Graves' disease and Hashimoto's thyroiditis in monozygotic twins: case study as well as transcriptomic and immunohistological analysis of thyroid tissues

OBJECTIVE

To report on the rare simultaneous occurrence of Graves' disease (GD) and Hashimoto's thyroiditis (HT) in monozygotic twins.

DESIGN

We compared the pattern of thyroid tissue-derived cDNAs to gain insight into previous and ongoing immune destruction and reconstruction processes using microarrays. The results were confirmed by immunohistology and real-time PCR.

RESULTS

Destruction of thyroid tissue in HT reduced levels of thyrocyte-related cDNAs and cDNAs encoding extracellular matrix components, but increased levels of proteases involved in extracellular matrix degradation compared with GD. Lymphocytic infiltrates forming ectopic follicles replaced the thyroid tissue almost completely in HT. Thus, lymphocyte-related cDNA levels were higher in HT than in GD. The same was true for many chemokines and their receptors, which not only enable migration towards the thyroid but also maintain the lymphocytic infiltrate. HT also showed increased levels of cDNAs encoding molecules related to apoptosis than did GD. Surprisingly, the Th1- and Th2-specific cytokine profiles suggested for HT and GD respectively could not be confirmed. cDNAs encoding factors and receptors involved in angiogenesis were increased in GD compared with HT.

CONCLUSIONS

Comparison of gene expression reflects the cellular differences between the two types of autoimmune thyroid disease in twins with identical genetic and similar environmental background.

Register zur bundesweiten Erfassung angeborener Gliedmaßenfehlbildungen

AIM

A detailed registration of the frequency and the aetiology of limb deficiencies has been established for the first time in Germany.

METHOD

According to the ESPED model (Documentation of rare paediatric diseases in Germany) we send out at an interval of three months a questionnaire for registration of live births, still births and their limb deficiencies to 1 073 gynaecological hospitals. In case of a positive response for a limb deficiency a second questionnaire is sent for details about pregnancy, birth and family. The limb defects are registered according to the ICD-10 classification and statistically analysed.

RESULTS

Current acquisition period: 48 months (April 2000-April 2004). Total number of registered births: 1 070 541. Number of live births with limb deficiencies: 1 534 (0.14 %). Number of still births with limb deficiencies: 55 (1.7 %). Minor limb deficiencies such as polydactyly (22.4 %) are more frequent than major deficiencies of the tibia (1.0 %) or of the fibula (1.6 %). A familiar disposition is found in 9.7 %. A correlation to the profession of parents or their age (mother: 29, father: 33), or nicotine abuse could not be detected. The numbers of special features during pregnancy (amniocentesis in 3.3 %, oligohydramnion in 0.5 %, polyhydramnion in 0.3 %, etc.) and during delivery (relation between normal delivery and caesarean section = 59.5 %/29 %, etc.) were similar to the frequencies in the normal population.

CONCLUSIONS

Our register represents the largest study world-wide in respect to the birth rate and the most accurate record of limb deficiencies. In the current acquisition period no correlation of the registered limb deficiencies to environmental effects, individual misbehaviour, exposed professional group and peculiarities during pregnancy and parturition could be found. The continuation of our register is essential for further detection of the incidence and aetiology of limb defects.

Humanbiomonitoring-Untersuchungen von Organohalogenverbindungen - PCB, DDE; HCB, β- und γ-HCH, PCDD/PCDF, koplanaren PCB sowie polybromierten Biphenylethern

Although PCB and PCB-containing materials are not processed for a long time, PCB is under discussion again and again caused by the pollution of indoor environments. To objectify the discussion, the dates of the PCB-biomonitoring, the organochlorine-compounds (DDE, HCB, beta-/gamma -HCH, PCDD/PCDF) and the polybrominated biphenyl ethers concerning the investigations within the project "Sentinel Health Departments" in Baden-Wurttemberg are represented. Additionally results from children from Kazakhstan (Aral-Sea area) and from teachers which are working in PCB polluted schools as well as from a long term investigated test person are reported. Blood concentrations of the following compounds decreased from 1996/97 to 2002/03: the sum of the concentration of PCB 138,153 and 180 decreased from 0.46 microg/L to 0.20 microg/L, DDE from 0.32 microg/L to 0.17 microg/, HCB from 0.20 microg/L to 0.08 microg/L, beta-HCH below the level of detection, I-TEQ NATO to 4.8 pg/g blood fat, TEQ WHO (without PCB) to 5.5 pg/g blood fat, PCB 126 to 18,8,pg/g blood fat and PCB 169 to 12.8 pg/g blood fat. The influence of breast feeding and the gender on the level of the pollution is conspicious. No local correlations were found in Baden-Wurttemberg, but they were found in comparison with the results of Kazakhstan (Aral-Sea area). The difficulty to produce time series while the analyzing pollutants are more and more decreasing, as well as the change of the calculation base of the summation of parameters like I-TEQ NATO to TEQ WHO are discussed.

[Diving accidents. Emergency treatment of serious diving accidents]

Decompression injuries are potentially life-threatening incidents mainly due to a rapid decline in ambient pressure. Decompression illness (DCI) results from the presence of gas bubbles in the blood and tissue. DCI may be classified as decompression sickness (DCS) generated from the liberation of gas bubbles following an oversaturation of tissues with inert gas and arterial gas embolism (AGE) mainly due to pulmonary barotrauma. People working under hyperbaric pressure, e.g. in a caisson for general construction under water, and scuba divers are exposed to certain risks. Diving accidents can be fatal and are often characterized by organ dysfunction, especially neurological deficits. They have become comparatively rare among professional divers and workers. However, since recreational scuba diving is gaining more and more popularity there is an increasing likelihood of severe diving accidents. Thus, emergency staff working close to areas with a high scuba diving activity, e.g. lakes or rivers, may be called more frequently to a scuba diving accident. The correct and professional emergency treatment on site, especially the immediate and continuous administration of normobaric oxygen, is decisive for the outcome of the accident victim. The definitive treatment includes rapid recompression with hyperbaric oxygen. The value of adjunctive medication, however, remains controversial.

[Left ventricular functional parameters: comparison of 16-slice spiral CT with MRI]

PURPOSE

The quantitative measurement of left ventricular functional parameters using multislice computed tomography (MSCT) with retrospective ECG-gating and comparison of the results with magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Thirty-one patients with suspected or known coronary artery disease underwent MSCT angiography with retrospective ECG-gating (Sensation 16, Siemens). Based on the CT data set, short axis reformations of the left ventricle were performed for functional analysis. On a commercially available workstation, end-diastolic- (EDV), end-systolic- (ESV), stroke volume (SV), ejection fraction (EF) and myocardial mass (MM) were calculated from MSCT (temporal resolution 105 - 210 ms) data according to the modified Simpson's rule and compared to MRI (1.5 T scanner, temporal resolution 48 ms) using a 2D TrueFISP cine sequence with respiration hold.

RESULTS

In all cases, the quality was adequate for both MSCT and MRI. MSCT and MRI had an excellent correlation for EDV (r = 0.86), ESV (r = 0.91), EF (r = 0.87) and MM (r = 0.88), and a good correlation for SV (r = 0.70). The mean difference was 13.2 +/- 21.9 ml for EDV, 8.7 +/- 15.9 ml for ESV, 4.6 +/- 12.3 ml for SV, 1.4 +/- 5.2 % for EF, and 11.9 +/- 13.8 g for MM. However, EDV (p = 0.002), ESV (p = 0.005), SV (p = 0.048), and MM (p < 0.0001) were significantly overestimated with MSCT compared to MRI. For EF, no significant difference between MSCT and MRI was found (p = 0.15).

CONCLUSION

For left ventricular functional parameters, MSCT of the heart with retrospective ECG-gating showed a high correlation with MRI, which has an important implication when using MSCT for non-invasive cardiac imaging. Despite the high correlation, overestimation of EDV, EVS, SV, and MM with MSCT has to be taken into account when applying this technology in clinical practice. EF was not significantly different between both modalities.

Multislice CT in cardiac and coronary angiography

In the last 2 years, mechanical multidetector-row CT (MDCT) systems with simultaneous acquisition of four slices and a half second scanner rotation time have become widely available. Data acquisition with these scanners allows for considerably faster coverage of the heart volume compared with single slice scanning. This increased scan speed can be used for retrospective gating together with 1 mm collimated slice widths and allows coverage of the entire cardiac volume in one breath-hold. First results from studies in correlation with intracoronary ultrasound suggest that MDCT technology not only offers the possibility to visualize intracoronary stenoses non-invasively, but also to differentiate plaque morphology. This is especially the case with the next generation of 16-row MDCT systems. An increased number of simultaneously acquired slices and submillimetre collimation for cardiac applications allows true isotropic scanning with high temporal resolution. Contrast-enhanced MDCT is a promising non-invasive technique for the detection, visualization and characterization of stenotic artery disease. It could act as a gatekeeper prior to cardiac catherization and finally replace conventional diagnostic modalities.

Absorption pattern of trospium chloride along the human gastrointestinal tract assessed using local enteral administration

BACKGROUND AND OBJECTIVES

The antimuscarinic drug trospium chloride is hydrophilic and therefore does not enter the CNS when used for the treatment of overactive bladder disturbances. However, the same property is the main reason for low and variable oral bioavailability. The present study was performed to assess the influence of intestinal site on absorption of the drug as the basis for the development of modified release preparations.

METHODS

In a change-over pilot study, 8 healthy male volunteers received single 20 mg doses oftrospium chloride orally as a tablet (reference), as Eudragit-coated tablets dissolving at pH 6.0 (local administration into the small intestine), and rectally via a mini enema (corresponding to local administration into the large intestine). Plasma concentrations of trospium chloride were determined up to 36 hours after administration using GC/MS.

RESULTS

Extent and rate of trospium chloride absorption declined rapidly upon administration into more distal regions of the gastrointestinal tract. C(max) (median: 6.42 ng/ml) and AUC(0.tlast) (42.28 ng/ml x h) were highest and t(max) (3.5 h) was shortest after administration of the reference tablet. AUC(0-tlast) reached 78% (90% CI 43 - 139%) after small intestine administration and 2% (90% CI 1 - 9%) following rectal administration, respectively, relative to the values for the oral tablet.

CONCLUSION

Trospium chloride is absorbed primarily in the upper gastrointestinal tract. Development of modified release preparations must balance prolonged apparent absorption rates of the drug against a decrease in bioavailability.

[Determination of mold concentrations in homes and schools in Baden-Württemberg]

So far there have been rather few reliable and comparable data available on indoor pollution with mould. Following the publication of the Federal Environmental Agency and the Health Agency Baden-Württemberg which supports the assessment of mould pollution of indoor air, it seemed advisable to investigate as to how far these criteria can be used for the assessing the mould pollution in daily practice. The results of investigations of 130 homes and 117 classrooms in Baden-Württemberg. will be represented.

Apoptose als Pathomechanismus in der Sepsis

Sepsis is still a leading cause of death in many intensive care patients. The pathophysiology of the disease is dominated by complex immune cascades. Recent research demonstrates that immune cells respond to sepsis with an increased rate of programmed cell death. Up-regulated apoptosis of leukocytes was observed in animal models of sepsis as well as in patients suffering from severe sepsis. The mitochondrial protein Bcl-2 and the caspase cascade play an important role in the regulation of apoptosis. Overexpression of Bcl-2 or inhibition of caspases resulted in an increased survival in animal models of sepsis. Recent reports indicate the relevance of apoptosis in patients with severe sepsis. These results may spawn novel immunomodulatory strategies in the treatment of sepsis.

Bestimmung linksventrikulärer Funktionsparameter mittels EKG-gesteuerter Mehrschicht-Computertomographie im Vergleich mit der invasiven Ventrikulographie

PURPOSE

To evaluate the accuracy of left ventricular function using a multidetector CT (MDCT) with retrospective ECG-gating and to compare the results with conventional ventriculography.

MATERIALS AND METHODS

In 26 patients, retrospectively ECG-gated MDCT of the heart (Volume Zoom, Siemens, Germany) as well as conventional coronary angiography including ventriculography was performed to exclude or follow coronary artery disease. CT examination (120 KV, 400 mAs) was carried out with 4 x 1 mm collimation (500 ms gantry rotation time). For CT angiography, 150 ml of contrast media was injected intravenously at a flow rate of 4 ml/s. All data sets of the functional cardiac parameters were reconstructed in end-systolic and end-diastolic phase. End-systolic volume (ESV), end-diastolic volume (EDV) and ejection fraction (EF) were determined from multiplanar reformations orthogonally through the cardiac short axis and analyzed using special evaluation software (ARGUS, Siemens). The results were compared with ESV, EDV and EF obtained from invasive ventriculography.

RESULTS

In all cases, a sufficient quality of the MDCT images was achieved. EDV (150.1 +/- 16.2 ml MDCT vs. 138.7 +/- 16.9 ml ventriculography; mean difference 11.4 +/- 12.7 ml; r = 0.51) had an acceptable correlation to conventional ventriculography, and ESV (58.1 +/- 14.6 ml vs. 50.2 +/- 13.4 ml; mean difference 7.9 +/- 8.8 ml; r = 0.81) and EF (60.9 +/- 13.6 % vs. 64.9 +/- 12.7 %; mean difference 4.0 +/- 6.2 %; r = 0.79) showed a good correlation. In comparison with invasive ventriculography, MDCT tended to overestimate significantly EDV (p = 0.008) and ESV (p = 0.003) and to underestimate EF (p = 0.001).

CONCLUSION

MDCT of the heart with retrospective ECG-gating enables efficient estimation of left ventricular function, providing important additional information of non-invasive cardiac imaging using MDCT. However, EDV and EVS were significantly overestimated and EF was underestimated in MDCT compared to ventriculography.

[Diagnostic relevance of multinucleated giant cells in papillary thyroid cancer. A cytological and histological study]

Cytological smears of 17 papillary carcinomas (PC) of the thyroid as well as histological slides of 58 PC and 50 follicular adenomas (FA) and 50 follicular carcinomas (FC) were reviewed to assess the presence of intrafollicularly located multinucleated giant cells. In accordance with the data published, such giant cells were found in 70% of PC but in only 8% of FA and FC. The presence of giant cells, which probably represents a foreign body reaction to, in case of PC, physicochemically altered colloid, is a useful additional criteria for the cytological and histological diagnosis of PC.

Estimation of radiation exposure in 16-detector row computed tomography of the heart with retrospective ECG-gating

PURPOSE

We sought to evaluate the radiation exposure of cardiac CT scans with 16-row multidetector computed tomography (MDCT). Additionally the possibility of dose reduction by using a ECG-controlled tube current modulation technique was evaluated.

METHODS AND MATERIAL

An Alderson Rando phantom equipped with thermoluminescent dosimeters was used for dose measurements. Effective dose was calculated according to ICRP 60. Exposure was performed on a 16-row MDCT scanner with standard protocols for CT coronary calcium scoring (120 kV, 133 mAs, 12 x 1.5 mm) and CT coronary angiography (120 kV, 400 mAs, 12 x 0.75 mm). Exposure was repeated at a simulated heart rate of 60 bpm with ECG-pulsed tube current modulation.

RESULTS

Effective dose was 2.9 mSv (male) and 3.6 mSv (female) for the calcium scoring protocol. CT coronary angiography resulted in an effective dose of 8.1 mSv (male) and 10.9 mSv (female). Using ECG-pulsed tube current modulation radiation exposure can significant reduced: by 46 % (1.6 mSv) in calcium scoring and by 47 % (4.3 mSv) in CT coronary angiography.

CONCLUSION

MDCT of the heart shows a significant radiation exposure, which can significantly be reduced by ECG-pulsed tube current modulation. Radiation exposure of cardiac MDCT is comparable to CT-examinations of chest or abdomen, but seem to be slightly higher compared to conventional coronary angiography.

[10 years of observation by public health offices in Baden-Württemberg--assessment of human biomonitoring for mercury due to dental amalgam fillings and other sources]

Since 1992, in Baden-Württemberg, ten-year old children have been surveyed in the project "Sentinel Health Departments" to study their exposure to environmental pollutants and possible health effects. In the four study areas 1200 children have been investigated every year initially, since 1996 every second year. The data for mercury in body fluids are reported here. The decrease in the body burden of mercury as a result of the declining usage of dental amalgam fillings, was been verified. In 1992/93, of all the children who had been surveyed, the 95 percentile for the body burden of mercury was 3.1 microg/l and in 2000/01 1.35 microg/l. Also to be discussed is the reason why mercury-based cosmetic ointments seriously exceed the HBM-II-intervention-value. Because of using these ointments, concentrations of mercury in urine up to 1400 microg/l were found. A study within the project "Sentinel Health Departments" compared the concentrations of mercury in the urine of adults with those in blood and salvia. The results support the opinion that mercury in urine is appropriate for estimating the mercury uptake from dental amalgam fillings. It can be assumed that these results reflect the situation in the entire Federal Republic of Germany. The ten years' experience confirms that the concept of the "Sentinel Health Departments" is excellently suited to obtain data relevant for environmental health of children. Environmental health protection and the essential gathering of data for future health observation in Baden-Württemberg.

[Visualization of pulmonary vein stenosis after radio frequency ablation for treatment of atrial fibrillation using multidetector computed tomography with retrospective gating]

PURPOSE

With the number of radio frequency ablations (RFA) for treatment of chronic atrial fibrillation increasing, the diagnostic evaluation for RFA associated pulmonary vein stenosis is getting more important. This study investigates the feasibility of the visualization of pulmonary vein stenosis using non-invasive multidetector computed tomography.

MATERIALS AND METHODS

Twenty-eight patients were examined following RFA-treatment. A 4-slice (20 patients) and a 16-slice (8 patients) multidetector CT scanner (SOMATOM Volume Zoom and Sensation 16, Siemens, Forchheim, Germany) with retrospective gating was used to assess the pulmonary veins. Lesion severity was determined on a semi-quantitative scale (< 30 %, 30 - 50 %, > 50 %).

RESULTS

CT was performed without any complications in all patients. Diagnostic image quality could be obtained in all examinations. The pulmonary veins showed lesions < 30 % in four patients, lesions of 30 -, 50 % in five patients and a stenosis > 50 % in one patient. Eighteen patients showed no lesions.

CONCLUSION

Multidetector CT of the pulmonary veins seems to be able to visualize high-grade and low-grade lesions, but larger catheter-controlled studies are needed for further assessment of the diagnostic accuracy and clinical reliability of this noninvasive method.

Reproducibility of coronary calcium quantification in repeat examinations with retrospectively ECG-gated multisection spiral CT

High reproducibility is a key requirement for coronary calcium scoring in follow-up examinations. We investigated the inter-examination reproducibility of calcium scoring with retrospectively ECG-gated multisection spiral CT (MSCT). Fifty patients were examined twice with MSCT. Slices were reconstructed with retrospective ECG gating in the diastolic phase with 3-mm slice width and up to 125-ms temporal resolution. We calculated the Agatston score, calcium volume with and without isotropic interpolation, and calcium mass, and derived the mean and median variability. We investigated the change of variability with use of 3-mm non-overlapping and overlapping increments (2, 1.5, 1 mm). Use of overlapping increment results in considerably reduced interscan variability. We observed a minimum mean variability of 12% and a minimum median variability of 9% for the Agatston score. For volume and mass quantification we obtained a minimum mean variability of 7.5% and a minimum median variability of 5%. Multisection spiral CT enables coronary calcium quantification with high reproducibility in follow-up examinations mainly founded on image data with reduced partial-volume errors due to overlapping increment.

[Visualization of coronary arteries in CT as assessed by a new 16 slice technology and reduced gantry rotation time: first experiences]

PURPOSE

First evaluation of image quality of a new 16-slice multidetector-row computed tomography (MDCT) for the assessment of coronary artery disease and lesion detection of the coronary arteries.

MATERIALS AND METHODS

On a newly developed 16-slice CT scanner (SOMATOM Sensation 16, Siemens, Forchheim, Germany) a calcium score as well as a contrast-enhanced CT angiography (CTA) were performed on 4 patients with retrospective ECG-gating and a gantry rotation time of 420 ms to exclude or follow-up coronary heart disease. CTA was performed after injecting 120 ml contrast media intravenously. After medication with a ss-Blocker, the heart rate was between 55 and 67 bpm.

RESULTS

The scan time for calcium score was 12 s, for CTA 18 s (scan range 15 and 12 cm, respectively). Volume score was between 0 and 256.4. In the CT angiography the entire coronary tree could be visualized in all patients up to the very distal subsegmental branches. In two patients a complete occlusion of the RCA and the LAD were depicted, respectively. In one of these patients, a large aneurysm of the left anterior ventricular wall was also delineated.

CONCLUSION

Considering our first experiences with the new 16-slice technology, an excellent visualization of the entire coronary tree including the very distal and side branches due to substantially increased spatial resolution seems to be achievable. In these patients the acquired image quality raises the hope for improved, non-invasive cardiac diagnostics. In larger studies, the clinical impact of this new technology needs to be further investigated.

[IUD-associated pseudoactinomycotic gradiate granules (Spendore-Hoeppli phenomenon) in uterine curettage]

Pseudoactinomycotic radiate granules, also known as the Splendore-Hoeppli phenomenon represent a response to organic and in-organic foreign substances and can be found at various locations in the body. They are frequently observed in uterine curettages, where they can be misinterpreted as actinomycotic sulfur granules. Here we report a case with Splendore-Hoeppli phenomenon in an intrauterine device (IUD)-associated genital actinomycosis. The morphological features of this phenomenon are presented using special staining methods and electron microscopy and the literature is reviewed.

Second German consensus on immunogenetic donor search for allotransplantation of hematopoietic stem cells

The present paper summarizes the results of the second German consensus meeting on immunogenetic donor search for allotransplantation of hematopoietic stem cells held in Essen in November 1999 under the auspices of the German Society for Immunogenetics (DGI) and the German Working Party for Blood and Marrow Transplantation (DAG-KBT). Immunogeneticists and transplant physicians from all over the country agreed to update the national standards for: (1) search strategy including the role of unrelated and extended family donor search after unsuccessful core family donor search, (2) histocompatibility loci to be typed, (3) histocompatibility typing techniques to be used (HLA serology vs DNA-based HLA typing, cellular tests, serum cross-match), and (4) acceptable HLA mismatches in the context of a defined underlying disease, donor type, and conditioning regimen.

First in vivo optical coherence tomography in the human bile duct

BACKGROUND AND STUDY AIMS

Optical coherence tomography (OCT) is a novel technique for performing high-resolution, cross-sectional tomographic imaging in human tissue, which allows resolution of up to 10 microm. The short depth of penetration allows assessment of the superficial 2 mm of the gastrointestinal tract, an area that is difficult to appraise even with high-frequency ultrasound. This is the first report on in vivo OCT of the human biliary system. The aim was to assess the feasibility of the technique.

PATIENTS AND METHODS

Four cases of intraductal OCT are presented. The probe was inserted through the working channel of a duodenoscope.

RESULTS

The connective tissue layer and the underlying retroperitoneal tissue, with less backscattering, could be clearly demonstrated. The images showed a layer architecture which was similar to that found histologically.

CONCLUSIONS

OCT of the biliary system is feasible in patients with biliary pathology. Interpretable images were obtained, and clinical use needs further assessment. As current OCT probes and processors do not yet provide optimal resolution, further generations of equipment with improved image quality are required.

[Effects of new cognitive-behavioral therapy programs for improvement of specific social skills of schizophrenics--a controlled study]

Based on the Integrated Psychological Therapy (IPT) for schizophrenia patients, the Berne group developed three specific cognitive behaviour therapy programmes for treating residential, vocational, and recreational functioning. We added new cognitive-emotional methods to these programmes that were devised especially for schizophrenia patients, taking into consideration the criticism of traditional social skill training methods. In the present multicentre study, these new programmes (experimental group) were compared with a traditional social skills training programme (control group, IPT "Social Skills" subprogramme). Both the therapy and aftercare phase each lasted 12 weeks and the follow-up phase 1 year. Assessment instruments covered psychopathology, cognitive functioning, and social adjustment. Higher ratings of global treatment effects and significant reductions in symptoms were obtained in the experimental group. In view of the favourable results, these newly designed social skill training programmes may replace more conventional therapy approaches in the future.

[Pathology of important diseases of endocrine organs (excluding the thyroid)]

Basic principles of classification of tumors of the pituitary, parathyroid glands, adrenals, paraganglionic system and endocrine pancreas and the differential diagnosis from non-endocrine tumors are presented. There are no uniform criteria of malignancy and common neuroendocrine immunohistological markers for unequivocal identification, as each organ has its own criteria. For pituitary tumors invasive growth is not a sign of malignancy, but only metastases. For tumors of the adrenal cortex a histopathological score has to be used for proving dignity. For pheochromocytomas, structural criteria (mitoses, angioinvasion) and immunostaining (S-100 protein, p53, Ki-67) are important. Endocrine tumors of the pancreas behave differently if they are angioinvasive or if they show more than two mitoses per 10 HPF, more than 2% Ki-67 positive nuclei or a size of more than 2 cm in diameter. They are malignant if gross local invasion or metastases are demonstrable. Clinical data have to be included in pathohistological reports. In many cases immunostaining in addition to structural analysis will be necessary.

Alloreactivity of natural killer cells in allogeneic liver transplantation

BACKGROUND

The cytolytic attack of natural killer (NK) cells is blocked by recognition of the idiotypic phenotype of certain polymorphisms in HLA class I molecules, specifically by HLA-C alleles (Asn77, Lys80 or Ser77, Asn80) or HLA-Bw4 allotypes. Because liver allograft rejection is associated closer with mismatch in HLA class I than class II, we investigated the role of NK cells in acute hepatic allograft rejection in vivo/in vitro.

METHODS

The HLA pattern was typed with serological and polymerase chain reaction (PCR) techniques. In 31 liver transplantations, mononuclear cells from donor spleen and peripheral blood of recipients (before/after transplantation) were cultured in mixed lymphocyte cultures (MLC). MLC-derived effector cells were analyzed by flow cytometry and tested in 51Cr-release assays.

RESULTS

Patients with NK allospecific constellations tended to have higher numbers of NK cells in peripheral blood during the first 4 weeks after transplantation, and patients' lymphocytes stimulated with donor cells had a significantly higher cytotoxic activity on days 14 and 21 compared with patients without NK allospecificity. However, acute rejection occurred with similar frequency in both groups (31% with allospecific constellations vs. 40% without). Moreover, acute rejection episodes were not associated with an increase in NK cells in vivo or enhanced cytotoxicity of NK cells to donor target cells.

CONCLUSIONS

Under standard immunosuppressive therapy, NK allospecific constellations did not seem play a major role in acute hepatic allograft rejection. Strategies to prevent or treat NK allospecific constellations after liver transplantation are not likely to reduce the incidence or severity of acute allograft rejection.

[Optimizing image reconstruction timing for the RR interval in imaging coronary arteries with multi-slice computerized tomography]

PURPOSE

Multislice spiral CT is a newly developed technology that allows the non-invasive detection of coronary stenoses and plaques. The acquired raw data are reconstructed at a given time point in the RR interval of the heart cycle. Thus, determination of this time point is a key factor for picture quality and for reliable diagnostic results. This study was performed to investigate the optimal time point for reconstruction within the RR interval.

MATERIALS AND METHODS

The coronary arteries of 13 patients were examined with CT. Raw data were reconstructed 250, 350, 450 and 550 ms before the following R wave (absolute reverse retrospective ECG gating) for each patient. Data were then analyzed with a volume rendering mode on a SIEMENS 3 D-Virtuoso workstation. A total of 91 segments (segments 1 and 2 of the RCA, segments 5, 6, 7 and proximal and distal parts of segment 11) were assessed and image quality was classified.

RESULTS

Visualization of the left main coronary artery was of a good quality at all time points, segments 6 and 7 of the LAD as well as the proximal and distal parts of segment 11 of the RCX had the best quality at 450 ms absolute reverse retrospective ECG gating. The segments 1 and 2 of the RCA were of best quality 550% ms absolute reverse to the R peak.

CONCLUSIONS

Classification of image quality of coronary artery CT scans after retrospectively ECG gated reconstruction is highly determined by the time point of reconstruction in the heart cycle. The optimization of this time point increases diagnostic accuracy and helps to avoid misinterpretation due to image artifacts.

The effects of prone positioning on intraabdominal pressure and cardiovascular and renal function in patients with acute lung injury

To detect any harmful effects of prone positioning on intraabdominal pressure (IAP) and cardiovascular and renal function, we studied 16 mechanically ventilated patients with acute lung injury randomly in prone and supine positions, without minimizing the restriction of the abdomen. Effective renal blood flow index and glomerular filtration rate index were determined by the paraaminohippurate and inulin clearance techniques. Prone positioning resulted in an increase in IAP from 12 +/- 4 to 14 +/- 5 mm Hg (P < 0.05), PaO(2)/fraction of inspired oxygen from 220 +/- 91 to 267 +/- 82 mm Hg (P < 0.05), cardiac index from 4.1 +/- 1.1 to 4.4 +/- 0.7 L/min (P < 0.05), mean arterial pressure from 77 +/- 10 to 82 +/- 11 mm Hg (P < 0.01), and oxygen delivery index from 600 +/- 156 to 648 +/- 95 mL. min(-)(1). m(-)(2) (P < 0.05). Renal fraction of cardiac output decreased from 19.1% +/- 12.5% to 15.5% +/- 8.8% (P < 0.05), and renal vascular resistance index increased from 11762 +/- 6554 dynes. s. cm(-)(5). m(2) to 15078 +/- 10594 dynes. s. cm(-)(5). m(2) (P < 0.05), whereas effective renal blood flow index, glomerular filtration rate index, filtration fraction, urine volume, fractional sodium excretion, and osmolar and free water clearances remained constant during prone positioning. Prone positioning, when used in patients with acute lung injury, although it is associated with a small increase in IAP, contributes to improved arterial oxygenation and systemic blood flow without affecting renal perfusion and function. Apparently, special support to allow free chest and abdominal movement seems unnecessary when mechanically ventilated, hemodynamically stable patients without abdominal hypertension are proned to improve gas exchange.

IMPLICATIONS

Prone positioning is increasingly used to improve gas exchange in patients with acute lung injury. However, during prone positioning an increase in intraabdominal pressure in these critically ill patients may promote dysfunction of other organs. Therefore, we performed a randomized study in mechanically ventilated patients with acute lung injury to investigate the cardiovascular and renal effects of prone positioning.