Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Variant classification”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63Linked to original sources
PubMed2003

Updated classification of hemangiomas and other vascular anomalies.

Vascular anomalies comprise a widely heterogenous group of tumors and malformations. Great confusion has arisen because of the term hemangioma has been and is continued to be used to represent a multitude of vascular entities. This review presents the updated classification of vascular anomalies with the goal of clarifying the term hemangioma. In addition, newer clinical concepts in hemangiomas and other vascular tumors is presented. Hemangioma subtypes and hemangioma variants are also discussed, and a brief review of pyogenic granuloma and Kaposiform hemangioendothelioma is provided. Finally, the immunohistochemical marker GLUT1 is reviewed, a marker that heralds a new era in vascular anomalies research.

Cardiovascular Abnormalities↗
PubMed2002

Cutaneous T-cell lymphoproliferative disorders: approach for the surgical pathologist: recent advances and clarification of confused issues.

Cutaneous T-cell lymphoproliferative disorders (CTCLs) remain a subject of confusion and controversy. In this review, the authors discuss diagnostic criteria and classification, including the role of immunohistochemistry and gene rearrangement studies. In addition, cutaneous T-cell pseudolymphomas, the current status of parapsoriasis and other premalignant syndromes, and the clinicopathological variants of mycosis fungoides are discussed. CD30-positive lymphoproliferative disorders and a number of rare variants of CTCL including granulamatous slack skin, subcutaneous (panniculitic) T-cell lymphoma, gamma-delta cutaneous lymphoma, NK/NK-like T-cell lymphoma, and primary cutaneous CD8-positive epidermotropic cytotoxic T-cell lymphoma are also considered.

Gene Rearrangement↗
PubMed2000

Malignant melanoma, dysplastic melanocytic nevi, and Spitz tumors. Histologic classification and characteristics.

The classification and pertinent histopathologic features of cutaneous melanoma, dysplastic melanocytic nevi, and Spitz tumors are presented. A discussion on melanoma emphasizes an objective approach to classification based on histomorphologic features including location in the skin, disposition and frequency of melanocytes, other specific morphologic features, and cell type. Other topics addressed include common and unusual variants of melanoma, the use of immunohistochemistry, and the histopathologic reporting of melanoma.

Adolescent↗
PubMedDate not supplied

[Heart conduction disorders in pediatric practice].

This study was prepared on the basis of the recent data published in the specialized literature, as well as on the personal experience of the authors, and is considered as a necessary updating in the field of heart rhythm disturbances which occur in the child. A review is presented of sinoatrial blocks, of atrioventricular conduction disturbances, and of intraventricular conduction abnormalities (branch blocks). A modern classification is used in the discussion of sinoatrial, and of atrioventricular blocks, with the three distinctive degrees (first degree block, second degree block--with type I and type II variants, and the third degree block). The authors have attempted, in their effort to present the data concerning each of the entities, to include a series of anatomical and electrophysiological notions, some of which represent modern acquisitions obtained by endocavitary electrocardiographic exploration, and which are considered to be essential for a good understanding of the material. An important place is given--for each of the entities discussed--to the etiological study, as well as to clinical semiology, and electrocardiography, to problems related to the positive and differential diagnosis, and to therapeutical means, as well as to evolution and prognosis. The study is concluded by a presentation of intraventricular conduction disturbances (branch blocks) which are evaluated in their distinct variants: the monofascicular block (single bundle block), the bi- and trifascicular bundle blocks, major or minor blocks, and functional rate-dependent blocks. In these cases also the authors have analysed etiologic aspects, the clinical picture, and the electrocardiographic aspects, as well as therapeutical, evolutive and prognostic features for each of the different forms.

Arrhythmias, Cardiac↗
PubMed1983

[Use of the coagglutination reaction for identifying Shigella flexneri].

The data on the use of the coagglutination test for the identification of Sh. flexneri are presented. The influence of different methods for the treatment of antisera on their heterologous reactions was studied and the advantage of coagglutinating reagents was revealed. 9 variants of coagglutinating preparations were obtained; their use made it possible to reduce the consumption of antisera and in some cases avoid their absorption. The problem of Sh. flexneri classification is discussed.

Adsorption↗
PubMed1984

[Current status of the problem of malignant lymphoma (on the centenary of the theory of malignant lymphoma)].

Malignant lymphomas (ML) differ from other neoplasms by an extreme variety of the morphological terms used for designation of different variants of these tumours and different terms are used to describe the same neoplasm. This resulted in the simultaneous use in different countries of not less than 6 ML classifications including the WHO histocytological classification (1976), which is not universally accepted. Kiel's classification of non-Hodgkin's ML (1974) is the most popular in the majority of the West and East European countries, in USA there is a similar classification by Lukes and Collins (1975). The "Working formulation of ML for the use in clinics" (USA, 1982) starts to be used, although it is simply a terminological compromise also containing certain faults. The historical review of the evolution of the ML concept is given starting from Th. Billroth' works (1883); the concrete examples are given illustrating the dynamics of the ML terms and evaluation of their nature. The singularity of the developmental steps of this concept is noted, in particular the "reticulosis era" (1923-1973). The dependence of ML estimate upon the existing, in a given period, schemes of hemopoiesis is pointed out. The data on the state of this problem in different countries are presented and the necessity of its joint discussion by pathologists and clinicians in order to work out the identical nomenclature for the designation of the same type of ML is outlined.

Animals↗
PubMedDate not supplied

Classification and surgical treatment of dissecting aortic aneurysms.

A classification of dissecting aortic aneurysms is presented. It allows one to determine more accurately any given pathology in any patient. It helps the surgeon select the most appropriate operative variant and to define tactics of treatment. For example, to discuss the necessity of repeated reconstruction. Our clinical cases have confirmed it.

Aortic Dissection↗
PubMed1998

G protein beta3 subunit variant and essential hypertension in Japanese.

Enhanced G protein activation has been implicated to underlie the increased sodium-proton transport in blood cells, an impaired characteristic observed in 30% to 50% of patients with essential hypertension. Recently, significant association between a C825T polymorphism of the gene encoding the G protein beta3 subunit and hypertension was demonstrated in a white population, together with the finding that the T825 variant might be related to alternative splicing through unidentified mechanisms. We therefore investigated the disease relevance of this candidate gene by conducting an association study in a relatively large Japanese population. Participants comprised 718 hypertensive case subjects (without diabetes mellitus), 515 normotensive control subjects, and 191 hypertensive subjects with borderline or established diabetes mellitus; all individuals were recruited at a single institution. Genotype distribution of the C825T polymorphism was compared between hypertensive subjects, with or without diabetes, and the control group with chi2 statistics. No significant association was observed in the present study. Results were still not significant when the case group was subdivided according to more stringent classification criteria. Allele frequencies of T825 proved to be almost concordant among the 3 study groups and higher in Japanese (49.0% to 49.6%) compared with a reported prevalence of 25% to 31% in whites. Our data suggest that the T825 variant of the G protein beta3 subunit gene is unlikely to constitute major susceptibility for essential hypertension in the Japanese population studied. However, further investigation is required to answer the question of whether the lack of association reflects ethnic differences in the nature of genetic susceptibility loci.

Aged↗
PubMed1998

Physical 'disability' in Bantu languages: understanding the relativity of classification and meaning.

The terminology related to 'physical disability' in proto-Bantu and in contemporary Bantu languages of Zone L are examined for a better understanding of African classification and meaning. The methods used in the examination include 'words and things' and ethnographic fieldwork. In proto-Bantu, nominal classes are used to categorize disability as both human and non-human. Based on the distribution of terminology, a support for differing regional and historical meaning is developed. The most ancient meaning links physical disability to 'becoming heavy' out of which variants developed. In contemporary Bantu languages in Zone L, the widespread use of the term -lema reemphasizes categorization in both human and non-human, and the use of meaning found in proto-Bantu is evident. However, ethnographic work in the same language area indicates that other terms are important to an understanding of classification and meaning related to physical disability in Zone L. These terms relate to sorcery or reincarnation as meanings attached to disability.

Africa↗
PubMed2004

[The treatment of varicosity associated with persistent edema of the lower limbs].

From February 1998 to September 2002, 36 patients suffering from varicosity of the saphenous veins of the lower limbs associated with edema were operated on. All of them were provided different variants of intraoperative sclerotherapy (IOST). By the character of venous disorders the patients were divided into 2 groups. The first group (n=19) comprised patients with stages 2 and 3 varicosity according to the clinical classification of the CEAP. The maximal diameter of the varicose greater saphenous vein (GSV) in these patients did not exceed 1 cm, with no trophic disorders. The second group (n=17) included patients suffering from stages 2-4 varicosity according to the clinical classification of the CEAP. In these patients, the diameter of the varicose GSV on the thigh exceeded 1 cm and there were trophic disorders on the leg in the form of pigmentation and/or skin induration. The first group patients underwent crossectomy and IOST of the GSV over the whole length. The second group patients were provided combined intervention: crossectomy, GSV stripping on the thigh and IOST: of the GSV on the leg. To define the effectiveness of the surgical treatment using sclerotherapy, the reference group including 38 persons with varicosity also complicated by edema of the lower limbs was under our observation. This group underwent surgical intervention which consisted in radical venectomy according to Babcock and excision of the lateral venous branches according to Narat. Analysis of the immediate results has demonstrated that in the basic group, the complications occurred in 5.6% of patients versus 29% in the reference group; the postoperative bed day in the basic group was 1.8 times less. Evaluation of the edematous syndrome carried out in the long-term period (after 2 years) showed its complete absence in 96,4% of the basic group patients versus 72.4% of the reference group patients. So, the use of different variants of IOST in the treatment of patients suffering from varicosity complicated by edema evidences the advantages of the treatment tactics offered by us as compared to the routine surgical techniques.

Adult↗
PubMed1999

Association of a variant of the angiotensinogen gene with pure type of hypertension in pregnancy in the Japanese: implication of a racial difference and significance of an age factor.

The contribution of genetic factors to hypertension in pregnancy, including pre-eclampsia, has been well documented. The association with a common molecular variant of the angiotensinogen (AGT) gene, in which methionine (M235) is substituted for threonine (T235) at residue 235, has been reported in both Caucasians and Japanese. In the present study, we examined 115 cases of pure type of hypertension in pregnancy (PHP) and 381 normal pregnant controls in order to look for subgroups in which the AGT gene is the major factor in the PHP pathogenesis. By classification of PHP cases according to the clinical diagnosis, gravidity, and maternal age, we found significantly higher frequencies of T235 in both all PHP patients and preeclampsia/eclampsia patients than in normal controls. These results are discordant with those reported for Caucasian subjects where only a group of preeclamptic primigravidae was associated with the AGT variant, possibly indicating the existence of a racial difference. We also found that the variant frequency was significantly higher in the PHP subgroup with maternal age of 20-34 years (0.93) than in a subgroup of multigravid PHP patients age 35 years or older (0.77, P < 0.05) or in normal controls of age 20-34 years (0.76, P < 0.001). The result indicates that the AGT variant plays a significant role in hypertension in the age group 20-34 years.

Adult↗
PubMed2005

Distinct allelic variants of TSC1 and TSC2 in epilepsy-associated cortical malformations without balloon cells.

Epilepsy-associated malformations of cortical development (MCDs) comprise a variety of dysplastic and neoplastic lesions of yet undetermined molecular pathology. Histopathologic similarities between MCDs and dysplastic brain lesions in the autosomal inherited neurocutaneous phacomatosis tuberous sclerosis (TSC), which affects the TSC1 and/or TSC2 genes, suggest common pathogenetic mechanisms. Previous studies revealed different alterations of TSC1 and TSC2 in epilepsy-associated malformations and glio-neuronal tumors despite histopathologic similarities. In order to examine current clinico-pathologic classification systems of cortical malformations on the molecular level, we carried out a mutational analysis of TSC1 and TSC2 in a series of surgical specimens obtained from patients with FCD without Taylor type balloon cells (FCDIIa; n = 20), architectural dysplasias (FCDI; n = 15), nodular cortical heterotopias (NCH; n = 4), and heterotopic white matter neurons (WMNH; n = 19). In FCDIIa, abundant genomic polymorphisms were detected in TSC2 (intron 4) but no allelic variants observed in exon 17 of TSC1. This allelic distribution pattern is in contrast to findings in FCDI and WMNH but also to those previously reported in FCDIIb (Taylor's balloon cell type). The latter revealed increased frequencies of specific alleles only in TSC1. The determination of characteristic molecular genetic alterations in specific epilepsy-associated malformations will support a comprehensive clinico-pathologic classification system and help to identify molecular pathways with potential pathogenetic relevance. Our work is supported by DFG (SFB TR3 [AJB], DFG Bl 421/1-1 [IB]), BONFOR, and Deutsche Krebshilfe.

Alleles↗
PubMed1989

A comparison of the clinical variations of the iridocorneal endothelial syndrome.

Iridocorneal endothelial syndrome is generally considered to have three major variations: Chandler's syndrome, progressive (essential) iris atrophy, and the Cogan-Reese syndrome. To better understand the clinical significance of this classification, we studied the medical records of 37 consecutive patients from our practice, comparing the presentation and course of the three subgroups. Chandler's syndrome was the most common clinical variant within this spectrum of disease (21 cases). Patients with Chandler's syndrome had more severe corneal edema than the rest of the group, while those with progressive iris atrophy (8 cases) or the Cogan-Reese syndrome (8 cases) had worse secondary glaucoma.

Adult↗
PubMed1990

DNA in chordomas of the clivus Blumenbachi.

Chordomas of the clivus are frequently denoted as malignant, mainly because of their propensity to recur, their crucial location and the fatal clinical course. Although microscopical examination commonly reveals pleomorphism, particularly of cells and nuclei, the histological assessment of malignancy is not always appropriate. The measurement of DNA could provide important information for a classification of their biological behavior (grading). Our examination of a chondroid chordoma revealed a typical diploid DNA curve within a "benign" 4C range concordant to the favorable course of this variant. Our second examination of a "typical" chordoma showed a wide pleomorphism of cell nuclei and moderate proliferation activity within a "low grade" scale. This pointed to a coming (fatal) recurrence 3.5 years after the first surgery. The third chordoma we examined presented an extraordinary 4C aneuploidy with hypertetraploid subpopulations and an increased number of bi- or poly-nucleated tumor cells with prominent nucleoli and some more mitotic figures. In 5 recurrences the DNA pattern remained principally unchanged.

Adult↗
PubMed2001

Frontotemporal dementia and tauopathy.

The presence of abundant neurofibrillary lesions made of hyperphosphorylated tau proteins is the characteristic neuropathology of a subset of neurodegenerative disorders classified as "tauopathies." The discovery of mutations in the tau gene in frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) constitutes convincing evidence that tau proteins play a key role in the pathogenesis of neurodegenerative disorders. Moreover, it now is known that the most common form of sporadic frontotemporal dementia (FTD), which is characterized by frontotemporal neuron loss, gliosis, and microvacuolar change, also is a tauopathy caused by a loss of tau protein expression. Thus, these discoveries have begun to change the classification and the neuropathologic diagnosis of FTD and tauopathies, as well as current understanding of the disease mechanisms underlying them. Although transgenic mice expressing wild-type human tau or variants thereof with an FTDP-17 mutation result in tau pathologies and brain degeneration similar to that seen in human tauopathies, the precise mechanisms leading to the onset and progression of neurodegenerative disorders remain incompletely understood. Here, we review current understanding of human neurodegenerative tauopathies and prospects for translative recent insights about these into therapeutic interventions to prevent or ameliorate them.

Dementia↗
PubMed1995

Desmoplastic low grade astrocytoma: a case report and review of literature.

A 7-year-old girl presented with focal seizures without symptoms of raised intracranial tension. Routine histological, immunocytochemical and ultrastructural methods revealed a desmoplastic low grade cerebral astrocytoma. Follow up for 2 years after biopsy did not show recruitment of neurological symptoms or signs. Biphasic tumours containing glial and mesenchymal elements have been described in the literature under various diagnostic headings. As the histologically benign variants of mixed glial and mesenchymal tumours appear to have a good prognosis, identification of these as separate entities seems imperative. With a review of literature we propose a pathological classification of mixed glial and mesenchymal tumours.

Arachnoid Cysts↗
PubMed2001

Identification of essential acidic residues of outer membrane protease OmpT supports a novel active site.

Escherichia coli outer membrane protease OmpT has previously been classified as a serine protease with Ser(99) and His(212) as active site residues. The recently solved X-ray structure of the enzyme was inconsistent with this classification, and the involvement of a nucleophilic water molecule was proposed. Here, we substituted all conserved aspartate and glutamate residues by alanines and measured the residual enzymatic activities of the variants. Our results support the involvement of a nucleophilic water molecule that is activated by the Asp(210)/His(212) catalytic dyad. Activity is also strongly dependent on Asp(83) and Asp(85). Both may function in binding of the water molecule and/or oxyanion stabilization. The proposed mechanism implies a novel proteolytic catalytic site.

Amino Acid Sequence↗
PubMed1987

Cystic cemento-ossifying fibroma of the ethmoidal cells (a case report).

A case report of an aggressive cystic cemento-ossifying fibroma of the ethmoidal cells is presented. Fibro-osseous lesions containing cementum are considered to be of periodontal membrane origin and are most common in the mandible and maxilla. Following the WHO classification, fibro-osseous lesions containing cementum are grouped together under the heading of cementoma and are divided into four subgroups. Cemento-ossifying fibroma is considered to be a variant of cementifying fibroma which is a sub-group of cementoma. The unique site of origin seen in this case is thought to have been the result of an ectopic periodontal membrane or of a primitive mesenchymal cell rest or incomplete migration of the medial part of the nasal anlage and differentiation into the periodontal membrane.

Adolescent↗