Human intestinal M cells exhibit enterocyte-like intermediate filaments

Background—The derivation and ultrastructuralcomposition of M cells covering the lymphoid follicles of Peyer'spatches is still unknown. Results from different animal models haveshown that there are species specific differences in the composition ofintermediate filaments between M cells and neighbouring enterocytes. Little is known, however, about intermediate filaments of human M cells.
Aims—To compare components of the cytoskeleton ofhuman M cells with those of adjacent absorptive enterocytes.
Methods—The expression and localisation ofdifferent cytokeratins, vimentin, and desmin in M cells was determinedon follicle associated epithelia of human appendix usingimmunohistochemistry and immunogold electron microscopy.
Results—Cytokeratins specific for humanintestinal epithelial cells such as cytokeratins 8, 18, 19, and 20 wereexpressed in both absorptive enterocytes and M cells with nodifferences in intensity and cellular distribution between both celltypes. Vimentin and desmin, tissue specific markers of eithermesenchymal or myogenic cells, as well as other cytokeratins were notdetectable in enterocytes or M cells.
Conclusion—This is the first study on thestructure of intermediate filaments in human intestinal M cells. Ourresults show that in contrast to several animal models, human M cellsapparently do not differ from adjacent enterocytes in the compositionof their intermediate filament cytoskeleton. The presence of enterocyte like cytokeratins and the absence of other cytokeratins as well as ofvimentin and desmin supports the hypothesis of an epithelial origin ofhuman intestinal M cells and suggests that M cells may derive fromdifferentiated enterocytes.

Keywords:human intestinal M cells; appendix; cytokeratin; intermediate filaments; follicle associated epithelium

     

Gastric mucosal blood flow and pepsin secretion in dogs--stimulation by 13-nle-motilin.

In response to graded doses of intravenous 13-norleucine-motilin (13-nle-motilin)--a synthetic analogue of motilin and biologically equivalent to the natural polypeptide-, gastric mucosal blood flow (GMBF) in canine vagally denervated fundic pouches was studied using the aminopyrine clearance technique. As 13-nle-motilin did not exert any detectable effect on gastric secretion of hydrogen ions, intraluminal instillation of 160 mM HCl was used to provide a pH gradient allowing aminopyrine to move into the pouch lumen. With increasing doses of 13-nle-motilin, GMBF increased to 148% of control values; pepsin secretion - due to augmented pepsin concentration - rose concomitantly. Enhanced pepsin secretion was not accompanied by an increase in cyclic 3',5'-adenosine monophosphate secretion.     

Surgical treatment of piles

PURPOSE: The present prospective, randomized clinical trial compares the outcome of surgical hemorrhoidectomy according to Parks and Milligan-Morgan in terms of hospital stay, duration of incapacity to work, symptom relief, length of morbidity, and patient convenience. METHODS: Thirty-four consecutive patients with third or fourth degree internal hemorrhoids were randomly allocated to the two groups. Before surgery, all patients were interviewed using a standard questionnaire, followed by rectal examination. All patients underwent a follow-up interview and examinations 1, 2, 4, 8, and 12 weeks after the operation. RESULTS: No serious postoperative complications were seen. Length of hospital stay (3.2 days for Parks hemorrhoidectomyvs. 4.6 days for Milligan-Morgan hemorrhoidectomy; 95 percent confidence interval, 0.2 and 2.6, respectively;P=0.02) and mean duration of incapacity to work (12.3 days for Parks hemorrhoidectomyvs. 20.2 days for Milligan-Morgan hemorrhoidectomy; 95 percent confidence interval, 5.7 and 10.2, respectively;P<0.001) differed significantly between the Milligan-Morgan and Parks patients. Until two weeks after the operation, Milligan-Morgan hemorrhoidectomy patients experienced significantly more pain. CONCLUSIONS: Our study confirms that both operations are safe, easy to perform, and lead to satisfactory results. However, the Parks procedure is the preferred option, because it minimizes patients' postoperative discomfort, is more economic, has a significantly reduced hospital stay, and has a shorter time for return to work.     

Acute ulcerative colitis--a rare complication of sulfasalazine therapy

A 43-year-old female suffering from ulcerative colitis did not improve under therapy with sulfasalazine. Following withdrawal of sulfasalazine and its replacement by systemic steroids and metronidazole++ she went into clinical and endoscopic remission. A second trial with sulfasalazine was, again, followed by a rapid and sever relapse of the colitis. On discontinuation of sulfasalazine therapy, gross inflammation resolved immediately. This adverse reaction to sulfasalazine has been reported previously in only four cases. The pathophysiology of this event is unknown.     

Long-term survival of a patient with congenital central hypoventilation syndrome despite the lack of continuous ventilatory support

Untreated idiopathic congenital central hypoventilation syndrome (CCHS) is thought to cause infant death within 1-2 months. Here we present an adult patient with CCHS who survived without continuous ventilatory support, despite hypoventilation from early childhood onward. The diagnosis was confirmed at the age of 22 years, when the patient presented with hypoventilation during the night (PaCO2 60 mm Hg, PaO2 56 mm Hg, pH 7.32 HCO3- 30 mmol/l) but hyperventilation when awake (PaCO2 26 mm Hg, PaO2 81 mm Hg, pH 7.56, HCO3- 23 mmol/l). The maximal hematocrit was 77%. Despite mental retardation, noninvasive positive pressure ventilation (NPPV) could be successfully established. NPPV-supported ventilation during the night (PaCO2 36, PaO2 84 mm Hg, pH 7.47, HCO3- 25 mmol/l) reduced hematocrit values (40.6 to 36.8%) over a period of 4 years. In conclusion, long-term survival with CCHS is possible without continuous ventilatory support. Spontaneous improvement of hypoventilation during sleep throughout childhood is possible and hyperventilation during wakefulness may occur in patients with CCHS. CCHS can be managed with NPPV despite mental retardation, even over a long-term period.     

High resolution copy number analysis of IRF4 translocation‐positive diffuse large B‐cell and follicular lymphomas

Translocations affecting chromosome subband 6p25.3 containing the IRF4 gene have been recently described as characteristic alterations in a molecularly distinct subset of germinal center B‐cell‐derived lymphomas. Secondary changes have yet only been described in few of these lymphomas. Here, we performed array‐comparative genomic hybridization and molecular inversion probe microarray analyses on DNA from 12 formalin‐fixed paraffin‐embedded and two fresh‐frozen IRF4 translocation‐positive lymphomas, which together with the previously published data on nine cases allowed the extension of copy number analyses to a total of 23 of these lymphomas. All except one case carried chromosomal imbalances, most frequently gains in Xq28, 11q22.3‐qter, and 7q32.1‐qter and losses in 6q13‐16.1, 15q14‐22.31, and 17p. No recurrent copy‐neutral losses of heterozygosity were observed. TP53 point mutations were detected in three of six cases with loss of 17p. Overall this study unravels a recurrent pattern of secondary genetic alterations in IRF4 translocation‐positive lymphomas. © 2012 Wiley Periodicals, Inc.     

Finite element analysis on the biomechanical stability of open porous titanium scaffolds for large segmental bone defects under physiological load conditions

Repairing large segmental defects in long bones caused by fracture, tumour or infection is still a challenging problem in orthopaedic surgery. Artificial materials, i.e. titanium and its alloys performed well in clinical applications, are plenary available, and can be manufactured in a wide range of scaffold designs. Although the mechanical properties are determined, studies about the biomechanical behaviour under physiological loading conditions are rare. The goal of our numerical study was to determine the suitability of open-porous titanium scaffolds to act as bone scaffolds. Hence, the mechanical stability of fourteen different scaffold designs was characterized under both axial compression and biomechanical loading within a large segmental distal femoral defect of 30 mm. This defect was stabilized with an osteosynthesis plate and physiological hip reaction forces as well as additional muscle forces were implemented to the femoral bone. Material properties of titanium scaffolds were evaluated from experimental testing. Scaffold porosity was varied between 64 and 80%. Furthermore, the amount of material was reduced up to 50%. Uniaxial compression testing revealed a structural modulus for the scaffolds between 3.5 GPa and 19.1 GPa depending on porosity and material consumption. The biomechanical testing showed defect gap alterations between 0.03 mm and 0.22 mm for the applied scaffolds and 0.09 mm for the intact bone. Our results revealed that minimizing the amount of material of the inner core has a smaller influence than increasing the porosity when the scaffolds are loaded under biomechanical loading. Furthermore, an advanced scaffold design was found acting similar as the intact bone.     

Implementing an Innovative Cardiac Assist System in a Nonuniversity Hospital—Feasibility,Complications, and First Results

To evaluate the feasibility of implementing a cardiac assist system in a nonuniversity hospital we analyzed 18 consecutive patients treated with venoarterial membrane oxygenation. The system was used electively in 5/18 (27.8%) patients during high‐risk interventions. Thirteen patients (72.2%) were treated in emergency situations. The extracorporal system could be initiated successfully in all patients. Periprocedural complications were hemolysis in 3/18 (16.7%), disseminated intravascular coagulation in 2/18 (11.1%), cerebral ischemia in 1/18 (5.6%), and local infection in 2/18 (11.1%) patients. None of these led to a discontinuation of the therapy. All electively treated patients were successfully weaned from the extracorporeal system. In 9/13 (69.2%) emergency patients the system was removed successfully. The 60‐day survival rate of the emergency patients was 53.8% (7/13). Our experience confirms that an innovative extracorporeal circulatory support system can be implemented in a nonuniversity hospital at a tolerable risk and a low complication and high procedural success rate.