A review of recent advancements in Actinium-225 labeled compounds and biomolecules for therapeutic purposes

In nuclear medicine, cancers that cannot be cured or can only be treated partially by traditional techniques like surgery or chemotherapy are killed by ionizing radiation as a form of therapeutic treatment. Actinium-225 is an alpha-emitting radionuclide that is highly encouraging as a therapeutic approach and more promising for targeted alpha therapy (TAT). Actinium-225 is the best candidate for tumor cells treatment and has physical characteristics such as high (LET) linear energy transfer (150 keV per μm), half-life (t_1/2 = 9.92d), and short ranges (400–100 μm) which prevent the damage of normal healthy tissues. The introduction of various new radiopharmaceuticals and radioisotopes has significantly assisted the advancement of nuclear medicine. Ac-225 radiopharmaceuticals continuously demonstrate their potential as targeted alpha therapeutics. ²²⁵Ac-labeled radiopharmaceuticals have confirmed their importance in medical and clinical areas by introducing [²²⁵Ac]Ac-PSMA-617, [²²⁵Ac]Ac-DOTATOC, [²²⁵Ac]Ac-DOTA-substance-P, reported significantly improved response in patients with prostate cancer, neuroendocrine, and glioma, respectively. The development of these radiopharmaceuticals required a suitable buffer, incubation time, optimal pH, and reaction temperature. There is a growing need to standardize quality control (QC) testing techniques such as radiochemical purity (RCP). This review aims to summarize the development of the Ac-225 labeled compounds and biomolecules. The current state of their reported resulting clinical applications is also summarized as well.     

Efficacy and safety of,and patient satisfaction with,colonoscopic-administered fecal microbiota transplantation in relapsing and refractory community- and hospital-acquired Clostridium difficile infection

OBJECTIVE:

To report the efficacy and safety of, and patient satisfaction with, colonoscopic fecal microbiota transplantation (FMT) for community- and hospital-acquired Clostridium difficile infection (CDI).

METHODS:

A retrospective medical records review of patients who underwent FMT between July 1, 2012 and August 31, 2013 was conducted. A total of 22 FMTs were performed on 20 patients via colonoscopy. The patients were divided into ‘community-acquired’ and ‘hospital-acquired’ CDI. Telephone surveys were conducted to determine procedure outcome and patient satisfaction. Primary cure rate was defined as resolution of diarrhea without recurrence within three months of FMT, whereas secondary cure rate described patients who experienced resolution of diarrhea and return of normal bowel function after a second course of FMT.

RESULTS:

Nine patients met the criteria for community-acquired CDI whereas 11 were categorized as hospital-acquired CDI. A female predominance in the community-acquired group (88.89% [eight of nine]) was found (P=0.048). The primary cure rate was 100% (nine of nine) and 81.8% (nine of 11 patients) in community- and hospital-acquired CDI groups, respectively (P=0.189). Two patients in the hospital-acquired group had to undergo a repeat FMT for persistent symptomatic infection; the secondary cure rate was 100%. During the six-month follow-up, all patients were extremely satisfied with the procedure and no complications or adverse events were reported.

CONCLUSION:

FMT was a highly successful and very acceptable treatment modality for treating both community- and hospital-acquired CDI.     

Vitamin E reversed nicotine-induced toxic effects on bone biochemical markers in male rats

Introduction

Vitamin E is beneficial in restoring bone histomorphometric parameters in nicotine-treated rats. This study determined the effectiveness of 3 forms of vitamin E in restoring bone metabolism in nicotine-treated rats.

Material and methods

Thirty-five male Sprague-Dawley rats were divided into 5 groups: (1) control (C), (2) nicotine cessation (NC), (3) α-tocopherol (ATF), (4) tocotrienol-enhanced fraction (TEF) and (5) γ-tocotrienol (GTT). Treatment was carried out for 4 months. The control group was administered normal saline and olive oil throughout the treatment period while treatment for groups 2-5 was performed in 2 phases. In the first phase, the groups received nicotine 7 mg/kg intraperitoneally for 2 months. The following 2 months, group 2 received normal saline and olive oil while groups 3-5 received ATF, TEF or GTT, 60 mg/kg orally. Pre-treatment and post-treatment serum was collected for bone biochemical marker measurement using the ELISA method.

Results

Nicotine increased serum bone-resorbing cytokines (interleukin-1 and interleukin-6) and the bone resorption marker pyridinoline (PYD) while reducing the bone formation marker osteocalcin after 2 months of nicotine treatment. The parameters failed to improve after nicotine was stopped for 2 months. Supplementation with the 3 forms of vitamin E improved the parameters, i.e. reduced the cytokines and pyridinoline as well as increased the osteocalcin. In addition, the TEF and GTT groups had a higher level of osteocalcin than the control group.

Conclusions

Nicotine impaired bone metabolism and cessation of nicotine treatment did not reverse the effects. Vitamin E, especially the tocotrienols, restored bone metabolism that was impaired due to nicotine.     

GeneXpert MTB/RIF Version G4 for Identification of Rifampin-Resistant Tuberculosis in a Programmatic Setting

A recent Cochrane review estimated GeneXpert MTB/RIF specificity for rifampin resistance as 98% (95% confidence interval [CI], 97 to 99), based on results from earlier test versions. The measured positive predictive value of the new generation test from programmatic implementation in Cape Town, South Africa, was 99.5% (95% CI, 98.5 to 100), confirming excellent specificity.