In vivo investigation of temporomandibular joint regeneration: development of a mouse model.

Temporomandibular joint (TMJ) reconstruction is traditionally invasive. Several investigators have developed animal models, including mouse models, to study the TMJ. However, there are no detailed descriptions of a mouse model to be followed for additional research. The goal of this project was to study minimally invasive TMJ regeneration using tissue engineering in mice. As part of the project, a detailed mouse model was developed, which is described in this article. Eight carcasses were used to study the anatomy of the TMJ of the mouse and 36 mice were used to describe the surgical approach and perioperative management. The study showed similarities and differences when compared to humans. One mouse died suddenly 10 days postoperatively, while 35 mice survived the operation. Keratitis and wound dehiscence were the most common complications. Investigators reviewing this paper should be able to use this mouse model to further study TMJ regeneration in mice.

Comparison of gene editing versus conventional breeding to introgress the POLLED allele into the US dairy cattle population.

Disbudding and dehorning are commonly used cattle management practices to protect animals and humans from injury. They are unpleasant, costly processes subject to increased public scrutiny as an animal welfare issue. Horns are a recessively inherited trait, so one option to eliminate dehorning is to breed for polled (hornlessness). However, due to the low genetic merit and scarcity of polled dairy sires, this approach has not been widely adopted. In March 2018, only 3 Holstein and 0 Jersey active homozygous polled sires were registered with the National Association of Animal Breeders. Alternatively, gene editing to produce high-genetic-merit polled sires has been proposed. To further explore this concept, introgression of the POLLED allele into both the US Holstein and Jersey cattle populations via conventional breeding or gene editing (top 1% of bulls/year) was simulated for 3 polled mating schemes and compared with baseline selection on lifetime net merit (NM$) alone, over the course of 20 yr. Scenarios were replicated 10 times and the changes in HORNED allele frequency, inbreeding, genetic gain (NM$), and number of unique sires used were calculated. Gene editing decreased the frequency of the HORNED allele to <0.1 after 20 yr, which was as fast or faster than conventional breeding for both breeds. In the mating scheme that required the use of only existing homozygous polled sires, inbreeding reached 17% (Holstein) and 14% (Jersey), compared with less than 7% in the baseline scenarios. However, gene editing in the same mating scheme resulted in significantly less inbreeding, 9% (Holstein) and 8% (Jersey). Also, gene editing resulted in significantly higher NM$ after 20 yr compared with conventional breeding for both breeds. Additionally, the gene editing scenarios of both breeds used a significantly greater number of unique sires compared with either the conventional breeding or baseline scenarios. Overall, our simulations show that, given the current genetic merit of horned and polled dairy sires, the use of conventional breeding methods to decrease the frequency of the HORNED allele will increase inbreeding and slow genetic improvement. Furthermore, this study demonstrates how gene editing could be used to rapidly decrease the frequency of the HORNED allele in US dairy cattle populations while maintaining the rate of genetic gain, constraining inbreeding to acceptable levels, and simultaneously addressing an emerging animal welfare concern.

Double trouble from sunburn: UVB-induced erythema is associated with a transient decrease in skin pigmentation.

BACKGROUND: Ultraviolet B (UVB) radiation may cause an immediate inflammatory response followed by a delayed increase in skin pigmentation. The early time course of erythema and pigmentation has so far not been monitored simultaneously by photometric measurements. METHODS: Test areas on the volar forearms of 15 volunteers were irradiated with 210 mJ/cm(2) UVB. Skin erythema and pigmentation were determined photometrically at time 0, after 6 h, and after 1, 2, 3 and 7 days. Punch biopsies were taken before irradiation, after 6 h and after 7 days. Melanocytes were stained using the DOPA method. RESULTS: UVB irradiation caused an increase in skin erythema at all time points, peaking at 24 h and slowly decreasing until day 7. Surprisingly, this was associated with a pronounced decrease in skin pigmentation at early readings. DOPA staining of melanocytes confirmed this observation. Only after 7 days was there an increase in skin pigmentation over the initial levels. CONCLUSIONS: Acute UVB-induced skin erythema seems to be associated with increased susceptibility to the deleterious effects of solar radiation due to a concomitant decrease in skin pigmentation. These findings underline the importance of avoiding even moderate sunburns and of slowly adapting the skin to solar radiation.

An XML-based system for the flexible classification and retrieval of clinical practice guidelines.

Beneficial effects of clinical practice guidelines (CPGs) have not yet reached expectations due to limited routine adoption. Electronic distribution and reminder systems have the potential to overcome implementation barriers. Existing electronic CPG repositories like the National Guideline Clearinghouse (NGC) provide individual access but lack standardized computer-readable interfaces necessary for automated guideline retrieval. The aim of this paper was to facilitate automated context-based selection and presentation of CPGs. Using attributes from the NGC classification scheme, an XML-based metadata repository was successfully implemented, providing document storage, classification and retrieval functionality. Semi-automated extraction of attributes was implemented for the import of XML guideline documents using XPath. A hospital information system interface was exemplarily implemented for diagnosis-based guideline invocation. Limitations of the implemented system are discussed and possible future work is outlined. Integration of standardized computer-readable search interfaces into existing CPG repositories is proposed.

Workflow analysis and evidence-based medicine: towards integration of knowledge-based functions in hospital information systems.

The large extent and complexity of scientific evidence described in the concept of evidence-based medicine often overwhelms clinicians who want to apply best external evidence. Hospital Information Systems usually do not provide knowledge-based functions to support context-sensitive linking to external information sources. Knowledge-based components need specific data, which must be entered manually and should be well adapted to clinical environment to be accepted by clinicians. This paper describes a workflow-based approach to understand and visualize clinical reality as a preliminary to designing software applications, and possible starting points for further software development.