Effect of brightness in the evaluation of lumbar pedicular screws position: clinical study

Artifact may lead to confusion when evaluating postoperative CT scans of lumbar pedicle screws. The aim of our study was to develop a specific metal artifact reduction image protocol, in order to reduce metal artifact caused by titanium pedicular screw in patients undergoing lumbar pathology by lumbar fusion. Therefore, the reduction in metal artifacts in lumbar pedicle screws allows surgeons to do an accurate diagnosis of the exact placement of inserted pedicle screws, minimizes false reexploration, and maximizes proper and prompt treatment of misplaced screw. In a first step, we performed a retrospective study of 103 titanium alloy pedicle screws in patients undergoing a lumbar instrumented fusion for treatment for degenerative disease. CT scan was performed postoperatively evaluating the possible overdimension caused by artifact. In a second step, a prospective study was performed using a 64-slice multidetector-row computed tomography (MDCT) in 104 titanium alloy pedicle screws in patients undergoing a lumbar instrumented fusion for treatment for degenerative disease. Our results show that on the group of sequential CT scan, mean overdimension (on each side) due to brightness was 1.045 mm (SD 0.45). On the group of 64-slice multichannel CT, mean overdimension (on each side) due to brightness was 0.005 mm at the proximal part of the screw and 0.025 mm at the distal part of the screw. The results observed suggest that beam-hardening artifacts caused by the screw on CT after lumbar fusion are dramatically reduced by using specific metal artifact reduction image protocol in a 64-slice MDCT.     

Applying Computer Adaptive Testing to Optimize Online Assessment of Suicidal Behavior: A Simulation Study

Background

The Internet is used increasingly for both suicide research and prevention. To optimize online assessment of suicidal patients, there is a need for short, good-quality tools to assess elevated risk of future suicidal behavior. Computer adaptive testing (CAT) can be used to reduce response burden and improve accuracy, and make the available pencil-and-paper tools more appropriate for online administration.

Objective

The aim was to test whether an item response–based computer adaptive simulation can be used to reduce the length of the Beck Scale for Suicide Ideation (BSS).

Methods

The data used for our simulation was obtained from a large multicenter trial from The Netherlands: the Professionals in Training to STOP suicide (PITSTOP suicide) study. We applied a principal components analysis (PCA), confirmatory factor analysis (CFA), a graded response model (GRM), and simulated a CAT.

Results

The scores of 505 patients were analyzed. Psychometric analyses showed the questionnaire to be unidimensional with good internal consistency. The computer adaptive simulation showed that for the estimation of elevation of risk of future suicidal behavior 4 items (instead of the full 19) were sufficient, on average.

Conclusions

This study demonstrated that CAT can be applied successfully to reduce the length of the Dutch version of the BSS. We argue that the use of CAT can improve the accuracy and the response burden when assessing the risk of future suicidal behavior online. Because CAT can be daunting for clinicians and applied scientists, we offer a concrete example of our computer adaptive simulation of the Dutch version of the BSS at the end of the paper.     

In vivo modulation of murine myelopoiesis following intravenous administration of prostaglandin E2

The effects of in vivo administration of prostaglandin E2 (PGE2) on several hematologic parameters were investigated in intact mice under both steady-state conditions and in mice hematopoietically rebounding following a sublethal injection of cyclophosphamide. Intravenous injection of native PGE2, or 16,16 dimethyl-PGE2, an enzymatically stable analog of PGE2, resulted in the significant suppression of nucleated bone marrow and splenic cellularity, total resident nucleated peritoneal cells, and the absolute number of detectable granulocyte- macrophage progenitor cells (CFU-GM) per femur or spleen when administered for 3 or 7 consecutive days. The in vivo effects of 16,16 dimethyl-PGE2 were more pronounced on the cyclophosphamide-treated mice. Dose titration analysis of the effects of 16,16 dimethyl-PGE2 revealed significant suppression of hematologic parameters over a concentration range of 10 micrograms-10(-5) micrograms/mouse/day (10(- 5) M-10(-11) M). The reduction in total nucleated marrow, splenic, and peritoneal cellularity observed following PGE2 administration resulted from a selective effect on nonspecific esterase-positive cells. In situ morphological analysis of the progeny of CFU-GM proliferating in cultures established from mice treated with PGE2 in vivo indicated that the reduction in absolute CFU-GM observed resulted from a preferential effect on those colony-forming cells restricted to monocyte-macrophage differentiation. Prostaglandin F2 alpha was without stimulatory or inhibitory effects in vivo on the hematopoietic parameters investigated.     

Circulating monoclonal B cells expressing P glycoprotein may be a reservoir of multidrug-resistant disease in multiple myeloma

Multiple myeloma is basically an incurable cancer. Most patients respond initially to chemotherapy with reduction in bone marrow (BM) plasma cells and monoclonal Ig levels, but the disease nearly always recurs and becomes refractory to therapy. The objective of this study was to characterize the expression of the multidrug transport pump, P- glycoprotein 170 (P-gp), in myeloma. The great majority of B cells from peripheral blood mononuclear cells (PBMCs) in myeloma express P-gp, detected by the monoclonal antibody MRK-16. P-gp+ blood B cells exhibit extensive DNA hyperdiploidy, suggesting replicative abnormality characteristic of malignant growth. We speculate these represent a stem cell population in myeloma. The proportion of B cells expressing P-gp was comparable among untreated myeloma patients and those treated with chemotherapy, biologic response modifiers, or off treatment. Among BM cells, P-gp was absent or low in untreated myeloma patients but was expressed at high levels on BM cells from patients previously treated with chemotherapy. For untreated patients the majority of B/plasma cells expressing P-gp are located in PBMCs, not the BM cells. Flow cytometric analysis of rhodamine 123 dye efflux indicated a functional P-gp that was efficiently blocked by verapamil or cyclosporin A (CsA). Both the CD11bhi CD19+ B cells and the T cells in myeloma PBMCs had active CsA-inhibited dye efflux, but monocytes lacked the ability to efflux dye. Nearly all CD38hi plasma cells from myeloma BM cells retained dye, indicating their lack of a functional transport pump. Thus, PBMC B cells may be the predominant set of drug-resistant tumor cells. Myeloma PBMC B cells were cultured with Adriamycin with or without CsA and drug toxicity evaluated by the induction of apoptosis, using flow cytometry to quantitate DNA disruption. No apoptosis was detectable at 0.01 microgram/mL adriamycin, the in vivo steady-state level, with or without CsA. With 0.1 microgram adriamycin, no apoptosis was detectable in the absence of CsA, but with CsA, 66% of B cells initiated DNA disruption, whereas most T cells were spared. This work suggests that currently used drug dosages are too low to effect P-gp+ B- cell death, even in the presence of CsA. We suggest that blood B cells comprise a highly drug-resistant subset of the myeloma B lineage that escapes conventional chemotherapy and may underlie the almost uniform fatal relapse in myeloma patients.     

Punitive laws,key population size estimates,and Global AIDS Response Progress Reports: an ecological study of 154 countries

Introduction : UN global plans on HIV/AIDS have committed to reducing the number of countries with punitive laws criminalizing key populations. This study explores whether punitive laws are associated with countries’ performance on targets set in the global plans. Methods : The study used chi‐square tests of independence to explore associations between legal status, key population size estimates, and HIV service coverage for 193 countries from 2007 to 2014. We used data reported by countries on United Nations Global AIDS Progress Report (GARPR) indicators, and legal data from UNAIDS, UNDP, and civil society organizations. Due to lack of sufficiently reliable legal data, only men who have sex with men (MSM) could be studied. The study utilized public data aggregated at the national level. Correspondence with individual experts in a subset of countries stated the purpose of the study, and all responses were anonymized. Results and Discussion : A significantly larger proportion of countries that criminalize same‐sex sexual behaviour reported implausibly low size estimates or no size estimates for MSM. This is consistent with findings in qualitative research that MSMs are marginalized and reluctant to be studied in countries where same‐sex sexuality is criminalized. Size estimates are often used as the denominators for national HIV service coverage reports. Initially, countries that criminalized same‐sex sexuality appeared to have higher HIV testing coverage among MSM than did countries where it is not criminalized. However, investigation of a subset of countries that have reported 90–100% HIV testing coverage among MSM found that most were based on implausibly low or absent size estimates. Conclusions : Criminalization of same‐sex sexuality is associated with implausibly low or absent MSM size estimates. Low size estimates may contribute to official denial of the existence of MSM; to failure to adequately address their needs; and to inflated HIV service coverage reports that paint a false picture of success. To enable and measure progress in the HIV response, UN agencies should lead a collaborative process to systematically, independently and rigorously gather data on laws and their enforcement.     

Incorporating Antiracism Coursework into a Cultural Competency Curriculum

Creating a socially conscious educational environment is an imperative if health care practitioners are to have a significant impact on health inequities. The effects of practitioner bias, prejudice, and discrimination on health and health outcomes have been well documented in the literature. Individuals being trained to provide health care will be entering into an increasingly diverse world and must be equipped with the appropriate knowledge and skills in order to meet the needs of those seeking their care. Cultural competency training in medical education has evolved over the past 15 years since the Institute of Medicine's 2002 report, Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care. As research on the effectiveness of this training has emerged, several authors have called for the integration of antiracism training into the cultural competency curriculum, but few have found effective ways of doing so. This article describes the approach of one midwifery program in order to inform clinical education programs across the spectrum of health care practitioners.     

Neither molecular diversity of the envelope,immunosuppression status,nor proviral load causes indeterminate HTLV western blot profiles in samples from human T‐cell lymphotropic virus type 2 (HTLV‐2)‐infected individuals

Although human T‐cell lymphotropic virus type 2 (HTLV‐2) is considered of low pathogenicity, serological diagnosis is important for counseling and monitoring. The confirmatory tests most used are Western blot (WB) and PCR. However, in high‐risk populations, about 50% of the indeterminate WB were HTLV‐2 positives by PCR. The insensitivity of the WB might be due to the use of recombinant proteins of strains that do not circulate in our country. Another possibility may be a high level of immunosuppression, which could lead to low production of virus, resulting in low stimulation of antibody. We found one mutation, proline to serine in the envelope region in the position 184, presented at least 1/3 of the samples, independent the indeterminate WB profile. In conclusion, we found no correlation of immune state, HTLV‐2 proviral load, or env diversity in the K55 region and WB indeterminate results. We believe that the only WB kit available in the market is probably more accurate to detect HTLV‐1 antibodies, and some improvement for HTLV‐2 detection should be done in the future, especially among high‐risk population. J. Med. Virol. 82: 837–842, 2010. © 2010 Wiley‐Liss, Inc.