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Results for “Variant classification”

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At least 613 records · Page 34Linked to original sources

PubMed2005

Molecular biology of opioid analgesia.

Opioids provide excellent pain relief in most patients. Yet the responses of patients to individual opioids can vary markedly, even among the mu opioids. Understanding this variability would greatly enhance our ability to treat patients appropriately. Classical pharmacological studies have long implied the existence of multiple subtypes of mu opioid receptors. More recently, a number of variants of the cloned mu opioid receptor have been described. These variants all show the same selectivity for mu opioids, confirming their classification as mu opioid receptors. Yet, they differ in their functional activation by opioids as well as in their localization within cells and regions in the brain. These multiple mu opioid receptors may help explain the range of responses seen clinically among patients for the various opioid drugs.

Analgesics, Opioid↗

PubMed1999

Mutation analysis and molecular genetics of epidermolysis bullosa.

Cutaneous basement membrane zone (BMZ) consists of a number of attachment structures that are critical for stable association of the epidermis to the underlying dermis. These include hemidesmosomes, anchoring filaments and anchoring fibrils which form an interconnecting network extending from the intracellular milieu of basal keratinocytes across the dermal-epidermal basement membrane to the underlying dermis. Aberrations in this network structure, e.g. due to genetic lesions in the corresponding genes, can result in fragility of the skin at the level of the cutaneous BMZ. The prototype of such diseases is epidermolysis bullosa (EB), a heterogeneous group of genodermatoses characterized by fragility and blistering of the skin, often associated with extracutaneous manifestations, and inherited either in an autosomal dominant or autosomal recessive manner. Based on constellations of the phenotypic manifestations, severity of the disease, and the level of tissue separation within the cutaneous BMZ, EB has been divided into clinically distinct subcategories, including the simplex, hemidesmosomal, junctional and dystrophic variants. Elucidation of BMZ gene/protein systems and development of mutation detection strategies have allowed identification of mutations in 10 different BMZ genes which can explain the clinical heterogeneity of EB. These include mutations in the type VII collagen gene (COL7A1) in the dystrophic (severely scarring) forms of EB; mutations in the laminin 5 genes (LAMA3, LAMB3 and LAMC2) in a lethal (Herlitz) variant of junctional EB; aberrations in the type XVII collagen gene (COL17A1) in non-lethal forms of junctional EB; mutations in the alpha6 and beta4 integrin genes in a distinct hemidesmosomal variant of EB with congenital pyloric atresia; and mutations in the plectin gene (PLEC1) in a form of EB associated with late-onset muscular dystrophy. Identification of mutations in these gene/protein systems attests to their critical importance in the overall stability of the cutaneous BMZ. Furthermore, elucidation of mutations in different variants of EB has direct clinical applications in terms of refined classification, improved genetic counseling, and development of DNA-based prenatal testing in families with EB.

Basement Membrane↗

PubMedDate not supplied

Quantitative self-organizing maps for clustering electron tomograms.

Tomography emerges as a powerful methodology for determining the complex architectures of biological specimens that are better regarded from the structural point of view as singular entities. However, once the structure of a sufficiently large number of singular specimens is solved, quite possibly structural patterns start to emerge. This latter situation is addressed here, where the clustering of a set of 3D reconstructions using a novel quantitative approach is presented. In general terms, we propose a new variant of a self-organizing neural network for the unsupervised classification of 3D reconstructions. The novelty of the algorithm lies in its rigorous mathematical formulation that, starting from a large set of noisy input data, finds a set of "representative" items, organized onto an ordered output map, such that the probability density of this set of representative items resembles at its possible best the probability density of the input data. In this study, we evaluate the feasibility of application of the proposed neural approach to the problem of identifying similar 3D motifs within tomograms of insect flight muscle. Our experimental results prove that this technique is suitable for this type of problem, providing the electron microscopy community with a new tool for exploring large sets of tomogram data to find complex patterns.

Algorithms↗

PubMed1999

Communicating defects of the triangular fibrocartilage complex without disruption of the triangular fibrocartilage: a report of two cases.

Perforations or communicating defects of the triangular fibrocartilage complex have been more commonly identified after Palmer published his classification system (J Hand Surg 1989;14A:594-606). To his variants of class 1B (traumatic) ulnar avulsion with or without distal ulnar fracture, a third category may be added: defects of the ulnar collateral ligament without any associated disruption of the triangular fibrocartilage. The ulnar collateral ligament can be defined as an ulnar capsular structure between the more discrete elements of the triangular fibrocartilage and the ulnar ligaments, with the defect or perforation being distal to the intact triangular fibrocartilage and exiting into the floor of the extensor carpi ulnaris sheath. We present 2 cases that illustrate the diagnosis, the use of both magnetic resonance imaging and arthrography to confirm the diagnosis, the associated dorsal ulnar cutaneous nerve pain distribution, and the open direct and retinacular flap repair.

Adult↗

PubMed1992

Truncus arteriosus communis associated with interrupted aortic arch: a report on two uncommon cases.

The paper presents two infants with the A-4 type of truncus arteriosus communis (according to Van Praagh's classification). One patient who survived a surgical procedure demonstrated a rare variant of aortic arch interruption to the left off the left subclavian artery (type A according to Celoria and Patton), whereas the second presented an uncommon anomaly in which the right subclavian artery originated from the descending aorta with associated severe truncal valve incompetency. The authors describe the clinical picture along with the surgical treatment of the first infant who being six days old was subjected to a correction employing the wide patent ductus arteriosus to reconstruct the aortic arch, following the method described by Gomes and McGoon. Subsequently an aortic homograft was implanted in order to connect the right ventricle and the pulmonary artery.

Aortic Arch Syndromes↗

PubMed2002

Localized cutaneous small to medium-sized pleomorphic T-cell lymphoma: a report of 3 cases stable for years.

Small to medium-sized pleomorphic cutaneous T-cell lymphomas represent a provisional entity in the new European Organization for Research and Treatment of Cancer classification. We describe 3 patients with a localized and outstanding stable variant of this tumor. A median follow-up period of 50 months did not reveal any spread into regional lymph nodes or to distant sites in any patient.

Adult↗

PubMed2026

Long-read based detection of large copy number variants with potential functional significance using the ContextSV structural variant caller.

Long-read sequencing enables improved detection of structural variants (SVs) in the human genome due to its substantially increased read lengths. However, currently widely used long-read SV callers primarily rely on alignment-based evidence, limiting their ability to detect large and complex SVs and potentially missing disease-relevant events. To address these limitations, we developed ContextSV, a framework that integrates alignment evidence with copy number predictions derived from sequencing coverage and single-nucleotide variant allele frequencies to improve SV detection, particularly for large copy number variants (CNVs). We additionally developed ContextScore, a machine learning-based classification model to assign SV confidence scores based on genomic context features and integrated it within ContextSV. Through benchmarking analyses on both simulated and real datasets, we demonstrate that ContextSV improves detection of large CNVs and inversions that may be missed by existing long-read SV callers. We further illustrate its utility by identifying and experimentally validating multiple large SVs in the KOLF2.1J reference stem cell line that were not detected by other methods. Collectively, our results demonstrate that ContextSV serves as a valuable complement to existing long-read SV detection approaches by improving sensitivity for large and clinically relevant SVs.

Humans↗

PubMedDate not supplied

CT appearance of microcystic meningioma.

Microcystic meningioma is an unusual variant, which has recently been proposed for inclusion in the WHO Classification of Central Nervous System Tumors. Its unique structure produces findings that may be confusing to radiologist and pathologist alike. A case is reported and the English language literature reviewed.

Aged↗

PubMed2002

The genetics of atopic dermatitis.

PURPOSE OF REVIEW: Atopic dermatitis is typified by itchy, inflamed skin. It is increasingly common in the developed world and is a major cause of morbidity in infants and young children. Most children with the disease have high levels of immunoglobulin E and many have concomitant asthma. The cause of the disease is unknown, but it is highly heritable. Identification of the genes and genetic variants underlying atopic dermatitis may lead to new treatments and better classification of children with the disease. RECENT FINDINGS: Preliminary genetic studies have identified genes or clusters of genes that are expressed in the outermost layer of the skin to be just as important as genes that may modify the atopic process. These genes may influence other diseases, including psoriasis. Genome screens in mouse models seem to indicate involvement of some of the equivalent chromosomal regions as for human disease. SUMMARY: The findings suggest that atopy in atopic dermatitis may be a secondary process, rather than the cause of the disease. The barrier function of the skin is seen not to be merely passive. Identification of the genes underlying atopic dermatitis is feasible and likely within a few years.

Allergens↗

PubMed1991

The syndrome of intermetamorphosis.

A series of 154 patients suffering from the syndrome of intermetamorphosis or its variants is discussed in terms of this misidentification syndrome's historical, classification, diagnostic, and psychosocial aspects. One case is presented in detail.

Adult↗

PubMed1996

Management of back pain in athletes.

Back pain affects millions of people. It affects 80% of the population and up to 52% at any given time. Back pain is not limited to sedentary individuals; it has significant effects on athletes as well. Depending upon the sport, incidence rates of back pain occur in athletes from 1.1% to as high as 30%. Athletes differ from the non-athletic population in that their incentives to return to activity are considerably different than non-athletes. The reasons may vary from the will to win through to significant financial considerations. Although reasons for recovery are different, the physiology and mechanics of repair of injured soft tissue in the athlete is the same as for the non-athlete. Proper management of the athlete requires ruling out emergent causes of back pain such as tumour, infection, acute fracture, progressive neurological deficit, visceral sources (e.g. pancreatitis, abdominal aortic aneurysm), and rheumatoid variants. Once a good history and physical is performed, a simple classification system can be utilised to manage the athlete presenting with back pain. This system can be expressed as: (a) regional back pain; (b) radicular leg pain; (c) radicular leg pain with progressive neurological deficit; and (d) cauda equina syndrome. Each of these categories needs to be managed in a specific manner and can provide the healthcare professional with simple, straightforward guidelines for handling the athlete with lower back pain. The key is to return the athlete to the field of play in a safe and timely manner.

Athletic Injuries↗

PubMed2001

[Clinical classification of benign ENT tumor].

The proposed clinical classification of benign ENT tumors is based on division of anatomic regions (the ear, nose, pharynx, larynx) into sections and fragments and allows to assess the spread of any ENT tumor. Moreover, it agrees with TNM classification. The symbols "T" and R are used which denote four variants (T1-4) or R1-4 for the tumor and recurrence, respectively.

Ear Neoplasms↗

PubMed2002

[Endoscopic diagnosis of chronic pancreatitis].

Endoscopy entered the diagnosis of pancreatic diseases in 1972 as the first endoscopic retrograde cholangiopancreaticography and during subsequent decades it markedly extended its field of action to comprise also endoscopic therapy of the pancreas. At present it represents together with abdominal sonography, computed tomography, endosonography, and nuclear magnetic resonance the basic spectrum of morphological examination methods of the pancreas. The disadvantage of endoscopic retrograde cholangiopancreaticography is the invasive character of this method associated with complications. In chronic pancreatitis this method can be used in particular to evaluate the extent of morphological changes--i.e. classification of chronic pancreatitis, whereby the most frequently used one is the Cambridge classification. The method, contrary to other morphological imaging methods can diagnose variants and malformations of the pancreatic efferent system, it cannot however, with the exception of chronic obstructive pancreatitis and chronic pancreatitis in pancreas divisum detect the cause of chronic pancreatitis and is also of very limited informative value in the differential diagnosis of chronic pancreatitis and carcinoma of the pancreas. Endoscopic retrograde pancreaticography cannot be implemented after some surgical operations of the pancreas.

Cholangiopancreatography, Endoscopic Retrograde↗

PubMed1989

[Classification of postoperative eventration].

On the basis of summarizing the experience with treatment of 280 patients, the authors suggest a classification of postoperative eventration. The tactics of treatment in its different variants was developed.

Abdominal Muscles↗

PubMedDate not supplied

[Clinico-morphologic basis for the orthodontic treatment of intra-alveolar tooth fractures in children and adolescents].

Analyzed were the results of treatment of 115 teeth with intraalveolar root fractures in 78 patients aged 8 to 18 years. Histological investigation was performed in 8 teeth extracted for clinical indications. Combined with the results of experiments conducted on 12 dogs, this allowed to establish that several variants of cicatrization were possible. An addition was offered to the classification of intraalveolar fractures. Orthopedic technique was designed on the basis of the pathogenesis of the lesion.

Adolescent↗

PubMed1987

[Classification of psychopathies].

The author proposes a new "ring-like" classification of psychopathies which includes the most definitely described prevalent clinical variants with due consideration of mutual transitions of some forms of psychopathy into others (mixed forms, "complex" psychopathic syndrome) and also an energy potential of individuals with some persons being referred to the sthenic (excitable) pole and others to the asthenic (inhibitory) pole. The main disorder obligate to all psychopathic personalities is mental infantilism whereas the inadequacy of emotional manifestations and alterations in the sphere of thinking are considered as secondary manifestations determining one or another clinical variant of psychopathy and are related to congenital mental activity of a given individual.

Brain Diseases↗

PubMed1987

[Evaluation of the classification of pathological personality development of exogenous organic origin by the main component method].

The author has tested the developed classification of the pathological personality development of the exogenic-organic genesis using the method of main components. On the basis of the mathematical processing of clinical symptomatology in 348 patients with various types of the pathological development (asthenic, hysteriform, hypochondriac, explosive) the author has defined three main components: "excitability", "inhibition" and "hypochondriac anger". An analysis of the distributional pattern of types of the pathological personality development in orthogonal planes of three main components has made it possible to establish the adequacy of the proposed classification of the internal structure of the disease and identify the variants appearing as "unifying" and "distinguishing" borderlines between individual types.

Borderline Personality Disorder↗

PubMed1986

[Comparative characteristics of the Haemophilus influenzae strains isolated from healthy children and from patients with acute and chronic bronchopulmonary diseases].

The comparative biochemical and serological characterization of 424 H. influenzae strains isolated from healthy children and patients with acute and chronic bronchopulmonary diseases is presented. As the result of biotyping H. influenzae strains, 82.3-90.9% of the strains isolated from both healthy children and patients with acute and chronic bronchopulmonary diseases were found to belong to the first three biotypes according to M. Kilian's classification. Among H. influenzae strains isolated from healthy children no capsular variants were detected in the coagglutination test. From patients with acute and chronic diseases of respiratory organs, as a rule, the capsular variants of H. influenzae were isolated (94.4% and 98.1%, respectively). In patients with chronic pneumonia biotypes I, II and III, more seldom biotype V, proved to be mo st invasive. In the determination of the minimum inhibiting concentration of ampicillin, no H. influenzae strains resistant to this antibiotic were detected.

Adolescent↗