[MR imaging of lymph nodes using Gadofluorine M: feasibility in a swine model at 1.5 and 3T]. / MR-Bildgebung von Lymphknoten mit Gadofluorine M in einem Schweinemodell bei 1,5 and 3T.

PURPOSE: To investigate the potential of Gadofluorine M for targeted lymph node imaging in a human size animal model and on a clinical MR scanner at 1.5 and 3 T. MATERIALS AND METHODS: Pelvic and cervical lymph nodes in a swine model were investigated prior to and 24 hours after intravenous administration of 50 micromol/kg body weight Gadofluorine M, an experimental contrast agent. MR imaging was carried out on clinical 1.5 T and 3 T whole-body MR systems using clinically available coils and T 1-weighted sequences. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) with respect to the surrounding tissue were assessed and compared using the Student's t-test. The Gd concentration in the lymph nodes (n = 43) was measured post mortem by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). RESULTS: Gadofluorine M allowed for high signal and high contrast visualization of lymph nodes in all stations on post-contrast images with a significantly increased SNR and CNR (SNR pelvic lymph nodes post vs. pre: 46 +/- 7 vs.14 +/- 3, SNR cervical lymph nodes post vs. pre: 105 +/- 64 vs. 32 +/- 21; CNR pelvic lymph node vs. muscle post vs. pre 28 +/- 5 vs. 0.2 +/- 0.5, CNR cervical lymph node vs. muscle post vs. pre 76 +/- 53 vs. 11 +/- 15, p < 0.05 for all comparisons). The SNR and CNR in the pelvis were further improved using 3 T compared to 1.5 T scanners (SNR lymph nodes 3 T vs. 1.5 T 84 +/- 6 vs. 46 +/- 7, CNR lymph node vs. muscle 3 T vs. 1.5 T 53 +/- 9 vs. 28 +/- 5 respectively, p < 0.05). A high concentration of Gd in the lymph nodes was found (149 +/- 25 mmol Gd/L). CONCLUSION: Gadofluorine M accumulates in the lymph nodes and allows for selective targeted high contrast MR imaging of lymph node tissue in a large animal model using clinically available MR imaging techniques. 3 T further improves SNR and CNR compared to 1.5 T.

[MRI of the heart following implantation of a left ventricular apico-aortic conduit]. / Kernspintomografie zur umfassenden Untersuchung des Herzens nach Implantation von linksventrikulären apikoaortalen Conduits.

PURPOSE: To investigate the potential of ECG-triggered MRI for the evaluation of postoperative anatomy and function of the heart and conduit following implantation of a left-ventricular apico-aortic conduit. MATERIALS AND METHODS: 5 patients (2 female, 3 male, mean age 72.5 years) were examined using a 1.5 Tesla whole-body MRI (Gyroscan Intera, Philips Medical Systems, Best, The Netherlands) following apico-aortic conduit surgery due to severe aortic valve stenosis. The reason for performing conduit implantation instead of aortic valve replacement was the risk of injuring a bypass graft from prior coronary artery bypass surgery. Cine steady-state-free-precession (SSFP) sequences were used to assess ventricular function, navigator-gated 3D-SSFP and breath-hold, time-resolved contrast-enhanced MR angiography was used to display the postoperative anatomy, and 2D-gradient echo sequences with an inversion pulse to suppress the signal of the healthy myocardium were used to evaluate potential myocardial scarring. Flow sensitive gradient echo sequences were performed to determine the blood flow in the conduit. RESULTS: In all patients the apico-aortic conduit proved to be open with a maximum flow velocity of 126 (+ 43) cm/s. The postoperative anatomy was able to be evaluated in all patients and perioperative myocardial infarction was able to be ruled out. The mean ejection fraction of the left ventricle was 44.2 + 6.2 % with a mean volume of 80 + 20.6 ml per heart beat. CONCLUSION: ECG-triggered MRI is a reliable method for the evaluation of postoperative anatomy and function following implantation of a left ventricular apico-aortic conduit.

Echocardiogram-gated multislice spiral CT in functionally univentricular heart following long-lasting Waterston-Cooley anastomosis.

Waterston-Cooley anastomosis may be carried out in patients with tricuspid atresia to provide pulmonary perfusion. It is associated with several complications, including preferential blood flow to the right lung, hypoplasia of the left pulmonary artery, obstruction of the anatomosis or rupture of pulmonary aneurysms. We study a patient with thrombosis in the pulmonary arteries following surgical construction of a Waterston shunt in childhood. Imaging findings and clinical symptoms are discussed with emphasis on echocardiogram-gated multislice spiral CT.

Calcium scoring of aortic valve calcification in aortic valve stenosis with a multislice computed tomography scanner: non-enhanced versus contrast-enhanced studies.

PURPOSE: Previous studies have shown a positive correlation between amount of aortic valve calcification (AVC) and degree of aortic valve stenosis (AVS). We have investigated whether calcium scoring of AVC from contrast-enhanced images is reliable. MATERIAL AND METHODS: Nineteen patients with suspected AVS underwent retrospectively ECG-gated multislice computed tomography (MSCT). Standardized scan protocols were applied prior to (120 KV, 133 mAseff) and after (120 KV, 500 mAseff) the administration of non-ionic contrast material. Image reconstruction was performed at 60% of the RR interval (slice thickness 3 mm, reconstruction increment 2 mm). AVC was quantified using Agatston score and calcium mass. The number of lesions was calculated. All nonenhanced images were scored using thresholds of 130 HU and 350 HU. Contrast-enhanced images were assessed with a threshold of 350 HU exclusively. RESULTS: Fifteen patients with AVCs were included in the statistical analysis. The mean Agatston score (calcium mass) in non-enhanced images was 2888.4 +/- 2844.4 (694.2 mg +/- 869.3 mg). Altering the threshold from 130 HU to 350 HU led to a 58.2% (30.5%) decrease in the AVC score (P values < 0.001). Contrast-enhanced images showed an increased Agatston score (calcium mass) of 56.2% (33.5%) compared to non-enhanced images (P values <0.05) with the same threshold of 350 HU. CONCLUSION: Quantification of AVC from contrast-enhanced images is not reliable, as contrast material simulates calcification.

Inguinal hernia on the internet: a critical comparison of Germany and the UK.

Despite containing an increasing amount of medical information, the Internet provides only rare benefits for surgical patients. Using "inguinal hernia" as a catchword, an amateur search was imitated on the British Internet market. Sixty-five pages, standardised regarding quality and efficiency, were evaluated. A comparison to the German Internet market was added. In summary, the broad majority of the pages revealed poor results. Technical appearance, quality of content, and target grouping show big deficiencies. The applicable laws on the European market are not yet established. The ranking lists of the search engines do not reflect the quality of the pages. Patients need competent guides to process surgical information from the Internet. The establishment of specialised institutions to control surgical Web sites according to quality, content, and legality on the European level is urgent.

[Information on the Internet for patients and general practitioners--critical analysis using the example of inguinal hernia]. / Internet-Informationen für Patient und Hausarzt als Leistungsanforderer. Eine kritische Analyse am Beispiel der Leistenhernie.

INTRODUCTION: The Internet offers an increasing amount of medical information, but its value for surgical patients is doubtful. METHODS: Using "inguinal hernia" as catchword, an amateur search was imitated on a German-speaking metasearch machine. One hundred fifty sites, standardized regarding quality and efficiency,were evaluated. RESULTS: In summary, more than 50% of the sites revealed poor results. Technical appearance, quality of content, and target grouping show big deficiencies. The applicable laws were mostly not respected. The ranking lists of the search machines do not reflect the quality of the sites. CONCLUSION: Patients need competent guides to process surgical information from the Internet. The establishment of a specialized institution to control surgical websites according to quality, content, and legality seems to be needed.

[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.

Enterostomy complications in infancy and childhood.

BACKGROUND: A number of severe gastrointestinal disorders in infancy and childhood may require the formation of an enterostomy as a crucial part of the treatment of the disease itself. This study reviews our pediatric patients with regard to the morbidity and mortality of enterostomy formation and closure over an 8-year period. PATIENTS AND METHODS: Sixty-eight enterostomies in infants and children and 60 consecutive enterostomy closures in retrospect are reported on. This includes colostomies, jejunostomies, ileostomies, and Mikulicz procedures. RESULTS: In most instances, a transverse colostomy was performed. The most frequent indications were intestinal obstruction and necrotizing enterocolitis. More than half of the children were less than 1 month of age at the time of surgery. We observed an overall complication rate of 38.2% following enterostomy formation, with stoma prolapse being the most common, but faced major complications (such as sepsis, peritonitis, and enterocutaneous fistula) in only 10.3%. Complications after enterostomy closure were encountered in 20%. The overall mortality was 7%. CONCLUSION: Enterostomy formation and closure in the pediatric age group with severe underlying disease is still associated with substantial morbidity.

Squamous cell carcinoma of the cervix metastatic to the skin.

Carcinoma of the cervix is a common neoplasm, which annually affects 50,000 women in the United States. When cervical carcinoma metastasizes, it most often involves the lung, bone, and liver; only rarely does it metastasize to the skin. We describe a patient with previously diagnosed carcinoma of the cervix who presented with a lesion on the lateral aspect of her left leg.

Rehabilitation considerations for the client with chronic, nonmalignant pain.

Chronic, nonmalignant pain is a significant stressor for one in five Americans. It robs society of productive work days and families of the stability generated through positive personal interaction, a steady, adequate source of income, and confidence in the ability to handle the future. On a personal level, there is increased stress, which generates increased attention to physical symptoms, a loss of self-esteem, and feelings of helplessness, powerlessness, and hopelessness. These psychological issues can spiral out of control, wreaking havoc not only in the client, but also in family dynamics and roles. Case managers are in an ideal position to help blunt the toll of this pain by active listening and focusing on interventions that help the client take an active role in his or her care and maintain as much independence as possible.

Electron beam-induced changes in vitreous sections of biological samples.

Nonpretreated high pressure frozen samples of Zea mays, cartilage and human erythrocytes were cryosectioned and observed at 110K in a cryoelectron microscope. Changes induced by medium doses of electron irradiation (< 10 ke nm-2) are described. After some ke nm-2, the most conspicuous cutting artefacts are erased to a large extent and the visibility of the cell organelles is improved. The sections, compressed in the cutting direction by the sectioning process, shrink once more, in the same direction, when irradiated. This shrinkage depends on the section support and on how the section is adsorbed to it. Shrinkage is not uniform: it is most pronounced in mitochondria, condensed chromatin and nucleolus. This differential shrinkage improves the visibility of major structures on the section and, as a result, 'nicer' images are recorded. However, this apparent improvement is a beam-induced artefact that must be paired with a loss of high resolution information.

Isoform-specific interactions of Na,K-ATPase subunits are mediated via extracellular domains and carbohydrates.

The functional unit of the Na,K-ATPase consists of a catalytic alpha subunit noncovalently linked with a glycoprotein subunit, beta. Using ouabain binding assays and immunoprecipitation of rodent alpha/beta complexes, we show here that all six possible isozymes between three alpha and two beta isoforms can be formed in Xenopus oocytes. Two isoform-specific differences in alpha/beta interactions are observed: (i) alpha1/beta1 and alpha2/beta2 complexes, in contrast to alpha1/beta2 complexes, are stable against Triton X-100-mediated dissociation, and (ii) beta2 subunits must carry N-glycans to combine with alpha1 but not with alpha2. The interacting surfaces are mainly exposed to the extracellular side because coexpression of a truncated beta1 subunit comprising the ectodomain results in assembly with alpha1 and alpha2, but not with alpha3; the beta2 ectodomain combines with alpha2 only. A chimera consisting of 81% and 19% of the alpha1 N terminus and alpha2 C terminus, respectively, behaves like alpha2 and coprecipitates with the beta2 ectodomain. In contrast, the reciprocal chimera does not coprecipitate with the beta2 ectodomain. These results provide evidence for a selective interaction of Na,K-ATPase alpha and beta subunits.

Relationship between ornithine decarboxylase and cytoskeletal organization in cultured human keratinocytes: cellular responses to phorbol esters, cytochalasins, and alpha-difluoromethylornithine.

Changes in cell shape occur during the cell cycle and influence cell proliferation and differentiation. In order to study how altered cell proliferation and cell shape are interrelated, we have studied ornithine decarboxylase (ODC) regulation in cultured normal human epidermal keratinocytes (NHEK). Cytoskeletal disruptors have been reported to modulate regulation of ODC; the products of ODC, the polyamines, influence actin polymerization rates in vitro, and polyamine auxotrophs have profoundly disrupted cytoskeletons. Therefore, altered ODC levels could be involved in signaling changes in cell shape and an intact cytoskeleton could transduce signals to regulate ODC levels. We had previously observed that the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), which profoundly alters cell shape, markedly suppresses ODC biosynthesis in NHEK solely at posttranscriptional/protein synthesis levels. TPA treatment caused NHEK to rapidly assume a rounded morphology that was accompanied by a change in actin organization, as determined by rhodamine-phalloidin labeling. Immunolocalization of ODC showed a perinuclear/nuclear distribution in untreated NHEK and a more diffuse pattern after TPA treatment that was apparent within 15-30 min. Changes in ODC enzyme activity are not significant until 60 min after TPA treatment. NHEK treated with cytochalasin B or D to inhibit actin polymerization exhibited a diffuse ODC localization that could be reversed by removal of the cytochalasin; inhibition of ODC by alpha-difluoromethylornithine caused a diffuse ODC localization. All treatments resulted in cytoskeletal remodeling. These data are the first evidence for a distinct subcellular localization for ODC and suggest that changes in ODC localization may be an initial step in regulation of ODC activity. Furthermore, changes in ODC activity cause an altered cytoskeleton, suggesting one means by which growth regulatory signals can be transduced to the cytoskeleton from various signaling pathways.

Post-transcriptional suppression of human ornithine decarboxylase gene expression by phorbol esters in human keratinocytes.

The induction of ornithine decarboxylase levels by the phorbol ester 12-0-tetradecanoyl-phorbol-13-acetate (TPA) in mouse skin has been shown to be integral to tumor promotion by TPA, and changes in ornithine decarboxylase activity indicate the proliferative state of many different cell types. However, in cultured human epidermal cells, TPA has been reported to be antiproliferative. Therefore, to elucidate pathways that TPA activates in cultured human skin cells, we have examined the levels at which TPA regulates ornithine decarboxylase gene expression in two immortalized human epidermal keratinocyte cell lines, and in normal neonatal keratinocytes. We have found that in cultured human keratinocytes, TPA cases a marked decrease in ornithine decarboxylase enzyme activity (50-90%), with no detectable effect on ornithine decarboxylase mRNA levels. TPA decreased steady-state levels of ornithine decarboxylase immunoreactive protein (approximately 50-67%), accounting for the 50-90% suppression of ornithine decarboxylase activity levels, as well as decreasing new synthesis of ornithine decarboxylase protein (48-50%). However, measurement of ornithine decarboxylase protein half-life showed no significant effect of TPA. Also, prolonged treatment of keratinocytes with phorbol esters abolished the suppression of ornithine decarboxylase activity by TPA. Our data, therefore, suggest that phorbol esters suppress ornithine decarboxylase gene expression predominantly by decreasing ornithine decarboxylase mRNA translatability.