Folic acid induces acute renal failure (ARF) by enhancing renal prooxidant state

Systemic administration of folic acid (FA) in mice was used for studying the pathogenesis associated with acute renal failure (ARF). However, the mechanism by which FA induces ARF remains poorly understood. The present study therefore, was planned to investigate the effect of folic acid administration on prooxidant state and associated ultrastructural changes in renal tissue. Balb/c male mice of 4–6 weeks old were divided into control and two folic acid treatment groups (Groups A and B). The animals in group A were administered intraperitoneal injection of folic acid (100 mg kg^?1 body weight) for a period of 7 consecutive days while the animal in group B were administered a single intraperitoneal dose of folic acid (250 mg kg^?1 body weight). The renal tissues were collected and used for the analyses of lipid peroxidative indices and activities of antioxidant enzymes in renal tissues. To corroborate biochemical findings scanning electron microscopy (SEM) in renal tissue was studied. Folic acid treated animals demonstrated marked renal hypertrophy accompanied by severe impairment of renal function. Glutathione levels (GSH) and antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) levels were significantly decreased and LPO levels increased following FA treatment. SEM results further substantiated the observed biochemical changes as evident by severe inflammation in glomeruli, swelling in primary and secondary pedicels, blebbing in villi, and tremendous deprivation of erythrocytes (RBCs) in FA treated kidneys. The present study therefore suggests that acute administration of folic acid leads to the generation of oxidative stress and altered membrane architecture responsible for folic acid induced ARF.     

A Review of “Optimal Fallow Period” Guidance Across Canadian Jurisdictions

IntroductionUnderstanding how different countries have responded to mitigate the risk of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) transmission in dental offices is important. This article describes the different approaches taken towards optimal fallow periods in Canadian jurisdictions.MethodsWe searched publicly available information from dentist and dental hygiene regulator websites across the 10 provinces and 3 territories in Canada. We also searched for guidance documents on dental associations’ websites or through personal communication with government officials. We extracted and tabulated information on fallow period recommendations or guidance, when available.ResultsNine jurisdictions (6 provinces and all 3 territories) acknowledge or provide guidance on fallow periods following aerosol-generating procedures. Among those who have provided guidance regarding a fallow period, recommendations follow the Centers for Disease Control and Prevention guidance if the air changes per hour (ACH) in the dental operatory is known.ConclusionThe evidence for deciding on optimal fallow period is limited and still being explored, resulting in substantial variation across Canadian jurisdictions. A focus on developing scientific evidence relevant to dentistry and assimilating existing science is crucial to establishing consistency and uniformity in information to deliver safe oral health care services.     

Association between inflammatory bowel disease and prostate cancer: A large-scale,prospective, population-based study

Inflammatory bowel disease (IBD) is an established risk factor for colorectal cancer. Recent reports suggesting IBD is also a risk factor for prostate cancer (PC) require further investigation. We studied 218 084 men in the population-based UK Biobank cohort, aged 40 to 69 at study entry between 2006 and 2010, with follow-up through mid-2015. We assessed the association between IBD and subsequent PC using multivariable Cox regression analyses, adjusting for age at assessment, ethnic group, UK region, smoking status, alcohol drinking frequency, body mass index, Townsend Deprivation Index, family history of PC and previous prostate-specific antigen testing. Mean age at study entry was 56 years, 94% of the men were white, and 1.1% (n = 2311) had a diagnosis of IBD. After a median follow-up of 78 months, men with IBD had an increased risk of PC (adjusted hazard ratio [aHR] = 1.31, 95% confidence interval [CI] = 1.03-1.67, P = .029). The association with PC was only among men with the ulcerative colitis (UC; aHR = 1.47, 95% CI = 1.11-1.95, P = .0070), and not Crohn's disease (aHR 1.06, 95% CI = 0.63-1.80, P = .82). Results are limited by lack of data on frequency of health care interactions. In a large-scale, prospective cohort study, we detected an association between IBD, and UC specifically, with incident PC diagnosis.     

Improved toxicity profile following high-dose postprostatectomy salvage radiation therapy with intensity-modulated radiation therapy

Background

With salvage radiation therapy (SRT) in the postprostatectomy setting, the need to deliver sufficient radiation doses to achieve a high probability of tumor control is balanced with the risk of increased toxicity. Intensity-modulated radiation therapy (IMRT) in the postprostatectomy salvage setting is gaining interest as a treatment strategy.

Objective

Compare acute and late toxicities in patients treated with IMRT and three-dimensional conformal radiation therapy (3D-CRT) in the postprostatectomy salvage setting.

Design, setting, and participants

A total of 285 patients who were treated at our institution between 1988 and 2007 with SRT after radical prostatectomy for biochemical recurrence were identified. All medical records were reviewed and toxicity recorded. Median follow-up was 60 mo.

Intervention

All patients were treated with SRT with either 3D-CRT (n = 109) or IMRT (n = 176). A total of 205 patients (72%) were treated with doses ≥70 Gy.

Measurements

Late gastrointestinal (GI) and genitourinary (GU) toxicities were recorded using the Common Terminology Criteria for Adverse Events v. 3.0 definition.

Results and limitations

The 5-yr actuarial rates of late grade ≥2 GI and GU toxicity were 5.2% and 17.0%, respectively. IMRT was independently associated with a reduction in grade ≥2 GI toxicity compared with 3D-CRT (5-yr IMRT, 1.9%; 5-yr 3D-CRT, 10.2%; p = 0.02). IMRT was not associated with a reduction in risk of grade ≥2 GU toxicity (5-yr IMRT, 16.8%; 5-yr 3D-CRT, 15.8%; p = 0.86), urinary incontinence (5-yr IMRT, 13.6%; 5-yr 3D-CRT, 7.9%; p = 0.25), or grade 3 erectile dysfunction (5-yr IMRT, 26%; 5-yr 3D-CRT, 30%; p = 0.82). Of patients who developed late grade ≥2 GI or GU toxicity, 38% and 44%, respectively, experienced resolution of their symptoms prior to the last follow-up.

Conclusions

Our experience with high-dose IMRT in the postprostatectomy salvage setting demonstrates that the treatment can be delivered safely with an associated reduction in late GI toxicity.     

Safety,tolerability and immunogenicity of GS-4774, a hepatitis B virus-specific therapeutic vaccine,in healthy subjects: A randomized study

Background

GS-4774 is a recombinant, heat-killed, yeast-based immunotherapy engineered to express hepatitis B virus (HBV)-specific antigens. GS-4774 is being developed as a therapeutic vaccine for chronic HBV infection. The aim of this study was to assess the safety, tolerability and immunogenicity of GS-4774 in healthy subjects.

Design

This was a randomized, open-label, dose-ascending study. Subjects were allocated to one of three dose groups (n = 20 per group) to receive 10, 40 or 80 yeast units (YU; 1 YU = 10⁷ yeast) of GS-4774 in two immunization regimens (five subcutaneous injections at weekly intervals with one monthly booster or three subcutaneous injections at monthly intervals). T-cell-mediated responses were determined by interferon (IFN)-γ enzyme-linked immunospot (ELISpot) assay and lymphocyte-proliferation assay (LPA).

Results

Adverse events were reported by 39 of 60 (65%) subjects; all were mild or moderate and none was serious. Adverse events occurred most frequently in the highest dose group, 80 YU, and the number of individual events was higher after weekly immunization than monthly. The most common adverse events were injection-site reactions. Most (88%) subjects responded to GS-4774 by at least one of the T-cell assays. Following immunization with GS-4774, IFN-γ-producing T-cells specific for HBV antigens were detectable in 30 (51%) subjects. The ELISpot response was observed at all doses, with the highest frequency of responders occurring at the highest dose (10 YU: 45%; 40 YU: 35%; 80 YU: 74%). Proliferative responses to HBV recombinant antigens were observed in 90% subjects; responses were mainly independent of GS-4774 dose and immunization regimen.

Conclusions

GS-4774 was safe and well-tolerated in healthy subjects with injection-site reactions being the most frequently reported adverse events. With both weekly and monthly regimens, GS-4774 provided HBV-specific immune responses at all doses evaluated. Further evaluation of GS-4774 is ongoing in patients with chronic HBV infection.Clinical trial registry: Clinicaltrials.gov (NCT01779505)