Feasibility of an MRI-only workflow for postimplant dosimetry of low-dose-rate prostate brachytherapy: Transition from phantoms to patients

PurposeThe lack of positive contrast from brachytherapy seeds in conventional MR images remains a major challenge toward an MRI-only workflow for postimplant dosimetry of low-dose-rate brachytherapy. In this work, the feasibility of our recently proposed MRI-only workflow in clinically relevant scenarios is investigated and the necessary modifications in image acquisition and processing pipeline are proposed for transition to the clinic.Methods and MaterialsFour prostate phantoms with a total of 321 I-125 implanted dummy seeds and three patients with a total of 168 implanted seeds were scanned using a gradient echo sequence on 1.5 T and 3T MR scanners. Quantitative susceptibility mapping (QSM) was performed for seed visualization. Before QSM, the seed-induced distortion correction was performed followed by edge enhancement. Seed localization was performed using spatial clustering algorithms and was compared with CT. In addition, feasibility of the proposed method on detection of prostatic calcifications was studied.ResultsThe proposed susceptibility-based algorithm generated consistent positive contrast for the seeds in phantoms and patients. All the 321 seeds in the four phantoms were correctly identified; the MR-derived seeds centroids agreed well with CT-derived positions (average error = 0.5 ± 0.3 mm). The proposed algorithm for seed visualization was found to be orientation invariant. In patient cases, all seeds were visualized and correctly localized (average error = 1.2 ± 0.9 mm); no significant differences between dose volume histogram parameters were found. Prostatic calcifications were depicted with negative contrast on QSM and spatially agreed with CT.ConclusionsThe proposed MRI-based approach has great potential to replace the current CT-based practices. Additional patient studies are necessary to further optimize and validate the workflow.     

Antimicrobial susceptibility differences among mucoid and non-mucoid Pseudomonas aeruginosa isolates

Pseudomonas aeruginosa is one of the most important opportunistic bacteria, causing a wide variety of infections particularly in immunocompromised patients. The extracellular glycocalyx is produced in copious amounts by mucoid strains of P. aeruginosa. Mucoid and non-mucoid P. aeruginosa strains show some differences in their antimicrobial susceptibility pattern. The aim of this study was to investigate the frequency of mucoid and non-mucoid types and their antimicrobial susceptibility patterns isolated from Milad and Mostafa Khomeini Hospital in Tehran, Iran. One hundred P. aeruginosa isolates were collected which all were confirmed by conventional biochemical tests and PCR assay using specific primers for oprI and oprL lipoproteins. Mucoid and non-mucoid types of isolates were determined by culturing isolates on BHI agar containing Congo red and Muir mordant staining method. The susceptibility pattern of isolates against 23 different antibiotics was assessed using MIC sensititre susceptibility plates.Fifty of 100 of isolates were mucoid type, of which 14 isolates were from Mostafa Khomeini Hospital. Frequency of mucoid type of P. aeruginosa in Mostafa Khomeini hospital (70%) was higher than that seen in Milad hospital (45%). The statistical analysis of MICs results showed significant differences in antimicrobial resistance among mucoid and non-mucoid types (non mucoid strains showed more resistance against tested antibiotics). This may be due to the tendency of some antibiotics to attach to extracellular glycocalyx of mucoid strains.     

Establishment of a fast and high yield method for routine production of [131I]MIBG and investigation of its radiochemical stability for diagnosis and treatment uses

In this work, exchange radioiodination of metaiodobenzylguanidine (MIBG) was carried out at optimum conditions that facilitates the production of [¹³¹I]MIBG both quickly and efficiently. The radiochemical purity and yield of the labeled product are typically as high as 99% and 90% for diagnostic dose and 95% and 80% for therapeutic dose, respectively. Stability studies show that labeled material at the room temperature met the demand of the clinical application. This labeling procedure will be used in the routine production process of [¹³¹I]MIBG for diagnosis and treatment uses.     

Efficacy of skin self‐examination for the early detection of melanoma

The National Cancer Institute's “Melanoma Action Plan” calls for reduction of melanoma mortality through early detection. Routine skin self‐examination (SSE) has the potential to increase chances of early detection and treatment and may be the key to melanoma survival. We provide a focused review of the accuracy of SSE for detecting premalignant lesions and cutaneous risk factors for melanoma, with suggestions for future directions for enhancing measurement of SSE accuracy and ways in which to improve the public's perceptions of melanoma efficacy. We examined published data on the efficacy of skin self‐examination for the early detection of melanoma. We searched the MEDLINE database for publications between January 1, 1987 and June 1, 2007 using search terms for “melanoma” and “self‐examination.” We found that sensitivity of skin self‐examination is low, ranging from 25% to 93%, while specificity is generally higher (83% to 97%). Attempts to increase improve the lay public's perceptions of the early signs of melanoma have proved effective, while those aimed at increasing accuracy of SSE with targeted interventions have been moderately successful. SSE's insensitivity for detection of pigmented lesions should prompt further investigation of educational interventions to enhance its accuracy and lead to its adoption as a cheap, simple screening tool. Assessment of the accuracy and efficacy of SSE should proceed using standardized definitions and measurements such that it is easier to pool data on the overall value of SSE as a screening modality.     

The Most Important Social Determinants of Slum Dwellers’ Health: A Scoping Review

ObjectivesGiven the importance of social determinants of health in promoting the health of slum residents, this study was conducted with the aim of identifying the main dimensions and components of these determinants.MethodsThis scoping review study was conducted according to the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews). A comprehensive search was performed of PubMed, ProQuest, Scopus, and Web of Science for articles conducted from 2010 to the end of 2019. Studies were selected based on inclusion criteria, with a special focus on studies dealing with the social determinants of physical and mental health or illness.ResultsThirty-three articles were selected to extract information on the social determinants of health. After reviewing the articles, 7 main dimensions (housing, socioeconomic status of the family, nutrition, neighborhood characteristics, social support and social capital, occupational factors, and health behaviors) and 87 components were extracted as social determinants of health among slum dwellers.ConclusionsThis framework could be used by planners, managers, and policy-makers when making decisions affecting the health of these settlements’ residents due to the common characteristics of slums around the world, especially in developing countries.     

Mitochondrial redox studies of oxidative stress in kidneys from diabetic mice

Chronic hyperglycemia during diabetes leads to increased production of reactive oxygen species (ROS) and increased oxidative stress (OS). Here we investigated whether changes in the metabolic state can be used as a marker of OS progression in kidneys. We examined redox states of kidneys from diabetic mice, Akita(/+) and Akita(/+);TSP1(-/-) mice (Akita mice lacking thrombospondin-1, TSP1) with increasing duration of diabetes. OS as measured by mitochondrial redox ratio (NADH/FAD) was detectable shortly after the onset of diabetes and further increased with the duration of diabetes. Thus, cryo fluorescence redox imaging was used as a quantitative marker of OS progression in kidneys from diabetic mice and demonstrated that alterations in the oxidative state of kidneys occur during the early stages of diabetes.     

Lower extremity reconstruction with the anterolateral thigh flap

The versatility and location of the anterolateral thigh (ALT) flap make it well suited for lower extremity reconstruction. The purpose of this study was to evaluate surgical and functional outcomes by specific anatomic regions in the lower extremity to better define the role of the ALT flap in lower extremity reconstruction. A retrospective review of patients undergoing lower extremity reconstruction with an ALT flap between July 2002 and December 2010 was performed. Total 46 patients underwent lower extremity reconstruction with an ALT flap, of whom 29 (63%) had a pedicled flap and 17 (37%) a microvascular free flap. Defects were located in the hip/buttocks (n = 8), groin (n = 13), thigh (n = 8), knee (n = 5), leg (n = 6), and foot/ankle (n = 6). The mean postoperative follow-up was 4 months. Total flap loss occurred in two patients (4%). There were 11 recipient site complications (24%). The most common complication was recipient site seroma, which occurred in five patients (11%), all of whom had hip/buttock or groin defects. Overall, 38 patients (83%) returned to their preoperative functional status. The ALT flap is an effective method of lower extremity reconstruction. It can be performed as a pedicled or free flap, with good surgical and functional outcomes.     

Detection of Mixed-Species Infections of Plasmodium falciparum and Plasmodium vivax by Nested PCR and Rapid Diagnostic Tests in Southeastern Iran

Coexistence of two species of Plasmodium in a single host has disrupted the diagnosis and treatment of malaria. This study was designed to evaluate the ability of rapid diagnostic test (RDT) kits for the diagnosis of mixed-species malaria infections in southeastern Iran. A total of 100 malaria patients were included in the study out of 164 randomly suspected symptomatic malaria patients from May to November 2012. Nested polymerase chain reaction (PCR) was also used to judge the ability of microscopy versus RDT kits for detecting mixed species. The sensitivity of light microscopy for the detection of mixed-species malaria infections was 16.6% (95% confidence interval [CI] = 3–49.1). Nested PCR revealed 12 patients with mixed-species infection. The CareStart Pv/Pf Combo kit detected 58% of the mixed-species infections, which were determined by nested PCR (sensitivity = 58.3%; 95% CI = 28.5–83.5). For identifying P. falciparum, P. vivax, and mixed-species infections, the concordance rates (kappa statistics) of microscopy and CareStart Pv/Pf Combo kit with nested PCR were 0.76 and 0.79, respectively (P = 0.001). This study underlines the effectiveness of RDT kits to improve the differentiation of mixed-species malaria infections in endemic areas where the prevalence of chloroquine resistance is high.