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At least 217 records · Page 12Linked to original sources
PubMed2026

Mitochondrial DNA diversity in Ecuadorian populations: Recurrence of variant 16136 within haplogroup B2.

The identification of lineage-defining variants, frequently found in the coding region of mitochondrial DNA (mtDNA), is essential for refining haplogroup classification. Most mtDNA studies in South American populations have focused on the control region (CR), which has provided important insights into population structure and maternal lineage origins, although information needed for more robust phylogenetic resolution has been neglected. This study investigates the maternal genetic structure of Ecuadorian populations by combining CR and whole mitogenome analyses. Sequences from the mtDNA CR were obtained from 461 individuals (253 Mestizos and 208 Native Americans), while complete mitogenomes were sequenced for 127 individuals to improve phylogenetic resolution by identifying lineage-defining variants present in coding region. Most mtDNA haplogroups in the two population groups analyzed were of Native American origin (A2, B2, B4, C1, D1, D4), with significant differences in the distribution of specific lineages between them. Among Mestizos, African haplogroups (all within the L branches) and Eurasian haplogroups (H, K, R, U) were detected at low frequencies, whereas no African lineages were observed among Native Americans. The results obtained highlighted a heterogeneity within Ecuadorian populations that must be considered when developing mtDNA haplotype databases for forensic purposes. Whole mitogenome sequences enabled the identification of variants that refined haplogroup classifications, provided a more accurate reconstruction of the maternal genetic diversity, and improve the discrimination between Native American and Asian maternal lineages within haplogroup B4b.

Humans↗
PubMed2026

Biallelic pathogenic variants in FLNB are associated with paediatric steroid-resistant nephrotic syndrome via podocyte cytoskeletal dysfunction.

BACKGROUND: Steroid-resistant nephrotic syndrome (SRNS) is a severe paediatric kidney disease and a leading cause of end-stage kidney disease in children, with a high genetic contribution. While over 80 monogenic causes of SRNS have been identified, a significant proportion of affected patients still lack a clear genetic diagnosis, indicating that additional causative genes remain to be discovered. METHODS: Through whole-exome sequencing of a paediatric SRNS cohort, we identified three probands carrying biallelic FLNB pathogenic variants. Sanger sequencing was performed for familial cosegregation verification and ACMG classification. Expression of Filamin B, Nephrin and Synaptopodin in renal tissues was assessed by immunohistochemistry/immunofluorescence. Wild-type and patient-derived variant FLNB plasmids were constructed and transfected into HEK293T cells and immortalised human podocytes (HPCs). The effects of these variants on protein expression, localisation and cytoskeletal organisation were assessed by western blotting and immunofluorescence. FLNB expression in HPCs was silenced using shRNA to evaluate the impact on podocyte marker proteins, cytoskeletal integrity and migratory capacity. A zebrafish flnb knockdown model was employed to validate its effects on renal development. RESULTS: All three probands presented with isolated SRNS without skeletal developmental abnormalities, and renal tissues showed significantly reduced Filamin B protein expression. In vitro, p.L117P and p.M1803L variants led to markedly reduced protein expression, while p.R470L and p.K2586R induced perinuclear aggregation of Filamin B accompanied by F-actin rearrangement. FLNB silencing led to downregulation of Nephrin and Synaptopodin, cytoskeletal disorganisation and impaired cell migration. Zebrafish flnb knockdown exhibited pericardial oedema, defective nephron development and abnormal podocyte foot processes. CONCLUSION: We report for the first time that biallelic FLNB pathogenic variants are associated with paediatric SRNS by disrupting Filamin B expression, cytoskeletal integrity and podocyte function, providing evidence that FLNB is a novel monogenic cause of SRNS.

Humans↗
PubMed1989

[Disseminated herpes zoster in chronic lymphatic leukemia].

A 73-year-old woman suffering from chronic lymphatic leukemia presented a rare variant of zoster with disseminated eruptions. Ultrastructural negative staining revealed viruses of the herpes group. Herpes simplex was excluded by means of fluorescence-labelled monoclonal antibodies (HSV-1/HSV-2 direct specimen identification/typing test). It is proposed that the conventional classification of zoster into a segmental and a generalized variant should be supplemented.

Aged↗
PubMed1987

[Psoriasis pustulosa generalisata--classification, clinical aspects and therapy. Review and experiences with 18 patients].

On the basis of clinico-morphological criteria we suggest the following classification of various pustular forms of psoriasis into four subtypes: generalized pustular psoriasis (von Zumbusch) and its atypical forms, erythema anulare centrifugum-like psoriasis with and without pustulation (EACP); psoriasis vulgaris with pustulation; palmo-plantar pustular psoriasis (Königsbeck-Barber) and its acral variant; acrodermatitis continua suppurativa (Hallopeau), and transitional forms. This classification takes into consideration both clinical aspects and response to treatment, and allows a prognosis of the various types of pustular psoriasis. Owing to its mild course and good treatment results, EACP represents a special form of psoriasis pustulosa generalisata. In our group of patients, systemic glucocorticosteroid therapy has proved deleterious, whereas oral photochemotherapy and etretinate have been found to be highly effective modes of therapy with only mild side effects and have been able to induce even permanent remission in EACP.

Adult↗
PubMed1981

[Characterization of genetic EEG-variations with the amplitude-interval-analysis. III. Assignment of new obtained EEGs to well-known types of bioelectric activities on the basis of data of amplitude-interval-analysis (author's transl)].

Quantitative description of some EEG-variants by amplitude-interval (time-domain) analysis revealed significant differences of parameter means but failed to give one single, sufficiently reliable criterion for classification. Therefore, we tried to solve the problem of classification through quantitative criteria by discriminant analysis. For each EEG, 128 different measurements were taken, but only 104 were included in the analysis; the rest failed to contribute any measurable information. For 243 of th 298 probands, the data were sufficient for inclusion in the study. Only 15 (6.2%) were classified falsely; this number was reduced to 3 (1.7%) when the calculation was performed leaving out the (64) controls. A control analysis by a Monte-Carlo-Method in which the classification criterium was calculated using 80% of all cases only, and the remaining 20% were then attributed tentatively to the variant groups, gave much less convincing results. It follows that more and better criteria for separation of these variants have to be developed before classification of EEGs exclusively on the basis of measurements will become possible.

Electroencephalography↗
PubMed1986

[Renal cell carcinoma--a classification based on cytomorphological criteria].

535 human renal cell carcinomas were classified using a classification system based on defined tumor cell types. The following tumor cell types were distinguished: clear cells (with variants: clear cell-eosinophilic, plasma-rich), chromophobe cells (with variants: eosinophilic, relatively light), chromophilic cells (basophilic, eosinophilic), spindleshaped/-pleomorphic cells. A group "still unclassified" is added. This classification largely rejects the term "granular" (which as a rule was combined with "eosinophilic"), because in our view this term referred to a heterogenic group of variants of different cell types. A cytological grading--based on nuclear morphology--is conducted using 3 grades (GI - III). Preliminary results from follow up studies (survival rates, metastases) suggest that this classification may also have clinical importance for tumor prognosis.

Adolescent↗
PubMed1988

Ocular palsy preceding chronic relapsing idiopathic polyneuropathy. Poor response to plasma exchange.

We report a case of chronic relapsing idiopathic polyneuropathy developing six weeks after the onset of extraocular palsy. As in the other four published cases, the patient failed to respond to steroids and also in this case to plasma exchange, thus confirming the poor prognosis. The electrophysiological features and poor response to plasma exchange are at variance with a demyelinating pathogenesis and suggest classification of this form as a distinct clinical variant.

Adult↗
PubMed1987

The immunologic approach to analysis of malignant lymphoma. Mantle zone lymphoma of the ileocecal region.

We studied an unusual type of lymphoma of the ileocecal region using an established protocol that combines morphologic, flow cytometric, and immunohistochemical analyses. This lymphoma grew as multiple submucosal nodules, some of which had coalesced into a mass in the terminal ileum. Histologically, the lesion resembled a lymphoma of follicular center-cell origin except for germinal centers that appeared reactive and greatly expanded follicular mantles. Flow cytometric studies showed that the lymphoma contained a monoclonal, kappa+ population of B-lymphocytes. Evaluation of sections of frozen tissue by an immunoperoxidase technique revealed that the germinal centers were polyclonal (nonneoplastic) and that the neoplastic cells were confined to the mantle zone. The additional information led to classification of the neoplasm as the mantle zone variant of intermediate lymphocytic lymphoma. This type of lymphoma may pursue a more aggressive course than a follicular lymphoma derived from the germinal center. We review our general approach to the analysis of hematolymphoid neoplasms and discuss how certain techniques may be useful adjuncts in the evaluation of these types of tumors.

Antibodies, Monoclonal↗
PubMed1990

Major retroperitoneal venous anomalies: surgical considerations.

Nineteen major anomalies of the vena cava or its branches were encountered in patients requiring abdominal vascular surgery and related procedures at Barnes Hospital during the past 5 years. The classification of these anomalies, their embryologic development, associated variants, and surgical considerations are discussed. Careful review of preoperative computed tomographic scans and familiarity with these anatomic variants may allow the surgeon effectively to avoid potentially disastrous intraoperative consequences.

Humans↗
PubMed1989

[Nephroblastomas (Wilms' tumors) and special variations of nephroblastomas].

The results of the National Wilms' Tumor Study (NWTS) enabled the subdivision of nephroblastomas into subtypes with "favorable and unfavorable histology". Nephroblastomas with "unfavorable histology" could be discriminated by identifying those tumors not responding to therapeutic regimes proven successful for most cases with "favorable histology". A major disadvantage of the NWTS classification has been the exclusion of cytodifferentiated nephroblastoma variants, which, in contrast to typical nephroblastomas, can be cured by complete nephrectomy with wide excision of perinephric soft tissue. In the current study all types of nephroblastoma and nephroblastoma variants were included to encompass the whole morphological spectrum which these tumors may assume. This unselected material is necessary to define the relation between morphology and prognosis and to compare the treatment results of various clinical trials. Three hundred and four cases of nephroblastoma and related neoplasms on file at the Pediatric Tumor Registry, Kiel, were investigated by conventional light microscopy, electron microscopy, immunohistochemistry and DNA-flow cytometry. Of the "typical" nephroblastomas 50% occurred in the left kidney, 45% in the right kidney, and 5% were bilateral. Five cases were located in extrarenal sites. There were 121 males and 114 females. The peak incidence was noted in the third year of life. Of 135 patients 111 are alive and well, nine are living with disease, and 10 patients have died of disease. The blastemal predominant and stromal predominant types in our study were more frequent than in the NWTS. By contrast, the mixed and epithelial predominant types were more frequent in the NWTS. Patients with nephroblastomas of mixed or blastemal predominant type were older than those with epithelial predominant or stromal predominant type. Electron microscopy showed that nephroblastoma is derived from metanephric blastema. Blastemal cells are capable of differentiating into tubular epithelial cells and stromal cells. Undifferentiated blastemal cells contain exclusively vimentin intermediate filaments, better differentiated blastemal cells vimentin and cytokeratin, and stromal cells exclusively vimentin. Preoperative radio- and/or chemotherapy led to a marked reduction of undifferentiated blastema and poorly differentiated tubules, whereas better differentiated tubules, striated muscle, hyaline cartilage, cells with anaplastic and sarcomatous elements were not affected. Thus, identification of highly malignant nephroblastomas with anaplasia and sarcomatous renal tumors was even possible after preoperative treatment. Congenital mesoblastic nephroma (CMN; n = 17) is a low-grade malignant, cytodifferentiated nephroblastoma which very rarely occurs beyond the fourth month of life and has an excellent prognosis, provided it has been completely resected.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1985

Prognostic implications of blast cell morphology in childhood acute lymphoblastic leukemia: a report from the Childrens Cancer Study Group.

The Childrens Cancer Study Group (CCSG) has evaluated French-American-British (FAB) morphology in newly diagnosed children with acute lymphoblastic leukemia (ALL) since 1975. A modification of the FAB system was used in which individual lymphoblast cells were scored and designated as either L1 or L2 on the basis of distinctive morphologic characteristics. L1 ALL was defined as less than 10% L2 cells and greater than 90% L1 cells; L2 ALL was defined as greater than or equal to 10% L2 cells and less than 90% L1 cells. FAB morphology was an independent predictor of overall survival (P = 0.02) in CCSG-141 and a highly significant predictor of successful induction of complete remission and event-free survival in the CCSG-160 series (P = 0.00001). These studies involved nearly 3900 patients. Two concordance studies have been performed. In the first (1981) study, overall concordance between the FAB reference laboratory and member institutions was 76% using a two-category system (L1, non-L1), 86% for L1 cases, and 47% for non-L1 cases. In the second (1984) concordance study, the use of more stringent, semiquantitative definitions of L1 and L2 lymphoblasts did not improve overall (75%), L1 (89%), or non-L1 (46%) concordance. The results of reference laboratory classification more powerfully predicted event-free survival than did member institutions (P = 0.016 vs P = 0.125). Quality control factors (slide preparation, cellularity, staining quality, and discipline of the reviewer) did not influence concordance. These results justify the continued assignment of patients to protocols of the CCSG-100 series on the basis of the modified FAB classification. The biological significance of the FAB morphologic variants remains to be determined.

Child↗
PubMed1985

[Clinico-morphological characteristics and working classification of kidney diseases in patients with systemic scleroderma].

Based on a study of 110 patients with systemic scleroderma (SSD) (74 had involved and 36 uninvolved kidneys) the authors provide the clinico-functional and morphological characteristics of renal lesions and the working classification of sclerodermic nephropathy (SN). The two basic variants of SN were recognized: acute and chronic. The latter one was subdivided into clinical, moderate and pronounced SN. A correlation was revealed between the functional (glomerular filtration lowering) and ultrastructural (reticulation of endotheliocytes and thickening of the basal membrane of the glomerular capillaries) signs evidencing derangement of the microcirculatory bed. Morphological examination of the kidneys disclosed alterations that mirror the complex pathogenesis of SSD: derangement of the microcirculatory bed, immunopathological disorders, activation of connective tissue components.

Adolescent↗
PubMed1990

[Classification of the types of blood supply of the muscles from the standpoint of plastic surgery].

Based on an experience with 120 composite flaps including the muscle and with special account of literature data the author describes a new classification of types of blood supply of muscles. The author proposes 6 types of blood supply of muscles and substantiates a direct relationship between the anatomy of muscle vessels and variants of its use for plasty. A comparison of the new classification and other classifications was made.

Blood Vessels↗
PubMed1991

[Effects of immunologic markers on prognosis in acute lymphoblastic leukemia in young children].

Altogether 77 children aged up to 3 years with acute lymphoblastic leukemia (ALL) were examined for the immunological phenotype of blast cells. L1, L1/L2, L2/L1, L2 variants of ALL and the undifferentiated one were established in accordance with criteria of the FAB classification. T1, zero and Ia immunosubvariants were recorded most frequently. Mature cell T2 and pre-B variants (3 and 2 cases, respectively) were rare; B-cellular acute lymphoblastic leukemia was lacking; the "common" subvariant was revealed in 28 patients. The patients' age produced the highest effect on the prognosis: the significantly least disease standing and remissions were noted in a group of children under 2 years as compared to those aged 2 to 3 years. As for immunological markers, expression of Thy1-antigen exerted an unfavourable effect on the prognosis and duration of the first remission.

Antibodies, Monoclonal↗
PubMed1976

Classification and survival rate of patients with serous cystadenocarcinoma of the ovaries.

The comparative evaluation of two stage classifications including USSR Ministry of Health stage classification and TNM system was performed on the base of studies of the end results of 419 patients with serous cystadenocarcinoma of the ovaries. It has been established that TNM system is of a greater importance in establishing more accurate prognosis than the stage classification of the Ministry of Health. In TNM system four variants of the degree of extension correspond to each stage that allows to evaluate not only the extent of the primary tumor that also of the metastatic spread. The achieved results point to the superiority of the TNM system and serve as a base for transition to the TNM system in the classification of ovarian carcinoma.

Cystadenocarcinoma↗
PubMedDate not supplied

Hürthle cell (oxyphilic) papillary thyroid carcinoma: a variant with more aggressive biologic behavior.

The latest World Health Organization International Classification defines papillary thyroid carcinoma by its "follicular cell differentiation...as well as characteristic nuclear changes". However the oxyphilic (Hürthle cell) papillary carcinoma have nuclei which generally resemble the nuclei seen in oxyphilic follicular carcinomas, and such oxyphilic papillary tumors may behave more aggressively than typical papillary cancers. To further characterize these rare tumors, we identified during a 32-year period 22 patients with oxyphilic papillary cancer and compared them with 1,084 patients with typical papillary cancers and 57 patients with oxyphilic follicular cancers treated by the Mayo surgical group during the same time period. Although typical papillary and oxyphilic papillary cancers were comparable with regards to patient age, tumor size and extent, TNM stage, and prognostic score (AGES), there were significant differences. Compared to typical papillary tumors, oxyphilic papillary cancers had fewer neck nodal metastases at primary diagnosis (5% vs 40%, p less than 0.0001), were more often DNA non-diploid (71% vs 21%, p less than 0.001), and after 10 postoperative years had higher rates of both tumor recurrence (28% vs 11%, p less than 0.0001) and cause-specific mortality (1.7% vs 4%, p less than 0.0005). In these four important respects the oxyphilic papillary cancers more resembled the oxyphilic follicular cancers. For oxyphilic follicular cancers, the frequency of initial neck nodal metastases was 7% (cf 5%); 83% of the oxyphilic follicular tumors were non-diploid (cf 71%), and at 10 years postoperatively the tumor recurrence and cause-specific mortality rates were 28% and 18%, insignificantly different from 28% and 17% seen with the oxyphilic papillary cancers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2025

Uveal Melanoma and the Lynch Syndrome Tumor Spectrum.

IMPORTANCE: To date, no environmental factors and few therapeutic options are known for uveal melanoma (UM), the most common malignant intraocular primary tumor in adults. Identification of new predisposition factors could lead to better monitoring and possibly improved treatments of patients with UM. OBJECTIVE: To identify new genetic alterations predisposing for UM. DESIGN, SETTING, AND PARTICIPANTS: This was a prospective cohort study conducted at Institut Curie in Paris, France, among 381 consecutive patients diagnosed with UM between July 2021 and February 2023. UM was diagnosed clinically by ophthalmologists, and a senior pathologist confirmed the diagnosis when tumor or biopsy was available. All participants received genetic counseling and consented to extended genetic testing. A panel of 122 genes predisposing to cancer were analyzed by targeted sequencing on germline DNA from these patients. MAIN OUTCOMES AND MEASURES: Frequency of pathogenic variants (PVs) in genes from a targeted panel, with classification of germline PVs done according to the American College of Medical Genetics and Genomics guidelines and the French Unicancer Genetics Group. RESULTS: A total of 79 PVs were identified in 70 participants (41 female and 29 male; mean [SD] age, 60.6 [15.3] years). Among them, 21 were found in clinically relevant genes, with an enrichment in the mismatch repair (MMR) genes, involved in Lynch syndrome, a frequent predisposition to colon and endometrial cancers. This finding suggested MMR germline PVs could also predispose to UM. One tumor was available from a participant carrying a MLH1 germline PV. The tumor exhibited a monosomy 3 with loss of the wild-type allele of MLH1, located on chromosome 3. Loss of expression of MLH1 was observed by immunohistochemistry, and MMR variant signatures SBS6, ID1, and ID2 were identified from the whole-genome sequencing of this tumor, supporting the possibility that MLH1 contributes to the oncogenesis of this UM. CONCLUSIONS AND RELEVANCE: This prospective germline study on patients with UM provided evidence supporting the notion that MMR germline alterations are enriched among patients with UM and may contribute to oncogenesis of UM, and that UM may therefore be a rare tumor manifestation of Lynch syndrome.

Humans↗
PubMed1988

Multilobated non-Hodgkin's lymphoma. A clinicopathologic entity.

Multilobated non-Hodgkin's lymphomas (NHL) have recently been recognized as an NHL variant. During a period of 10 years we observed 30 individuals with NHL in which more than 30% of the malignant cells had a characteristic multilobation. The immunologic phenotype was determined in 14 of these cases. One was of T-cell lineage, and the others exhibited B-lymphoid markers. Sixty-eight percent of the patients presented with extranodal localizations. In the clinical follow-up a complete remission was observed in 78% of patients with a mean duration of 37 months (range, 5 to 120 months). The actuarial survival after 5 years was 45%. From these data we conclude that multilobated NHL are comparable to diffuse, large cleaved-cell NHL of an intermediate grade malignancy according to the Working Formulation or are comparable to the diffuse centrocytic-centroblastic NHL according to the Kiel classification. The neoplastic cells are to be considered as variants of follicle center cells, but the clinicopathologic correlation indicates that multilobated NHL represent a distinct nosologic entity.

Adolescent↗