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PubMed1999

TATA element recognition by the TATA box-binding protein has been conserved throughout evolution.

Cocrystal structures of wild-type TATA box-binding protein (TBP) recognizing 10 naturally occurring TATA elements have been determined at 2.3-1.8 A resolution, and compared with our 1.9 A resolution structure of TBP bound to the Adenovirus major late promoter (AdMLP) TATA box (5'-TATAAAAG-3'). Minor-groove recognition by the saddle-shaped protein induces the same conformational change in each of these oligonucleotides, despite variations in promoter sequence that reduce the efficiency of transcription initiation. Three molecular mechanisms explain assembly of diverse TBP-TATA element complexes. (1) T --> A and A --> T transversions leave the minor-groove face unchanged, permitting formation of TBP-DNA complexes on many A/T-rich core promoter sequences. (2) Cavities in the interface between TBP and the minor-groove face of the AdMLP TATA box accommodate the exocyclic NH(2) groups of G in a TACA box and in a TATAAG box. (3) Formation of a C:G Hoogsteen basepair in a TATAAAC box eliminates steric clashes that would be produced by the Watson-Crick base pair. We conclude that the structure of the TBP-TATA box complex found at the heart of the polymerase II (pol II) transcription machinery has remained constant over the course of evolution, despite variations in TBP and its DNA targets.

Amino Acid Sequence↗
PubMed2003

An angel with Down syndrome in a sixteenth century Flemish Nativity painting.

Artistic representation of malformation syndromes has been of ongoing interest, often as a point of departure for discussion of medical history. We have identified a 16th-century Flemish Nativity painting in which one angelic figure appears distinctly different from other individuals in the painting with an appearance of Down syndrome. Several prior observers have identified Down syndrome in premodern art, sometimes stimulating ongoing discussions concerning its history, its prevalence, and its relationship to hypothyroidism. This may be one of the earliest European representations of Down syndrome. The depiction of an individual with Down syndrome as an angel raises several questions regarding the status of such an individual in late medieval times and societal recognition of minor anomalies, as contrasted with major malformations, in their predictive value for disabilities. In contrast, Langdon Down's description of the condition occurred only after evolution of concepts regarding the clinical significance of physical appearance and measurement.

Down Syndrome↗
PubMed2002

Phylogenetic analysis of Brassiceae based on the nucleotide sequences of the S-locus related gene, SLR1.

Nucleotide sequences of orthologs of the S-locus related gene, SLR1, in 20 species of Brassicaceae were determined and compared with the previously reported SLR1 sequences of six species. Identities of deduced amino-acid sequences with Brassica oleracea SLR1 ranged from 66.0% to 97.6%, and those with B. oleracea SRK and SLR2 were less than 62% and 55%, respectively. In multiple alignment of deduced amino-acid sequences, the 180-190th amino-acid residues from the initial methionine were highly variable, this variable region corresponding to hypervariable region I of SLG and SRK. A phylogenetic tree based on the deduced amino-acid sequences showed a close relationship of SLR1 orthologs of species in the Brassicinae and Raphaninae. Brassica nigra SLR1 was found to belong to the same clade as Sinapis arvensis and Diplotaxis siifolia, while the sequences of the other Brassica species belonged to another clade together with B. oleracea and Brassica rapa. The phylogenetic tree was similar to previously reported trees constructed using the data of electrophoretic band patterns of chloroplast DNA, though minor differences were found. Based on synonymous substitution rates in SLR1, the diversification time of SLR1 orthologs between species in the Brassicinae was estimated. The evolution and function of SLR1 and the phylogenetic relationship of Brassiceae plants are discussed.

Journal Article↗
PubMed1986

Involvement of chromosomes 12 and 14 in the cutaneous stage of mycosis fungoides: cytogenetic evidence for a multistep pathogenesis of the disease.

Cytogenetic studies were performed on the cells of bone marrow, peripheral blood, and skin tumor biopsies from a patient with mycosis fungoides at an early stage. Chromosome abnormalities were detected in 100% of the cells harvested from the cutaneous specimen, whereas the cells of the bone marrow and blood were karyotypically normal. Three related clones, showing increasing cytogenetic complexity, were found. Chromosome #12 was abnormal in all metaphases, and an abnormal 14q chromosome was present in a minority of cells belonging to the most complex emerging subclone. These data, along with the findings of important signs of chromosome imbalance, suggest a polyphasic evolution of this chronic T lymphoproliferative disease.

Chromosomes, Human, 13-15↗
PubMed2003

[Prospective clinical and sonographic assessment of uterine artery embolization as the treatment of symptomatic uterine leiomyomata].

OBJECTIVE: To evaluate the effectiveness of the uterine artery embolization as the treatment of symptomatic uterine leiomyomata. PATIENTS AND METHODS: Eighty-five women with symptoms caused by uterine leiomyomata underwent uterine artery embolization as an alternative to surgery from january 1997 to june 2000. The effectiveness of this method was evaluated by clinical and sonographic examination. RESULTS: The recession average was of 18.9 months. There were ten failures. We had immediate failures (n = 5) with a case of technical failure, one endometrium cancer, one adenomyosis, one larger subserosal leiomyomata and one parametrial leiomyomata. We had recurrences (n = 5) with the occurrence of new leiomyomatas (1 intramural and 3 submucosal) and an evolution of previous leiomyomata. The average volume reduction was 51% for the uterus and 65% for the main fibroid at one year follow-up. Minor complications occurred in 5%. Permanent amenorrhoea was observed for 3.75% of the women. Using cox model, no predictive factors of embolisation effectiveness were found. DISCUSSION AND CONCLUSION: In the treatment of symptomatic uterine leiomyoma, uterine artery embolization is an effective alternative to surgery. After one year and half, we had 12.5% of failures.

Adult↗
PubMed2007

HIV-1 drug resistance in variants from the female genital tract and plasma.

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) drug-resistance mutations may arise in a fraction of viral variants, and these variants may differ between compartments, including the genital tract and blood. METHODS: We studied 14 women with detectable HIV-1 in both the genital tract and plasma despite antiretroviral treatment. We obtained HIV-1 RNA sequences from 280 unique viral variants and then determined the resistance genotype and the predicted phenotype (Virtual Phenotype; Virco BVBA) of each variant. RESULTS: Eight patients (57%) displayed mutations conferring high-level HIV-1 drug resistance. Although we observed differences in specific mutations among viral variants, 13 of the 14 women showed highly concordant HIV-1 genotypic and predicted phenotypic resistance patterns in the 2 compartments. In 1 patient, resistance mutations appeared only in plasma; all variants in her genital tract, which displayed a low viral load, were susceptible. CONCLUSIONS: These data suggest that, for the majority of women, determination of HIV-1 drug resistance in the plasma will approximate the drug-resistance pattern in the genital tract. Analysis of individual variants enabled us to identify minority species bearing distinctive linked mutations, which may serve as a source of novel resistance genotypes. These data are relevant to clinical management and the evolution of drug resistance.

Adult↗
PubMed2000

Structural and interactional homology of clinically potential trypsin inhibitors: molecular modelling of cucurbitaceae family peptides using the X-ray structure of MCTI-II.

Several trypsin inhibitor peptides (with 28-32 amino acid residues) belonging to the Cucurbitaceae (LA-1, LA-2, MCTI-I, CMTI-I, CMTI-III, CMTI-IV), characterized by a distinctive tertiary fold with three conserved disulphide bonds and with mostly arginine at their active centre, were modelled using the high-resolution X-ray structure of a homologous inhibitor, MCTI-II, isolated from bitter gourd. All the inhibitors were modelled in both their native and complexed state with the trypsin molecule, keeping the active site the same as was observed in the trypsin-MCTI-II complex, by homology modelling using the InsightII program. The minimized energy profile supported the binding constants (binding behaviour) of the inhibitor-trypsin complexes in the solution state. A difference accessible surface area (DASA) study of the trypsin with and without inhibitors revealed the subsites of trypsin where the inhibitors bind. It revealed that the role of mutation of these peptides through evolution is to modulate their inhibitory function depending on the biological need rather than changing the overall structural folding characteristics which are highly conserved. The minor changes of amino acids in the non-conserved regions do not influence significantly the basic conformational and interactional sequences at the trypsin binding subsites during complex formation.

Amino Acid Sequence↗
PubMed1990

Labour migration and the single European market: a synthetic and prospective note.

"The present paper is an attempt to analyse and forecast the following major issues relating to migration in Europe after 1992: (i) the evolution and structure of intra-European flows in the forthcoming single European market; (ii) the integration, after 1992, of established immigrant communities, including ethnic minorities and second generation groups; (iii) future immigration from non-EC member states.... The article explains that, in addition to policy-related mutations inherent in the completion of the internal market, other factors (demographic changes and insufficient enrolment of national graduate students in key disciplines) and issues (emergence of atypical groups such as second generation and Eastern European migrants), are due to generate new patterns and modified interests in European labour migration after 1992."

Acculturation↗
PubMed1999

[Alcohol withdrawal syndrome in the hospital].

Contrary to widely held belief, physical dependency is not systematic in alcohol dependence. Alcohol withdrawal syndrome can appear even without stopping (or sharply decreasing) high or chronic alcohol intake. It occurs through revelation of a physicochemical cerebral response (membrane changes and decrease in modulation systems) to chronic intoxication. Given the differences in severity, the lability of symptoms and the rapid evolution of the syndrome, the repeated use of scales to evaluate intensity is suggested. Management should be based on this index in order to treat minor forms and to avoid a course to severe forms, which should be transferred to the intensive care unit.

Alcohol Withdrawal Delirium↗
PubMed1992

The impact of molecular biology on understanding renal signal transduction.

The information that cells require to grow and prosper comes from diverse sources, adjacent to them and from considerable distances. Through evolution, cells have developed multiple mechanisms to acquire and process information. When a signaling mechanism has been successful, it has been used repeatedly with relatively minor modifications, and consequently is seen throughout biology. Specificity comes from using precise combinations of signaling molecules to achieve different ends in different cell types. Among the signaling systems that fit this description include the receptor and nonreceptor tyrosine kinases, G protein-coupled receptors, cell attachment receptors, guanylate cyclases, ligand-gated ion channels, the second messenger dependent and independent protein kinases and phosphatases, and transcription factors. The consequence of this conservation of molecular mechanisms is that many basic regulatory systems, which cannot be dissected free of the complexity of mammals, can be understood in relatively simple, manipulable experimental systems. With information from simple systems and the tools of genetics and molecular biology, complex problems such as human physiology and disease may be understood and eventually controlled.

Animals↗
PubMed1984

[Spontaneous dissecting aneurysms of the internal carotid artery. Prospective evaluation of the prognosis and arterial repermeation in 14 cases].

Fourteen patients with a spontaneous dissecting aneurysm of an internal carotid artery (ICA) have been admitted in our service since 1979 (incidence of 0,5 per 100,000 inhabitants per year). All these patients have been prospectively followed in order to determine their functional prognosis and a possible recanalization of the ICA. Three patients quickly died from an extensive middle cerebral artery infarct with brainstem compression. Among the 11 survivors, 7 completely recovered their functional ability or were left with very minor sequelae, and could go back to work. The 4 other patients remained with severe sequelae and could not work anymore. In the latter patients Doppler ultrasonographic study showed a persisting occlusion of the ICA, whereas a complete recanalization occurred in the former 7, usually as soon as the first month, on anticoagulant treatment. The presence on admission of a minor or moderate neurological deficit, a normal state of consciousness, an age above 45 years, and a patent collateral circulation allows to predict a favorable evolution (p less than 0.05). The same is true for the development of a partial or complete recanalization of the ICA on Doppler ultrasonography performed 2 to 4 weeks after admission. Sex, angiographic aspects of the dissection, and occurrence of headache or warning transient ischemic attacks had no prognostic significance in our study. Spontaneous dissecting aneurysms of the ICA can be a very serious disease, though nearly 50 p. 100 of the patients completely recover during the first months. Immediate anticoagulant therapy is still the treatment of choice and surgery is indicated only in those patients with recurrent episodes or a progressing stroke despite adequate anticoagulation.

Adult↗
PubMed1998

Transient and heritable mutators in adaptive evolution in the lab and in nature.

Major advances in understanding the molecular mechanism of recombination-dependent stationary-phase mutation in Escherichia coli occurred this past year. These advances are reviewed here, and we also present new evidence that the mutagenic state responsible is transient. We find that most stationary-phase mutants do not possess a heritable stationary-phase mutator phenotype, although a small proportion of heritable mutators was found previously. We outline similarities between this well-studied system and several recent examples of adaptive evolution associated with heritable mutator phenotype in a similarly small proportion of survivors of selection in nature and in the lab. We suggest the following: (1) Transient mutator states may also be a predominant source of adaptive mutations in these latter systems, the heritable mutators being a minority (Rosenberg 1997); (2) heritable mutators may sometimes be a product of, rather than the cause of, hypermutation that gives rise to adaptive mutations.

Adaptation, Biological↗
PubMed2000

Morphological and cytogenetic changes in therapy-related leukemia developed in a t(8;21)-acute myeloid leukemia (M2) patient: sequential cytogenetic and molecular analyses.

A patient with acute myeloid leukemia (AML)-M2 with t(8;21)(q22;q22) achieved complete remission with remission-induction chemotherapy followed by consolidation and intensification chemotherapies. T(8;21)(q22;q22) disappeared, but chimeric AML1/MTG8 was continuously detected in bone marrow cells. Following the development of therapy-related leukemia after 1 year, evolution of therapy-related AML-M4 with t(11;17)(q23;q25) and the rearrangement of the MLL gene were observed, while AML/MTG8 disappeared. After reinduction and following intermittent chemotherapies, a subsequent alternative transformation to AML-M2 occurred after detection of t(3;21)(q21;q22), with a break in the AML1 gene shown by interphase fluorescence in situ hybridization analysis. This leukemia transformed to AML-M4 after t(9;22)(q34;q11), with a minor BCR/ABL rearrangement, and then finally to AML-M2. This therapy-related leukemia was resistant to chemotherapy. These findings indicate that alterations in cytogenetic and molecular events caused by chemotherapeutic agents contribute to the sequential evolution of new leukemic clones with different morphology.

Adult↗
PubMed2000

The importance of the quasispecies nature of hepatitis C virus (HCV) for the evolution of HCV populations in patients: study on a single source outbreak of HCV infection.

The quasispecies populations of hepatitis C virus (HCV) in the infectious source (IS) and in patients of a single source outbreak were characterized. A predominant variant AD78-1 and some minor variants of HCV 5' NCR were identified in IS. Different complex HCV populations emerged rapidly in patients though HCV populations in chronic infection were rather simple and stable. AD78-1 remained predominant in 17/24 chronically infected patients while new predominant variants with distinct nucleotide substitutions persisted in 7 other patients. Thus, only distinct variants are involved in viral persistence and the genetic heterogeneity of HCV does not successively increase with time.

Acute Disease↗
PubMed2002

The mechanisms of morph determination in the amphipod Jassa: implications for the evolution of alternative male phenotypes.

The proximal basis for and the maintenance of alternative male reproductive strategies and tactics are generally not understood in most species, despite the occurrence of male polymorphism across many taxa. In the marine amphipod Jassa marmorata, males differ in morphology as well as behaviour. This dimorphism corresponds to two contrasting reproductive strategies: small sneaker males or 'minors', and large fighter males or 'majors'. This study uses quantitative genetic analyses in conjunction with experimental manipulations to assess the relative importance of genetic versus environmental factors in the determination and maintenance of these alternative mating strategies. Heritability analyses indicated the reproductive phenotypes do not reflect genetic differences between dimorphic males. By contrast, morph determination was significantly affected by diet quality. Majors essentially only developed on high-protein diets. Field studies also identified a strong correlation between seasonal shifts in the relative proportions of morphs and changes in food (i.e. phytoplankton) quantity and composition, corroborating that diet cues the switch between alternative reproductive tactics. Moreover, the comparison of major and minor growth trajectories identified a heterochronic shift in maturation times between morphs, indicating that ecological selective pressures, rather than just sexual selection, may be involved in the maintenance of this conditional strategy.

Amphipoda↗
PubMedDate not supplied

Histological alterations found in the ureter during organ preservation and early phases of renal transplantation.

INTRODUCTION: There are no studies on the phenomena that occur on the ureter during organ preservation and immediately after transplantation. MATERIAL AND METHODS: We studied ureteral fragments obtained during organ harvesting in the cadaver (n = 9), after cold preservation period (n = 18), and immediately after kidney graft reperfusion (n = 126). In addition to the histological analysis, we evaluated the risk factors for the development of lesions and their relation to the evolution of the transplant. RESULTS: Alterations were detected in 120 of the 126 fragments studied after graft reperfusion. Global cellular infiltration was considered to be normal, mild, and moderate to severe in 34.9%, 41.3%, and 23.8%, respectively, consisting mainly of CD8(+) T lymphocytes. Urothelial exfoliation and cell vacuolization were detected in 42% and 52.4% of the cases, respectively. There was an inverse relationship between donor ventilation time and the intensity of the cellular infiltration. Seven and three of the nine fragments obtained during organ harvesting showed mild cellular infiltration of the chorion and urothelium, respectively. Cold storage promoted minor histological changes. After reperfusion, there was increased urothelial infiltration in 11 of the 18 cases. There was no relation between the lesions encountered and human leukocyte antigen compatibilities, renal rejections episodes, or the evolution of the graft itself. CONCLUSIONS: Consequences of brain death mechanical ventilation were detected at the ureteral level, with abnormal lymphocytic infiltration in most cases. Cold storage did not produce any major histological changes. The lesions detected after graft reperfusion do not seem to involve immunological phenomena.

Adult↗
PubMed2000

Evolution of the Sabin strain of type 3 poliovirus in an immunodeficient patient during the entire 637-day period of virus excretion.

A 20-year-old female hypogammaglobulinemic patient received monotypic Sabin 3 vaccine in 1962. The patient excreted type 3 poliovirus for a period of 637 days without developing any symptoms of poliomyelitis, after which excretion appeared to have ceased spontaneously. The evolution of Sabin 3 throughout the entire period of virus excretion was studied by characterization of seven sequential isolates from the patient. The isolates were analyzed in terms of their antigenic properties, virulence, sensitivity for growth at high temperatures, and differences in nucleotide sequence from the Sabin type 3 vaccine. The isolates followed a main lineage of evolution with a rate of nucleotide substitution that was very similar to that estimated for wild-type poliovirus during person-to-person transmission. There was a delay in the appearance of antigenic variants compared to sequential type 3 isolates from healthy vaccines, which could be one of the possible explanations for the long-term excretion of virus from the patient. The distribution of mutations in the isolates identified regions of the virus possibly involved in adaptation for growth in the human gut and virus persistence. None of the isolates showed a full reversion of the attenuated and temperature-sensitive phenotypes of Sabin 3. Information of this sort will help in the assessment of the risk of spread of virulent polioviruses from long-term excretors and in the design of therapies to stop long-term excretion. This will make an important contribution to the decision-making process on when to stop vaccination once wild poliovirus has been eradicated.

3C Viral Proteases↗
PubMed2026

Case Report: Immune-driven clonal selection underlying lineage switch from B-Precursor acute lymphoblastic leukemia to acute myeloid leukemia following inotuzumab ozogamicin.

Lineage switch (LS), defined as a change in leukemic lineage during the disease course, is a rare but clinically significant event in acute leukemia and is typically associated with poor prognosis. Although LS has been increasingly reported following targeted immunotherapies, the clonal mechanisms underlying this phenomenon remain incompletely understood, particularly in cases without KMT2A rearrangement. We report a case of LS from B-precursor acute lymphoblastic leukemia (BCP-ALL) to acute myeloid leukemia (AML) following treatment with the CD22-targeted antibody-drug conjugate inotuzumab ozogamicin. To elucidate the clonal architecture underlying LS, targeted next-generation sequencing was performed on bone marrow samples obtained at multiple time points throughout the disease course. Genomic analysis demonstrated that the lymphoid and myeloid disease phases shared ancestral genetic alterations but displayed distinct mutational profiles. At the time of LS, TP53 and SMC1A mutations newly emerged, whereas only a subset of mutations detected at ALL relapse was retained. These findings suggest that the AML phase most likely resulted from the selective expansion of a genetically distinct subclone derived from a common progenitor, rather than the direct transdifferentiation of the dominant ALL clone, consistent with immunotherapy-driven clonal selection. Longitudinal genomic profiling revealed stepwise clonal evolution during disease progression, supporting a model of immunotherapy-driven clonal selection leading to LS. This case provides molecular evidence suggesting that immune-targeted therapy can promote expansion of minor pre-existing subclones with alternative lineage potential within a common progenitor even in non-KMT2A-rearranged leukemia. Our findings highlight the importance of comprehensive genomic monitoring during immunotherapy to identify therapy-resistant subclones and better understand mechanisms of lineage plasticity in acute leukemia.

Humans↗