Does simulation-based training facilitate the integration of human anatomy with surgery? A report of a novel Surgical Anatomy Course.

BACKGROUND: Knowledge of gross anatomy, as a basic core subject, is fundamental for medical students and essential to medical practitioners, particularly for those intending a surgical career. However, both medical students and clinical teachers have found a significant gap in teaching basic sciences and the transition into clinical skills. The authors present a Surgical Anatomy Course developed to teach the anatomical basis of surgical procedures with particular emphasis on laparo-scopic skills while incorporating medical simulation. MATERIALS AND METHODS: An evaluation of the students' satisfaction of the Surgical Anatomy Course was completed using a mix of multiple choice and open-ended questions, and a six-point Likert Scale. Questions were asked about the students' perceived improvement in surgical and laparoscopic skills. Manual skills were assessed using a laparoscopic simulator. RESULTS: Both evaluation of the course structure and the general impression of the course were positive. Most students believed the course should be an integral part of a modern curriculum. The course supported the traditional surgical classes and improved anatomical knowledge and strengthened students' confidentiality and facilitated understanding and taking surgical rotations. CONCLUSIONS: A medical course combining the practical learning of anatomy and surgical-based approaches will bring out the best from the students. Medical students positively evaluated the Surgical Anatomy Course as useful and benefi-cial regarding understanding anatomical structure and relationship necessary for further surgical education. (Folia Morphol 2018; 77, 2: 279-285).

Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials.

Epsilon-Near-Zero materials exhibit a transition in the real part of the dielectric permittivity from positive to negative value as a function of wavelength. Here we study metal-dielectric layered metamaterials in the homogenised regime (each layer has strongly subwavelength thickness) with zero real part of the permittivity in the near-infrared region. By optically pumping the metamaterial we experimentally show that close to the Epsilon-Near-Zero (ENZ) wavelength the permittivity exhibits a marked transition from metallic (negative permittivity) to dielectric (positive permittivity) as a function of the optical power. Remarkably, this transition is linear as a function of pump power and occurs on time scales of the order of the 100 fs pump pulse that need not be tuned to a specific wavelength. The linearity of the permittivity increase allows us to express the response of the metamaterial in terms of a standard third order optical nonlinearity: this shows a clear inversion of the roles of the real and imaginary parts in crossing the ENZ wavelength, further supporting an optically induced change in the physical behaviour of the metamaterial.

Enhanced Nonlinear Refractive Index in ε-Near-Zero Materials.

New propagation regimes for light arise from the ability to tune the dielectric permittivity to extremely low values. Here, we demonstrate a universal approach based on the low linear permittivity values attained in the ε-near-zero (ENZ) regime for enhancing the nonlinear refractive index, which enables remarkable light-induced changes of the material properties. Experiments performed on Al-doped ZnO (AZO) thin films show a sixfold increase of the Kerr nonlinear refractive index (n_{2}) at the ENZ wavelength, located in the 1300 nm region. This in turn leads to ultrafast light-induced refractive index changes of the order of unity, thus representing a new paradigm for nonlinear optics.

Assessing the effect of a true-positive recall case in screening mammography: does perceptual priming alter radiologists' performance?

OBJECTIVE: To measure the effect of the insertion of less-difficult malignant cases on subsequent breast cancer detection by breast imaging radiologists. METHODS: The research comprises two studies. Study 1: 8 radiologists read 2 sets of images each consisting of 40 mammographic cases. Set A contained four abnormal cases, and Set B contained six abnormal cases, including two priming cases (less difficult malignancies) placed at intervals of three and five subsequent cases before a subtle cancer. Study 2: 16 radiologists read a third condition of the same cases, known as Set C, containing six abnormal cases and two priming cases immediately preceding the subtle cancer cases. The readers were asked to localize malignancies and give confidence ratings on decisions. RESULTS: Although not significant, a decrease in performance was observed in Set B compared with in Set A. There was a significant increase in the receiver operating characteristic (ROC) area under the curve (z = -2.532; p = 0.0114) and location sensitivity (z = -2.128; p = 0.0333) between the first and second halves of Set A and a marginal improvement in jackknife free-response ROC figure of merit (z = -1.89; p = 0.0587) between the first and second halves of Set B. In Study 2, Set C yielded no significant differences between the two halves of the study. CONCLUSION: Overall findings show no evidence that priming with lower difficulty malignant cases affects the detection of higher difficulty cancers; however, performance may decrease with priming. ADVANCES IN KNOWLEDGE: This research suggests that inserting additional malignant cases in screening mammography sets as an audit tool may potentially lead to a decrease in performance of experienced breast radiologists.

Digital tomosynthesis: a new future for breast imaging?

The aim of this article is to review the major limitations in current mammography and to describe how these may be addressed by digital breast tomosynthesis (DBT). DBT is a novel imaging technology in which an x-ray fan beam sweeps in an arc across the breast, producing tomographic images and enabling the production of volumetric, three-dimensional (3D) data. It can reduce tissue overlap encountered in conventional two-dimensional (2D) mammography, and thus has the potential to improve detection of breast cancer, reduce the suspicious presentations of normal tissues, and facilitate accurate differentiation of lesion types. This paper reviews the latest studies of this new technology. Issues including diagnostic efficacy, reading time, radiation dose, and level of compression; cost and new innovations are considered.

Graft function, cardiovascular risk factors, and sex hormones in renal transplant recipients on an immunosuppressive regimen of everolimus, reduced dose of cyclosporine, and basiliximab.

A prospective, randomized trial evaluated the combination of everolimus of 1.5 or 3 mg/d with steroids, basiliximab, and low-dose cyclosporine (CsA) adjusted by C2 monitoring in 256 renal transplant recipients. CsA C2 target levels, initially set at 600 ng/mL, were tapered over time posttransplant. The median serum creatinine concentrations were 130 mumol/L in both sirolimus groups (1.5 and 3 mg/d) at 6 months. Biopsy-proven acute rejection (BPAR) occurred in 13.7% and 15.1% of patients in the 1.5 and 3 mg/d groups, respectively. The incidence of BPAR was significantly higher among patients with everolimus trough levels < 3 ng/mL. Posttransplant diabetes mellitus occurred rarely, and blood pressure control appeared favorable; however, serum cholesterol levels were increased by approximately 50%, and serum triglycerides by approximately 100%. Serum testosterone concentrations increased after renal transplantation in both everolimus groups. Concentration-controlled everolimus therapy combined with low-dose CsA provides effective protection against rejection with good renal function and safety profiles.

Cardiovascular risk estimates and risk factors in renal transplant recipients.

Cardiovascular morbidity, including coronary artery disease and left ventricular hypertrophy, and mortality are high in patients following renal transplantation. Cardiovascular disease is thought to be due to traditional (hypertension, hyperlipidemia, diabetes mellitus and smoking) as well as nontraditional cardiovascular risk factors (microinflammation). Furthermore, immunosuppressive drugs, namely, calcineurin inhibitors, sirolimus, and steroids, have been reported to adversely affect cardiovascular risk factors (e.g., hypertension, hyperlipidemia, hyperglycemia). Evidence from comparative trials and from conversion studies suggest that blood pressure, hyperlipidemia, and hyperglycemia after renal transplantation may be differentially affected by the calcineurin inhibitors cyclosporine and tacrolimus. In the European Tacrolimus versus Cyclosporin A Microemulsion Renal Transplantation Study, 557 patients were randomly allocated to therapy with tacrolimus (n = 286) versus cyclosporine (n = 271). In addition, to blood pressure, serum cholesterol, HDL cholesterol, triglycerides, and blood glucose, we estimated the 10-year risk of coronary heart disease (Framingham risk score). Tacrolimus resulted in a significantly lower time-weighted average of serum cholesterol (P < .001), and mean arterial blood pressure (P < .05), but a higher time-weighted average of blood glucose (P < .01) than cyclosporine. Mean 10-year coronary artery disease risk estimate was significantly lower in men treated with tacrolimus, (10.0% versus 13.2%; P < .01) but was unchanged in women (4.7% versus 7.0%). Tacrolimus and cyclosporine microemulsion have compound-specific effects on cardiovascular risk factors that differentially affect the predicted rate of coronary artery disease.

Quantitative gene expression analysis of fractalkine using laser microdissection in biopsies from kidney allografts with acute rejection.

Percutaneous biopsy of the kidney remains the gold standard to establish a diagnosis in renal diseases. Only semiquantitative assessments of gene expression on biopsies have been possible so far. We studied gene expression of the chemokine fractalkine (FKN) in 12 biopsies from laser microdissected kidney allografts that showed histologic signs of acute rejection and 10 controls. As quantified by real-time PCR, the relative tubular FKN expression increased from 1.0 [0.81 to 2.95] (median [range]) in controls to 12.44 [0.90 to 191.0] in acute rejection (P < .01); glomerular FKN expression from 1.3 [0.07 to 27.44] to 12.22 [1.32 to 50.23] (P < .05); and vascular expression, from 0.72 [0.37 to 5.11] to 7.07 [1.19 to 73.49] (P < .01). Furthermore, there was a trend toward higher glomerular FKN expression among patients with more severe rejection. Our results suggest a role of FKN in acute renal allograft rejection.

[Lipid and protein peroxidation process and catalase activity in pre-eclamptic placenta]. / Procesy peroksydacji lipidów i bialek oraz aktywnosc katalazy w lozyskach z ciaz powiklanych stanem przedrzucawkowym.

There are some suggestions that free radicals are involved in some dysfunctions observed in preeclampsia. In this study we have examined the antioxidant status of preeclamptic placentas. We have used placentas obtained from normal pregnant women and women with preeclampsia. Lipoperoxidative process was measured by means of Okhawa method. Sedlak method was used to measured the total thiol groups. The catalase activity was measured by means of Pffeifer method. The results show that the catalase activity decreases, the amount of MDA increases and the total amount of thiol groups is smaller in preeclamptic placentas. The level of lipid peroxides in preeclamptic placentas is about 1.8 times higher in comparison with normal placentas. The decreased level of total thiol groups in preeclamptic placentas can be caused by a more intensive process of protein peroxidation. Catalase is less active in preeclamptic placentas. It can be due to lower activity of antioxidant systems or the destruction of antioxidant systems by reactive oxygen species. The results of our experiments confirm lower antioxidant status in preeclamptic placentas and suggest that peroxidative reaction may cause many dysfunctions associated with preeclampsia.

[The effect of Trolox-vitamin E analog on placental lipid peroxidation with physiologic pregnancies and pregnancies complicated by pre-eclampsia]. / Wplyw troloxu-analogu witaminy E na procesy peroksydacji lipidów w lozyskach kobiet z ciaz fizjologicznych oraz powiklanych stanem przedrzucawkowym.

There are suggestions that free radicals are involved in some dysfunctions observed in preeclampsia. In this study we have examined the effect of Trolox (water soluble vitamin E analog) on placental lipid peroxidation. Placentas from 20 normal and 20 preeclamptic woman were used in this study. Lipoperoxidative process was measured by means of Okhawa method. The level of lipid peroxides in preeclamptic placentas is higher than in normal placentas. In normal placentas 20 microM, of Trolox caused the greatest fall in MDA level (about 25%) in comparison with the control MDA level (only with peroxidative system without Trolox). In preeclamptic placentas the greatest fall in lipooxygenation process (about 14%) was caused by 25 microM. of Trolox. The influence of Trolox on the level of lipid peroxides in preeclamptic placentas is less effective in comparison with normal placentas.

[Results of surgical treatment of stress urinary incontinence in women in light of urethral flow studies]. / Wyniki operacyjnego leczenia wysilkowego nietrzymania moczu u kobiet w swietle badan przeplywów cewkowych.

Forty-six women are presented, aged from 38 to 62 years, treated surgically by Marshall-Marchetti-Krantz method for effort urinary incontinence. The postoperative results were subjected to analysis and their objective value was assessed by carried out uroflowmetric studies. The necessity of uroflowmetry before starting the operation was assessed.

Transplantation of hematopoietic stem cells obtained by a combined dye method fractionation of murine bone marrow.

Hematopoietic stem cells were purified from murine bone marrow cells (BMC). Their characteristic density, size, internal complexity, Hoechst 33342 dye uptake, and wheat germ agglutinin (WGA) affinity were used to distinguish them from other cells in the bone marrow. BMC suspensions were centrifuged over Ficoll Lymphocyte Separation Media (Organon Teknika, Durham, NC; density 1.077 to 1.08). The lower-density cells were drawn off, stained with Hoechst and labeled with biotinylated WGA bound to streptavidin conjugated to phycoerythrin (WGA-B*A-PE) or with WGA conjugated to Texas Red. These cells were then analyzed and sorted by an Ortho Cytofluorograph 50-H cell sorter. The cells exhibiting medium to high forward light scatter, low to medium right angle light scatter, low Hoechst intensity, and high WGA affinity were selected. Sorted BMC (SBMC) were stained with Romanowsky-type stains for morphologic assay, and were assayed in lethally irradiated (LI) mice for their ability to produce colony-forming units in the spleen (CFU-S) and for their ability to produce survival. The spleen seeding factor for day 8 CFU-S upon retransplantation of the isolated cells was 0.1. The isolated cells were found to have consistent morphology, were enriched up to 135-fold as indicated by day 8 CFU-S assay, 195-fold as indicated by day 14 CFU-S assay, and 150 sorter-selected BMC were able to produce long-term survival in LI mice with retention of donor karyotype. When recipients of this first transplantation were themselves used as BMC donors, their number of day 8 and day 12 CFU-S were found to be reduced. However, 3 X 10(5) of their BMC provided 100% survival among secondary recipients. When the previously SBMC were competed after one transplantation against fresh nonsorted BMC in a mixed donor transplant, they showed the decline in hematopoietic potency normally seen in previously transplanted BMC. We conclude that the use of combinations of vital dyes for fluorescence-activated cell sorting (FACS) selection of survival-promoting murine hematopoietic stem cells provides results comparable with those produced by antibody-selected FACS and has the advantage of a method directly transferable to human BMC.

Cycling patterns of hemopoietic stem cell subpopulations in young and old BDF1 mice.

We have previously reported that two or more different subpopulations of bone marrow stem cells exist in mice as determined by cycling status of day-8 and day-14 CFU-S in long term bromodeoxyuridine (BrdU) infusion studies. In the present report, comparisons between cycling of stem cell subpopulations in old and young mice show that, while the general patterns persist, there are some statistically significant differences between corresponding time points of early and late CFU-S cycling patterns in young and old BDF1 mice. In both populations of CFU-S there exist cells which do not enter cycle over a five week period. The method which we have employed allowed the cycling measurements to be made in unstimulated steady-state bone marrow cell populations, since no cell death is caused in vivo.

Evaluation of stem cell reserve using serial bone marrow transplantation and competitive repopulation in a murine model of chronic hemolytic anemia.

Serial transplantation and competitive repopulation were used to evaluate any loss of self-replicative capacity of bone marrow stem cells in a mouse model with increased and persistent hemopoietic demands. Congenic marrows from old control and from young and old mice with hereditary spherocytic anemia (sphha/sphha) were serially transplanted at 35-day intervals into normal irradiated recipients. Old anemic marrow failed or reverted to recipient karyotype at a mean of 3.5 transplants, and young anemic marrow reverted at a mean of 4.0 transplants, whereas controls did so at a mean of 5.0 transplants. In a competitive assay in which a mixture of anemic and control marrow was transplanted, the anemic marrow persisted to 10 months following transplantation; anemic marrow repopulation was greater if anemic marrow sex matched with the host. It is possible that lifelong stress of severe anemia decreases stem cell reserve in the anemic sphha/sphha mouse marrow. However, marginal differences in serial transplantation number and the maintenance of anemic marrow in a competition assay would suggest that marrow stem cells, under prolonged stress, are capable of exhibiting good repopulating and self-replicating abilities.

Normal cycling patterns of hematopoietic stem cell subpopulations: an assay using long-term in vivo BrdU infusion.

It was found in a long-term bromodeoxyuridine (BrdU) infusion study that two or more different subpopulations of bone marrow stem cells exist in mice. One of these subpopulations appears to be noncycling and forms approximately 10% of eight-day CFU-S. Another one, a subpopulation of slowly cycling bone marrow cells, is represented as 14-day CFU-S. The 14-day CFU-S have a regular increment in the percentage of the subpopulation entering the cycle over time, with a cell generation half-time of 21 days. The cycling status in these experiments was ascertained by in vivo continuous long-term BrdU infusion. An improved method is presented for long-term BrdU infusion with UV killing of cycled cells.