The “Ice Age” of Anatomy and Obstetrics: Hand and Eye in the Promotion of Frozen Sections around 1900

In the late nineteenth century anatomists claimed a new technique—slicing frozen corpses into sections—translated the three-dimensional complexity of the human body into flat, visually striking, and unprecedentedly accurate images. Traditionally hostile to visual aids, elite anatomists controversially claimed frozen sections had replaced dissection as the “true anatomy.” Some obstetricians adopted frozen sectioning to challenge anatomists’ authority and reform how clinicians made and used pictures. To explain the successes and failures of the technique, this article reconstructs the debates through which practitioners learned to make and interpret, to promote or denigrate frozen sections in teaching and research. Focusing on Britain, the author shows that attempts to introduce frozen sectioning into anatomy and obstetrics shaped and were shaped by negotiations over the epistemological standing of hand and eye in medicineThis work was supported by the Wellcome Trust through enhancement and strategic awards in the history of medicine on the theme “Generation to Reproduction” (074298, 088708)

Intradepartmental Collaboration to Improve the Quality of Engineering Drawings Created by Students in Senior Design Project

Engineers use engineering graphics to describe their design, to exchange ideas, and to communicate with others. As an important communication tool, most engineering department commits at least two courses on engineering graphics. The mechanical engineering technology at the college offers three engineering graphics courses for its associate degree program. The objective is to give students opportunity to get familiar with different type of engineering graphics from 2D to 3D and from general graphics to mechanical engineering specific graphics gradually so they can apply these engineering graphics skills in their senior courses such as in machine design. Despite the extensive offering of engineering graphics courses to students, a review of students design work in senior design project of the machine design course revealed that students still lacked certain skills and understanding when creating their design models and working drawings. For examples, many students didn’t understand the difference between working drawings and the corresponding 3D objects, they had difficulty in creating sheet metal components and gears, and most importantly, and many students still treated engineering graphics work in product design as design of unrelated individual components instead of treating them as integral part of a system. In fall 2012 the instructor who teaches senior design project, started to collaborate with instructors who teach engineering graphics to address these issues mentioned above. Students were given a design project that require the students to create many common mechanical components used in product design such as gears, sheet metal components, and mechanical subsystems such as differential drive and steering system. Students not only have to pay attention on how to create these components correctly, they have to pay attention on the relationships among these components when they are assembled together. This gives students a better understanding on how to use engineering graphics in product design. The details concerning the implementation of intradepartmental collaborative work including assessment will be discussed this paper as well as in future papers

Advanced Design and Fabrication of Prosthetic and Medical Devices

The department of Mechanical Engineering and Industrial Design Technology (MEIDT) at City Tech is seeking to strengthening the skills of its students in manufacturing and design to respond to the urgent needs of the manufacturing industry in general and the prosthetic and medical devices (P&MD) industry in particular to high-skilled engineers and technicians and to provide a national model for advanced technology education. Medical Devices will include: (a) Surgical and Medical Instruments; (b) Surgical Appliances and Supplies; and (c) Dental Equipment and Supplies. The educational merit of the project is that it motivates students to do engineering rather than studying engineering. Students will get the opportunity to connect classroom experience to the medical device industry through intensive hands on experience in medical imaging and concepts of P&MD. Curriculum will be linked to practice so students will apply what they learn in the classroom in Computer Aided Design (CAD), Engineering Materials, Manufacturing Processes, Computer Aided Manufacturing (CAM), Mechatronics, Tolerance, Product Life Cycle and Management, and Engineering Analysis. Furthermore, the project will adopt advance STEM strategies such as Project-based-Learning and best strategies to teach STEM courses by moving from particular experience (design and manufacturing of medical devices) to general experience (design, manufacturing, materials,…etc). Additionally, the project will build on current ATE centers successful strategies to recruit female students to STEM through introducing them to bio-related projects. The technical merit of the project lies in providing students with the opportunity to collaborate with the industry to work in real-life projects

Senior Design Case Study: Application of System Engineering Concepts in the Design of a Router

System engineering (SE) is a multidisciplinary approach for the design, management, and realization of a complex system. In product development, SE is utilized on structuring a product development process into simple and collaborative activities that proceed throughout the entire product life-cycle, while at the same time, supporting engineers’ decision making. Project based engineering design classes are suitable for undergraduate students to study and practice the concepts of SE while solving real-world design problems. In this paper, we document the product development process, especially the structured design methodologies used in an undergraduate Senior Design project. Student learning outcomes are assessed and compared with previous semesters. We have observed overall satisfying student learning in nearly all aspects. Hence, we believe the multidisciplinary project helps students learn valuable knowledge of SE that is usually acquired through real world working experiences

The leakage current components as a diagnostic tool to estimate contamination level on high voltage insulators

The current paper presents an alternative and innovative technique to predict the severity of pollution of high voltage insulator using a higher harmonics component with up to the 7th component of leakage current. The leakage current was measured using a current transformer and a shunt resistor. Next, laboratory tests were conducted on glass and porcelain insulators with artificial pollution under salt-fog pollution state which is further represented by three levels, namely light, medium, and high contamination. In this case, the formulation of a new severity of harmonic index refers to a ratio of the sum of 5th and 7th to the 3rd harmonic component. More importantly, the new index managed to provide more accurate results when used as a diagnostic tool for the levels of pollution, compared to the ratio of the total harmonic distortion (THD) to the number of odd harmonics components (n) as the boundaries. In this case, the insulators were found to be in a clean and normal condition when the K(5+7)/3 value was greater than 3%. Contrastingly, the insulators were in an extreme condition when the K(5+7)/3 was lower than 3%. Nevertheless, there is a high probability of a flashover in glass and porcelain insulators if the K(5+7)/3 value is less than 2%. The present study shows the possibility of utilizing the value of strange harmonics up to the 7th component of leakage current as the parameter for the monitoring of leakage current in overhead insulators in the presence of contamination. Overall, it can be concluded that the 3rd, 5th, and 7th harmonics details extracted from the leakage current act as a good indicator for the level of contamination

Potentiation of thrombus instability: a contributory mechanism to the effectiveness of antithrombotic medications

© The Author(s) 2018The stability of an arterial thrombus, determined by its structure and ability to resist endogenous fibrinolysis, is a major determinant of the extent of infarction that results from coronary or cerebrovascular thrombosis. There is ample evidence from both laboratory and clinical studies to suggest that in addition to inhibiting platelet aggregation, antithrombotic medications have shear-dependent effects, potentiating thrombus fragility and/or enhancing endogenous fibrinolysis. Such shear-dependent effects, potentiating the fragility of the growing thrombus and/or enhancing endogenous thrombolytic activity, likely contribute to the clinical effectiveness of such medications. It is not clear how much these effects relate to the measured inhibition of platelet aggregation in response to specific agonists. These effects are observable only with techniques that subject the growing thrombus to arterial flow and shear conditions. The effects of antithrombotic medications on thrombus stability and ways of assessing this are reviewed herein, and it is proposed that thrombus stability could become a new target for pharmacological intervention.Peer reviewedFinal Published versio

Excess of heme induces tissue factor-dependent activation of coagulation in mice

An excess of free heme is present in the blood during many types of hemolytic anemia. This has been linked to organ damage caused by heme-mediated oxidative stress and vascular inflammation. We investigated the mechanism of heme-induced coagulation activation in vivo. Heme caused coagulation activation in wild-type mice that was attenuated by an anti-tissue factor antibody and in mice expressing low levels of tissue factor. In contrast, neither factor XI deletion nor inhibition of factor XIIa-mediated factor XI activation reduced heme-induced coagulation activation, suggesting that the intrinsic coagulation pathway is not involved. We investigated the source of tissue factor in heme-induced coagulation activation. Heme increased the procoagulant activity of mouse macrophages and human PBMCs. Tissue factor-positive staining was observed on leukocytes isolated from the blood of heme-treated mice but not on endothelial cells in the lungs. Furthermore, heme increased vascular permeability in the mouse lungs, kidney and heart. Deletion of tissue factor from either myeloid cells, hematopoietic or endothelial cells, or inhibition of tissue factor expressed by non-hematopoietic cells did not reduce heme-induced coagulation activation. However, heme-induced activation of coagulation was abolished when both non-hematopoietic and hematopoietic cell tissue factor was inhibited. Finally, we demonstrated that coagulation activation was partially attenuated in sickle cell mice treated with recombinant hemopexin to neutralize free heme. Our results indicate that heme promotes tissue factor-dependent coagulation activation and induces tissue factor expression on leukocytes in vivo. We also demonstrated that free heme may contribute to thrombin generation in a mouse model of sickle cell disease

Kallikrein directly interacts with and activates Factor IX, resulting in thrombin generation and fibrin formation independent of Factor XI

Kallikrein (PKa), generated by activation of its precursor prekallikrein (PK), plays a role in the contact activation phase of coagulation and functions in the kallikrein-kinin system to generate bradykinin. The general dogma has been that the contribution of PKa to the coagulation cascade is dependent on its action on FXII. Recently this dogma has been challenged by studies in human plasma showing thrombin generation due to PKa activity on FIX and also by murine studies showing formation of FIXa-antithrombin complexes in FXI deficient mice. In this study, we demonstrate high-affinity binding interactions between PK(a) and FIX(a) using surface plasmon resonance and show that these interactions are likely to occur under physiological conditions. Furthermore, we directly demonstrate dose- and time-dependent cleavage of FIX by PKa in a purified system by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and chromogenic assays. By using normal pooled plasma and a range of coagulation factor-deficient plasmas, we show that this action of PKa on FIX not only results in thrombin generation, but also promotes fibrin formation in the absence of FXII or FXI. Comparison of the kinetics of either FXIa- or PKa-induced activation of FIX suggest that PKa could be a significant physiological activator of FIX. Our data indicate that the coagulation cascade needs to be redefined to indicate that PKa can directly activate FIX. The circumstances that drive PKa substrate specificity remain to be determined

A novel DFP tripeptide motif interacts with the coagulation factor XI apple 2 domain

Factor XI (FXI) is the zymogen of FXIa, which cleaves FIX in the intrinsic pathway of coagulation. FXI is known to exist as a dimer and interacts with multiple proteins via its 4 apple domains in the “saucer section” of the enzyme; however, to date, no complex crystal structure has been described. To investigate protein interactions of FXI, a large random peptide library consisting of 106 to 107 peptides was screened for FXI binding, which identified a series of FXI binding motifs containing the signature Asp-Phe-Pro (DFP) tripeptide. Motifs containing this core tripeptide were found in diverse proteins, including the known ligand high-molecular-weight kininogen (HK), as well as the extracellular matrix proteins laminin and collagen V. To define the binding site on FXI, we determined the crystal structure of FXI in complex with the HK-derived peptide NPISDFPDT. This revealed the location of the DFP peptide bound to the FXI apple 2 domain, and central to the interaction, the DFP phenylalanine side-chain inserts into a major hydrophobic pocket in the apple 2 domain and the isoleucine occupies a flanking minor pocket. Two further structures of FXI in complex with the laminin-derived peptide EFPDFP and a DFP peptide from the random screen demonstrated binding in the same pocket, although in a slightly different conformation, thus revealing some flexibility in the molecular interactions of the FXI apple 2 domain. (Blood. 2016;00(00):1-9

Gallbladder adenocarcinoma with human chorionic gonadotropin: a case report and review of literature

<p>Abstract</p> <p>Background</p> <p>The case of adenocarcinoma with human chorionic gonadtropin (HCG), primary in the male gallbladder, is extremely rare. A Medline search has shown only a few similar cases reported.</p> <p>Methods</p> <p>We herein describe a case of primary gallbladder adenocarcinoma associated by ectopic HCG positive tumor cells in a 79-year-old male.</p> <p>Results</p> <p>Pathological examination showed a mixture of moderately and poorly differentiated adenocarcinoma with ectopic HCG and placental alkaline phosphatase (PlAP) in tumor cells, though the increase of serum or urinary HCG secretion was not confirmed. The literatures were also reviewed.</p> <p>Conclusions</p> <p>A case of gallbladder cancer with ectopic HCG production is quite rare in the literature, though many similar cases in other site, especially in GI tract, are reported. Embryological consideration suggests the increased frequency of similar cases more than being thought now.</p