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P Rogalla

Publications and source records attributed to P Rogalla.

At least 73 records · Page 4Linked to original sources
PubMed2000

A novel high mobility group protein gene is a candidate for Xp22 abnormalities in uterine leiomyomas and other benign tumors.

Because genes of the high mobility group protein family HMGI(Y) are known to take part in the development of a variety of benign solid tumors, the aim of the present study was to search for further members of that family in the human genome. Analysis for HMGI(Y)-related sequences by the polymerase chain reaction (PCR) with the use of cDNA-specific primers offered evidence for HMGIY-like sequences, whereas HMGIC-related sequences were apparently absent. By chromosomal assignment of somatic cell hybrids PCR, HMGIY cDNA-related sequences were detected on seven chromosomes. Positive clones were obtained by screening of a P1-derived artificial chromosome library and mapped by fluorescence in situ hybridization. One of these clones assigned to Xp22.1 was chosen for further analysis because Xp22 is a target region for clonal aberrations in benign solid tumors. Sequence analysis of a DNA fragment of this clone, designated as HMGIYL1, revealed a 94.4% homology to the coding region of HMGIY. Within the HMGIYL1 sequence, no nucleotide sequence divergences leading to a frame shift or a new termination codon compared to HMGIY were found, and a TATA-box-like motif 5' of it was detected. By reverse transcriptase PCR experiments with the use of HeLa cells and human fetal tissue, HMGIYL1 expression was not detectable. Nevertheless, if not active by itself, it is possible that HMGIYL1 may become activated by chromosomal rearrangements of Xp22 observed in benign solid tumors.

Amino Acid Sequence↗
PubMed2000

Colonography using multislice CT.

Computed tomography (CT) represents the preferred imaging modality for imaging the large bowel when virtual endoscopic reconstructions are desired. Using the spiral acquisition technique, it has become possible to scan the entire abdomen within a single breathhold, however, slice thicknesses of 5 mm or more are necessary should the breathhold not last longer than 30-40 s. With the advent of multislice CT, contiguous 1-mm slices can be obtained through the entire abdomen while even shortening the breathhold to 25-30 s. The improved speed and spatial resolution of multislice CT results in remarkably sharp virtual reconstructions allowing detection of polyps with sizes less than 3 mm. The disadvantages must still be considered including a dataset consisting of up to 800 images representing a new challenge for postprocessing hard- and software.

Colon↗
PubMed2000

[Virtual otoscopy--technique, indications and initial experiences with multislice spiral CT].

UNLABELLED: We report the standardized postprocessing of high-resolution CT data acquired by incremental CT and multi-slice CT in patients with suspected middle ear disorders to generate three-dimensional endoluminal views known as virtual otoscopy. MATERIALS AND METHODS: Subsequent to the definition of a postprocessing protocol, standardized endoluminal views of the middle ear were generated according to their otological relevance. The HRCT data sets of 26 ENT patients were transferred to a workstation and postprocessed to 52 virtual otoscopies. RESULTS: Generation of predefined endoluminal views from the HRCT data sets was possible in all patients. Virtual endoscopic views added meaningful information to the primary cross-sectional data in patients suffering from ossicular pathology, having contraindications for invasive tympanic endoscopy or being assessed for surgery of the tympanic cavity. Multi slice CT improved the visualization of subtle anatomic details such as the stapes suprastructure and reduced the scanning time. CONCLUSION: Virtual endoscopy allows for the non invasive endoluminal visualization of various tympanic lesions. Use of the multi-slice CT technique reduces the scanning time and improves image quality in terms of detail resolution.

Adolescent↗
PubMed2000

An identical HMGIC-LPP fusion transcript is consistently expressed in pulmonary chondroid hamartomas with t(3;12)(q27-28;q14-15).

The high frequency of the t(3;12)(q27-28;q14-15) in lipomas and pulmonary chondroid hamartomas (PCHs) makes the HMGIC-LPP fusion gene the most common fusion gene in a human tumor known so far. Nevertheless, there is no in-depth molecular analysis of the HMGIC-LPP fusion transcripts in PCHs. Certainly, a possible molecular variability of the HMGIC-LPP fusion may contribute to a better understanding of the histologic differences between lipomas and PCHs and the intratumoral histologic heterogeneity of PCHs. By RT-PCR and restriction analysis, we have investigated the HMGIC-LPP fusion transcripts in a series of 13 PCHs with t(3;12)(q27-28;q14-q15). HMGIC-LPP fusion transcripts of identical size were found in all PCHs tested. In all tumors investigated, the fusion transcripts had the same structure, i.e., exons 1 to 3 of HMGIC and exons 9 to 11 of LPP encoding a protein composed of three AT-hooks and two LIM-domains. Our results clearly show that neither the histologic differences between lipomas and PCHs nor the histologic heterogeneity of PCHs can be explained by a molecular diversity of the HMGIC-LPP fusion transcript.

Chromosomes, Human, Pair 12↗
PubMed1999

Deletion of HMG17 in uterine leiomyomas with ring chromosome 1.

Uterine leiomyomas are characterized by several subgroups with characteristic chromosomal aberrations, mainly 12q14-15, 6p21, or interstitial deletions of chromosomes 3 and 7. For the first two subgroups, aberrations of the HMGIC and HMGIY genes have been described and are held responsible for tumor initiation. For other subgroups no molecular findings have been described as of yet. We focus here on a smaller subgroup of uterine leiomyomas with a ring chromosome 1 either as the only karyotypic deviation or occurring along with other abnormalities. In the p-arm of chromosome 1 HMG17, another member of the high-mobility group of proteins has been localized to the short arm of chromosome 1 (1p35) with two PAC clones on metaphase spreads of a uterine leiomyoma ring(1). Hybridization signals for these probes were not detected within the ring chromosome consistent with loss or deletion of HMG17. These findings suggest that HMG17 does not play a mechanistic role in leiomyoma similar to that observed with other high-mobility proteins.

Chromosomes, Human, Pair 1↗
PubMed1999

[CT studies in children. Methods and indications].

Technical advantages of spiral technology are of great usefulness in diagnostic imaging of thorax and abdomen in children. The rapid imaging time allows the examination of an entire organ while scanning with breath holding or while the child is quietly breathing, resulting in a decreased need for sedation. In addition especially examinations of the chest an to some extend CT-investigations of the abdomen are performed with reduced radiation dose achieved by reducing the tube loading. Radiation dose reduction of 70% is possible without loss of relevant diagnostic information. Spiral low-dose CT in pediatric chest imaging is useful in evaluating parenchymal lung diseases, mediastinal masses and central airway malformations. Whether abdominal helical CT can be replaced by MRI has to be decided in each individual case. When an exact protocol is used, sufficient contrast material given, scan-delay optimized and postprocessing reconstructions are performed, useful additional diagnostic informations are obtained by the method.

Adolescent↗
PubMed1999

Low-dose spiral CT: applicability to paediatric chest imaging.

BACKGROUND: Spiral CT of the chest is an imaging technique with unequivocal indications and proven higher sensitivity and specificity than conventional chest X-rays. However, particularly in children, attempts should be made to reduce radiation exposure to a minimum. OBJECTIVE. To evaluate whether a low-dose technique in spiral CT scanning results in adequate diagnostic information. MATERIALS AND METHODS: In a prospective study, 27 children (range 3 weeks to 14 years, mean 7 years) underwent a low-dose CT examination of the chest for various indications. The tube energy was 12.5 mAs (n = 5), 25 mAs (n = 17), 50 mAs (n = 3), or 75 mAs (n = 2) per slice. Two radiologists evaluated, in consensus, the CT scans with respect to their diagnostic value and comparison was made with 20 standard-dose chest CT examinations of adults (175 mAs per slice, mean age 56 years) with respect to technical image quality (noise and artefacts). In a second part of the study, dose measurements were carried out by means of exposing thermoluminescent dosimeters attached to a water/air phantom simulating a child's chest. RESULTS: All low-dose CT scans were of diagnostic image quality and no additional studies were necessary. The average image noise was significantly higher than in standard-dose CT examinations (SD 39.5 compared with 12.5 for unenhanced soft tissue, P < 0.01), but did not hinder accurate diagnosis. Artefacts were exclusively due to patient motion. Radiation exposure per slice was approx. 4 mGy at 25 mAs and 34 mGy at 250 mAs, regardless of slice thickness. CONCLUSIONS: For all indications in paediatric CT scanning of the chest, low-dose technique provides adequate image quality without loss of diagnostic information. The radiation exposure is approximately 5-20 % of a standard-dose CT.

Adolescent↗
PubMed1999

Pleomorphic adenomas of the salivary glands: absence of HMGIY rearrangements.

Rearrangements of chromosome region 12q14-15 affecting the HMGIC gene are a frequent finding in benign solid tumors. Another non-random chromosomal alteration observed in subgroups of several of the tumor entities with 12q14-15 changes are rearrangements of 6p21 resulting in alterations of the HMGIY gene, which have so far not been documented in pleomorphic adenomas of the salivary glands. In our series of 335 pleomorphic adenomas, karyotypic changes affecting chromosomal region 6p21-23 were observed in five tumors all showing either a simple or complex t(6;8)(p21-p23;q12). Molecular cytogenetic studies of two of these tumors revealed that the 6p-breakpoint of this translocation maps distal to HMGIY, not affecting the gene or its closer vicinity. The results strongly suggest that pleomorphic adenomas are the only exception to the rule that entities of benign tumors with HMGIC rearrangements also have subtypes with HMGIY rearrangements. The difference from the other tumors is discussed in terms of tissue specificity of both HMG protein genes.

Adenoma, Pleomorphic↗
PubMed1999

Popliteal artery occlusion as a late complication of liquid acrylate embolization for cerebral vascular malformation.

Occlusion of arteriovenous malformations of the brain (BAVMs) by means of an endovascular approach with liquid acrylate glue is an established treatment modality. The specific hazards of this procedure are related to the central nervous system. In the case of unexpectedly rapid polymerization of the cyanoacrylate glue and adhesion of the delivering microcatheter to the BAVM, severing the catheter at the site of vascular access is considered an acceptable and safe management. We present a unique complication related to this technique that has not been described yet. Fragmentation and migration of the microcatheter, originally left in place, had caused popliteal artery occlusion, which required saphenous vein interposition, in a 25-year-old man. Suggestions for avoiding this complication are discussed.

Adult↗
PubMed1999

A new bronchoscopic method to measure airway size.

Bronchoscopic evaluation of stenosis is limited due to radial distortion of bronchoscopic images and the unknown distance between the endoscope and the stenotic area. The purpose of this study was the development and validation of a method for measuring cross-sectional areas in large airways. Distance measurements were performed using a laser probe inserted into the working channel of a bronchoscope. The laser probe was positioned to the locus of interest in the airway, a ring of light (helium/neon) projected on to the luminal wall and the images acquired using an electronic bronchoscope. The images taken were distortion-corrected by means of a computer program. The method was validated by simulating airways using tubes of known diameter. Additionally, distortion-corrected bronchoscopic images were compared with distortion-free videoscopic image analysis of tracheal slices taken from pigs. In the case of the plastic tubes, Pearson's correlation coefficient (r) as well as the intraclass correlation coefficient (ICC) were slightly higher (r=0.99, p<0.01, ICC=0.97) than the correlation of cross-sectional areas between bronchoscopic and videoscopic images of tracheal slices (r=0.88, p<0.01, ICC=0.87). This concept allows accurate and reproducible determination of cross-sectional areas in large airways.

Animals↗
PubMed1999

Dissecting aneurysm of the infrarenal abdominal aorta.

The aim of this study was to report the case of a patient with chronic dissecting infrarenal abdominal aortic aneurysm (AAA) and to review the literature for this rare vascular disorder. The preoperative assessment, surgical treatment, and postoperative course of a patient with a dissecting AAA and associated left iliac artery dissection were analyzed. The literature is reviewed with respect to etiology and pathogenesis as well as diagnostic and therapeutic management of infrarenal dissecting AAA. The preoperative diagnosis of dissecting infrarenal AAA was made by computed tomography and aortography and confirmed during surgery. Successful repair was accomplished by use of a bifurcated aortobiiliacal Dacron graft. A review of the literature demonstrates the rarity of dissecting aneurysm exclusively involving the infrarenal aortic segment. Primary dissecting aneurysm of the infrarenal abdominal aorta is a rare morphologic finding. Principles of diagnostic and therapeutic management of common atherosclerotic AAA also apply to dissecting AAA.

Aortic Dissection↗
PubMed1998

The t(3;12)(q27;q14-q15) with underlying HMGIC-LPP fusion is not determining an adipocytic phenotype.

The HMGIC gene, located in chromosome band 12q15, is rearranged in many different benign human tumors, often resulting in its fusion to ectopic sequences from other genes. The t(3;12)(q27;q14-q15) fuses HMGIC with the LPP gene and has so far been described exclusively in lipomas. Thus, it can be hypothesized that this particular gene fusion determines the adipocytic differentiation. We studied five pulmonary chondroid hamartomas all showing a t(3;12)(q27;q14-q15) that apparently was identical to the one observed in lipomas. By fluorescence in situ hybridization we found that both HMGIC and LPP are disrupted by this translocation. By RT-PCR the existence of a HMGIC/LPP fusion gene was confirmed. These results show that the fusion is not specific for lipomas. We favor the hypothesis that it is an ectopic sequence fused to HMGIC that is responsible for a cell shift to an embryogenic stage. Following this hypothesis the phenotype of the tumor may be induced by extracellular signal transduction.

Adipocytes↗
PubMed1998

[Thoracic diagnosis with electron-beam computed tomography].

The electron beam computed tomography (EBCT) is characterised by an up to 10-fold increased speed in comparison to a spiral CT scanner. Although originally designed for diagnosing the heart, some indications in the chest and for the vessels have also become well established. In the forefront exists the possibility to exam a large volume with a small slice thickness in a short time period without having to sacrifice on important features of spiral CT scanning. During one breathhold, the thorax can be continually examined with 1.5 mm slice thickness, which means that indications for high-resolution (HR-) CT, spiral-CT and for virtual bronchoscopy can be combined into one examination. Beyond the artefact-reduced images, the EBCT presents image data which, following image processing (sliding MIPs, coronal reconstructions), allow recognition of a new horizon in thoracic diagnostics.

Aged↗
PubMed1998

Safe and easy power injection of contrast material through a central line.

Power-assisted injection of contrast material into an antecubital vein is commonly used in CT and has been proven superior to manual injection. Power-assisted injection through a central line bares the risk of rupturing the line because manual control over the pressure applied by the power injector is lacking. We present a simple safety device which allows manual control of the pressure by means of an interposed three-way stopcock combined with a small syringe for pressure equalization.

Catheterization, Central Venous↗
PubMed1998

Virtual endoscopy of the small bowel: phantom study and preliminary clinical results.

The purpose of this study was to determine the optimal scanning technique for lesion detection in a small bowel phantom and to evaluate the virtual endoscopy (VE) technique in patients. A small bowel phantom with a fold thickness of 7 mm and length of 115 cm was prepared with nine round lesions (3 x 1 mm, 2 x 2 mm, 2 x 3 mm, 2 x 4 mm). Spiral CT parameters were 7/7/4, 3/5/2, 3/5/1, 1.5/3/1 (slice thickness/table feed/reconstruction interval). VE was done using volume rendering technique with 1 cm distance between images and 120 degrees viewing angle. Two masked readers were asked to determine the number and location of the lesions. Seven patients underwent an abdominal CT during one breathhold after placement of a duodenal tube and filling of the small bowel with methyl cellulose contrast solution. VE images were compared with the axial slices with respect to detectability of pathology. With the 7/7/4 protocol only the 4-mm lesions were visualised with fuzzy contours. The 3/5/2 protocol showed both 4-mm lesions, one 3-mm lesion and one false positive lesion. The 3/5/1 protocol showed both 4-mm and both 3-mm (one uncertain) lesions with improved sharpness, and no false positive lesions. One 2-mm and one 1-mm lesion were additionally seen with the 1.5/3/1 protocol. Path definition was difficult in sharp turns or kinks in the lumen. In all patients, no difference was found between VE and axial slices for bowel pathology; however, axial slices showed 'outside' information that was not included in VE. We conclude that the 3/5/2 protocol may be regarded as an optimal compromise between lesion detection, coverage during one breathhold, and number of reconstructed images in patients; round lesions of 4 mm in diameter can be detected with high certainty.

Adult↗