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1.
Prenat Diagn ; 44(8): 988-995, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38797992

ABSTRACT

OBJECTIVE: We aim to provide a template structured report of fetal Magnetic Resonance Imaging in congenital diaphragmatic hernia (CDH) that was locally validated by the CDH study group in Mannheim. METHODS: A selection of 50 fetal MRIs of patients with an isolated diaphragmatic hernia and associated radiology reports from five different senior radiologists from a single center resulted in a primary structured report, which was put into practice by using dedicated software. A questionnaire survey of the interdisciplinary CDH study group Mannheim was used to adapt the report to the clinical requirements. RESULTS: There was a huge variability in how deep the free text reports go into detail. The side of the hernia was named in 94% of cases. In 58%, both the lung volume and the total lung volume were reported. A comparison with the expected lung volume was reported in 66% of cases. Additional findings, such as herniated organs, were reported in 96% of cases. Overall satisfaction with the newly established structured report was high within the CDH study group with a mean of 4.7. CONCLUSIONS: The use of the structured report of this study can optimize the interdisciplinary dialog, the standardization of report content, increase report completeness and improve quality.


Subject(s)
Hernias, Diaphragmatic, Congenital , Magnetic Resonance Imaging , Humans , Hernias, Diaphragmatic, Congenital/diagnostic imaging , Magnetic Resonance Imaging/methods , Female , Pregnancy , Prenatal Diagnosis/methods , Surveys and Questionnaires
2.
Eur Radiol ; 26(12): 4231-4238, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27048538

ABSTRACT

OBJECTIVE: With a region of interest (ROI)-based approach 2-year-old children after congenital diaphragmatic hernia (CDH) show reduced MR lung perfusion values on the ipsilateral side compared to the contralateral. This study evaluates whether results can be reproduced by segmentation of whole-lung and whether there are differences between the ROI-based and whole-lung measurements. METHODS: Using dynamic contrast-enhanced (DCE) MRI, pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) were quantified in 30 children after CDH repair. Quantification results of an ROI-based (six cylindrical ROIs generated of five adjacent slices per lung-side) and a whole-lung segmentation approach were compared. RESULTS: In both approaches PBF and PBV were significantly reduced on the ipsilateral side (p always <0.0001). In ipsilateral lungs, PBF of the ROI-based and the whole-lung segmentation-based approach was equal (p=0.50). In contralateral lungs, the ROI-based approach significantly overestimated PBF in comparison to the whole-lung segmentation approach by approximately 9.5 % (p=0.0013). CONCLUSIONS: MR lung perfusion in 2-year-old children after CDH is significantly reduced ipsilaterally. In the contralateral lung, the ROI-based approach significantly overestimates perfusion, which can be explained by exclusion of the most ventral parts of the lung. Therefore whole-lung segmentation should be preferred. KEY POINTS: • Ipsilaterally, absolute lung perfusion after CDH is reduced in whole-lung analysis. • Ipsilaterally, the ROI- and whole-lung-based approaches generate identical results. • Contralaterally, the ROI-based approach significantly overestimates perfusion results. • Whole lung should be analysed in MR lung perfusion imaging. • MR lung perfusion measurement is a radiation-free parameter of lung function.


Subject(s)
Hernias, Diaphragmatic, Congenital/surgery , Lung/blood supply , Lung/diagnostic imaging , Magnetic Resonance Imaging/methods , Postoperative Care/methods , Regional Blood Flow/physiology , Blood Volume , Child, Preschool , Contrast Media , Female , Humans , Image Enhancement , Male , Reproducibility of Results
3.
Eur Radiol ; 24(10): 2427-34, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25038855

ABSTRACT

OBJECTIVES: Congenital diaphragmatic hernia (CDH) leads to lung hypoplasia. Using dynamic contrast-enhanced (DCE) MR imaging, lung perfusion can be quantified. As MR perfusion values depend on temporal resolution, we compared two protocols to investigate whether ipsilateral lung perfusion is impaired after CDH, whether there are protocol-dependent differences, and which protocol is preferred. METHODS: DCE-MRI was performed in 36 2-year old children after CDH on a 3 T MRI system; protocol A (n = 18) based on a high spatial (3.0 s; voxel: 1.25 mm(3)) and protocol B (n = 18) on a high temporal resolution (1.5 s; voxel: 2 mm(3)). Pulmonary blood flow (PBF), pulmonary blood volume (PBV), mean transit time (MTT), and peak-contrast-to-noise-ratio (PCNR) were quantified. RESULTS: PBF was reduced ipsilaterally, with ipsilateral PBF of 45 ± 26 ml/100 ml/min to contralateral PBF of 63 ± 28 ml/100 ml/min (p = 0.0016) for protocol A; and for protocol B, side differences were equivalent (ipsilateral PBF = 62 ± 24 vs. contralateral PBF = 85 ± 30 ml/100 ml/min; p = 0.0034). PCNR was higher for protocol B (30 ± 18 vs. 20 ± 9; p = 0.0294). Protocol B showed higher values of PBF in comparison to protocol A (p always <0.05). CONCLUSIONS: Ipsilateral lung perfusion is reduced in 2-year old children following CDH repair. Higher temporal resolution and increased voxel size show a gain in PCNR and lead to higher perfusion values. Protocol B is therefore preferred. KEY POINTS: • Quantitative lung perfusion parameters depend on temporal and spatial resolution. • Reduction of lung perfusion in CDH can be measured with different MR protocols. • Temporal resolution of 1.5 s with spatial resolution of 2 mm (3) is suitable.


Subject(s)
Hernias, Diaphragmatic, Congenital/diagnosis , Herniorrhaphy , Lung Diseases/diagnosis , Lung/pathology , Magnetic Resonance Imaging/methods , Perfusion Imaging/methods , Child, Preschool , Contrast Media , Female , Hernias, Diaphragmatic, Congenital/complications , Hernias, Diaphragmatic, Congenital/surgery , Humans , Lung Diseases/etiology , Male , Postoperative Period , Reproducibility of Results
4.
Eur Radiol ; 22(12): 2743-9, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22692394

ABSTRACT

OBJECTIVE: To investigate whether dynamic contrast-enhanced MR imaging of the lung following congenital diaphragmatic hernia repair is feasible at 3.0 T in 2-year-old children and whether associated lung hypoplasia (reflected in reduced pulmonary microcirculation) can be demonstrated in MRI. METHODS: Twelve children with a mean age 2.0 ± 0.2 years after hernia repair underwent DCE-MRI at 3.0 T using a time-resolved angiography with stochastic trajectories sequence. Quantification of lung perfusion was performed using a pixel-by-pixel deconvolution approach. Six regions of interest were placed (upper, middle and lower parts of right and left lung) to assess differences in pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) while avoiding the inclusion of larger pulmonary arteries and veins. RESULTS: The difference in PBF and PBV between ipsilateral and contralateral lung was significant (P < 0.5). No significant differences could be detected for the MTT (P = 0.5). CONCLUSION: DCE-MRI in 2-year-old patients is feasible at 3.0 T. Reduced perfusion in the ipsilateral lung is reflected by significantly lower PBF values compared with the contralateral lung. DCE-MRI of the lung in congenital diaphragmatic hernia can help to characterise lung hypoplasia initially and in the long-term follow-up of children after diaphragmatic repair. KEY POINTS: Congenital diaphragmatic hernia often leads to lung hypoplasia and secondary pulmonary hypertension. Dynamic contrast-enhanced 3-T magnetic resonance can assess these complications in 2-year-olds. The affected ipsilateral lung shows reduced perfusion and lower pulmonary blood flow. Thoracic DCE-MRI helps characterise lung hypoplasia in children after hernia repair.


Subject(s)
Hernias, Diaphragmatic, Congenital , Magnetic Resonance Angiography/methods , Postoperative Complications/diagnosis , Contrast Media , Female , Hernia, Diaphragmatic/surgery , Humans , Infant , Male , Meglumine , Organometallic Compounds
5.
Radiologe ; 50(12): 1128-31, 2010 Dec.
Article in German | MEDLINE | ID: mdl-21153521

ABSTRACT

Foreign body ingestion is a common pediatric emergency and if the foreign body cannot be detected radiologically or endoscopically further investigations are required. In this article the case of a radiolucent, ingested foreign body (mini-candleholder of a birthday cake) is presented. The foreign body could not initially be identified via X-ray and endoscopy due to its parapharyngeal localization but was finally visualized by magnetic resonance imaging (MRI) which additionally uncovered the co-existence of acute mediastinal inflammation.


Subject(s)
Esophagus , Foreign-Body Migration/diagnosis , Image Enhancement , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Mediastinitis/diagnosis , Pharynx , C-Reactive Protein/analysis , Child, Preschool , Contrast Media , Esophageal Perforation/diagnosis , Esophageal Perforation/pathology , Esophagus/pathology , Female , Foreign-Body Migration/therapy , Humans , Laryngoscopes , Leukocyte Count , Pharynx/pathology , Pneumonia/diagnosis
6.
Urologe A ; 59(3): 278-283, 2020 Mar.
Article in German | MEDLINE | ID: mdl-32020239

ABSTRACT

In prepubertal boys, testicular tumors are rare with an incidence between 2 and 5/million. In contrast to testicular tumors in adolescents and adults, more than 2/3 of these tumors are benign. Unfortunately, in Germany in most cases, only malignant tumors (usually yolk sac tumors) are reported to the study center (MAKEI IV and now V). Therefore, the incidence in Germany is unknown. Since the introduction of polychemotherapy in the 1970s, the prognosis of malignant testicular tumors has improved enormously and has become a curable disease, even in the case of recurrence. Today the orchiectomy, which was usually carried out in the past, appears to be no longer justified in most prepubertal boys due to the high incidence of benign tumors. It has been shown in various studies that organ-sparing surgery in germ cell tumors (epidermoid cysts, teratoma); gonadal stoma tumors (Sertoli, Leydig and granulosa cell tumors) and cystic lesions (intratesticular cysts and tubular ectasia of the rete testis) is reliable and safe. In cases with preoperative significantly increased AFP (caution: norm values not valid in the first year of life) and a clear testicular tumor in the ultrasound (yolk sac tumor) or if no testicular parenchyma is sonographically detectable, orchiectomy can still be carried out. Today orchiectomies in prepubertal boys should be an exception and the reasons for an orchiectomy must be well documented.


Subject(s)
Neoplasms, Germ Cell and Embryonal/surgery , Orchiectomy , Organ Preservation , Testicular Neoplasms/surgery , Adolescent , Biomarkers, Tumor , Germany , Humans , Male , Neoplasm Recurrence, Local , Neoplasms, Germ Cell and Embryonal/pathology , Testicular Neoplasms/pathology
7.
J Cell Biol ; 79(3): 833-8, 1978 Dec.
Article in English | MEDLINE | ID: mdl-730769

ABSTRACT

Abundant cytoplasmic proteins pulse-labeled with [35S]methionine at specific times throughout the HeLa cell cycle were analyzed with two-dimensional gel electrophoresis. More than 300 proteins could be resolved in this way. The frequency of appearance of label in the most abundant 90 proteins, ranging from 4% to less than 0.1% of the total methionine incorporated, was determined at six time points in the cell cycle. 84 of these proteins were made as a similar proportion of the total at all times during the cell cycle. A nonmuscle actin protein (spot 1) identified by molecular weight and isoelectric point represented 2-4% of the total methionine incorporated at all the time points. Only six proteins were found which varied by greater than fourfold during cell division, four appearing to represent a greater proportion of the total synthesis during the period at or immediately surrounding M (spots 31b, 44, 53, and 70d). Two appear to represent a smaller percentage of total synthesis during the early (spot 78) or the total (spot 74) G2 period.


Subject(s)
Actins/biosynthesis , Cell Cycle , HeLa Cells/metabolism , Neoplasm Proteins/biosynthesis , Histones/biosynthesis , Molecular Weight , Peptide Biosynthesis
8.
Science ; 236(4800): 416-22, 1987 Apr 24.
Article in English | MEDLINE | ID: mdl-2951850

ABSTRACT

Replication initiation in bacteriophage lambda appears to require wrapping of origin DNA on an approximately 50 angstrom radius in or around the complex with the initiator protein O. Since short lengths of DNA are not that flexible, it may be that runs of coherently spaced deoxyadenylate residues constitute bend sites in the ori sequence that facilitate the process. Earlier data showed that ori DNA has electrophoretic anomalies characteristic of bend sites and that these are augmented by initiator protein binding. Here origin bending is examined by direct measurement of the ability of polymerized ori sequences to form small circles. The smallest circles observed (84 residues) are compatible with the required radius of curvature. Bend sites within the O protein binding sites, bend sites in the spacers between them, plus the inherent flexibility of non-bent DNA in the origin may all contribute to origin bending. The data also show that a bend site is required for O protein binding to DNA.


Subject(s)
Bacteriophage lambda/genetics , DNA Replication , DNA, Viral , Bacteriophage lambda/ultrastructure , Binding Sites , DNA-Binding Proteins/metabolism , Nucleic Acid Conformation , Oligodeoxyribonucleotides , Protein Binding , Viral Proteins/metabolism , Virus Replication
9.
J Pediatr Gastroenterol Nutr ; 47(5): 573-8, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18979580

ABSTRACT

OBJECTIVES: Longitudinal intestinal lengthening and tailoring (LILT) is a well-established surgical treatment for short bowel syndrome. It has been shown to enhance peristalsis, decrease bacterial overgrowth, and extend mucosal contact time for nutrients. We present the results of a long-term follow-up of patients who underwent LILT and define prognostic parameters for the survival of these patients. PATIENTS AND METHODS: Between 1987 and 2006, 53 patients underwent LILT in our institution. The main diagnoses were gastroschisis, intestinal volvulus, intestinal atresias, and necrotizing enterocolitis. LILT was performed at a mean age of 24 months (range 4144 months). The follow-up time was 79.76 months (range 6234 months). RESULTS: After LILT, 41 of 53 patients survived, and 36 of 41 surviving patients were successfully weaned from parenteral nutrition (PN). In long-term follow-up 79% stayed free of PN. The overall survival rate was 77.36%. Weight gain occurred in 58% of the patients after LILT. The quality of life after LILT is on a high level, with most patients having normal physical strength and participating in normal social life and education. Prognostic factors for survival after LILT in short bowel syndrome are length of small intestine (0.06582 + 0.0131 x bowel cm), length of large bowel (P = 0.039), preoperative liver function, and successful weaning from PN within 18 months postoperatively (P = 0.0032). CONCLUSIONS: Patients undergoing LILT in short bowel syndrome have a high survival rate, weight gain, and a high quality of life. Autologous gastrointestinal reconstruction remains therefore the first choice in the treatment of patients with short bowel syndrome.


Subject(s)
Intestines/surgery , Short Bowel Syndrome/surgery , Body Height , Body Weight , Child , Child, Preschool , Follow-Up Studies , Humans , Infant , Intestinal Mucosa/physiopathology , Intestinal Mucosa/surgery , Intestine, Small/anatomy & histology , Intestine, Small/pathology , Parenteral Nutrition , Retrospective Studies , Short Bowel Syndrome/mortality , Survival Rate , Survivors , Time Factors , Treatment Outcome
10.
Eur J Pediatr Surg ; 18(4): 249-53, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18704888

ABSTRACT

INTRODUCTION: Short bowel syndrome is a functional or anatomic loss of major parts of the small bowel leading to severe malnutrition. The limiting factor for the survival of these patients remains parenteral nutrition-related liver damage leading to end-stage liver failure. Longitudinal intestinal lengthening and tailoring (LILT) has been proven to enhance peristalsis, to decrease bacterial overgrowth and to extend the mucosal contact time for the absorption of nutrients. The aim of this study was to show the impact of LILT on the development of parenteral nutrition-related liver damage. PATIENTS AND METHODS: A cohort of 55 patients with short bowel syndrome managed with LILT in our institution between 1987 and 2007 was retrospectively reviewed. LILT was performed at a mean age of 24 months (range 4 - 150 months). Mean follow-up time was 83.76 months (range 5 - 240 months). We obtained reliable data from 31 patients with regard to liver enzymes and function parameters in blood samples before LILT and at the present time. Liver biopsy was performed in 14 patients prior to LILT. RESULTS: Liver enzymes ALAT (mean 121 U/l), ASAT (mean 166 U/l) and bilirubin (mean 2.49 mg/dl) were elevated preoperatively in 27/31 children. After the lengthening procedure, ALAT (mean 50 U/l), ASAT (mean 63 U/l) and bilirubin (mean 1.059 mg/dl) normalized except in 5 of 8 patients who could not be weaned from parenteral nutrition after LILT. Liver function parameters such as the international normal ratio (INR) were slightly elevated in 5/31 patients. Albumin was generally low, probably due to parenteral nutrition. Liver biopsy was performed in 14 patients preoperatively, showing 4 patients with low-grade, 6 patients with intermediate and 4 patients with high-grade fibrosis. End-stage liver disease with cirrhosis was an exclusion criterion for LILT. All patients with liver fibrosis showed a normalization of liver enzymes when they were weaned from parenteral nutrition. But patients with higher grade liver fibrosis tend to develop more complications perioperatively. CONCLUSION: After LILT, all patients with liver fibrosis who could be weaned from parenteral nutrition showed a normalization of liver enzymes. Preoperative liver biopsy is mandatory in order to differentiate reversible liver fibrosis from end-stage liver disease. A higher grade of liver fibrosis and elevated INR has been shown to be a sensitive parameter for peri- and postoperative complications.


Subject(s)
Intestines/surgery , Liver Cirrhosis/etiology , Short Bowel Syndrome/surgery , Adult , Alanine Transaminase/blood , Female , Humans , Liver Cirrhosis/enzymology , Liver Cirrhosis/pathology , Liver Cirrhosis/physiopathology , Male , Parenteral Nutrition , Retrospective Studies , Short Bowel Syndrome/complications , Short Bowel Syndrome/mortality , Short Bowel Syndrome/physiopathology , Short Bowel Syndrome/therapy
11.
Vet Comp Orthop Traumatol ; 21(3): 185-94, 2008.
Article in English | MEDLINE | ID: mdl-18536843

ABSTRACT

OBJECTIVE: To compare the stiffness and strength of AO bone plates (DCP, LC-DCP, VCP, RCP, and LP) and the Clamp-Rod Internal Fixation System (CRIF). STUDY DESIGN: In vitro. SAMPLE SIZE: 12 individual implants of 18 plate dimensions and four sizes of CRIF, each corresponding to 2.0, 2.4/2.7, 3.5, or 4.5 mm screw sizes. METHODS: Implant-constructs of each plate and CRIF were created using Canevasit rods as a bone substitute in an unstable gap fracture model. Six implant-constructs of each type were tested under single cycle four-point bending loading, and six were tested under single cycle torsional loading until permanent plastic deformation occurred. RESULTS: Torsional stiffness and yield load of the DCP were always significantly greater than the CRIF within the same group. Bending properties of the 2.0 DCP were not significantly different to the 2.0 CRIF. The 2.7 DCP had significantly higher bending values than the 2.7 CRIF. The bending stiffness of the 3.5 DCP and 4.5 DCP was significantly less than their CRIF counterparts. While the bending yield load of the 3.5 DCP was significantly greater than the 3.5 CRIF, the bending yield load of the 4.5 DCP was significantly less than the 4.5 CRIF. CONCLUSION: A weakness was found in the torsional resistance of the CRIF constructs compared to the DCP constructs. CLINICAL SIGNIFICANCE: Bone holding power and applied screw torque should be considered when using the CRIF system in clinical application.


Subject(s)
Bone Plates/veterinary , Bone Screws/veterinary , Fracture Fixation, Internal/veterinary , Fractures, Bone/veterinary , Internal Fixators/veterinary , Stress, Mechanical , Animals , Biomechanical Phenomena , Bone Plates/standards , Bone Screws/standards , Bone Substitutes , Compressive Strength , Dogs , Fracture Fixation, Internal/methods , Fractures, Bone/surgery , Internal Fixators/standards , Tensile Strength , Torsion Abnormality
12.
Vet Comp Orthop Traumatol ; 20(4): 256-63, 2007.
Article in English | MEDLINE | ID: mdl-18038000

ABSTRACT

The goal of this retrospective study was to describe dowel pinning, and to compare the results of osteosynthesis and external coaptation of metacarpal and metatarsal fractures in cats. Evaluation of the medical records of 351 cats yielded 63 cats treated with dowel pinning, 35 cats treated with external coaptation and 14 cats treated with both methods within the same limb. All of the cats had been re-evaluated at an average of 2.8 years (six months - 15 years) postoperatively. Dowel pinning was superior to external coaptation when all fractured bones of a limb could be pinned. When internal fixation of multiple fractures was not feasible in all fractured bones due to comminution or fragments that were too short to pin, the outcome was not significantly different from cases treated with external coaptation alone. Malunion was seen in 16% of fractured bones in cats treated with external coaptation and occurred secondary to implant bending in 3% of fractured bones treated with dowel pinning. The latter refers to one operated cat, which had four metacarpal fractures in the same limb. Radiographs taken at re-evaluation showed implant migration within the medullary canal in two cats, although neither showed any signs of non-union or lameness. Non-union was seen in one operated cat, in which the fracture (MC IV) could not be completely reduced with a K-wire. Osteomyelitis did not occur. Dowel pinning is an easy, inexpensive and effective technique for repair of metacarpal and metatarsal fractures in cats.


Subject(s)
Bone Nails/veterinary , Cats/injuries , Fracture Fixation, Intramedullary/veterinary , Fractures, Bone/veterinary , Metacarpal Bones/injuries , Metatarsal Bones/injuries , Animals , Cats/surgery , Female , Fracture Fixation, Intramedullary/instrumentation , Fracture Fixation, Intramedullary/methods , Fractures, Bone/diagnostic imaging , Fractures, Bone/surgery , Male , Metacarpal Bones/surgery , Metatarsal Bones/surgery , Radiography , Treatment Outcome
13.
Nucleic Acids Res ; 28(23): 4623-33, 2000 Dec 01.
Article in English | MEDLINE | ID: mdl-11095671

ABSTRACT

Widespread occurrence of a separate small RNA derived from the 5'-end of 23S rRNA and of an intervening sequence (IVS) which separates this domain from the main segment of 23S rRNA in the alpha-proteobacteria implies that processing reactions which act to excise the IVS are also maintained in this group. We previously characterized the first example of processing of this IVS in Rhodopseudomonas palustris, which is classified with the Bradyrhizobia In this case, IVS excision occurs by a multistep process and RNase III appears to act at an early step. Here, we characterize in vivo and in vitro IVS processing in two other related, but phenotypically distinct, Bradyrhizobia We also examine in vivo and in vitro processing of rRNA precursors from a more distantly related alpha-proteobacterium, Rhodobacter sphaeroides which produces a separate 5' 23S rRNA domain but has different sequences in the 5' 23S rRNA IVS. The details of the in vivo processing of all of the Bradyrhizobial rRNAs closely resemble the R. palustris example and in vitro studies suggest that all of the Bradyrhizobia utilize RNase III in the first step of IVS cleavage. Remarkably, in vivo and in vitro studies with R.sphaeroides indicate that initial IVS cleavage uses a different mechanism. While the mechanism of IVS cleavage differs among these alpha-proteobacteria, in all of these cases the limits of the internal segments processed in vivo are almost identical and occur far beyond the initial cleavage sites within the IVSs. We propose that these bacteria possess common secondary maturation pathways which enable them to generate similarly processed 23S rRNA 5'- and 3'-ends.


Subject(s)
Alphaproteobacteria/genetics , DNA, Ribosomal Spacer/genetics , RNA Processing, Post-Transcriptional , RNA, Ribosomal, 23S/genetics , Base Sequence , Bradyrhizobium/genetics , DNA, Ribosomal Spacer/chemistry , Endoribonucleases/metabolism , Methylobacterium extorquens/genetics , Molecular Sequence Data , Nucleic Acid Conformation , RNA, Bacterial/genetics , RNA, Bacterial/metabolism , RNA, Ribosomal, 23S/chemistry , Rhodobacter sphaeroides/genetics , Ribonuclease III , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Nucleic Acid
14.
Nucleic Acids Res ; 27(21): 4241-50, 1999 Nov 01.
Article in English | MEDLINE | ID: mdl-10518617

ABSTRACT

We demonstrate the presence of a separate processed domain derived from the 5' end of 23S rRNA in ribosomes of Rhodopseudomonas palustris, a member of the alpha-++proteobacteria. Previous sequencing studies predicted intervening sequences (IVS) at homologous positions within the 23S rRNA genes of several alpha-proteobacteria, including R.palustris, and we find a processed 23S rRNA 5' domain in unfractionated RNA from several species. 5.8S rRNA from eukaryotic cytoplasmic large subunit ribosomes and the bacterial processed 23S rRNA 5' domain share homology, possess similar structures and are both derived by processing of large precursors. However, the internal transcribed spacer regions or IVSs separating them from the main large subunit rRNAs are evolutionarily unrelated. Consistent with the difference in sequence, we find that the site and mechanism of IVS processing also differs. Rhodopseudomonas palustris IVS-containing RNA precursors are cleaved in vitro by Escherichia coli RNase III or a similar activity present in R.palustris extracts at a processing site distinct from that found in eukaryotic systems and this results in only partial processing of the IVS. Surprisingly, in a reaction unlike characterized cases of eubacterial IVS processing, an RNA segment larger than the corresponding DNA insertion is removed which contains conserved sequences. These sequences, by analogy, serve to link the 23S rRNA 5' rRNA domains or 5.8S rRNAs to the main portion of other prokaryotic 23S rRNAs or to eukaryotic 28S rRNAs, respectively.


Subject(s)
Escherichia coli Proteins , RNA Processing, Post-Transcriptional , RNA, Ribosomal, 23S/genetics , RNA, Ribosomal, 23S/metabolism , Rhodopseudomonas/genetics , Alphaproteobacteria/genetics , Base Sequence , Centrifugation, Density Gradient , Endoribonucleases/chemistry , Endoribonucleases/genetics , Endoribonucleases/metabolism , Escherichia coli/enzymology , Escherichia coli/genetics , Evolution, Molecular , Kinetics , Molecular Sequence Data , Molecular Weight , Nucleic Acid Conformation , RNA/analysis , RNA/chemistry , RNA/genetics , RNA Precursors/chemistry , RNA Precursors/genetics , RNA Precursors/metabolism , RNA, Bacterial/chemistry , RNA, Bacterial/genetics , RNA, Bacterial/isolation & purification , RNA, Bacterial/metabolism , RNA, Ribosomal, 23S/chemistry , RNA, Ribosomal, 23S/isolation & purification , Rhodopseudomonas/cytology , Rhodopseudomonas/enzymology , Ribonuclease III , Ribosomes/genetics , Ribosomes/metabolism , Sequence Homology, Nucleic Acid
15.
Genetics ; 140(3): 909-15, 1995 Jul.
Article in English | MEDLINE | ID: mdl-7545627

ABSTRACT

Chimeras of RNA and DNA have distinctive physical and biological properties. Chimeric oligonucleotides that contained one, two or three ribonucleotides whose phosphodiester backbone was covalently continuous with DNA were synthesized. Site-directed mutagenesis was used to assess genetic information transfer from the ribonucleotide positions. Transfer was scored by the formation or reversion of an ochre site that also corresponded to a restriction cleavage site. This allowed physical as well as genetic assay of mutational events. Bases attached to the ribonucleotides were able to accurately direct the synthesis of progeny DNA. The results suggest that in vivo DNA polymerases utilize a "running start" on a DNA backbone to continue across a covalent backbone junction into a region of ribonucleotides and then back again onto a normal DNA backbone. The phenomenon is designated short-patch reverse transcription (SPRT) by analogy to short-patch mismatch correction and reverse transcription as the term is generally used. The possibility is considered that SPRT contributes to an unrecognized pathway of mutagenesis.


Subject(s)
DNA, Bacterial/metabolism , DNA-Directed DNA Polymerase/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , RNA, Bacterial/metabolism , Transcription, Genetic , Base Sequence , Chimera , DNA Primers , DNA, Bacterial/genetics , Molecular Sequence Data , Plasmids , Polymerase Chain Reaction , RNA, Bacterial/genetics , Restriction Mapping
17.
Phys Rev Lett ; 85(17): 3656-9, 2000 Oct 23.
Article in English | MEDLINE | ID: mdl-11030974

ABSTRACT

The two-dimensional (2D) melting transition is analyzed on the basis of the long-time behavior of a modified Lindemann parameter in 2D gamma(L)(t) and the bond-angular correlation function g(6)(t). Using video microscopy complete positional data are obtained over five decades in time for an ensemble of superparamagnetic colloidal particles confined to an air-water interface. We find that each of the three phases (solid/hexatic/isotropic liquid) is uniquely characterized by the long-time behavior of gamma(L)(t), g(6)(t), and the non-Gaussian parameter of the relative neighbor-neighbor displacement.

18.
Arch Ophthalmol ; 95(7): 1274-80, 1977 Jul.
Article in English | MEDLINE | ID: mdl-880088

ABSTRACT

Two fundus cameras were used in the development of a setup for bilateral fluorescein angiography. The indications for this method are listed and examples of simultaneous fluoroangiograms are given. This technique allows the simultaneous study of hemodynamics in the carotid artery, the study of intraocular and anterior eye segment circulatory disturbances, and it is time-saving in bilateral pathology.


Subject(s)
Fluorescein Angiography , Adult , Aged , Blood Circulation , Carotid Artery Diseases/diagnosis , Diabetic Retinopathy/diagnosis , Female , Humans , Male , Middle Aged
19.
J Morphol ; 246(3): 249-59, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11077435

ABSTRACT

A combination of histology, whole muscle force physiology, glycogen depletion, and venom expulsion analyses using transonic probes to measure venom flow and fluid pressure transducers to measure venom pressure was performed on the m. compressor glandulae and m. pterygoideus glandulae. The m. pterygoideus glandulae has less than one-third the cross-sectional area of the m. compressor glandulae, and produces approximately one-fifth the total twitch and tetanic force; however, in situ surface stimulation of the muscle produces venom flow and pressure levels that are similar to those produced by the m. compressor glandulae. The similarity in venom output following stimulation reflects in part the functional role of the larger m. compressor glandulae in jaw adduction, but also the functional subdivisions within this muscle. The m. compressor glandulae is divided into a series of columnar fascicles that run from the surface of the muscle to the venom gland. The combined results of clearing and staining and glycogen depletion studies suggest that these fascicles may represent functional compartments. Identical stimulations applied to different regions of the m. compressor glandulae result in up to a six-fold difference in venom expulsion. This functional specialization may play a role in the regulation of venom flow during offensive and defensive strikes.


Subject(s)
Crotalid Venoms , Crotalus/physiology , Muscle Contraction , Muscles/physiology , Animals , Exocrine Glands/physiology , Glycogen/metabolism , Mouth/anatomy & histology , Mouth/physiology , Muscles/anatomy & histology
20.
Rofo ; 156(5): 425-8, 1992 May.
Article in German | MEDLINE | ID: mdl-1596543

ABSTRACT

The important dimensions of pelvimetry were evaluated from 467 CT studies of the pelvis by trigonometric deduction. The age of the women was between 18 and 88 years. In addition to the diameters, which are routinely used for pelvimetry, transverse and sagittal diameters, pelvic angles and areas of pelvic planes were calculated. On condition that the pelvic dimensions do not depend on age the parameters can be regarded as representative of sexual maturity. 5 parameters showed highly significant and 7 parameters showed significant differences between the age-classes 1901-1920 and 1950-1971. An increase of pelvic dimensions (1950-1971) was found at the planes of the pelvic inlet and outlet in contrast to the dimensions of the pelvic center. The results confirm the importance of the bispinous diameter for pelvimetry as well as the demand for a revision of the standard values of the first half of the century.


Subject(s)
Pelvic Bones/diagnostic imaging , Pelvimetry , Tomography, X-Ray Computed , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Middle Aged , Pelvic Bones/growth & development , Pelvimetry/statistics & numerical data , Pregnancy , Reference Values , Regression Analysis , Retrospective Studies , Tomography, X-Ray Computed/statistics & numerical data
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