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PubMed2004

Evolution of ciliary patterns in the Oligotrichida (Ciliophora, Spirotricha) and its taxonomic implications.

Although the somatic ciliature of the Oligotrichida typically comprises only a girdle and ventral kinety, a considerable diversity of ciliary patterns occurs. The four main girdle kinety patterns are identically found in tailed and tail-less species. The contractile tail has a complicated and unique ultrastructure and is potentially useful for the cell's movement and/or stabilization during feeding. Accordingly, I assume that this structure has evolved only once, namely, in the Tontoniidae nov. fam., and that the different girdle kinety patterns developed convergently in the tailed and tail-less taxa. Further distinct features suggest the establishment of the families Cyrtostrombidiidae nov. fam. (with cyrtos-like pharyngeal fibres and lack of ventral membranelles and endoral) and Pelagostrombidiidae nov. fam. (with neoformation organelle). An attempt is made to reconstruct the evolution of the kinety patterns based on morphologic, ontogenetic, and ultrastructural data. Some genera of tail-less Oligotrichida base on differences in the ciliary pattern; Omegastrombidium nov. gen. is erected for a further girdle kinety pattern. Likewise, the tailed genus Tontonia is split, resulting in two new genera, viz., Pseudotontonia nov. gen. and Spirotontonia nov. gen. Furthermore, the genus Spirostrombidium is split due to the different origin of the parallel course of girdle and ventral kinety, and Parallelostrombidium nov. gen. is established. However, the genus Thigmostrombidium is rejected because its enlarged thigmotactic membranelles are interpreted as an adaptation to the benthic lifestyle, which occurred several times within different girdle kinety patterns.

Journal Article↗
PubMed1986

Tender points: evolution of concepts of the fibrositis/fibromyalgia syndrome.

The association of chronic pain, exhaustion, and multiple somatic complaints with apparent physical good health and long survival has a long history. The syndrome was called by many names including neuresthenia, rheumatism, and invalidism. When skeletal pain and stiffness were prominent, many observers recorded the existence of sites of tenderness and sometimes of areas of induration. The work of Lewis and Kellgren provided an experimentally reproducible method of study of the phenomena of referred pain and referred tenderness, which led to hypotheses about the nature of many of these syndromes, which were unfortunately too numerous and often contradictory. More recently, it has been learned that the sites of tenderness are precisely predictable in location and, under some circumstances, experimentally inducible. They are unknown to the patient and, therefore, due to mechanisms other than distortions of interpretation. The association with a variety of forms of sleep disturbance was discovered. These events have permitted the rapid evolution of controlled, numerical studies of these associations, which are reviewed briefly in this article.

Fibromyalgia↗
PubMed1991

Sequence and structural organization of the human gene encoding ciliary neurotrophic factor.

Ciliary neurotrophic factor (CNTF) is a potent polypeptide hormone whose actions appear to be restricted to the nervous system where it promotes survival, neurotransmitter synthesis and neurite outgrowth in certain neuronal populations. We have cloned the gene encoding human CNTF (hCNTF) and have characterized its structure and organization. The hCNTF gene appears to be a unique-copy gene with a simple genetic organization, since only a single intron interrupts the coding domain. The hCNTF gene is located on chromosome 11, as determined using human-hamster somatic cell hybrids. The CNTF protein is highly conserved in evolution. The amino acid (aa) sequences of rat and rabbit CNTF translated from cDNAs display approx. 85% homology with the deduced aa sequence encoding hCNTF.

Amino Acid Sequence↗
PubMed2005

Identical phenotype in patients with somatic and germline CD95 mutations requires a new diagnostic approach to autoimmune lymphoproliferative syndrome.

In a patient with a somatic mutation in the CD95 gene, the long-term evolution of the clinical phenotype was indistinguishable from that of patients with autoimmune lymphoproliferative syndrome caused by germline CD95 mutations. A new diagnostic algorithm for autoimmune lymphoproliferative syndrome is suggested incorporating studies on sorted TCRalpha/beta+CD3+CD8-CD4- T cells.

Algorithms↗
PubMed1989

Establishment and functional implications of B-cell connectivity.

We have discussed some aspects of the structure of the normal immune system, particularly the B-cell compartment. We have argued: that a basic property of the natural antibody repertoire is constituted by high degrees of connectivity within the immune system as well as between the system and other components of the organism; that the complementarities constituting this connectivity are based on self-self interactions, high degrees of degeneracy or somatically selected interactions and that these properties are conserved through evolution, to ensure self-reference; that by evolutionary selection, antibody V-genes encoding such structural properties are ensured to be expressed early in ontogeny. The set of highly connected cells will be kept through ontogeny and form the basis for a compartment of naturally-activated lymphocytes making up 10-15% of the total lymphocyte population. As suggested before, this pool of connected cells may be responsible for maintenance of normal network dynamics and prevention of autoaggression.

Amino Acid Sequence↗
PubMed1994

Adaptation, allometry, and hypertension.

Essential hypertension is a "disease of civilization" but has a clear genetic component. From an evolutionary perspective, persistence in the human genome of elements capable of raising blood pressure presupposes their adaptive significance. Recently, two hypotheses that explicitly appeal to selectionist arguments, the "slavery" and "thrifty gene" theories, have been forwarded. We find neither completely successful, and we advance an alternative explanation of the adaptive importance of genes responsible for hypertension. We propose that blood pressure rises during childhood and adolescence to subserve homeostatic needs of the organism. Specifically, we contend that blood pressure is a flexible element in the repertoire of renal homeostatic mechanisms serving to match renal function to growth. The effect of modern diet and lifestyle on human growth stimulates earlier and more vigorous development, straining biologically necessary relationships between renal and general somatic growth and requiring compensation via homeostatic mechanisms preserved during evolution. Prime among such mechanisms is blood pressure, which rises as a compensation to maintain renal function in the face of greater growth. Since virtually all members of acculturated societies share in the modern lifestyle, the demands imposed by accelerated growth and development result in a populational shift to higher blood pressures, with a consequent increase in the prevalence of hypertension. We propose that hypertension is the product of maladaptation of highly genetically conserved mechanisms subserving important biological homeostatic needs. Elucidation of the mechanisms underlying hypertension will require approaches that examine the developmental processes linking growth to blood pressure.

Adaptation, Physiological↗
PubMed2004

Protein dynamics and the immunological evolution of molecular recognition.

While it is accepted that protein flexibility plays a role in protein folding, catalysis, and molecular recognition, few techniques are capable of the rigorous measurement of protein motions required to quantify flexibility. Three-pulse photon echo shift spectroscopy can be used to measure the time scale of protein motions, and we have used this technique, along with steady-state spectroscopy and binding and structural data, to examine the immunological evolution of protein flexibility in an anti-fluorescein antibody. Two light chain somatic mutations increase affinity for fluorescein by 12-fold but also significantly affect flexibility. Specifically, a rigidification of the protein is seen in each of three observable motions; two slower motions undergo decreased amplitudes of displacement, by 3- and 20-fold, respectively, in response to an applied force, and the distribution associated with the amplitude of a faster motion is narrowed upon somatic mutation. The somatic mutations appear to rigidify the antibody-fluorescein complex by more strongly anchoring fluorescein to the protein and by more tightly packing the complex. The data demonstrate that in addition to affinity, antibody dynamics are systematically manipulated during affinity maturation, and they imply that the evolution of protein flexibility may be a central component of the immune response. The results also reflect the type of protein rigidification that may be important for other biological interactions, such as protein-protein, protein-ligand or protein-drug, and enzyme-substrate recognition.

5' Untranslated Regions↗
PubMed2005

Idiopathic headache in children under six years of age: a follow-up study.

OBJECTIVE: To assess the evolution of idiopathic headache with early onset and to investigate the influence of early somatic disorders, "life events," and psychiatric disorders on the onset and the course of headache. We also studied the possible prognostic role of gender, headache diagnosis at onset, and history of headache in family members on the course of headache. We also investigated the applicability of the ICHD-II criteria to idiopathic headache in preschool children. METHODS: Prospective evaluation of 25 consecutive headache patients referred before the age of 6 years. Headache diagnosis was based on the IHS 1988 criteria, on the ICHD-II criteria, and on "alternative" clinical criteria [eg, duration less than 1 hour in migraine without aura (MWA), less than 30 minutes in tension-type headache (TTH)]. All patients were assessed by a structured interview to detect early developmental disorders (eg, feeding difficulties or sleep disorders) and "life events" (eg, parents' separation and others according to DSM-IV). All patients underwent clinical observations and assessment of psychiatric comorbidity (ICD-10) by means of interviews and the Child Behaviour Check List. All the above-mentioned evaluations were performed at recruitment (T0) and at the end of the follow-up period (T1). RESULTS: A total of 25 children with headache (12 males; 13 females) were monitored through long-term clinical follow-up (mean duration: 4.2 years; range: 2.8 to 6.6 years). The "definite" diagnosis of migraine without aura or TTH at T0 was possible in only 6/25 (24%) and 9/25 patients (36%) applying the IHS 1988 criteria and the ICHD-II criteria respectively, but in 20/25 (80%) applying the "alternative" clinical criteria. Evaluation of headache at T1 revealed: remission in 16/25 (64%) patients and persistence in 9/25 (36%). At T1, the ICHD-II diagnosis was possible in 100% of the children with headache persistence (1/9 migraine without aura and 8/9 TTH) and these diagnoses were found to be perfectly concordant with those obtained applying the "alternative criteria." Early developmental disorders were present in 11/25 children, with a significantly higher prevalence in children with headache persistence compared to children showing headache remission (78% vs. 25%; P < .05). No significant differences were found between patients with headache persistence and patients with headache remission with regard to gender, history of headache in family members, headache diagnosis at onset, psychiatric comorbidity at T0, and with regard to "life events" at both T0 and T1. Conversely, the children presenting psychiatric disorders at T1 were more frequently affected by headache than those without psychiatric disorders (59% vs. 15%; P < .05). CONCLUSIONS: Our results suggest that the ICHD-II criteria are too restrictive to allow the classification of migraine without aura and TTH in preschool children. Nevertheless, a diagnosis based on these criteria was possible in all the patients with headache persistence at the end of several years' follow-up. We found a significant association between early somatic disorders and persistence of headache and also between the presence of psychiatric disorders at the end of follow-up and the persistence of headache. "Life events," on the other hand, while not showing a statistically significant association with the evolution of the headache, may nevertheless influence the course of the headache in some patients. Our results suggest that environmental and psychological factors play an important role in idiopathic headache with onset in preschool age, and thus that the diagnostic-therapeutic approach must take these factors into account.

Age of Onset↗
PubMed1979

Origins of polyploids.

1. Polyploidy is a conspicuous feature of chromosomal evolution in higher plants. It is common in many genera, and numerous species are characterized by diploid and polyploid races. 2. Polyploid evolution is a process not an event. 3. Polyploid may involve somatic chromsome doubling or sexual functioning of cytologically non-reduced gametes. 4. Spontaneous chromosome doubling, either in the zygote to produce a polyploid is plant or in apical meristem to produce a polyploid chimera, is a rare event. 5. The common mode of polyploidy is through the formation and sexual functioning of cytologically non-reduced gametes. Increased in chromosome number can occur in the first or later hybrid generations. 6. Polyploid via cytologically non-reduced gametes is commonly a two step process. A diploid (2n) female gamete is fertilized by a haploid (n) male gamete to produce a triploid (3x), which in turn produces cytologically non-reduced triploid (3n) female gametes that are fertilized by haploid (n) gametes of the diploid parents and result in tetraploid (4x) offspring. 7. Fertilization of a rare diploid (2n) female gamete by an equally rare diploid (2n) male gamete to directly produce a tetraploid (4x) is extremely rare but does occur. 8. Polyploidy is successful only if the new polyploids are able to complete with their parents. Success depends on availability of suitable habitals, as well as the ability to produce successful offspring. 9. The most successful polyploids combine the diploid genomes of cytogenetically allied, but differently adapted taxa. 10. Fertility is restored in polyploids through cytological diploidization of the genomes or through gametophytic apomixis. 11. Reversible tetaploidy is part of polyploid evolution.

Biological Evolution↗
PubMed2003

The digital origin of human language--a synthesis.

The fact that all languages known are digital poses the question of their origin. The answer developed here treats language as the interface of information theory and molecular development by showing previously unrecognized isomorphisms between the analog and digital features of language and life at the molecular level. Human language is a special case of signal transduction and hence is subject to the coding aspects of Shannon's theorems and the analog aspects of pattern recognition, each represented by genotype and phenotype. Digital language acquisition is late in evolution and postnatal development and requires a neural reorganization by a mechanism of somatic network programming in response to the environment. Such a mechanism would solve the Chomsky conundrum of how children can learn any language without knowing rules of grammar too numerous to be encoded genotypically.

Biological Evolution↗
PubMed2004

Immunoglobulin superfamily receptors in protochordates: before RAG time.

Urochordates and cephalochordates do not have an adaptive immune system involving the somatic rearrangement of their antigen receptor genes. They do not have antigen-presenting molecules of the major histocompatibility complex (MHC)-linked class I and II types. In the absence of such a system, the status of their genes reflects perhaps a primitive pre-recombination-activating gene (RAG) stage that could suggest the pathway leading to the genesis of the T-cell receptor (TCR) and antibodies. In the genome of Ciona intestinalis, genes that encode molecules with membrane receptor features have been found among many members of the immunoglobulin superfamily (Igsf). They use the domains typical of vertebrate antigen receptors and class I and II: the V, and C1-like domains. These genes belong to two families with recognizable homologs in vertebrates: the junctional adhesion molecule (JAM)/cortical thymocyte marker of Xenopus (CTX) family and the nectin family. The human homologs of these genes segregate in a single unit of four paralogous segments on chromosomes 1q, 3q, 11p, and 21q. These regions contain nowadays several genes involved in the adaptive immune system, and some related members are present in the MHC paralogs as well. They also contain receptor-like genes without homologs in Ciona but with related members in the protostome Drosophila. It looks as if in Ciona one detects what looks like the 'fossil' of one group of genes bound to duplicate and give rise to many crucial elements of the adaptive immune system. The modern homologs of these JAM, CTX, and nectins are all or almost all virus receptors, and the hypothesis is formulated that this property was taken advantage of during evolution to participate in the elaboration of either or both the somatically generated antigen-recognizing receptors and the antigen-presenting molecules.

Animals↗
PubMed1985

A model for transposon-based eucaryote regulatory evolution.

This paper presents a compact model of the role of transposable elements in eucaryote evolution which, although forward looking, is consistent with both experimental results and theories of gene regulation. The model postulates that a principal factor in the emergence of the eucaryotes was the development of a symbiotic relationship between reverse transcribing transposable elements and RNA based gene regulation, which we will call structural symbiosis. Thus, although transposable elements follow their own evolutionary protocol, structural homologies between "cellular" and "viral" genomes result in selective mutagenesis, a situation where transposon mutations are permitted because they can result in phenotypic mutations of the regulatory process with reduced probability of deleterious mutation of structural genes. The incorporation of this scheme into the life cycle of higher organisms results in two forms of integral evolution. Exogenous, in which differing species in an ecosystem share genetic information through viral transfer, and endogenous in which somatically induced regulatory mutations can be mapped back into the germ line.

Biological Evolution↗
PubMed1997

HIV genetic variation is directed and restricted by DNA precursor availability.

The effects of deoxynucleoside triphosphate (dNTP) imbalances on the fidelity of human immunodeficiency virus type 1 (HIV-1) replication were investigated. Using detergent permeabilized virions and biased dNTP concentrations different types of hypermutants were readily produced. However, the mutant spectrum was different from naturally occurring hypermutants demonstrating that the host cell may restrict variation. Using a genetic screen based on the blue/white beta-galactosidase complementation assay, G --> A hypermutants were recovered from HIV-infected thymidine treated U937 cells. Furthermore, hypermutants were recovered from 1 to 2% of resting or activated peripheral blood mononuclear cells indicating that small proportions of primary cells had distorted intracellular [dTTP] and [dCTP]. Such imbalances may underlie a proportion of somatic and germline point mutations and shape to some extent the evolution of mammalian and viral genomes.

Base Sequence↗
PubMed1999

Truths, errors, and lies around "reflex sympathetic dystrophy" and "complex regional pain syndrome".

The shifting paradigm of reflex sympathetic dystrophy-sympathetically maintained pains-complex regional pain syndrome is characterized by vestigial truths and understandable errors, but also unjustifiable lies. It is true that patients with organically based neuropathic pain harbor unquestionable and physiologically demonstrable evidence of nerve fiber dysfunction leading to a predictable clinical profile with stereotyped temporal evolution. In turn, patients with psychogenic pseudoneuropathy, sustained by conversion-somatization-malingering, not only lack physiological evidence of structural nerve fiber disease but display a characteristically atypical, half-subjective, psychophysical sensory-motor profile. The objective vasomotor signs may have any variety of neurogenic, vasogenic, and psychogenic origins. Neurological differential diagnosis of "neuropathic pain" versus pseudoneuropathy is straight forward provided that stringent requirements of neurological semeiology are not bypassed. Embarrassing conceptual errors explain the assumption that there exists a clinically relevant "sympathetically maintained pain" status. Errors include historical misinterpretation of vasomotor signs in symptomatic body parts, and misconstruing symptomatic relief after "diagnostic" sympathetic blocks, due to lack of consideration of the placebo effect which explains the outcome. It is a lie that sympatholysis may specifically cure patients with unqualified "reflex sympathetic dystrophy." This was already stated by the father of sympathectomy, René Leriche, more than half a century ago. As extrapolated from observations in animals with gross experimental nerve injury, adducing hypothetical, untestable, secondary central neuron sensitization to explain psychophysical sensory-motor complaints displayed by patients with blatantly absent nerve fiber injury, is not an error, but a lie. While conceptual errors are not only forgivable, but natural to inexact medical science, lies particularly when entrepreneurially inspired are condemnable and call for peer intervention.

Causalgia↗
PubMed2002

Detection of c-kit point mutation Asp-816 --> Val in microdissected pooled single mast cells and leukemic cells in a patient with systemic mastocytosis and concomitant chronic myelomonocytic leukemia.

The c-kit mutation Asp-816-->Val is detectable not only in neoplastic mast cells (MCs) in patients with systemic mastocytosis (SM) but also in most associated hematologic non-MC lineage disease (AHNMD). In order to prove a monoclonal disease evolution we investigated DNA of pooled microdissected single cells for the presence of the mutation in a patient with SM and concomitant chronic myelomonocytic leukemia (CMML). LightCycler melting curve analysis and direct sequencing of nested polymerase chain reaction (PCR) products revealed the c-kit mutation in tryptase-positive MC and in leukemic CD15-positive cells in bone marrow infiltrates, but not in colonic epithelial cells, thus, suggesting a monoclonal evolution of SM and concurrent CMML on the basis of a somatic mutation in a common hematologic progenitor.

Aged↗
PubMed1998

Nuclear basic proteins in spermiogenesis.

In animal species, spermiogenesis, the late stage of spermatogenesis, is characterized by a dramatic remodelling of chromatin which involves morphological changes and various modifications in the nature of the nuclear basic proteins. According to the evolution of species, three situations can be observed: a) persistence of somatic histones or appearance of sperm-specific histones; b) direct replacement of histones by generally smaller and more basic proteins called protamines; and c) occurrence of a double nuclear basic protein transition: histones are not directly replaced by protamines but by intermediate basic proteins which are themselves replaced by one or several protamines. However, in some species, two kinds of intermediate basic proteins can be distinguished in spermatid nuclei: transition proteins and protamine precursors. Whereas transition proteins are not structurally related either to histones or to protamines, protamine precursors are further processed at the end of spermiogenesis to give rise to the mature protamine. The molecular characteristics of the protamines as well as number of protamine types present in the spermatozoon vary from species to species. In some cases, protamine-encoding genes, although present, are not expressed to a significant level. The diversity and the precise function of intermediate basic proteins remain open to discussion. Some of them are the precursors of protamines but the mechanism, sequential or not, as well as the enzyme(s) involved in the proteolytic processing, remain to be discovered.

Amino Acid Sequence↗
PubMedDate not supplied

[The growth hormone axis and insulin-like growth factors].

INTRODUCTION: Growth is regulated by the interaction of environmental signals with endogenous neuroendocrine responses to the genetic programs that determine the body plan. The insulin-like growth factors (IGFs) are integral components of multiple systems controlling both growth and metabolism. THE IGF SYSTEM: The IGF system is thouht to be more complex than other endocrine systems, as genes for six IGF-binding proteins (IGFBPs) have been identified so far. The IGFs play a critical role in both cell cycle control and apoptosis, two functions involved in regulation of tumorigenesis. Insulin-like growth factor-I (IGF-I) is essential for normal growth. Confirmation of the significance of IGF-I in human physiology was obtained by the discovery of a patient with intrauterine growth retardation and postnatal growth failure associated with a mutation in the IGF-I gene. STAGES OF EVOLUTION OF THE SOMATOMEDIN HYPOTHESIS: The original somatomedin hypothesis postulated that somatic growth was regulated by growth hormone's (GH's) stimulation of hepatic IGF-I production, with IGF-I acting in an endocrine fashion to promote growth. The dual effector theory proposed an alternative view, involving direct effects by GH on peripheral tissues not mediated by IGF-I and GH-stimulated local IGF-I production for autocrine/paracrine action. It is now clear that GH stimulates the formation of ternary IGF binding complex, which stabilizes IGF-I in the serum.

Animals↗
PubMedDate not supplied

[Neonatal Cornelia de Lange syndrome].

INTRODUCTION: Cornelia de Lange syndrome is a rare polimalformative association that shows an expresivity of unknown etiology being most cases sporadic. The diagnosis is clinical. CASE REPORTS: Two female newborns without remarkable antecedents affected of intrauterine growth retardation were born by cesarean section due to risk of perinatal asphyxia. Both cases had a harmonic hypotrophy and a very similar clinical phenotype, especially the craniofacial anomalies, with typical facial features and limb alterations. Besides, the evolution confirms the diagnosis because in both cases the delay of somatic development and microcephaly, as well as moderate-severe psychomotor delay and behavior alterations were present. Likewise, both cases have developed typical medical complications of the condition. The complementary study showed in both patients an important dysfunction of the auditory ways and a atrial septal defect. They were soon included in sensory and motor program of rehabilitation. CONCLUSION: We present two cases of Cornelia de Lange syndrome of neonatal diagnosis that we consider of interest due to the importance of an early recognition of the clinical condition for the family advice and the medical aid and for an appropriate development.

De Lange Syndrome↗