Among Wolves, Ethnography and the Immersive Study of Power — Book Review of a Play

Timothy Pachirat’s (2018) Among Wolves: Ethnography and the Immersive Study of Power is an atypical book about doing and thinking about ethnography, presented in play format. I reviewed the book as a doctoral student and novice qualitative researcher as a part of a process to explore a developing interest in ethnography. The book’s conversational format intertwined with perspective from acclaimed contemporary ethnographers’ work helps both the novice ethnographer with a worldview of what doing ethnography entails and the seasoned ethnographer in thinking about reflexivity. The academic rigor and extensive coverage of issues about power, subjectivity and fieldwork, makes it an essential read for ethnographers and those working in interpretive traditions — irrespective of their experience in respective domains

A Novel Tenorrhaphy Suture Technique with Tissue Engineered Collagen Graft to Repair Large Tendon Defects

Surgical management of large tendon defects with tendon grafts is challenging, as there are a finite number of sites where donors can be readily identified and used. Currently, this gap is filled with tendon auto-, allo-, xeno-, or artificial grafts, but clinical methods to secure them are not necessarily translatable to animals because of the scale. In order to evaluate new biomaterials or study a tendon graft made up of collagen type 1, we have developed a modified suture technique to help maintain the engineered tendon in alignment with the tendon ends. Mechanical properties of these grafts are inferior to the native tendon. To incorporate engineered tendon into clinically relevant models of loaded repair, a strategy was adopted to offload the tissue engineered tendon graft and allow for the maturation and integration of the engineered tendon in vivo until a mechanically sound neo-tendon was formed. We describe this technique using incorporation of the collagen type 1 tissue engineered tendon construct

Engineering of a functional tendon

Reconstruction of a tendon following rupture is surgically challenging as each end of the tendon retracts leaving a substantial gap so that direct repair is often not feasible. To restore function, a tendon graft is required to bridge this defect and presently these gaps are filled with auto-, allo- or, synthetic grafts but they all have clinical limitations. To overcome this problem, tissue engineered collagen grafts were developed by a rapid process using compressed cell seeded type I collagen. Previously these constructs were tested in vivo in intercostal spaces of a lapine model to test immunocompatibility but material properties of the tissue engineered collagen grafts are currently unsuitable to withstand complete load bearing in vivo. A modified suture technique was developed to physiologically withstand and off load the tissue engineered collagen graft to aid integration in vivo. This modified suture method allowed only partial load to be transferred onto the tissue engineered collagen graft. Lapine tendons were used to test mechanical strength of repairs and a stress model was built. The break point for modified suture technique with tissue engineered collagen graft in situ was significantly higher compared to standard modified Kessler suture technique. To test the effect of the partial load on tenocytes, mechanobiology was studied under static and 10% cyclic loads using custom designed tensioning culture force monitors with immunohistology and matrix remodelling gene expression as quantifiable outcomes. Tendon fibroblast seeded tissue engineered collagen grafts were tested in vivo in a lapine model up to 12 weeks without immobilization. The gross observation at 3 and 12 weeks showed bridged integration of the graft without any adhesion with significant increase in the mechanical properties for 3 and 12 weeks as compared to 1 week. Histological analysis showed that tendon fibroblasts from the native tendon were able to migrate into the graft with higher collagen remodelling and graft maturation at 12 weeks as compared to 3 and 1 week. Insertion of tissue engineered collagen graft using a novel load bearing suture technique which partially loads in vivo showed integration, greater mechanical strength and no adhesion formation in the time period tested and it has inherent advantages as compared to the present day tendon grafts

Bio-jetted human adipose-derived stem cells remain viable

Direct cell handling processes are increasingly becoming important as they allow the controlled deposition of living cells, with precision for a vast number of applications, spanning the printing of cells in either 2D/3D for the reconstruction of fully functional tissues to the delivery of therapeutic architectures bearing cells and genes of interest. Architectures reconstructed with such cells etc are most useful as models, for studying a wide range of molecular and cellular behaviours, to the development of personalised medicines. Our previous work demonstrated the ability for aerodynamically assisted bio-jets to process single and multiple cell-bearing suspensions, to whole fertilised embryos. Those studies found that the post-treated cells and embryos were indistinguishable from untreated controls. In the present study the authors further validate this jetting technology for the direct handling of stem cells, by demonstrating their viability post-treatment and their capacity to differentiate in comparison to controls. These studies together with our previous work unveil, aerodynamically assisted bio-jets as a platform biotechnology for the direct handling of a wide range of cells and embryos

The mechanobiology of tendon fibroblasts under static and uniaxial cyclic load in a 3D tissue engineered model mimicking native ECM

Tendon mechanobiology plays a vital role in tendon repair and regeneration; however, this mechanism is currently poorly understood. We tested the role of different mechanical loads on extracellular matrix (ECM) remodelling gene expression and the morphology of tendon fibroblasts in collagen hydrogels, designed to mimic native tissue. Hydrogels were subjected to precise static or uniaxial loading patterns of known magnitudes and sampled to analyse gene expression of known mechano‐responsive ECM‐associated genes (Collagen I, Collagen III, Tenomodulin, and TGF‐β). Tendon fibroblast cytomechanics was studied under load by using a tension culture force monitor, with immunofluorescence and immunohistological staining used to examine cell morphology. Tendon fibroblasts subjected to cyclic load showed that endogenous matrix tension was maintained, with significant concomitant upregulation of ECM remodelling genes, Collagen I, Collagen III, Tenomodulin, and TGF‐β when compared with static load and control samples. These data indicate that tendon fibroblasts acutely adapt to the mechanical forces placed upon them, transmitting forces across the ECM without losing mechanical dynamism. This model demonstrates cell‐material (ECM) interaction and remodelling in preclinical a platform, which can be used as a screening tool to understand tendon regeneration

Intern’s knowledge of clinical pharmacology and therapeutics at Puducherry: a cross-sectional study

Background: Internship is the intermediate period between under-graduation and general practice. The dexterity of health professional relies upon prescribing practices. Clinical pharmacology and therapeutics (CPT) is a crucial discipline for interns to acquire safe and rational prescription of drugs. Cultivating sound knowledge about CPT during under graduation is, henceforth, mandatory.Aims and objectives:To assess whether the undergraduate CPT teaching and internship training had prepared interns adequately for safe and rational prescription.To assess the awareness and reporting of adverse drug reaction (ADR).Methods: 110 interns were enrolled after obtaining informed written consent. A structured questionnaire was given to them including basic demographic information, undergraduate CPT teaching, experience of ADR and any deficiency in the under-graduate CPT teaching.Results: Response rate was 91 % in which 53 were males and 47 females. 81 considered themselves aware of CPT. 56% & 57% interns were able to prescribe drug safely and rationally respectively. Without supervision, they were confident to prescribe antacids (93%), vitamins and minerals (90%), NSAIDS (85%), antihistamines (82%), antibiotics (75%), antiemetics (62%) and antiasthmatics (52%). Only 22% had reported ADR and opined that it could lead to hospitalization (51%), prolonged hospital stay (33%), morbidity (16%) and death (21%). According to interns, the topics where more emphasis needed were ADR, dosage calculation, pediatric and emergency medicine and therapeutic drug monitoring during undergraduate CPT teaching.Conclusion: CPT teaching should be improved at undergraduate level for safe and rational prescribing including ADR monitoring, ADR reporting and dosage calculation

A review on the use of cell therapy in the treatment of tendon disease and injuries

Tendon disease and injuries carry significant morbidity worldwide in both athletic and non-athletic populations. It is estimated that tendon injuries account for 30%−50% of all musculoskeletal injuries globally. Current treatments have been inadequate in providing an accelerated process of repair resulting in high relapse rates. Modern concepts in tissue engineering and regenerative medicine have led to increasing interest in the application of cell therapy for the treatment of tendon disease. This review will explore the use of cell therapy, by bringing together up-to-date evidence from in vivo human and animal studies, and discuss the issues surrounding the safety and efficacy of its use in the treatment of tendon disease

Cell morphology as a design parameter in the bioengineering of cell-biomaterial surface interactions

Control of cell–surface interaction is necessary for biomaterial applications such as cell sheets, intelligent cell culture surfaces, or functional coatings. In this paper, we propose the emergent property of cell morphology as a design parameter in the bioengineering of cell–biomaterial surface interactions. Cell morphology measured through various parameters can indicate ideal candidates for these various applications thus reducing the time taken for the screening and development process. The hypothesis of this study is that there is an optimal cell morphology range for enhanced cell proliferation and migration on the surface of biomaterials. To test the hypothesis, primary porcine dermal fibroblasts (PDF, 3 biological replicates) were cultured on ten different surfaces comprising components of the natural extracellular matrix of tissues. Results suggested an optimal morphology with a cell aspect ratio (CAR) between 0.2 and 0.4 for both increased cell proliferation and migration. If the CAR was below 0.2 (very elongated cell), cell proliferation was increased whilst migration was reduced. A CAR of 0.4+ (rounded cell) favoured cell migration over proliferation. The screening process, when it comes to biomaterials is a long, repetitive, arduous but necessary event. This study highlights the beneficial use of testing the cell morphology on prospective prototypes, eliminating those that do not support an optimal cell shape. We believe that the research presented in this paper is important as we can help address this screening inefficiency through the use of the emergent property of cell morphology. Future work involves automating CAR quantification for high throughput screening of prototypes

3D Porous Binary Composites of Collagen, Elastin, and Fibrin Proteins Orchestrate Adipose Tissue Regeneration

The objective for this study is to advance the development of a specialized biomaterial that can effectively facilitate the regeneration of adipose tissue. In prior studies, the assessment of collagen (Col), elastin (Ela), and fibrin (Fib) unary scaffolds has been conducted. However, it is important to note that native adipose tissue is comprised of a diverse array of extracellular matrix (ECM) constituents. To mimic this behavior, binary compositions of collagen, elastin, and fibrin are fabricated in a 1:1 ratio, resulting in the formation of Col/Ela, Col/Fib, and Ela/Fib composites through a customized fabrication procedure. The physical properties of these scaffolds are comprehensively analyzed using a range of material characterization techniques. Additionally, the biological properties of the scaffolds are investigated by examining the survival, proliferation, and phenotype of adipose-derived stem cells. Subsequently, the aforementioned binary scaffolds are implanted into a rodent model for 28 days. the explants are analysed through X-ray microtomography, histology, and immunohistochemistry. The findings of the study demonstrate that the utilization of binary combinations of Col/Ela, Col/Fib, and Ela/Fib has a discernible impact on the physical and biological characteristics of the scaffolds. Nevertheless, Ela/Fib exhibits characteristics that make it a suitable candidate for adipogenesis due to its notable upregulation of caveolin-1 expression in both acellular and cellular cohorts. The combination of two natural polymers in this cell–material interaction has significantly enhanced the comprehension of adipogenesis

Three dimensional porous scaffolds derived from collagen, elastin and fibrin proteins orchestrate adipose tissue regeneration

Current gold standard to treat soft tissue injuries caused by trauma and pathological condition are autografts and off the shelf fillers, but they have inherent weaknesses like donor site morbidity, immuno-compatibility and graft failure. To overcome these limitations, tissue-engineered polymers are seeded with stem cells to improve the potential to restore tissue function. However, their interaction with native tissue is poorly understood so far. To study these interactions and improve outcomes, we have fabricated scaffolds from natural polymers (collagen, fibrin and elastin) by custom-designed processes and their material properties such as surface morphology, swelling, wettability and chemical cross-linking ability were characterised. By using 3D scaffolds, we comprehensive assessed survival, proliferation and phenotype of adipose-derived stem cells in vitro. In vivo, scaffolds were seeded with adipose-derived stem cells and implanted in a rodent model, with X-ray microtomography, histology and immunohistochemistry as read-outs. Collagen-based materials showed higher cell adhesion and proliferation in vitro as well as higher adipogenic properties in vivo. In contrast, fibrin demonstrated poor cellular and adipogenesis properties but higher angiogenesis. Elastin formed the most porous scaffold, with cells displaying a non-aggregated morphology in vitro while in vivo elastin was the most degraded scaffold. These findings of how polymers present in the natural polymers mimicking ECM and seeded with stem cells affect adipogenesis in vitro and in vivo can open avenues to design 3D grafts for soft tissue repair