Evidence for accelerated colorectal adenoma--carcinoma progression in MUTYH-associated polyposis?

BACKGROUND AND AIM

MUTYH-associated polyposis (MAP) is an autosomal recessive inherited disorder characterised by the development of polyposis in the upper and lower gastrointestinal tract and a high risk of colorectal cancer (CRC). We evaluated the natural history of the disease and the outcome of colorectal surveillance and management.

METHODS

A large Western European dataset of biallelic MUTYH mutation carriers comprising 254 patients was used. Detailed information was collected on polyp and cancer development in the colorectum, and the outcome of surveillance and surgery. Survival methods were used to calculate the risk of CRC development.

RESULTS

The mean follow-up was 9.8 years. Colorectal polyposis was diagnosed at a mean age of 44.8 years (range: 12-77 years). Most patients had <100 colorectal adenomas at diagnosis. CRC was diagnosed in 147 (58%) of the 254 patients (mean age at diagnosis: 48.5, range: 21-77 years). The cumulative lifetime risk of CRC was 63% at age 60 years. There was no correlation between the number of adenomas and the presence of CRC. The cumulative risk of CRC in patients presenting with polyps was 9% after 5 years of follow-up. Patients presenting with CRC had 11% risk of developing a metachronous CRC at 5 years after surgery. Thirty-seven per cent of patients with MAP with CRC who underwent partial colonic resection needed secondary surgery shortly afterwards.

CONCLUSIONS

The high risk of developing CRC under surveillance in patients with MAP may suggest an accelerated carcinogenesis. Surveillance of these patients should therefore include colonoscopy at short intervals, for example, at 1-2-year intervals starting from the age of 18 to 20 years. If surgery for CRC is warranted, a (sub)total colectomy is recommended.

Suicide by multiple blunt head traumatisation using a stone

Apart from collisions with road or rail vehicles and falls from height, self inflicted blunt force is a rare suicide method and mainly seen in psychiatric patients. The paper presents a rare case of suicide by active blunt force. A 68-year-old man committed suicide by repeatedly hitting his head with a stone. He sustained a craniocerebral trauma and finally died from hypothermia due to the low outdoor temperature. According to the relatives, the man was not diagnosed with a mental disorder or suicidal tendencies. Uncommon manners of self-harm are challenging for those involved in the investigation, and a differentiation between suicide, accident and homicide can only be made in synopsis of all findings.

Separation of plasmid DNA from protein and bacterial lipopolysaccharides using displacement chromatography

The preparation of plasmid DNA at large scale constitutes a pressing problem in bioseparation. This paper describes a first investigation of displacement chromatography as a means to separate plasmid DNA (4.7 kb) from E. coli lipopolysaccharides and protein (holo transferrin), respectively. Displacement chromatography has advantages in this regard, since the substance mixture is resolved into rectangular zones of the individual components rather than into peaks. Thus a higher total concentration can be maintained in the pooled product fractions. Hydroxyapatite (type I and II) and anion exchange stationary phases were included in the experiments. In addition to a conventional anion exchange column packed with porous particles, the recently introduced continuous bed UNOTM anion exchange column was investigated. No DNA purification was possible with either hydroxyapatite material. Conventional particle based columns in general were not suited to the separation of any two substances varying considerably in molecular mass, e.g. plasmid DNA and standard protein. Presumably, the direct competition for the binding sites, which is essential in displacement chromatography, was restricted by the size dependency of the accessible stationary phase surface area in this case. Better results were obtained with the continuous bed column, in which the adsorptive surface coincides with the walls of the flow through pores. As a result the accessible surface does not vary as much with the size of the interacting molecules as for the conventional stationary phase materials. Sharper transitions were also observed between substance zones recovered from the UNOTM column. The steric mass action model was used to aid method development in case of the anion exchange approach. While further research in obviously necessary, displacement chromatography on continuous bed columns has been shown to be capable of separating plasmid DNA from typical impurities.

Paradoxical embolization of brachiocephalic and pulmonary arteries in a case of persistent foramen ovale: a case report

Paradoxical embolism is the result of systemic arterial embolism and pulmonary embolism. It indicates the presence of an intracardial defect in the area of the atrial or ventricular septum. The most frequent cause of an intracardiac defect associated with paradoxical embolism is a patent foramen ovale (PFO). In the case presented here, the symptoms, diagnostics and surgical therapy are discussed.

Klinik und Genetik des familiären Darmkrebses

Eine familiäre Häufung von Dickdarmkrebs (CRC) und ein früher Erkrankungsbeginn sind Hinweise auf erbliche Tumorsyndrome, die für etwa 3–5% aller CRC verantwortlich sind. Bei diesen monogenen Dispositionen wird der erbliche Dickdarmkrebs ohne Polyposis (HNPCC/Lynch-Syndrom) von der Gruppe der gastrointestinalen Polyposis-Syndrome unterschieden. Bei vielen hereditären Formen besteht ein z. T. charakteristisches Spektrum extrakolonischer Tumoren. Die frühe Erkennung und korrekte Einordnung ist wichtig, da effektive Methoden der Vorsorge und Therapie für Betroffene und Risikopersonen bestehen.

Die Initialdiagnostik umfasst das endoskopische Bild und den histologischen Befund, ergänzt um extraintestinale Manifestationen und die Familienanamnese. Die molekulargenetische Abklärung erfolgt nach weitgehend etablierten und standardisierten Algorithmen. Differenzialdiagnostische Probleme bereiten insbesondere Patienten mit wenigen kolorektalen Adenomen sowie phänotypische Überlappungen bei hamartomatösen Polyposis-Syndromen. Für HNPCC und häufige Polyposis-Syndrome existieren etablierte risikoadaptierte Früherkennungsprogramme.

Der außerhalb der etablierten Tumorsyndrome beobachteten familiären Häufung des – oft spätmanifesten – CRC und dem Auftreten weniger Adenome liegt vermutlich eine multifaktorielle Ätiologie zugrunde. Die Aufklärung der genetischen Faktoren und das Verständnis der beteiligten Signalwege steht hier noch am Anfang, macht aber durch die rasanten methodischen Entwicklungen (z. B. genomweite Assoziationsstudien, CNV-Analysen) rasche Fortschritte.

Generation and characterization of a human acellular meniscus scaffold for tissue engineering

Meniscus tears are frequent indications for arthroscopic evaluation which can result in partial or total meniscectomy. Allografts or synthetic meniscus scaffolds have been used with varying success to prevent early degenerative joint disease in these cases. Problems related to reduced initial and long-term stability, as well as immunological reactions prevent widespread clinical use so far. Therefore, the aim of this study was to develop a new construct for tissue engineering of the human meniscus based on an acellular meniscus allograft. Human menisci (n = 16) were collected and acellularized using the detergent sodium dodecyl sulfate as the main ingredient or left untreated as control group. These acellularized menisci were characterized biomechanically using a repetitive ball indentation test (Stiffness N/mm, residual force N, relative compression force N) and by histological (hematoxylin-eosin, phase-contrast) as well as immunohistochemical (collagen I, II, VI) investigation. The processed menisci histologically appeared cell-free and had biomechanical properties similar to the intact meniscus samples (p > 0.05). The collagen fiber arrangement was not altered, according to phase-contrast microscopy and immunohistochemical labeling. The removal of the immunogenic cell components combined with the preservation of the mechanically relevant parts of the extracellular matrix could make these scaffolds ideal implants for future tissue engineering of the meniscus.