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At least 1,621 records · Page 90Linked to original sources
PubMed2004

Molecular phylogenetics suggest a North American link between the anthropogenic dry rot fungus Serpula lacrymans and its wild relative S. himantioides.

The dry rot fungus Serpula lacrymans causes damages in wooden buildings and constructions in temperate regions worldwide. In this study, the global phylogeography of S. lacrymans and its wild relative S. himantioides has been investigated to clarify genealogical relationships and determine the origin and spread of the building strains. Internal transcribed spacer (ITS) nrDNA and parts of the beta-tubulin (tub) and the translation elongation factor (efa) 1a genes were sequenced, and phylogenetic relationships inferred. Some analyses suggest that S. lacrymans may have originated from an ancient S. himantioides lineage, but most results support that S. lacrymans and S. himantioides are monophyletic sister species. Phylogenetic analysis of the ITS data revealed two subgroups within S. lacrymans corresponding to two earlier described varieties; one group occurring frequently in houses worldwide ('Domesticus'), and one group represented by individuals from forests in Northern California ('Shastensis'). A few collections from nature were included in the Domesticus group as well, among other specimens from two newly discovered localities in Far East Russia and Siberia. In the Domesticus group little sequence variation occurs, suggesting a recent worldwide dispersal, possibly linked to human activity. Phylogenetic analyses indicate that the Domesticus group may have originated from an ancient lineage related closely to the Shastensis group. A remarkable shift in morphology and habitat preferences has occurred during the evolution of the Domesticus lineage, linked to the transition from nature to human-made habitats.

Base Sequence↗
PubMedDate not supplied

Comparison of ribosomal and isozymic phylogenies of tetrahymenine ciliates.

A recent analysis of sequence variations in ribosomal RNA's from 31 species of tetrahymenine ciliates groups them into 9 sets referred to as "ribosets." These species associations are not well correlated with the distributions of distinctive morphological characteristics. The phylogenetic structure suggests that modern "pyriform" tetrahymenines may be paraphyletic survivors of primitive design and that the morphologically distinctive forms may include examples of convergent evolution of derived forms. Alternatively, the common ancestor may have been a polymorphic species that has lost its plasticity in some derived lineages. In an attempt to test the ribosomal phylogeny, we here compare it with a phylogeny based on isozymic variation. The main features of the ribosomal and isozymic phylogenies are similar. The carnivorous (macrostome-forming) species are widely scattered in both, as are the bacteriophagous pyriform species. Isozymic and ribosomal analyses are optimally useful, however, in different contexts. Isozymic variations can distinguish species that are ribosomally identical. Ribosomal variations provide more secure evaluations of distant relationships.

Animals↗
PubMed2005

Segmental ulcerative vasculitis: a cutaneous manifestation of Takayasu's arteritis.

A 16-year-old girl with pyoderma gangrenosum (PG)-like skin lesions on the extremities, trunk and face developed Takayasu's arteritis (TA; pulseless disease). After 3 years under maintenance cyclosporin A therapy, the patient developed an ischaemic cerebral accident. Severe obstruction of both subclavian and left carotid arteries was found by Doppler sonography, angiography and computerised axial tomography. Evolution of this disease showed some characteristic findings: (a) PG-like lesions as the first cutaneous manifestation of pulseless disease; (b) methotrexate and cyclosporin A giving good results for the cutaneous lesions, but apparently not exerting an influence on the evolution of TA and the fatal outcome. This morphologic pattern may reflect underlying TA or Wegener's arteritis, and should be termed segmental ulcerative vasculitis.

Adolescent↗
PubMed2006

A global view of genetic diversity in cultivated sorghums using a core collection.

We report here an analysis of the structure of genetic diversity in cultivated sorghums. A core collection of 210 landraces representative of race, latitude of origin, response to day length, and production system was analysed with 74 RFLP probes dispersed throughout the genome. Multivariate analyses showed the specificity of the subrace guinea margaritiferum, as well as the geographical and racial pattern of genetic diversity. Neighbour-joining analysis revealed a clear differentiation between northern and southern equatorial African accessions. The presence of Asian accessions in these 2 major geographical poles for sorghum evolution indicated two introductions of sorghum into Asia. Morphological race also influenced the pattern of sorghum genetic diversity. A single predominant race was identified in 8 of 10 clusters of accessions, i.e., 1 kafir, 1 durra, 4 guinea, and 2 caudatum clusters. Guinea sorghums, with the exception of accessions in the margaritiferum subrace, clustered in 3 geographical groups, i.e., western African, southern African, and Asian guinea clusters; the latter two appeared more closely related. Caudatum were mainly distributed in 2 clusters, the African Great Lakes caudatum cluster and those African caudatum originating from other African regions. This last differentiation appears related to contrasting photoperiod responses. These results aid in the optimization of sampling accessions for introgression in breeding programs.

Alleles↗
PubMed1995

Ancient DNA.

The investigation of molecular traits for evolutionary studies is a valuable alternative to the classic morphological approach. Since the mid-1980s molecular evolution has extended its field of investigation into the past. This has become possible with development of the polymerase chain reaction, which allows amplification of, and hence the study of, DNA from individuals long since dead. Many ancient, mostly extinct, animals and plants have been studied in order to determine their phylogenetic relationships with extant species. The biochemical properties of ancient DNA are also under investigation. The modifications that this molecule undergoes over long periods of time are of great interest as attempts are made to retrieve DNA from increasingly older remains.

Animals↗
PubMed2026

Generational variation and stabilization in resynthesized allotetraploid Brassica juncea derived from diploid progenitors B. rapa and B. nigra.

BACKGROUND: Polyploidy is a major driver of plant evolution and crop improvement, generating novel variation in morphology, physiology, and agronomic traits. Brassica juncea (AABB, 2n = 36), a natural allotetraploid derived from B. rapa (AA) and B. nigra (BB), is an important oilseed and vegetable crop; however, its narrow genetic base limits further breeding gains. Resynthesized B. juncea (RBJ), developed from known progenitors, provides a tractable system to investigate polyploid stabilization, trait diversification, and generational variation. This study evaluated RBJ across nine generations (F1-S8) to elucidate generational variation in morphological, molecular, cytological, and oil content traits during progressive stabilization. RESULTS: Substantial variation was observed for key yield-related traits, including siliqua length, seeds per siliqua, and thousand-seed weight. High estimates of heritability, genotypic variance, and genetic advance indicated their potential utility in selection based improvement. Comparative analyses revealed a clear generational progression, characterized by relatively enhanced performance in early generations, increased recombination-driven variability in intermediate generations, and the partial stabilization of several traits in later generations. Generation mean analysis suggested the involvement of additive, dominance, and epistatic gene effects in trait inheritance. Molecular analysis using SSR markers confirmed the amphidiploid origin and genomic integrity of RBJ generations. Cytological assessments, pollen viability assays, and flow cytometric analysis collectively demonstrated stable chromosome numbers, improved fertility, and maintenance of ploidy stability across successive generations. CONCLUSIONS: The study provides valuable insights into the generational variation and stabilization of morphological, molecular, and oil content traits in resynthesized B. juncea. The findings suggest that variability arising from polyploidization and interspecific hybridization undergoes gradual reorganization across successive generations, leading to increased trait stabilization and more consistent expression of selected agronomic characteristics. Collectively, these results contribute to the understanding of early stabilization processes in RBJ, highlighting resynthesized polyploids as useful systems for studying variation and stabilization in allopolyploid crops.

Mustard Plant↗
PubMed1993

Acquisition of CD13 and CD33 expression at relapse on acute myeloid leukemia cells with an unusual phenotype: MPO+CD13-CD33-.

A case of acute myeloid leukemia (AML) with an unusual phenotype which was negative for a panel of myeloid antigens determined by flow cytometry, but was strongly positive for myeloperoxidase has recently been reported. We herein describe a case of AML with this unusual phenotype at diagnosis; relapse occurred with the acquisition of CD13 and CD33 expressions. Morphological features of the blasts at relapse seemed to be more compatible with myeloblasts than those at diagnosis. These phenotypic and morphological changes are suggestive of asynchronous differentiation, clonal evolution or clonal change of leukemic cells.

Antigens, CD↗
PubMed1987

Chondroid chordoma.

We reject the notion that the concept of "chondroid chordoma" be abandoned in favor of an interpretation of the cartilaginous origin of these lesions. We have demonstrated by electron microscopic and immunohistochemical means that these neoplasms can exhibit distinctly epithelial characteristics in their chondroid as well as their epithelial areas. The presence of desmosomes, cytokeratin, carcinoembryonic, and epithelial membrane antigen in the cells of the chondroid as well as the epithelial areas; the presence of the microtubular inclusions, vimentin, and S-100 protein in the cells of the epithelial as well as chondroid areas; and the intermingling of the two and gradual transitions from one to the other all point to the conclusion that the chondroid and epithelial areas are only differing morphologic expressions of the same entity. The gradual evolution witnessed in the sequential biopsies of this case study, through which a predominantly chondromatous neoplasm became a chordoma of typical histologic appearance, provides further strong evidence to support the contention that chondroid chordoma is a variant of chordoma and not a primary chondrocytic neoplasm.

Adolescent↗
PubMed1999

[A strategy for the prevention of male infertility].

Since 1990 there has been a simultaneous reduction of natality in Flanders (by approximately 12%) with increased demand for assisted reproduction, while sperm quality, mostly motility and morphology, have clearly deteriorated over recent decades. This evolution has been ascribed to the deleterious effects of hormone disrupting substances in the environment, synergistically enhancing unfavorable influences from life style and possible genito urinary diseases that can impair the function of the testes and accessory sex glands. It is probable that this synergistic effect is exerted through the intermediate of free oxygen radicals (also called reactive oxygen species) that damage both the sperm membrane and sperm DNA, which could allow certain minimal inborn genetic defects (such as point lesions) to come to expression. Both pseudo- or xeno-estrogens (such as certain organo chlorides, alkyl phenols, phthalates, etc.) and anti-androgens are held responsible for prenatal testicular damage and increased prevalence of testicular carcinoma and oligozoospermia, for anatomical malformations, as well as postnatal depression of testicular function and spermatogenesis. However, methods presently available to detect hormone disrupters are tedious and not fully adequate. A first strategic goal is to develop a simple method for the detection of these substances so that environmental pollution can be mapped. Fazing out the production and application of hormone disrupters, and removing them from the environment are the second strategic step. Also, a health food is being developed that will inhibit the absorption of these chemicals from the intestinal tract. In addition it is projected to detect and treat common genital diseases that can cause infertility, such as varicocele and infection of the urinary tract and accessory sex glands. The first could be organized to take place during medical examinations at school, whereas the second requires correct medical treatment of any cysto urethritis in adolescents. Non surgical treatment of varicocele by means of transcatheter embolization offers a cost effective approach, with minimal risk and complications, and high level of efficacy. Improving food quality and educational efforts aimed at a healthier life style should score high priority. The suggested strategy uses several entries in order to address the multifactorial mechanisms involved in the pathogenesis of male infertility. Preliminary epidemiological and biological data suggest that the proposed strategy can, indeed, be successful within a relatively short lapse of time.

Belgium↗
PubMed1992

[Reconstruction of the external ear].

The authors after a short morphological description of the microtia, expose the surgical evolution which had led to the actual auricular reconstruction technique, using a costal cartilage framework. This technique requiring several steps is exposed in the typical case of microtia. It is the preferential method. The difficult reconstructions due to the poor quality of the skin are exposed by degree of complexity: in these cases, tissue expansion, fascia temporalis superficialis can be useful and finally auricular prostheses, attached to bone-integrated implants, can be recommended. The functional surgery of the middle ear is also replaced in the context of the auricular reconstruction which is done around 8 years old.

Burns↗
PubMedDate not supplied

[Malignant liver hemangiopericytoma ruptured after an abdominal traumatism].

This paper reports a case of malignant liver hemangiopericytoma broken after an abdominal traumatism which revealed that the patient has this disease. This case is interesting because the abdominal traumatism gave us the opportunity of making a precocious diagnosis. The clinical and paraclinical signs of acute abdomen fastened surgery. The paper reviews the medical literature linked to these rare tumors. The paper also describes morphological features typical for these vascular tumors, whose evolution is unpredictable.

Abdominal Injuries↗
PubMed1991

[Ulcer perforation--a risk factor in the evolution and treatment of duodenal ulcer].

In 49.84% of the cases of duodenal ulcer operated in the clinic, the authors were confronted with one of the dangerous complications of this disease--the ulcerous penetration. This experience permitted to differentiate the surgical act according to the evolutive degree of this complication and to its morphological character. The literature related to this problem is reviewed.

Duodenal Ulcer↗
PubMedDate not supplied

[Therapeutic effectiveness and safety of prazosin in the symptomatic treatment of benign prostatic hypertrophy].

74 patients diagnosed as suffering from benign prostatic hypertrophy (BPH) were treated with prazosin for 8 weeks. We look at the evolution of the symptomatology and the urodynamic and morphologic parameters during the treatment and they are compared with the basal ones. The irritative symptoms (nocturia, pollakiuria, imperiosity and dysuria), evaluated by means of a quantitative scale, undergo significant statistical improvement. The same occurred with the obstructive symptoms. Urodynamically, an increase took place in total vesical capacity, maximum, and mean flow, as well as a drop or reduction in non-inhibited contractions. 27 patients suffered adverse effects, which obliged 8 of them to abandon the treatment. Global efficacy was excellent in 20% and good in 52%, whilst it was fair and ineffective in 19 and 9%, respectively.

Aged↗
PubMed1988

The ultrastructure of A, B and D pancreatic cells in normal and in diabetic ducks.

Ultrastructurally and immunocytochemically identified A, B and D cells are highly concentrated in the splenic bulb of the duck pancreas. Ultrastructural features of normal A, B and D cells are similar in the duck and in other species so far studied. However, normal D cells present a striking characteristic, i.e. apical accumulation of dense bodies, which seem to derive from multivesicular bodies and are probably involved in a catabolic regulatory process. Subtotal pancreatectomy in the duck, leaving the splenic bulb and inducing transient diabetes, produces strong secretory stimulation of A and B cells, as indicated by the development of the rough endoplasmic reticulum and the Golgi apparatus and transient degranulation, more marked in B cells. Numerous B cells with degenerative aspects, observed after 12 days, seem to be exhausted following prolonged hyperstimulation: this could explain why diabetes reappears in some cases. In contrast, in D cells, functional inhibition after surgery is suggested by a dramatic increase in the number and size of the dense bodies, associated with a marked decrease in secretory vesicle storage. The morphological data correlate well with the previously reported evolution of plasma and pancreatic hormone concentration after surgery, and suggest that the normal inhibitory control of glucagon and insulin secretion by the local release of somatostatin might be reduced or suppressed during transient diabetes in subtotally depancreatized ducks.

Animals↗
PubMed1983

[Administration of diethylstilbestrol during pregnancy, a public health problem].

The analysis of the health risks associated with the administration of diethylstilbestrol (DES) during pregnancy (for the prevention or treatment of threatened abortions) has been largely published. Concerning mothers, a relationship between DES exposure during pregnancy and risk of cancer is unproved. However, existing studies are sufficient cause for serious concern over drug's carcinogenic potential, and further follow-up studies are required. Concerning daughters, a clear association between in utero exposure to DES and clear cell adenocarcinoma of the vagina or cervix is established (incidence between 0.14 and 1.4 per 1000 through age 24). The risk for squamous cell cancer of the vagina and cervix does not seem to be increased. Cervico-vaginal adenosis is frequent (20% to 60% of exposed subjects). This is not a pre-cancerous lesion, its spontaneous evolution is towards regression. No treatment is prescribed. Morphological changes of the genital tract have been described, their consequences on fertility and pregnancy are not clear. Concerning sons, an excess of genital abnormalities (especially of the epididymis and undescended testis) has been reported, but information on the fertility implications of these findings is not available. There is no evidence of an increased risk of testicular cancer. The analysis of all these informations should allow to bring up a policy to take into account these risks in the population.

Adult↗
PubMed1978

[Experimental transection of the spinal cord (author's transl)].

Twenty-three dogs underwent a complete transection of the spinal cord at L 1 level. Section was followed in eighteen animals by reconstruction effected through suture of the arachnoide with the aid of monofilament 10 X 0 thread. The operation was in all cases concluded by an osteosynthesis with metallic material in order to prevent any movements in the operated site, and a tight dural closure was achieved in order to prevent propagation of any epidural hematoma or secondary granuloma. This technique did not prevent an unfavorable evolution of the suture, which demonstrated three different morphological features:--necrosis of the spinal cord cut ends with secondary formation of a transverse cyst;--secondary infiltration of the operated focus by a fibrous scar growing from the inner aspect of the dura;--failure of axon regeneration through this fibrous block in spite of noteworthy proliferation of axons coming from the dorsal roots. A critical analysis of those results led to a comparaison with various previous works on the same subject. The most recent of these works have led to promising prospects which need confirmation.

Animals↗
PubMed1982

Chromosomal phylogeny of forty-two species or subspecies of cercopithecoids (Primates Catarrhini).

After comparison of the chromosomes of 42 species or subspecies belonging to Cercopithecinae, Papioninae and Colobidae, a phylogeny based on the sequence of chromosomal rearrangements is proposed for Cercopithecoidea. From their last common ancestor, which possessed 46 chromosomes, a trifurcation gave 3 branches, very unequal as regards chromosomal rearrangements. One, very short, leads to Papioninae. Another, still poorly known, leads to Colobidae. The last branch leads to a further bifurcation, separating 2 groups of Cercopithecinae, with underwent the most active chromosomal evolution. A tentative to reconcile chromosomal, biochemical and morphological data is presented for Papioninae, for which chromosome study alone is not sufficient to construct a cladogram.

Animals↗
PubMed1982

[Effects of nitrous oxide on the female gonad in the rat].

Female rats have been exposed (24 hours for 15 days) to N2O 60% in normo-oxic blend of N2 and O2. Vaginal smears have been observed daily. At the end of the experiment the ovaries have been removed and the following morphological parameters have been statistically evaluated: number of evolutive follicles and corpora lutea, amount of interstitial tissue. Our results seem to account for a remarkable toxic effect of N2O on the rat gonad. Such effect is testified by alterations of the oestrous cycle and, at the ovary, a decrease in the number of evolutive follicles and functioning corpora lutea and by a sharp increase of atretic phenomena.

Animals↗