Chemical Clearing and Dehydration of GFP Expressing Mouse Brains

Generally, chemical tissue clearing is performed by a solution consisting of two parts benzyl benzoate and one part benzyl alcohol. However, prolonged exposure to this mixture markedly reduces the fluorescence of GFP expressing specimens, so that one has to compromise between clearing quality and fluorescence preservation. This can be a severe drawback when working with specimens exhibiting low GFP expression rates. Thus, we screened for a substitute and found that dibenzyl ether (phenylmethoxymethylbenzene, CAS 103-50-4) can be applied as a more GFP-friendly clearing medium. Clearing with dibenzyl ether provides improved tissue transparency and strikingly improved fluorescence intensity in GFP expressing mouse brains and other samples as mouse spinal cords, or embryos. Chemical clearing, staining, and embedding of biological samples mostly requires careful foregoing tissue dehydration. The commonly applied tissue dehydration medium is ethanol, which also can markedly impair GFP fluorescence. Screening for a substitute also for ethanol we found that tetrahydrofuran (CAS 109-99-9) is a more GFP-friendly dehydration medium than ethanol, providing better tissue transparency obtained by successive clearing. Combined, tetrahydrofuran and dibenzyl ether allow dehydration and chemical clearing of even delicate samples for UM, confocal microscopy, and other microscopy techniques

The registry of the German Network for Systemic Scleroderma: frequency of disease subsets and patterns of organ involvement

Objective. Systemic sclerosis (SSc) is a rare, heterogeneous disease, which affects different organs and therefore requires interdisciplinary diagnostic and therapeutic management. To improve the detection and follow-up of patients presenting with different disease manifestations, an interdisciplinary registry was founded with contributions from different subspecialties involved in the care of patients with SSc

Maude Abbott and the origin and mysterious disappearance of the Canadian Medical War Museum

From the mid-1960s a new breed of scientific instrument curators emerged in the United Kingdom. This small community of practice developed in parallel to but Context.—In the early 1900s, it was common practice to retain, prepare, and display instructive pathologic specimens to teach pathology to medical trainees and practitioners; these collections were called medical museums. Maude Abbott established her reputation by developing expertise in all aspects of medical museum work. She was afounder of the International Association of Medical Museums (later renamed the International Academy of Pathology) and became an internationally renowned expert on congenital heart disease. Her involvement in the Canadian Medical War Museum (CMWM) is less well known. Objective.—To explore Abbott’s role in the development of the CMWM during and after World War I and to trace its history. Design.—Available primary and secondary historical sources were reviewed. Results.—Instructive pathologic specimens derived from Canadian soldiers dying during World War I were shipped to the Royal College of Surgeons in London, which served as a clearinghouse for museum specimens from Dominion forces. The Canadian specimens were repatriated to Canada, prepared by Abbott, and displayed at several medical meetings. Abbott, because she was a woman, could not enlist and so she reported to a series of enlisted physicians with no expertise in museology. Plans for a permanent CMWM building in Ottawa eventually failed and Abbott maintained the collection at McGill (Montreal, Quebec, Canada) until her death in 1940. We trace the CMWM after her death. Conclusions.—Sadly, after Abbott had meticulously prepared these precious teaching specimens so that their previous owners’ ultimate sacrifice would continue to help their military brethren, the relics were bureaucratically lost

Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry

OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc). METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers. RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group. CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies