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At least 235 records · Page 13Linked to original sources

[Primary study on the electrophoresis atlas of the PCR products of the internal transcribed spacerl regions of the rRNA gene from home-planted and wild Gentiana macrophylla, G. straminea].

OBJECTIVE: To analyse the electrophoresis atlas of the PCR amplified products of the internal transcribed spacerl regions of the rRNA gene in DNA extracted from home-planted and wild Gentiana macrophylla, G. straminea in Gansu. METHODS: With synthetic peculiar PCR primer, internal transcribed spacerl sequences of rRNA gene were amplified in DNA extracted from home-planted and wild Gentiana macrophylla, G. straminea. And then the electrophoretic atlas of nPCR amplified products on the agar sugar gel were analysed. RESULT: The electrophoresis atlas showed that the lengths of the internal transcribed spacerl regions of the rRNA gene in DNA from Gentiana macrophylla, G. straminea had the same region 360 bp. The length had enough genetic information to analyse base sequence. CONCLUSION: The PCR amplified products electrophoretic atlas of internal transcribed spacerl regions of the rRNA gene in DNA from Gentiana macrophylla, G. straminea can be used as one of signs for identification on molecule level.

DNA, Plant↗

Efficacy assessment of cerebral arterial bypass surgery using statistical parametric mapping and probabilistic brain atlas on basal/acetazolamide brain perfusion SPECT.

UNLABELLED: The efficacy of cerebral arterial bypass surgery was assessed on brain perfusion SPECT using statistical parametric mapping (SPM) and a probabilistic brain atlas. METHODS: Fifteen patients with ischemia in the internal carotid artery (ICA) territory and 21 age-matched healthy volunteers were enrolled. (99m)Tc-HMPAO basal/acetazolamide brain perfusion SPECT was performed 2 wk before and after bypass surgery and also on a healthy control group. Using SPM analysis, group comparisons were made between pre- and postoperative SPECT for each basal/acetazolamide image, and improvements of perfusion and perfusion reserve were assessed. The number of significant voxels on the SPM analysis was defined as the extent of ischemia. With the use of the probabilistic brain atlas, the counts for the cerebral lobes and the ICA territory were automatically calculated for each image and compared. RESULTS: The group comparisons by SPM between patients and healthy volunteers showed a significant improvement in general perfusion status in the ICA territory. The improvement in perfusion reserve was more extensive than the improvement in perfusion. The extent of ischemia was also significantly decreased after surgery (1,693 +/- 2,604 to 371 +/- 523 voxels in basal images, P = 0.060; 11,879 +/- 6,449 to 5,997 +/- 3,864 voxels in acetazolamide images, P = 0.005). In the analysis using the probabilistic brain atlas, the preoperatively decreased perfusion was normalized after surgery, but a residual decrease in the perfusion reserve was also observed in the ICA territory. The counts in the volume of interest of the ICA territory were significantly improved (38.5 +/- 4.1 to 41.5 +/- 2.7 in basal images, P = 0.024; 34.2 +/- 4.4 to 38.8 +/- 2.9 in acetazolamide images, P = 0.003). One patient showing a decrease in perfusion had a perioperative cerebral infarct. CONCLUSION: Using SPM and a probabilistic brain atlas, the perfusion, the perfusion reserve, and changes in both after cerebral arterial bypass surgery were effectively assessed and correlated well with physiologic reasoning.

Acetazolamide↗

Atlas-based segmentation of pathological knee joints.

Efficiency, comparability and simplicity are key aspects for user acceptance of surgical planning systems in the long term. Automatic segmentation and identification of geometric reference systems of the anatomical structures are essential to fulfill these requirements. A statistical motivated shape atlas of the knee joint, based on 235 normal and abnormal MR and CT volume sets, is constructed for automatic segmentation of CT image data. In the first step of the atlas construction, the bony structures of the knee were segmented semi-automatically and processed into a dense and a sparse triangulated surface mesh to obtain training data sets. To establish an inter-individual correspondence, a skeleton-based registration method is used. The registered sparse surface meshes are retriangulated to estimate a pointwise inter-individual correspondence. The shape atlas is build upon these correspondences and integrated into a segmentation algorithm. An iterative segmentation scheme is proposed, which consists of a combination of the iterative-closest-point algorithm for spatial registration and of a downhill-simplex optimization procedure for deformation of the statistical motivated shape atlas to the image data. We expect the statistical shape model to be a robust and image modality independent method for the segmentation of pathological knee joints in CT image data.

Arthroplasty, Replacement, Knee↗

Adjustable computerized stereotaxic brain atlas for transmission and emission tomography.

A computerized brain atlas adjustable to the patient's anatomy would serve serveral purposes. It could be used in stereotaxic surgery. Even more important would be its use in medical imaging to identify various brain structures, such as the basal ganglia and their nuclei, as well as individual cortical gyri. This atlas could be used for additional mapping of nonvisible structures in images obtained with methods having a high spatial resolution, such as computed tomography and nuclear magnetic resonance. Anatomic information obtained in this way might then be transferred to images of low resolution, such as those obtained in positron emission tomography or single-photon emission computed tomography, in order to select anatomically correct regions of interest. The methods used in the construction of such an atlas are briefly described. An attempt to implement such an atlas based on digitized photographs of brain slices is described.

Brain↗

[Electrophysiological atlas of human thalamus and adjacent structures.--Microcomputer assisted mapping of neurophysiological data and its application to stereotaxic surgery].

During stereotaxic surgery anatomical structures and their extent on trajectories were identified by neural noise (field potential) obtained by semi-microelectrode technique. Locations of anatomical structures (the white mater, caudate nucleus, thalamus, subthalamic field and nuclei in the subthalamic field) were fed into microcomputer (NEC PC-8001) as 3 dimensional correlates and stored in minifloppy disc system (NEC PC-8031). Data with satisfactory recordings from 48 trajectories from 30 patients (18 parkinsonism, 5 central pain, 7 others) entered this study. Microcomputer was so programmed that locations of the trajectories and electrophysiologically identified anatomical structures at that location in various coronal, sagittal and horizontal planes were displayed. Accumulation of this display from various groups of patients automatically created electrophysiological atlas. For comparison of thus created electrophysiological atlas with anatomical atlas display was made on various sections of the Schaltenbrand and Bailey's Atlas which were also stored in the mimifloppy disc system. Electrophysiological topography of the thalamus and adjacent structures was reasonably similar to anatomical topography with minor, but significant individual variations. In most cases the ventral border of the thalamus was located in the close vicinity of CA-CP line, however, in some cases the thalamus was located deep into the subthalamic field. This was thought to be due to the difficulty in identifying the ventral border of the thalamus by this technique and in such occasions other neurophysiological method for identifying the ventral border of the thalamus, i.e., thalamocortical evoked potential and other stimulation technique, were necessary. Medial aspect of the V. im. nucleus emitted neural noise of different characteristics which in current program was recognized as the subthalamic field. This implies that the medial and lateral aspects of the V. im. nucleus are cytoarchitecturally different and that it is possible to differentiate the medial and lateral aspects of the V. im. nucleus by this technique. The lateral thalamic border, i.e., thalamocapsular border, also showed relatively wide range of individual variations. When various parameters including age, sex, diagnosis and width of the 3rd ventricles were examined for possible cause of these variations, a tendency was noted that the thalamocapsular border was medially placed when the width of the 3rd ventricle was small. In this system it is possible to display sequentially electrophysiologically identified structures along any trajectory. This display method, which was called "tract study," was very usefull for comprehensive understanding of location of trajectory in relation to individually varying anatomical structures...

Adolescent↗

Reliability of grading scales for individual radiographic features of osteoarthritis of the knee. The Baltimore longitudinal study of aging atlas of knee osteoarthritis.

RATIONALE AND OBJECTIVES: The authors present an atlas of individual radiographic features of osteoarthritis of the knee and evaluate the inter- and intra-reader reliability of trained readers using this atlas. METHODS: Four trained readers graded 30 standing anterior-posterior knee radiographs for eight selected features of osteoarthritis (medial and lateral osteophytes, joint space narrowing, and sclerosis; osteophytes of the tibial spines and chondrocalcinosis) as well as the Kellgren-Lawrence global scale. Inter- and intra-reader reliability were calculated using intraclass correlation coefficients. RESULTS: For all features except sclerosis and osteophytes of the tibial spines, inter-reader reliability ranged from 0.63 to 0.83, whereas intra-reader reliability ranged from 0.82 to 0.95. CONCLUSION: Using this atlas, trained readers are reliable in measuring the presence and severity of individual radiographic features of osteoarthritis of the knee. This atlas should be useful in clinical and epidemiologic studies of osteoarthritis of the knee.

Adult↗

Methodological issues in the development of the Canadian Cancer Incidence Atlas.

The Canadian Cancer Incidence Atlas is among recent national atlases using incidence rather than mortality data. Methods used to assess the significance and spatial correlation of the age-standardized rates (ASIRs) for the 290 census divisions are described. The expected number of cases by area was used to determine cancer sites with sufficient cases to be mapped. ASIR significance was assessed using a simulation based on a Poisson distribution. The consistency of the observed case distributions with the Poisson distribution was examined. The bootstrap confidence interval (CI) for the ASIR developed by Swift was used in the atlas. Spatial correlation was assessed with Moran's I/I(max) and the significance determined by a simulation in order to allow for area population variation. Data quality indicators typically used for cancer registries were presented, supplemented by a registry questionnaire.

Atlases as Topic↗

The development of the series of U.S. cancer atlases: implications for future epidemiologic research.

An historic perspective on the development of the National Cancer Institute's series of cancer atlases is provided. Emphasis is placed on the role which emergent questions concerning environmental determinants of cancer played in the acquisition and utilization of data resources. Studies which were fielded as a consequence of the atlases are highlighted. The legacy of the collective effort of many persons who worked on the development of the cancer atlases-the facilitation of many current epidemiologic investigations-is discussed.

Atlases as Topic↗

Atlas fractures: treatment and long-term results.

Fractures of the first cervical vertebra (C1) represent approximately 7% of all acute cervical spine fractures. Frequently, the atlas will be fractured in combination with the axis (44% of cases). Treatment of isolated C1 fractures should be governed by the rules of Spence. The treatment of combination C1-C2 fractures is dictated by the type and severity of the C2 fracture. Experience with 57 cases of acute traumatic atlas fractures are reviewed. The long-term outcome from an atlas fracture is good (median follow-up, 40 months).

Adolescent↗

Rotational synkineses of occiput and atlas on lateral inclination.

An X-ray analysis was performed with regard to the question of synkinetic rotational movements of occiput and atlas on lateral inclination of the head and neck. It was found that the frequent synkinetic rotation of the head from the side of inclination can be taken for a stereotype that is ten times more frequent than the rotation towards the side of inclination. However, it does not represent an essential or indispensable feature of the synkinetic reaction. The associated rotation of the atlas from the side of inclination cannot be looked upon as a normal and constant element of the synkinetic response on lateral inclination, as it does not occur in nearly one-half of cases. Moreover, these studies have shown that the rotational movement between occiput and atlas is possible not only in the final stage of maximum forced rotation of the head, but that it belongs to normal dynamic features of the synkinetic response on lateral inclination of the head and neck.

Cervical Atlas↗

[Atlas fractures].

Fractures of the atlas account for 1-2% of all vertebral fractures. We divide atlas fractures into 5 groups: isolated fractures of the anterior arch of the atlas, isolated fractures of the posterior arch, combined fractures of the anterior and posterior arch (so-called Jefferson fractures), isolated fractures of the lateral mass and fractures of the transverse process. Isolated fractures of the anterior or posterior arch are benign and are treated conservatively with a soft collar until the neck pain has disappeared. Jefferson fractures are divided into stable and unstable fracture depending on the integrity of the transverse ligament. Stable Jefferson fractures are treated conservatively with good outcome while unstable Jefferson fractures are probably best treated operatively with a posterior atlanto-axial or occipito-axial stabilization and fusion. The authors preferred treatment modality is the immediate open reduction of the dislocated lateral masses combined with a stabilization in the reduced position using a transarticular screw fixation C1/C2 according to Magerl. This has the advantage of saving the atlanto-occipital joints and offering an immediate stability which makes immobilization in an halo or Minerva cast superfluous. In late instabilities C1/2 with incongruency of the lateral masses occurring after primary conservative treatment, an occipito-cervical fusion is indicated. Isolated fractures of the lateral masses are very rare and may, if the lateral mass is totally destroyed, be a reason for an occipito-cervical fusion. Fractures of the transverse processes may be the cause for a thrombosis of the vertebral artery. No treatment is necessary for the fracture itself.

Bone Nails↗

A rare cause of cervical spinal stenosis: posterior arch hypoplasia in a bipartite atlas.

We describe CT and MRI of a previously unreported combination of atlantoaxial anomalies consisting of posterior arch hypoplasia in a bipartite atlas with an os odontoideum, in a 30-year-old woman presenting with neck and left arm pain. MRI showed the os odontoideum, marked stenosis of the spinal canal at the level of the atlas, with cord compression and evidence of myelopathy. CT revealed a bipartite atlas with midline clefts in anterior and posterior arches, thickening in the anterior arch and hypoplasia of the posterior arch with incurving of both hemiarches. Flexion and extension radiographs demonstrated atlantoaxial instability.

Adult↗

Toward atlas-assisted automatic interpretation of MRI morphological brain scans in the presence of tumor.

RATIONALE AND OBJECTIVES: Determination of distorted brain anatomy surrounding a tumor causing a mass effect is much more difficult than interpretation of normal brain scans, particularly because this distortion is not easily predictable a tumor may be located in any place and vary substantially in size, shape, and radiological appearance. The objective of our work is to provide a qualitative means for rapid estimation of brain anatomy distorted by tumor. MATERIALS AND METHODS: Toward achieving this objective, we use an electronic and deformable brain atlas of gross anatomy along with a fast atlas-to-data warping technique. The deformed atlas determines the distorted anatomy surrounding a tumor and can be used for structure labeling (naming). The warping algorithm uses the Talairach transformation followed by three-dimensional nonlinear tumor deformation based on a geometric assumption that the tumor, delineated on radiological images, compresses its surrounding tissues radially. RESULTS: The approach is implemented and a dedicated application is developed. It processes the data automatically in five steps: (1) load data, (2) set the Talairach landmarks and perform the Talairach transformation, (3) segment the tumor, (4) warp the scan nonlinearly in three dimensions, and (5) explore the scan. The approach is very fast, and a magnetic resonance imaging scan is processed in 10-15 seconds on a standard personal computer. It is fully automatic and gives the user control over the entire process. CONCLUSION: Despite its limitations in modeling and validation, this practical solution provides a rapid and potentially useful qualitative assessment of anatomy deformed by a mass effect tumor.

Anatomy, Artistic↗

A single-nucleus transcriptome atlas of soybean anthers.

Anther development is crucial for plant sexual reproduction. However, a high-resolution, cell-type-specific transcriptomic atlas of this process is lacking for the legume crop soybean (Glycine max). Here, we construct a comprehensive transcriptional atlas of developing soybean anthers using single-nucleus RNA sequencing (snRNA-seq). We identify and characterize nine distinct cell types spanning both somatic and reproductive lineages. Our analysis reveals robust transcriptional continuity across anther developmental stages and dynamic reprogramming during key transitions. Notably, the shift from diploid meiocytes to haploid unicellular microspores is marked by the induction of previously inactive genes, despite an overall reduction in transcript abundance. Subsequently, within bicellular microspores, generative and vegetative cell lineages exhibit sharply divergent transcriptional programs: generative cells specialize in mRNA export and turnover, whereas vegetative cells up-regulate translational machinery. Evolutionary analysis further indicates that generative-cell-specific genes are subject to more relaxed purifying selection compared to those specific to vegetative cells. Functional validation using mutants generated by CRISPR/Cas9-mediated genome editing and EMS mutagenesis reveals the essential roles of OSD1A and PKSA in pollen development and fertility. This high-resolution atlas provides fundamental insights into the transcriptional regulation of soybean anther development and serves as a valuable resource for manipulating male fertility to advance hybrid breeding programs. The data are available at https://databases.genedenovo.com/pollen.

Glycine max↗

Do evidence-based treatments provide incremental benefits to patients with congestive heart failure already receiving angiotensin-converting enzyme inhibitors? A secondary analysis of one-year outcomes from the Assessment of Treatment with Lisinopril and Survival (ATLAS) study.

BACKGROUND: In patients with congestive heart failure (CHF), use of submaximal doses of angiotensin-converting enzyme (ACE) inhibitors (ie, low-dose ACE inhibitors) represents usual care in routine clinical practice, whereas high-dose ACE inhibitors, beta-blockers, and digoxin have each been shown to improve outcomes. OBJECTIVE: We examined whether treatment with high dose-ACE inhibitors, beta-blockers, and digoxin would each provide incremental benefits over that achieved with usual care and whether concurrent use of high-dose ACE inhibitors, beta-blockers, and digoxin would provide maximal benefits. METHODS: We conducted a secondary analysis of a randomized, controlled, active-comparator trial. Specifically, we studied 1-year outcomes data from the Assessment of Treatment with Lisinopril and Survival trial (ATLAS), which assessed high-dose ACE inhibitors (mean dosage, 33.2 mg daily lisinopril) versus low-dose ACE inhibitors (mean dosage, 4.5 mg daily lisinopril) in patients of any age with advanced CHF in 287 centers in 19 countries in the 1990s. In our analysis, patients were classified by their use of low-dose or high-dose ACE inhibitors, beta-blockers, and/or digoxin at the time of randomization. The primary outcome of interest was the ATLAS composite end point of all-cause mortality or hospitalization for any reason at 1 year. Multiple logistic regression analyses were used to adjust for baseline differences in patient characteristics. RESULTS: The 3164 patients in the ATLAS study had a mean (SD) age of 64 (10) years; 2516 patients (80%) were men and 648 (20%) were women; mean (SD) left-ventricular ejection fraction was 23% (6%); and 2671 patients (84%) had New York Heart Association class III or IV symptoms. At 1 year, the mortality rate was 13% (408 patients); 43% (1369 patients) had > or =1 hospitalization; and the composite end point of mortality or hospitalization was 47% (1489 patients). Most patients (2873; 91%) remained on their initial treatment regimen. Compared with low-dose ACE inhibitors (n = 471), the composite end point decreased incrementally with the use of high-dose ACE inhibitors (n = 475) (adjusted odds ratio [aOR], 0.93; P = NS), high-dose ACE inhibitors plus beta-blockers (n = 72) (aOR, 0.89; P = NS), and high-dose ACE inhibitors plus beta-blockers plus digoxin (n = 77) (aOR, 0.47; P = 0.006). In absolute proportions, patients receiving high-dose ACE inhibitors plus beta-blockers plus digoxin for 1 year had 12% fewer deaths and hospitalizations than patients receiving low-dose ACE inhibitors alone. CONCLUSIONS: Compared with usual care for patients with CHF, in this analysis, an evidence-based strategy that incorporated high-dose ACE inhibitors plus beta-blockers plus digoxin was associated with incrementally greater reductions in morbidity and mortality. These findings support treatment guidelines that recommend the concurrent use of all available proven efficacious treatment in patients with advanced CHF.

Adrenergic beta-Antagonists↗

Estimation of fetal age from dimensions of atlas and axis ossification centers.

The atlas and axis ossification centers of 106 human fetal and neonate skeletons were measured. The skeletons belong to the collection in the Department of Forensic Medicine of the Albert Szent-Györgyi Medical University, Szeged, Hungary. The age of the skeletons ranged from 4 to 10 lunar months. Nine linear measurements on the atlas, seven on the axis neural arches ossification centers and three on each one of the axis centra ossification centers were taken. We did simple and multiple linear regression analysis to estimate the age of fetuses. The results show that it is possible to use regression equations to estimate the fetal body length and age from atlas and axis ossification centers measurements during the whole period of development studied. The study of size and shape of the ossification centers using factorial analysis (principal component analysis) shows that the shape of the dens of the axis might be useful to estimate fetal viability.

Age Determination by Skeleton↗

Abnormal bony protuberance of anterior atlas causing dysphagia. A rare congenital anomaly.

STUDY DESIGN: A Case report. OBJECTIVE: To report an exceedingly rare case of dysphagia caused by abnormal bony protuberance of anterior atlas. SETTING: Kocaeli University Faculty of Medicine, Departments of Neurosurgery and Otorhinolaryngology. METHOD: Radiological examinations revealed a large anterior abnormal bony tuberance of atlas in an 11-year-old boy who complained of dysphagia of 5 years donation. RESULT: The anterior bony tuberance of the atlas was resected by a transoral approach. Histopathological examination of the surgical specimens showed normal bone tissue. Resection resulted in complete resolution of the dysphagia. CONCLUSIONS: Dysphagia can be caused by disorders of the cervical spine. These disorders are usually seen in elderly adults. In the pediatric population, spinal abnormality is an exceedingly rare cause of dysphagia. Abnormal inductive signals from the adjacent notocord and ventral neural tube may play role in the pathogenesis of this abnormal bony protuberance.

Cervical Atlas↗

Myelopathy due to hypoplasia of the atlas. A case report.

The authors report a 73-year-old woman who had spinal cord compression develop because of hypoplasia of the atlas associated with a retroodontoid pseudotumor diagnosed by magnetic resonance imaging. Radiographs of the cervical spine showed narrowing of the spinal canal at the level of the atlas and severe osteoarthrosis of the atlantoaxial joint without atlantoaxial subluxation. A remarkable neurologic recovery followed decompressive laminectomy of the atlas with posterior occipitocervical fusion. Postoperative magnetic resonance imaging showed significant reduction of the retroodontoid pseudotumor by fusion alone. The magnetic resonance imaging finding of spontaneous reduction of retroodontoid pseudotumor after posterior fusion argues against a need for transoral removal, which has a significant complication rate.

Aged↗