Suppression of ICE and Apoptosis in Mammary Epithelial Cells by Extracellular Matrix Nancy Boudreau,* Carolyn J. Sympson, Zena Werb, Mina J. Bissell N. Boudreau and M. J. Bissell Life Sciences Division, Lawrence Berkeley Laboratory 1 Cyclotron Road, Building 83, Berkeley, CA 94720, USA. C. J. Sympson Life Sciences Division, Lawrence Berkeley Laboratory 1 Cyclotron Road, Building 83, Berkeley, CA 94720, USA Laboratory of Radiobiology and Environmental Health University of California, San Francisco, CA 94143, USA. Z. Werb Laboratory of Radiobiology and Environmental Health University of California, San Francisco, CA 94143, USA. *To whom correspondence should be addressed. LBNL/DOE funding & contract number: DE-AC02-05CH11231 DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or The Regents of the University of California.

Suppression of ICE and Apoptosis in Mammary Epithelial Cells by Extracellular Matrix

The potential for ischemic preconditioning to reduce infarct size was first recognized more than 30 years ago. Despite extension of the concept to ischemic postconditioning and remote ischemic conditioning and literally thousands of experimental studies in various species and models which identified a multitude of signaling steps, so far there is only a single and very recent study, which has unequivocally translated cardioprotection to improved clinical outcome as the primary endpoint in patients. Many potential reasons for this disappointing lack of clinical translation of cardioprotection have been proposed, including lack of rigor and reproducibility in preclinical studies, and poor design and conduct of clinical trials. There is, however, universal agreement that robust preclinical data are a mandatory prerequisite to initiate a meaningful clinical trial. In this context, it is disconcerting that the CAESAR consortium (Consortium for preclinicAl assESsment of cARdioprotective therapies) in a highly standardized multi-center approach of preclinical studies identified only ischemic preconditioning, but not nitrite or sildenafil, when given as adjunct to reperfusion, to reduce infarct size. However, ischemic preconditioning—due to its very nature—can only be used in elective interventions, and not in acute myocardial infarction. Therefore, better strategies to identify robust and reproducible strategies of cardioprotection, which can subsequently be tested in clinical trials must be developed. We refer to the recent guidelines for experimental models of myocardial ischemia and infarction, and aim to provide now practical guidelines to ensure rigor and reproducibility in preclinical and clinical studies on cardioprotection. In line with the above guideline, we define rigor as standardized state-of-the-art design, conduct and reporting of a study, which is then a prerequisite for reproducibility, i.e. replication of results by another laboratory when performing exactly the same experiment.

/pdf/practical-guidelines-for-rigor-and-reproducibility-in-3vd3h9gm16.pdf

Practical guidelines for rigor and reproducibility in preclinical and clinical studies on cardioprotection.

Platelet rich plasma (PRP) has been utilized in regenerative dentistry as a supra-physiological concentrate of autologous growth factors capable of stimulating tissue regeneration. Despite this, concerns have been expressed regarding the use of anti-coagulants, agents known to inhibit wound healing. In this study, a liquid formulation of platelet rich fibrin (PRF) termed injectable-PRF (i-PRF) without the use of anti-coagulants was investigated. Standard PRP and i-PRF (centrifuged at 700 rpm (60G) for 3 min) were compared for growth factor release up to 10 days (8 donor samples). Furthermore, fibroblast biocompatibility at 24 h (live/dead assay); migration at 24 h; proliferation at 1, 3, and 5 days, and expression of PDGF, TGF-β, and collagen1 at 3 and 7 days were investigated. Growth factor release demonstrated that in general PRP had higher early release of growth factors whereas i-PRF showed significantly higher levels of total long-term release of PDGF-AA, PDGF-AB, EGF, and IGF-1 after 10 days. PRP showed higher levels of TGF-β1 and VEGF at 10 days. While both formulations exhibited high biocompatibility and higher fibroblast migration and proliferation when compared to control tissue-culture plastic, i-PRF induced significantly highest migration whereas PRP demonstrated significantly highest cellular proliferation. Furthermore, i-PRF showed significantly highest mRNA levels of TGF-β at 7 days, PDGF at 3 days, and collagen1 expression at both 3 and 7 days when compared to PRP. i-PRF demonstrated the ability to release higher concentrations of various growth factors and induced higher fibroblast migration and expression of PDGF, TGF-β, and collagen1. Future animal research is now necessary to further validate the use of i-PRF as a bioactive agent capable of stimulating tissue regeneration. The findings from the present study demonstrate that a potent formulation of liquid platelet concentrates could be obtained without use of anti-coagulants.

Injectable platelet rich fibrin (i-PRF): opportunities in regenerative dentistry?

The growing multidisciplinary field of tissue engineering aims at predictably regenerating, enhancing, or replacing damaged or missing tissues for a variety of conditions caused by trauma, disease, and old age. One area of research that has gained tremendous awareness in recent years is that of platelet-rich fibrin (PRF), which has been utilized across a wide variety of medical fields for the regeneration of soft tissues. This systematic review gathered all the currently available in vitro, in vivo, and clinical literature utilizing PRF for soft tissue regeneration, augmentation, and/or wound healing. In total, 164 publications met the original search criteria, with a total of 48 publications meeting inclusion criteria (kappa score = 94%). These studies were divided into 7 in vitro, 11 in vivo, and 31 clinical studies. In summary, 6 out of 7 (85.7%) and 11 out of 11 (100%) of the in vitro and in vivo studies, respectively, demonstrated a statistically significant advantage for combining PRF to their regenerative therapies. Out of the remaining 31 clinical studies, a total of 8 reported the effects of PRF in a randomized clinical trial, with 5 additional studies (13 total) reporting appropriate controls. In those clinical studies, 9 out of the 13 studies (69.2%) demonstrated a statistically relevant positive outcome for the primary endpoints measured. In total, 18 studies (58% of clinical studies) reported positive wound-healing events associated with the use of PRF, despite using controls. Furthermore, 27 of the 31 clinical studies (87%) supported the use of PRF for soft tissue regeneration and wound healing for a variety of procedures in medicine and dentistry. In conclusion, the results from the present systematic review highlight the positive effects of PRF on wound healing after regenerative therapy for the management of various soft tissue defects found in medicine and dentistry.

Platelet-Rich Fibrin and Soft Tissue Wound Healing: A Systematic Review

Premature rupture of fetal membranes

Animal experimentation is carried out in consultation with the veterinary wing but it is essential that be familiar with experimental protocols of animal model to be able to design an approriate study. This is more so in place where the veterinary facilities are not easily available.Span Rabbits are commonly used as subjects for screening implant material. They have gained favour for their numerous advantages even though they should be ideally used prior to testing in a larger animal model. Though experimentation on rabbits seems to be easy there are many pitfalls. Our endeavor in this article is to integrate all the data about maintaining rabbits as a model and to critically analyze it on the basis of our experimentation. Key Words: Animal model, experimental model, rabbit model

http://drj.mui.ac.ir/index.php/drj/article/download/908/167

Rabbit as an animal model for experimental research.

Background: As one of India's premier dental schools, the Manipal College of Dental Sciences, Manipal, has strived to be in the forefront of dental education ever since its inception in 1965. But one of our main drawbacks has been the lack of students’ perceptions about the educational atmosphere in our institution.Aim: (1) To understand the students’ perceptions of the educational environment. (2) To compare the results with those of other dental/medical schools.Methods: Dundee Ready Education Environment Measure (DREEM) was used to gather information about the environment in our institution. The same was administered to first year and final year students (63 each).Results: The main area of convergence of both groups was that the social atmosphere was not very congenial. But the thought provoking finding was that both groups felt that the teachers were authoritarian.Conclusion: The lack of congenial atmosphere in our institution seems to be due to the attitude of the course organizers. A need for makeove...

https://www.tandfonline.com/doi/pdf/10.1080/01421590802516749

Students’ perceptions regarding educational environment in an Indian dental school

Background: Owing to its stimulatory effect on angiogenesis and epithelialization, platelet-rich fibrin (PRF) is an excellent material for enhancing wound healing. The use of PRF dressings may be a simple and effective method of reducing the morbidity associated with donor sites of autogenous free gingival grafts (FGGs). The purpose of this case series is to document the beneficial role of PRF in the healing of FGG donor sites. Materials and Methods: A total of 18 patients treated with FGGs could be classified into two groups. PRF was prepared, compressed and used to dress the palatal wound followed by a periodontal pack in one group (10 patients) and only a periodontal pack was used in the other group (8 patients). Post-operative healing was assessed clinically at 7, 14 and 21 days and the morbidity was assessed qualitatively by an interview. Results: Sites where PRF was used showed complete wound closure by 14 days and these patients reported lesser post-operative morbidity than patients in whom PRF was not used. Conclusions: PRF as a dressing is an effective method of enhancing the healing of the palatal donor site and consequently reducing the post-operative morbidity.

Platelet-rich fibrin as an adjunct to palatal wound healing after harvesting a free gingival graft: A case series.

There are many studies documenting increased prevalence of periodontal infection in women with preeclampsia. But, very few studies have attempted to establish causal relationship between the two. To find out causal circumstantial evidence by isolating specific periodontal pathogens in oral and placental samples. Antenatal periodontal screening and subgingival plaque collection was carried out in ten women with hypertension in pregnancy and ten normotensive controls on their hospital admission at term for cesarean delivery. Placental biopsy was obtained after aseptic placental collection at the time of elective cesarean delivery. Subgingival plaque and placental biopsy were studied for Porphyromonas gingivalis, Fusobacterium nucleatum, Treponema denticola, Prevotella intermedia and Aggregatibacter actinomycetemcomitans using quantitative polymerase chain reaction technique. Periodontist and laboratory personnel were unaware of case or control status. Periodontal status was not informed to the obstetrician recruiting the cases and laboratory. Microbiology report was not revealed till end of the study. Periodontal pathogens were found to be high in the group with hypertension than the controls. P gingivalis was found in all the samples from subgingival plaque and placenta, irrespective of the periodontal disease status. In cases with hypertension, periodontal pathogens are present in higher proportion in subgingival plaque and placenta.

Simultaneous detection of periodontal pathogens in subgingival plaque and placenta of women with hypertension in pregnancy

Amniotic membrane is the inner most lining of the human placenta that is normally discarded after parturition. The membrane has numerous growth factors, proteins and stem cell reserves that help in accelerating wound healing with regeneration of the lost tissues. The preserved human amniotic membrane is a novel tissue engineerined biomaterial that is recently tired in field of medicine and dentistry to regenerate the lost tissues and accelerate repair. This review paper unfolds the inherent structure, properties, mechanisms and the applications of this neglected tissue that makes it a potential material for regeneration especially in the field of oral and periodontal surgeries.

Betsy S Thomas

Papers

Rabbit as an animal model for experimental research.

Students’ perceptions regarding educational environment in an Indian dental school

Platelet-rich fibrin as an adjunct to palatal wound healing after harvesting a free gingival graft: A case series.

Simultaneous detection of periodontal pathogens in subgingival plaque and placenta of women with hypertension in pregnancy

Amniotic Membrane: A Novel Material for Regeneration and Repair