Guidelines to support the design, and selection and appraisal of multimedia teaching aids for microbiology education.

Microbiology education has a serious handicap - the lack of visibility of the players of the subject and their interactions - which engenders a disproportionate reliance upon multimedia teaching aids (MTAs). The International Microbiology Literacy Initiative (IMiLI) is creating educational resources in societally-relevant microbiology complemented by appropriate MTAs. However, proper guidance supporting microbiology educators in locating and selecting, or commissioning the creation of, adequate MTAs for different target audiences and learning objectives is lacking. The aims of this study were to (i) identify important considerations regarding educational/didactical standards and the design of educational multimedia and (ii) create an evidence-based guideline for selecting and appraising existing, and informing the creation of new, microbiology MTAs. This investigation is based on an exploratory, mixed-methods approach. The results of two literature reviews (covering educational and good practice multimedia design) informed the collation of a preliminary appraisal guideline for videos, animations, comics, and video games. A web-scraping approach was utilised to locate and retrieve existing exemplars of the four multimedia types and create four pertinent multimedia databases (including metadata). The preliminary guideline was piloted (and revised accordingly) by appraising quasi-random (or purposive) samples of each multimedia type. Educational multimedia experts were interviewed to discuss the findings. Finally, the guideline was updated to reflect the expert comments together with the results of the pilot appraisals. The final guideline has four components: (i) central considerations for selecting and appraising multimedia for specific audiences and educational purposes, (ii) multimedia selection tool, (iii) multimedia appraisal tools, and (iv) extensive background information as appendices linking all sections for further comprehension. Broad utilisation of the guideline has significant potential for simplifying and systematising multimedia selection/creation, leading to superior multimedia-based learning outcomes, establishing a rapid selection database (pre-appraised multimedia), reducing disparities in microbiology education and incentivising educational content creators.

Moderate hypothermia during cardiopulmonary bypass reduces myocardial cell damage and myocardial cell death related to cardiac surgery.

OBJECTIVES: The goal of this study was to test the hypothesis that moderate hypothermia during cardiopulmonary bypass (CPB) provides myocardial protection by enhancing intra-myocardial anti-inflammatory cytokine balance. BACKGROUND: Moderate hypothermia during experimental CPB stimulates production of interleukin-10 (IL10) and blunts release of tumor necrosis factor-alpha (TNFalpha). METHODS: Twelve young pigs were assigned to a temperature (T degrees ) regimen during CPB: moderate hypothermia (T degrees : 28 degrees C; n = 6) and normothermia (T degrees : 37 degrees C; n = 6). Intra-myocardial TNFalpha- and IL10-messenger RNA were detected by competitive reverse transcriptase polymerase chain reaction and quantification of cytokine synthesis by Western blot. Levels of cardiac troponin I (cTnI) in cardiac lymph and in arterial and coronary venous blood were examined during and after CPB. Myocardial cell damage was assessed by histologic and ultrastructural anomalies of tissue probes taken 6 h after CPB. RESULTS: Synthesis of IL10 was significantly higher, while that of TNFalpha was significantly lower, in pigs that were in moderate hypothermia during surgery than in the others. In contrast with normothermia, moderate hypothermia was also associated with significantly lower cumulative cardiac lymphatic flow during and after CPB, significantly lower lymphatic cTnI concentrations after CPB, significantly lower percentages of myocardial cell necrosis and a significantly lower score of ultrastructural anomalies of myocardial cells. While the percentage of apoptotic cells was not different between groups, the apoptosis/necrosis ratio tended to be higher in animals that were in moderate hypothermia during surgery. In all animals, TNFalpha synthesis correlated positively while IL10 production correlated negatively with necrosis and total cell death, respectively. CONCLUSIONS: Our results suggest that moderate hypothermia during CPB provides myocardial protection by enhancing intra-myocardial anti-inflammatory cytokine balance.

Radionuclide imaging of the painful hip arthroplasty: positron-emission tomography versus triple-phase bone scanning.

Two major complications of hip replacement are loosening and infection. Reliable differentiation between these pathological processes is difficult since both may be accompanied by similar symptoms. Our aim was to assess the diagnostic ability of triple-phase bone scanning (TPBS) and positron-emission tomography (PET) to detect and differentiate these complications in patients with a hip arthroplasty. Both TPBS and PET were performed in 63 patients (92 prostheses). The radiotracer for PET imaging was (18)F-fluorodeoxyglucose (FDG). Image interpretation was performed according to qualitative and quantitative criteria although the final diagnosis was based upon either surgical findings or clinical follow-up. The sensitivity, specificity and accuracy of PET was 0.94, 0.95 and 0.95 respectively, compared with 0.68, 0.76 and 0.74 for TPBS. We found that an image interpretation based exclusively upon quantitative criteria was inappropriate because of its low selectivity. The histological examination indicated that increased periprosthetic uptake of FDG in patients with aseptic loosening was caused by wear-induced polyethylene particles and the subsequent growth of aggressive granulomatous tissue.

Charcot-Marie-Tooth neuropathy type 2 and P0 point mutations: two novel amino acid substitutions (Asp61Gly; Tyr119Cys) and a possible "hotspot" on Thr124Met.

Mutations in the gene for the major protein component of peripheral nerve myelin, myelin protein zero (MPZ, P0), cause hereditary disorders of Schwann cell myelin such as Charcot-Marie-Tooth neuropathy type 1B (CMT1B), Dejerine-Sottas syndrome (DSS), and congenital hypomyelinating neuropathy (CHN). More recently, P0 mutations were identified in the axonal type of CMT neuropathy, CMT2, which is different from the demyelinating variants with respect to electroneurography and nerve pathology. We screened 49 patients with a clinical and histopathological diagnosis of CMT2 for mutations in the P0 gene. Three heterozygous single nucleotide changes were detected: two novel missense mutations, Asp61Gly and Tyr119Cys, and the known Thr124Met substitution, that has already been reported in several CMT patients from different European countries. Haplotype analysis for the P0 locus proved that our patients with the 124Met allele were not related to a cohort of patients with the same mutation, all of Belgian descent and all found to share a common ancestor. Our data suggest that P0 mutations account for a detectable proportion of CMT2 cases with virtually every patient harbouring a different mutation but recurrence of the Thr124Met amino acid substitution. The high frequency of this peculiar genotype in the European CMT population is presumably not only due to a founder effect but Thr124Met might constitute a mutation hotspot in the P0 gene as well.

Pathomorphological aspects of heparin-induced thrombocytopenia II (HIT-II syndrome).

The therapeutic use of heparin results in thrombocytopenia in 5-30% of patients. In 0.1-1% of patients treated with heparin, the platelet count decreases to between 100 x 10(9)/l and 50 x 10(9)/l and leads to severe synchronous central arterial and venous thrombosis with a mortality of 18-36%. This is known as "white-clot syndrome" or heparin-induced thrombocytopenia II (HIT-II syndrome). Whilst the clinical aspects and the central type of thrombosis in HIT-II syndrome are well documented, the histomorphology and differential diagnosis of thrombosis are not. We report three cases of HIT-II syndrome with thrombosis of the central arteries and veins. The HIT-II thrombi could be differentiated from thrombi of other origins, particularly from mural thrombi. Heparin-induced thrombi were seen on microscopical examination to be like onion skin in structure, and immunohistochemistry showed that they had a markedly reduced content of fibrin and clearly enhanced amounts of IgG and IgM. The layered structure thus implied appositional growth. The thrombi in HIT-II syndrome do not seem to be induced by activation of the coagulation cascade, but by platelet aggregation mediated by anti-platelet antibodies.

Peripheral neuropathy associated with hereditary and sporadic inclusion body myositis: confirmation by electron microscopy and morphometry.

Inclusion body myositis (IBM) is a disabling myopathy affecting proximal and distal muscle groups. The involvement of peripheral nerves in IBM is still a controversial matter. In a previous morphometric study at the light microscopic level only, we described a peripheral neuropathy in sural nerve biopsies of eight patients with sporadic IBM (s-IBM). Here we present a larger series of 14 cases in which a combined muscle and nerve biopsy was available for additional electron microscopic investigation. In two of the new cases, the IBM had a hereditary background (h-IBM). The presence of neuropathy was confirmed in all 14 cases studied. Morphometry using an optic-electronic, digital evaluation system showed large variation of severity presumably due to age and coincidal factors such as diabetes mellitus or lymphoma. Ultrastructural analysis revealed a variety of changes considered to be non-specific. Signs of axonal damage predominated. In addition, there were numerous changes in Schwann cells and myelin sheaths. Neither inflammatory changes nor tubulofilamentous inclusions were detectable in the sural nerves. Peripheral neuropathy, although occasionally without apparent clinical manifestation, appears to be a common and aggravating feature in IBM; its pathogenesis, however, remains elusive.

X-linked dominant Charcot-Marie-Tooth neuropathy: clinical, electrophysiological, and morphological phenotype in four families with different connexin32 mutations(1).

The sensorimotor neuropathy of the Charcot-Marie-Tooth type (CMT) is the most common hereditary disorder of the peripheral nervous system. The X-linked dominant form of CMT (CMTX) is associated with mutations in the gene for the gap junction protein connexin32. We examined four CMTX pedigrees two of which had potentially novel mutations in the only coding exon of connexin32. One previously unreported missense mutation, Ala39Val, was found in a family displaying a CMT phenotype with additional upper limb postural tremor reminiscent of a Roussy-Lévy syndrome. A novel single base insertion, 679insT, is among the first mutations found in the fourth transmembrane domain of connexin32. Frameshift and premature stop of translation are supposed to result in a non-functional carboxy-terminus. Two further families had the known missense mutations Arg15Trp and Arg22Gln. Several female carriers were found normal on clinical presentation, however, the genotype was paralleled by decreased nerve conduction velocities (NCV) and slowed central conduction of brain stem auditory evoked responses (BAER). Median motor NCVs showed mild (in women) to intermediate (in males) reduction, indicating a peripheral neuropathy with a predominating axonal component. Nerve biopsy findings were consistent with the electrophysiological data showing a marked loss of large myelinated fibres and clusters of regenerating axons. Electron microscopy revealed various alterations of the axoglial attachment zone. This suggests defective axon-Schwann cell interactions which may induce the axonopathy in CMTX.

Coronary vasculopathy in polycythemia vera.

Thrombosis is a common complication in polycythemia often causing death. In coronary artery occlusion, thrombosis due to hyperviscosity and thrombocytosis is mostly discussed as the origin of the infarction. We discuss the case of a 30-year-old male patient, with polycythemia, who died of myocardial infarction. On autopsy the vessels showed neither ateriosclerotic changes nor thrombotic occlusions. Instead, a marked intima proliferation was found leading to multiple occlusions whereas media and adventitia were unchanged. This pattern of a coronary vasculopathy has not been described before, and can be interpreted as an alternative mechanism for vascular occlusion in polycythemia. Similar histopathological changes have already been found in skin lesions in erythromelalgia, a common symptom in polycythemia.

Fulminant toxoplasmosis in a heart transplant recipient.

Toxoplasma gondii infections in heart transplant recipients emerge in most cases as newly acquired infections of the immunocompromised sero-negative patient from an exogenous source, usually the donor organ. We report on a 64-year-old heart transplant recipient who developed pneumonitis, myocarditis, and hyperacute encephalitis three weeks after transplantation. Histopathological examination of an endomyocardial biopsy revealed fulminant T. gondii infection. Although appropriate chemotherapy was administered immediately, the patient died the next day. Our case demonstrates that if a histological diagnosis is not rendered in time, fulminant toxoplasmosis may lead to a fatal outcome. In conclusion, a general screening of the donors and recipients for opportunistic infections, including toxoplasmosis, and an appropriate prophylaxis should always be considered.

[A novel hirudin coating of vascular endoprostheses: experimental results]. / Eine neuartige Hirudinbeschichtung vaskulärer Endoprothesen: Experimentelle Ergebnisse.

PURPOSE: Does hirudin coating improve the patency of iliac artery endoprostheses in comparison to non-hirudin-coated endoprostheses? MATERIALS AND METHODS: Nitinol stents and stentgrafts covered with polytetrafluoroethylene (PTFE) were coated with the polymer polyamino-p-xylylene-co-poly-p-xylylene using chemical vapor deposition (CVD) technique. Hirudin was covalently bound to the surface of the endoprostheses via the amino-group. External factors (mounting of the prosthesis, sterilization, storage time and temperature, release) affecting the hirudin activity were evaluated in vitro. Five types of prostheses were compared in vivo: (1) plain and (2) CVD- and hirudin-coated stents; (3) plain, (4) CVD-coated, and (5) CVD- and hirudin-coated PTFE-stentgrafts. In 20 sheep, 16 protheses of each type were inserted in arteries pretreated with a Fogarty maneuver. The animals were followed for either 1 (n = 10) or 6 (n = 10) months. Immediately after implantation and after 1, 3, and 6 months, intravascular ultrasound (IVUS) and angiography were performed. The vascular specimens were analyzed histologically. RESULTS: Within 10 weeks, the hirudin activity of coated stents dropped 60 % due to external factors; the activity of coated PTFE stentgrafts dropped 20 %. After 1, 3, and 6 months, IVUS and histology revealed a significantly reduced patency of the hirudin-coated stentgrafts compared to the other prostheses. Only IVUS showed a significantly reduced patency of hirudin coated stents after 1 and 3 months compared to plain and CVD-coated PTFE-stentgrafts. The reduced patency was caused by neointimal hyperplasia. CONCLUSIONS: In an experimental setting, hirudin coating did not improve the patency of vascular endoprostheses.

Preoperative PET activation for assessment of motor cortex area in precentral chondroma.

BACKGROUND: A main problem in the preoperative planning for precentral tumors is the exact assessment of the spatial relationship between the tumor and the functionally relevant brain areas, which may be difficult using only morphologically oriented imaging (CT, MRI). Therefore, we applied motor activation PET and PET/MRI overlay in a patient with a precentral tumor. DESCRIPTION: We report the case of a 21-year-old woman suffering from progressive right-sided headache and intermittent dysesthesia of the left leg. MRI showed a hypointense tumor with inhomogenous contrast enhancement in the right precentral area. For preoperative assessment of the spatial relationship between the tumor and the motor cortex area, the patient underwent two F-18-fluorodeoxyglucose positron emission tomography (PET) scans (1. resting condition and 2. motor activation of the left leg) and subsequent calculation of subtraction images of activation minus rest. Fusion of PET and MRI data (PET/MRI overlay) was performed for bimodal function and morphology presentation. PET revealed an activation pattern behind and below the tumor, indicating that the motor cortex area was shifted to the back. PET findings were confirmed by intraoperative electrophysiology. Cortical stimulation combined with intraoperative neuronavigation localized the motor area of the left foot and leg exactly at the dorsal border, below and lateral to the lesion. After complete resection of the solid tumor, histopathological examination revealed a chondroma. The postoperative course was uneventful, and the patient was discharged without neurological deficits. CONCLUSIONS: This case shows that biomodal imaging (PET/MRI) provides a noninvasive exact assessment of functionally important cortex areas for preoperative planning in patients with cerebral lesions.

[Pathology of traditional surgical nets for hernia repair after long-term implantation in humans]. / Pathologie traditioneller chirurgischer Netze zur Hernienreparation nach Langzeitimplantation im Menschen.

The widespread use of alloplastic materials as the standard procedure for hernia repair makes an evaluation of the long-term integration of these implants imperative. A total of 121 explanted meshes (mean implantation time 23.2 & 19.7 months) of polypropylene (Atrium((R)), n = 20; Marlex((R)), n = 50; Prolene((R)), n = 21), Polyester (Mersilene((R)), n = 19) and PTFE (Gore-Tex((R)), n = 11) were analyzed in regard to the tissue and cell response within the interface mesh-fiber/tissue. The mesh samples were investigated by light and electronmicroscopy, as well as immunohistochemistry. The morphometric results confirmed a persisting inflammatory proliferative foreign-body reaction with increased cell turnover in the recipient tissues. This reaction is mainly influenced by the selected mesh modification. The consequences of the arising "chronic wound" are discussed in detail, in particular with regard to possible malignant transformation.

[Primary angiosarcoma of the lung]. / Das primäre Angiosarkom der Lunge.

INTRODUCTION: Angiosarcomas are uncommon neoplasias, normally located in the skin, liver or heart. Primary angiosarcoma of the lung is rare. CASE REPORT: We report on a 41-year-old patient who presented increasing dyspnea. A 10-cm-angiosarcoma of the inferior lobe of the left lung was detected. After preoperative chemo- and radiotherapy the patient was referred to our clinic for surgical intervention. Resection of the inferior lobe of the lung, resection of part of the diaphragm, lymphadenectomy and replacement with a Vypro-II mesh was performed. Histological examination showed a mesenchymal neoplasia with myxoid tumor tissue, variable cell density and small proliferations of vessels. The immunohistochemical analysis confirmed the diagnosis of an angiosarcoma. The patient was discharged in a good general state for further ambulatory radiochemotherapy. DISCUSSION: Angiosarcoma of the lung must always be included in the differential diagnosis of lung nodules and diffuse infiltrates despite its rare occurrence. Success with neoadjuvant therapy has been reported, but radical resection is recommended due to the cumulative bad prognosis.

[Tuberculosis of the gall bladder]. / Gallenblasentuberkulose.

We report a case of gall bladder tuberculosis in a 64-year-old male. The gall bladder is an extremely rare localization of an infectious disease seen frequently worldwide--tuberculosis. The reason for this special resistance against the mycobacteria is not clear and is controversial. In imaging, the disease can mimic acute or chronic cholecystitis or carcinoma of the gall bladder. It is important to consider tuberculous cholecystitis in differential diagnosis and to do tuberculin skin tests in case of suspicion. This test is technically easy and cost-effective. Since 1968, isolated tuberculosis of the gall bladder has not been reported in western civilization. This case study was done because of the rareness of the disease,and we review the literature on this topic.

[Chronic recurrent multifocal osteomyelitis and tumoral calcinosis--is there an association?]. / Die chronisch-rezidivierende multifokale Osteomyelitis und die tumoröse Kalzinose--assoziierte Erkrankungen?

BACKGROUND: Idiopathic tumorous calcinosis is a rare benign disease of the periarticular tissue near large joints. Deposits of hydroxyapatite in single or multiple pseudocysts lead to consecutive pain or complaints by attaching the surrounding tissues. The etiology of this disease is not definitively clear. CASE REPORT: We describe the case of an 11-year-old turkish girl with a well known chronic recurrent multifocal osteomyelitis (CRMO) and hyperphosphataemia. Furthermore, she developed a tumorous calcinosis around the left hip, which recurred after surgery, and around the ankle joint. CONCLUSIONS: CRMO and tumorous calcinosis can be associated diseases. The development of tumorous calcinosis in patients with CRMO and hyperphosphataemia should be excluded.

The rare epidemiologic coincidence of diverticular disease and advanced colonic neoplasia.

BACKGROUND AND AIMS: In Western industrialised countries the prevalence of neoplastic colonic lesions and diverticular disease markedly increases with age. In contrast, the coincident occurrence of both diseases seems to fall below their individual epidemiologic estimates. Because directly comparing data are rare, this retrospective study evaluates the coincidence of neoplastic lesions and diverticular disease. PATIENT AND METHODS: A total of 1,838 patients from 1986 to 2000 were admitted to the study. For 1,326 patients-56% male (n=741), 44% female (n=585), mean age 64 (+/-11.83 SD)-with a resection due to colonic cancer, the documented findings of colonoscopy, colonic contrast enema, and/or histopathology were analysed with regard to the prevalence of colonic diverticulosis. In 512 patients--51% male (n=263), 49% female (n=249), mean age 60 (+/-12.59 SD)--with a colonic resection due to diverticulitis, the synchronous or metachronous occurrence of neoplastic colonic lesions was recorded using the database of the Tumour Centre, Aachen. To compare the observed results with published epidemiology, statistical analysis included age-referred binomial tests and an age-stratified analysis (Cochran-Mantel-Haenszel test). Odds ratios (OR) were also calculated. P<0.05 was considered to indicate locally statistical significance. RESULTS: In the cancer group, we found a statistically significant reduced rate of diverticula in nearly all age categories and the age-stratified analyses (corresponding OR 0.30-0.51). Consistently, the diverticulitis group revealed a statistically significant decreased rate of advanced colonic neoplastic lesion in nearly all age categories and all age-stratified analyses (corresponding OR 0.13-0.43). CONCLUSION: Our results indicate that patients with colonic neoplastic lesions or diverticular disease probably form heterogeneous groups. Because current results from molecular biology emphasize the impact of the extracellular matrix on the genesis of diverticulosis and colonic cancer, the observed heterogeneity could be an expression of a distinct composition of the local milieu.

Influence of implantation interval on the long-term biocompatibility of surgical mesh.

BACKGROUND: The aim was to study the long-term tissue response to polypropylene mesh. METHODS: This was a retrieval study that investigated 76 polypropylene meshes with a median implantation interval of 18 (range 2-180) months. Mesh was explanted following hernia recurrence, infection or pain. The median implantation interval was 20 (range 4-180) months in the recurrence group, 30 (range 5-48) months in the pain group and 10 (range 2-56) months in the infection group (P < 0.05, infection versus pain or recurrence). The inflammatory response was determined by immunohistochemistry of macrophages (CD68), polymorphonuclear granulocytes (CD15) and T and B lymphocytes (CD3 and CD20). The cell turnover within the interface mesh fibre-recipient tissue was measured by TUNEL for apoptosis or DNA strand breaks, Ki67 for cell proliferation and heat-shock protein (HSP) 70 for cell stress. RESULTS: With the exception of HSP-70, levels of all variables decreased over time. Sex, age, type of previous operation or location of the mesh did not have a significant influence. CONCLUSION: Long-term incorporated polypropylene mesh in humans has a more favourable tissue response with increasing implantation interval.

[Recurrent pigmented villonodular synovitis (PVNS)]. / Rezidiv einer pigmentierten villo-nodulären Synovialitis (PVNS).

AIM: The pigmented vilionodular synovitis (PVNS) is a tumour like disease of unknown origin that often shows recurrence. The pathogenesis is still unknown and therefore the question of the right therapy is not resolved. MATERIAL: With a case report of a patient with recurrence after two arthroscopic synovectomies, PVNS is discussed against the background of the clinical, histological, and radiological features. RESULTS: We performed an open synovectomy and cystic lesions in both condyles of the femur and proximal tibia were filled with homologous and autologous cancellous bone. Three months later the patient had no pain and the bone density in the former cystic lesions was appropriate. DISCUSSION: The pathogenesis is still unknown. Diagnosis often is obtained much too late due to missing specific symptoms. PVNS occurs in local forms as well as in a diffuse growth pattern. Recurrence rates of up to 78% are very high. Besides arthroscopic and open synovectomy, the treatment with radiosynoviorthesis must be considered. Depending on the growth pattern, the tumour masses, and the affected joint, the therapy has to be chosen very carefully and sometimes different forms have to be combined if a recurrence--free result is to be achieved.

Congenital pseudarthrosis of the tibia in pediatric patients: MR imaging.

OBJECTIVE: The purpose of this study was to describe the characteristics of congenital pseudarthrosis of the tibia on MR images of infants and children and to assess the value of MR imaging in evaluating this disease. CONCLUSION: MR imaging of congenital pseudarthrosis allows assessment of the type and extension of the disease. It is especially recommended for the evaluation of periosteal and soft-tissue changes near the pseudarthrosis.