≤ ROS < 60 RLU/s per 10⁶ spermatozoa) and group D; (n = 43, ROS ≥ 60 RLU/s per 10⁶ spermatozoa). Keap1 methylation status was assessed using methylation‐specific PCR along with seminal total antioxidant capacity. The results showed no significant alterations in keap1 methylation in any groups, whereas the total antioxidant capacity enhanced with increasing levels of ROS exposure. These results indicate that keap1 was not methylated during ROS elevation and oxidative stress, suggesting that the cells have adopted other mechanisms to elevate antioxidant level.     

Can thrombin‐activated platelet releasate compensate the age‐induced decrease in cell proliferation of MSC?

Mesenchymal progenitor cells (MSCs) are promising for cell‐based regeneration therapies. In elderly patients a reduced proliferation of MSCs has been described. Platelet‐rich plasma (PRP) contains important factors necessary for osteogenic regeneration. The aim of this study was to find out whether the age‐induced decrease in cell proliferation can be compensated by the use of supernatant of centrifuged, activated PRP (tPR). MSCs of donors of three age groups (A: young, 14–16 years, B: middle age, 36–46 years, C: older, 74–83 years) were expanded with 20% FCS alone or supplemented with thrombin‐activated platelet releasate (tPR) (1%, 2.5%, and 5%) or platelet‐poor plasma (PPP 5%). Cell proliferation and differentiation was measured on days 0, 3, and 7. Proliferation increased significantly in groups A and B with tPR, and non‐significantly in group C. The generation times of MSCs of elderly patients were significantly increased in group C compared to groups A and B. Addition of 1% or 2.5% tPR significantly reduced population doubling times of all age groups. Adding tPR stimulates the proliferation rate of MSCs independent of donor age. For juvenile and middle‐aged patients this influence was significant. Cells differentiation into osteoblasts was not influenced by addition of tPR. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1786–1795, 2013     

Can color doppler predict the uniformity of HIFU‐induced prostate tissue destruction?

BACKGROUND: Tissue blood perfusion influences the results of some hyperthermia and thermotherapy procedures, but its role in the outcome of prostate cancer treatment by high-intensity focused ultrasound (HIFU) has not been evaluated yet. We evaluated preoperative prostate color Doppler as a predictor of the efficacy of HIFU treatment. METHODS: Thirty-five patients underwent pre- and post-contrast color Doppler examination of the prostate before HIFU treatment. Specific software was used to calculate, on color Doppler images, the color pixel density (CPD), and the specific flow (SF, i.e., mean velocity x CPD) in different regions of interest. Post-treatment sextant biopsies were obtained in 31 patients, 5.8 +/- 2.8 months after HIFU treatment. RESULTS: No significant correlation was found between the uniformity of HIFU-induced tissue destruction observed on control biopsies and the pre-treatment CPD/SF values in any region of interest, either before or after contrast injection. On the other hand, history of radiation therapy was significantly associated with homogeneous tissue destruction and history of hormone therapy was significantly associated with incomplete tissue destruction. CONCLUSIONS: Color Doppler cannot predict the uniformity of HIFU-induced tissue destruction. History of radiation therapy was found to be a factor of favorable prognosis and history of hormone therapy was found to be a factor of poor prognosis in our population.     

Do pre‐irradiation dental extractions reduce the risk of osteoradionecrosis of the mandible?

BACKGROUND: This study was done to determine if pre-radiotherapy (pre-RT) dental extractions reduce the risk of osteoradionecrosis (ORN). METHODS: Between 1987 and 2004, 413 patients with oropharyngeal carcinomas were treated with definitive RT at the University of Florida. Dentate patients underwent pretreatment dental evaluation. Teeth in the RT field were usually extracted if thought to have poor long-term prognosis from dental disease. The endpoint was > or = grade 2 ORN using a modified staging system. Patients were excluded for local recurrence, additional RT above the clavicles, or head and neck surgery besides neck dissection. RESULTS: ORN rates were as follows: edentulous, <1%; teeth in-field with pre-RT extractions, 15%; and teeth in-field without pre-RT extractions, 9%. Patients with poor in-field teeth and pre-RT extractions had a higher 5-year incidence of ORN than those who did not have pre-RT extractions (16% vs 6%, p = .48). Likewise, for those with in-field teeth in good condition and pre-RT extractions, the 5-year ORN incidence was higher than for those who did not undergo extractions (15% vs 2%, p = .42). Multivariate analysis revealed increased ORN risk with doses of >70 Gy, once-daily fractionation, or brachytherapy. CONCLUSION: Pre-RT extractions do not appear to reduce the risk of ORN.     

Short‐term administration of prulifloxacin in patients with nonmuscle‐invasive bladder cancer: an effective option for the prevention of bacillus Calmette‐Guérin‐induced toxicity?

OBJECTIVE

To determine whether the new fluoroquinolone prulifloxacin might improve tolerance to Bacillus Calmette‐Guérin (BCG) intravesical therapy in patients with bladder cancer.

PATIENTS AND METHODS

A series of 72 patients with intermediate‐ or high‐risk nonmuscle‐invasive bladder cancer were enrolled in this prospective, randomized, open‐label, controlled clinical trial performed at a single tertiary care institution. After complete transurethral resection, patients were randomized to receive induction treatment with BCG and three capsules of prulifloxacin 600 mg or no prophylactic treatment (control group). Adverse events (AEs) were self‐recorded by the patients after each instillation and classified by the investigator according to a classification grid considering account duration and intensity. Cystoscopy findings at 3 and 6 months were also recorded.

RESULTS

There was no significant difference in baseline symptoms between the groups. Overall, there was a significant decrease in the percentage of patients with at least one AE between instillations in prulifloxacin‐treated group. The proportion of patients with moderate to severe AEs after the fourth instillation was significantly less in the prulifloxacin‐treated group. There was a significant effect of prulifloxacin on the need for anti‐tuberculosis treatment. More patients in the control group stopped or delayed the full induction course of BCG instillations (34% vs 19%, P = 0.04). Recurrence rates were not affected by prulifloxacin treatment.

CONCLUSION

Prulifloxacin reduces the incidence of moderate to severe AEs from BCG intravesical therapy in patients with nonmuscle‐invasive bladder cancer, improving compliance to the induction BCG course. These preliminary findings warrant further clinical research.     

Do NK Cells Contribute to the Pathophysiology of Transplant‐Associated Thrombotic Microangiopathy?

Transplant‐associated thrombotic microangiopathy (TA‐TMA) is a life‐threatening complication caused by the aggregation of platelets exposed to the thrombogenic subendothelial matrix of injured endothelial cells. Here, we present a case of a patient transplanted for idiopathic aplastic anemia with a T‐cell depleted hematopoietic stem cell graft from an HLA‐C mismatched unrelated donor. At day 7 posttransplant, she suffered from acute renal failure with hematuria. The presence of numerous schistocytes, an increased level of lactate dehydrogenase and a renal biopsy with multiple vascular injuries confirmed the diagnosis of severe TA‐TMA. At day 14, she developed graft versus host disease and died 7 months posttransplantation of multiorgan failure. At day 15, we observed a sizable population of natural killer (NK) cells in the peripheral blood, the number of which reached 0.8 G/L at 4 months posttransplant. Most NK cells lacked inhibitory killer immunoglobulin‐like receptors (KIR) specific for the KIR‐ligands expressed in the patient. NK cells were also abundantly present in pericardial and pleural fluids and had invaded the kidney, where they colocalized with the renal vasculopathy. Because there are several mechanisms through which NK cells and platelets can activate each other reciprocally, it is conceivable that NK cells contribute to TA‐TMA and its progression.     

Inflammatory mechanisms of ventilator‐induced lung injury: a time to stop and think?

Ventilator‐induced lung injury (VILI) is the phenomenon by which mechanical ventilation exacerbates lung injury in critically ill patients. It is particularly relevant for those suffering from acute respiratory distress syndrome, in which the iatrogenic injury caused by VILI contributes to their high mortality. The innate immune system is widely accepted to play an important role during VILI. However, it is our belief that the identification of inflammatory mediators that are crucial during VILI, and thus may make useful therapeutic targets, has become obscured by the wide variety of pre‐clinical animal models of VILI reported in the literature. We aim here to summarise some of our work addressing this issue over the last 10 years, and thus, we hope, make interpretation of a convoluted field a little clearer.     

Do penile haemodynamics change in the presence of hydrogen sulphide (H2S) donor in metabolic syndrome‐induced erectile dysfunction?

Erectile dysfunction (ED) is defined in relation to the metabolic syndrome (metS). Hydrogen sulphide (H₂S), a gasotransmitter, has been revealed to get involved in hypertension, insulin secretion and regulation of vascular tone especially in erectile physiology. This study aimed to investigate the effect of H₂S on metS‐induced ED. Animals were divided into two groups as control and metS, which were fed with standard diet or 60% high‐fructose diet for 10 weeks respectively. The metS model was evaluated with biochemical analyses, waist circumference/tibia length ratio and HOMA index. Penile hemodynamic parameters were evaluated by the measurement of intracavernous pressure/mean arterial pressure ratio during cavernous nerve stimulation in the presence and absence of intracavernous injection of NaHS (100 μg/50 μl) and its control 0.9%NaCl (50 μl) in both groups. H₂S levels were measured in penile tissues by methylene blue assay. H₂S levels were significantly decreased in the penile tissues of the metS group. Decreased intracavernous pressure/mean arterial pressure ratio improved after intracavernous administration of NaHS in the metS group. These results suggest the significant role of H₂S in the metS‐induced erectile dysfunction that could be a new therapeutic target.