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At least 55 records · Page 3Linked to original sources
PubMed1988

Complete pattern of ocular dominance stripes in V1 of a New World monkey, Cebus apella.

The presence of ocular dominance (OD) stripes in layer IVc of striate cortex (V1) is characteristic of all Old World simians so far studied. In contrast, some species of New World monkeys do not have ocular dominance stripes, and in those that do, the pattern of stripes may be different from that shown in Old World monkeys. This difference has led to the suggestion that OD stripes evolved independently in both groups. We have mapped the entire system of OD stripes in the New World monkey Cebus, by means of cytochrome oxidase histochemistry after monocular enucleation. A striking similarity was found between the patterns in Cebus and Macaca, which is suggestive of common ancestry, rather than parallel evolution.

Animals↗
PubMed1988

Cross-coupled effects of repeated vestibular and optokinetic stimulations on the dynamics of the vestibulo-ocular and optokinetic reflexes in the cat.

Cats were submitted to repeated step stimulations either vestibular or optokinetic. Regardless of which of the two stimuli was used, dynamic modifications were observed in both vestibulo-ocular response and optokinetic after-nystagmus (OKAN). The progressive changes in post-rotational nystagmus and OKAN were quantified by measuring the duration of their primary phase. A parallel evolution of these two parameters was found. When repeated unidirectional vestibular stimulations were used, the same asymmetry was induced in both vestibuloocular responses and OKAN. These results support the hypothesis that the vestibulo-ocular and the optokinetic reflex share a common velocity storage mechanism, although alternative hypotheses cannot be excluded.

Animals↗
PubMed1978

Habitat selection and evolutionary strategies in Drosophila: an invited address.

There is an association among resource utilization divergence, habitat selection, and taxonomic divergence in the genus Drosophila. Given permissive conditions of temperature, humidity, and light intensity, an enormous vairety of resources is used in a diversity of habitats. These resources are considered in the cosmopolitan and endemic Australian fauna, providing evidence for habitat selection in the laboratory and field. Lek behavior in picture-winged species of subgenus Hirtodrosophila, a case of parallel evolution with lek behavior in subgenus Drosophila in Hawaii, is discussed in detail. Other examples of habitat selection discussed concern behavioral reactions of larvae to alcohol and other metabolites and the avoidance by adults of extreme physical environments. Evolutionary strategies involved in habitat selection are considered at various taxonomic levels in Drosophila. These considerations show that it is essential to relate results from laboratory studies to natural environments in order to explore the genetics of habitat selection.

Animals↗
PubMedDate not supplied

Activity of the neurons of the medial region of the septum of the rabbit brain in early ontogenesis.

In rabbits aged from seven days to two and a half months the activity of individual cells of the nucleus of the diagonal band of Broca (NDB) and of the medial nuclei of the septum (MNS) of the brain and the EEG of the dorsal hippocampus (DH) - the CA2-CA3 zones - have been recorded simultaneously. It has been found that the specific (burst) activity of the neurons of the septum appears first on the 8th-11th day of the background of the action of eserine. The distinct bimodal nature of the histograms of the interimpulse intervals characteristic of the burst sequence of distribution of the potentials appears only from an age of 14 days. The deficient nature of impulse-formation of the NDB and of the MNS is acquired at about the 20th day of life. A parallel evolution of the impulse activity of the cells of the medial region of the septum and the synchronized activity of the hippocampus in ontogenesis is traced. The formation of the theta activity correlates with an increase in frequency of the burst activity of the neurons of the septum connected with an increase in the mean frequency of impulse formation of the cells, the concentration of the impulses into a packet, and the growth of the regularity of the burst discharges with age.

Age Factors↗
PubMed1989

Avascular necrosis of the femoral head in long-term follow-up of systemic sclerosis: report of two cases.

A long-term follow-up of two patients with scleroderma (SS) who developed a polyarthritis with bilateral femoral head osteonecrosis is reported. The severe parallel evolution of the small and large joint lesions and the late appearance of osteonecrotic changes in our patients suggest that avascular osteonecrosis is related to the osteoarticular progression of the longstanding SS.

Adult↗
PubMed1992

Laminar, columnar and topographic aspects of ocular dominance in the primary visual cortex of Cebus monkeys.

The representation of the two eyes in striate cortex (V1) of Cebus monkeys was studied by electrophysiological single-unit recordings in normal animals and by morphometric analysis of the pattern of ocular dominance (OD) stripes, as revealed by cytochrome oxidase histochemistry in V1 flat-mounts of enucleated animals. Single-unit recordings revealed that the large majority of V1 neurons respond to the stimulation of either eye but are more strongly activated by one of them. As in other species of monkey, neurons with preference for the stimulation of the same eye are grouped in columns 300-400 microns wide, spanning all cortical layers. Monocular neurons are clustered in layer IVc, specially in its deeper half (IVc-beta), and constitute less than 10% of the population of other layers. Neurons with equal responses to each eye are more commonly found in layer V than elsewhere in V1. In the supragranular layers and in granular layer IVc-alpha neurons strongly dominated by one of the eyes tend to be broadly tuned for orientation, while binocularly balanced neurons tend to be sharply tuned for this parameter. No such correlation was detected in the infragranular layers, and most neurons in layer IVc-beta responded regardless of stimulus orientation. Ocular dominance stripes are present throughout most of V1 as long, parallel or bifurcating bands alternately dominated by the ipsi- or the contralateral eye. They are absent from the cortical representations of the blind spot and the monocular crescent. The domains of each eye occupy nearly equal portions of the surface of binocular V1, except for the representation of the periphery, where the contralateral eye has a larger domain, and a narrow strip along the border of V1 with V2, where either eye may predominate. The orderliness of the pattern of stripes and the relationship between stripe arrangement and the representation of the visual meridians vary with eccentricity and polar angle but follow the same rules in different animals. These results demonstrate that the laminar, columnar and topographic distribution of neurons with different degrees of OD in V1 is qualitatively similar in New- and Old World monkeys of similar sizes and suggest that common ancestry, rather than parallel evolution, may account for the OD phenotypes of contemporaneous simians.

Animals↗
PubMed1990

Effects of moderate dietary supplementations with n-3 fatty acids on macrophage and lymphocyte phospholipids and macrophage eicosanoid synthesis in the rat.

The effects of a moderate dietary intake of n-3 polyunsaturated fatty acids were determined on the eicosanoid synthesis by rat peritoneal macrophages: the availability of arachidonic acid (20:4 (n-6)) and eicosapentaenoic acid (20:5 (n-3] in the membrane phospholipids of peritoneal macrophages and splenic lymphocytes and the synthesis of the main eicosanoids were evaluated in parallel. The n-6/n-3 ratio was decreased from 13.5 in the control diet rich in 18:2(n-6) to about 2 by an addition of either linseed oil providing 18:3(n-3) (linseed oil diet) or fish oil providing 20:5(n-3) and 22:6(n-3) (fish oil diet). The dietary linoleic acid content was at least 3.5% of energy in each diet. In peritoneal macrophage and splenic lymphocyte membrane phospholipids, arachidonic acid content was significantly decreased with the linseed oil and fish oil diets. 20:5(n-3) content was significantly raised up in the linseed oil group (3-fold in macrophage phospholipids) and more strikely in the fish oil group (7-fold). In response to a stimulation by the calcium ionophore A23187, peritoneal macrophages released 6-ketoPGF1 alpha, TXB2, PGE2 and LTB4 and/or 5, but no or few peptidoleukotrienes. The linseed oil did not affect significantly the synthesis of these eicosanoids, except for LTB5, which was increased 2-fold. In contrast, the fish oil diet led to significant decreases in the productions of 6-ketoPGF1 alpha and PGE2 (-50%) and LTB4 (-40%) and to a 10-fold increase in the release of LTB5. TXB2 was also decreased (-35%), but not significantly. These results and the parallel evolutions of the two ratios 20:4(n-6)/20:5(n-3) and LTB4/LTB5 showed that eicosanoid synthesis is greatly dependent on the relative availability of the two substrates in competition.

6-Ketoprostaglandin F1 alpha↗
PubMed1992

A second auditory area in the non-cortical telencephalon of a reptile.

Injections of horseradish peroxidase (HRP) into a caudocentral portion of the non-cortical telencephalon of Caiman known as the dorsolateral area (dorsal ventricular ridge) resulted in retrogradely labeled neurons throughout the entire extent of the ipsilateral nucleus reuniens. HRP-positive cells were most numerous in nucleus reuniens pars diffusa with only sparse labeling of neurons in nucleus reuniens pars centralis. The results of the present experiment, when compared with those of a prior study that determined the telencephalic connections of nucleus reuniens pars centralis, suggested that these two forebrain areas are separate. Staining with succinate dehydrogenase and acetylcholinesterase revealed that nucleus reuniens pars centralis and pars diffusa and their respective telencephalic projection areas can be differentiated on the basis of histochemical features. These findings in Caiman suggest that certain thalamic and telencephalic auditory areas in birds and crocodilians are most likely the result of common ancestry rather than examples of parallel evolution.

Acetylcholinesterase↗
PubMed1989

Ileocolonoscopy in seronegative spondylarthropathy.

A prospective endoscopic and histologic study of terminal ileum and colorectum in 211 patients with seronegative spondylarthropathy revealed macroscopic inflammatory lesions varying from erythema to superficial erosions in 30% of the patients and microscopic inflammation in 61%. Two types of inflammation were observed: an acute inflammation resembling an infectious enterocolitis and a chronic inflammation. In idiopathic reactive arthritis both types of inflammation were equally present, whereas chronic inflammation predominated in patients with ankylosing spondylitis. In 32% of patients with chronic inflammation, the lesions particularly resembled early Crohn's disease. Repeat ileocolonscopy on 19 patients demonstrated a parallel evolution of joint symptoms and histologic lesions. All patients with acute inflammation went into clinical and histologic remission, whereas lesions persisted in patients with Crohn-like inflammation. In patients with chronic inflammation, remission and persistence were observed equally. This study identified a group of patients with seronegative spondylarthropathy which, even in the absence of gastrointestinal symptoms, showed evidence of gut inflammation, probably inducing an increased gut permeability with transgression of the oral tolerance and absorption of provocative antigens into the circulation. It is also possible that both diseases reflect a common underlying process.

Arthritis↗
PubMed1976

Adjacent repeating units of Xenopus laevis 5S DNA can be heterogeneous in length.

The distribution of length heterogeneity in adjacent repeating units of X. laevis 5S DNA has been examined by "cloning" 5S DNA in bacteria. Fragments of 5S DNA produced by partial digestion with Hind III and containing 1, 4, and 5 repeating units have been inserted at the single Hind III site of the tetracycline-resistance plasmid, pSC101, and the hybrid plasmids cloned in E. coli. Adjacent 5S DNA repeats in the cloned multi-repeat fragments can differ in length. This finding rules out some mechanisms which have been proposed to account for the parallel evolution of tandem repeated DNAs. The results are consistent with an unequal crossing-over mechanism and place some constraints on the molecular processes in this recombinatory event.

Animals↗
PubMed1990

[Use of psychotropic drugs and addiction: approaches to epidemiologic research].

Although the phenomenon of drug abuse in France is well delimited, it constitutes a public health problem. The way it spreads is sometimes 'epidemic' in sub-groups especially exposed. The somtic or relational consequences are short-term and it concerns more and more adolescents or young adults. Two main research axes have been developed: studies in the general population, adolescents or adults, in order to know the general context of licit and illicit psychotropic use in France, and specific studies in detoxification centers in order to describe the characteristics of drug addicts and to evaluate their requirements. Results of some recent surveys can illustrate these axes. Total abstinence is exceptional. Psychotropic drug abuse is deeply established in traditional French social customs. Most subjects had a narrow relation with psychoactive drugs. The variety as well as quantity of products allow everyone to adopt a style of consumption. Globally, alcohol consumption has decreased. Moderate consumers seem to be those who especially confine their drinking to daily wine consumption. On the other hand, the consumption of aperitifs and other drinks in on the increase. The dissociation of alcohol consumption from meals enhances drunkness. Nicotine-poisoning in men had a parallel evolution and has increased in women. Psychotropic drugs (tranquillizers and hypnotics) are specially used by aged women on medical prescription. For the study of drug abuse, data is collected in specialised centers and prisons regarding socio-demographic variables, intoxication profile and medical and social consequences. For both the general and addict population, epidemiological research, especially typological analysis, allows to identify some sub-groups at risk of drug addiction.

Adolescent↗
PubMed1988

The spider monkey psi eta-globin gene and surrounding sequences: recent or ancient insertions of LINEs and SINEs?

A phylogenetic comparison of the psi eta-globin DNA sequence of the spider monkey (Ateles geoffroyi) to orthologous sequences from other primates provides evidence for an evolutionarily recent (less than 17 million years ago (MYA] insertion of a truncated L1 LINE (long interspersed repetitive element). An Alu SINE (short interspersed element), found 3 kb downstream of the poly(A) addition site, arose less than 40 MYA subsequent to the divergence of platyrrhinies (New World monkeys) from catarrhines (humans, apes, and Old World monkeys). Another Alu element, which appears in the catarrhines 588 bp upstream from the psi eta gene, is absent in Ateles, thus placing its possible time of insertion between 20 and 40 MYA. Alignment of the Ateles psi eta sequence with orthologous hominoid sequences (M. M. Miyamoto, J. L. Slightom, and M. Goodman, 1987, Science 238: 369-373) provides unequivocal evidence against the view (J. H. Schwartz, 1987, "The Red Ape: Orang-utans and Human Origins," Houghton Mifflin, Boston, MA) that the orangutan forms a monophyletic group with human. Furthermore, a critical analysis of potential sources of homoplasy (i.e., parallel evolution) reaffirms a Homo-Pan monophyletic clade (Miyamoto et al., 1987). Reconstruction of primate psi eta sequence phylogeny suggests Ateles and Aotus shared a common ancestor only 16 +/- 1.5 MYA. Finally, the results show a mutation rate of 1.7 +/- 0.2 x 10(-9) mutations site-1 year-1 during the evolution of the Ateles psi eta-globin region since the divergence of catarrhines from platyrrhinies.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Follicle-stimulating hormone bioactivity in idiopathic normogonadotropic oligoasthenozoospermia: double-blind trial with gonadotropin-releasing hormone.

OBJECTIVE: To identify, among patients with idiopathic normogonadotropic oligoasthenozoospermia, those with low bioactive follicle-stimulating hormone (FSH), possibly because of inadequate gonadotropin-releasing hormone (GnRH) pulsatility, whose bioactive FSH and sperm could be improved by GnRH treatment. DESIGN: Randomized, double-blind, placebo-controlled trial with intranasal (IN) GnRH, followed by open GnRH treatment. SETTING: Outpatient endocrinology clinic. PATIENTS: Twenty-eight infertile men with idiopathic normogonadotropic oligoasthenozoospermia. INTERVENTIONS: Gonadotropin-releasing hormone or placebo was self-administered IN every 2 hours. MAIN OUTCOME MEASURES: Serum immunoreactive and bioactive FSH and semen analyses. RESULTS: Ten men showed a low basal FSH bioactive/immunoreactive ratio, which increased in 5 of them under GnRH without parallel sperm modification. Sperm improvements were observed in 10 patients with no parallel evolution of FSH bioactive/immunoreactive ratio. Unpredicted by sperm changes, three pregnancies developed on placebo and 5 on GnRH. CONCLUSIONS: Low bioactive FSH was not the cause of idiopathic normogonadotropic oligoasthenozoospermia in our patients and could not predict response to GnRH. Pulsatile GnRH did not improve sperm beyond random fluctuations.

Administration, Intranasal↗
PubMedDate not supplied

[Destructive polyarthritis in Behcet's disease. Apropos of a case and review of the literature].

The authors report a case of a 37 years old man with Behçet's disease since 7 years who develops a destructive chronic polyarthritis involving wrists, hands and one knee. The parallel evolution between recurrent orogenital ulceration and arthritis added to the absence of other associated destructive rheumatism permit to link this polyarthritis to Behçet disease. In spite of the few reports, the occurrence of destructive arthritis can't exclude absolutely the diagnosis of this affection.

Adult↗
PubMed1984

[Place of VEP's and ERG in neonatal encephalopathies and impaired visual maturation in the infant and young child].

Visual evoked potentials (VEPs) induced by brief flashes and electroretinograms (ERGs) were recorded in 15 infants (9 prematures and 6 babies with perinatal cerebral injuries) suffering from important disturbances in their visual behavior (abnormal fixation, cortical blindness). The parallel evolution of the visual symptoms and the electrophysiological signs were studied and a good correlation was observed between these clinical and electrical signs. The authors insist on the clinical and prognostic value of the VEP in this category of infants.

Blindness↗
PubMedDate not supplied

Rational drug treatment of the hypertensive diabetic with nephropathy.

Development of hypertension in Type I diabetics parallels evolution of nephropathy. In Type II diabetics, excessive prevalence of hypertension prior to the appearance of proteinuria suggests that factors other than nephropathy are operative in its pathogenesis. On the other hand, the risk of nephropathy in Type II diabetics is higher than previously appreciated. Recent evidence suggests that angiotensin II plays an important role in the induction and progression of diabetic nephropathy. This provides a rationale for antihypertensive therapy with converting enzyme inhibitors in nephropathic diabetics in whom they have been shown to lower blood pressure and diminish proteinuria. Furthermore, in a retrospective study of patients with various renal diseases (including diabetic nephropathy), the authors found suggestive evidence that converting enzyme inhibitors may also attenuate progression of renal failure to a greater extent than other antihypertensive drugs.

Antihypertensive Agents↗
PubMed1992

Search for the mechanism of toxicity of dioxins. A lesson in toxicology.

The development of modern toxicology was strongly influenced by parallel evolutions of sister disciplines as well as regulatory requirements. This led to an overemphasis of some areas of toxicology while other aspects of it experienced at least a temporary benign neglect. The author of this paper believes that the few and far between successes in elucidating the mechanism of toxicity of chemicals are related to this uneven approach to a very complex problem. Based on one of the most important and controversial contemporary issues in toxicology, viz. that of dioxins, it is argued that by a systematic step-wise use of methodologies borrowed from sister disciplines, our capabilities of elucidating the mechanism of action of toxicants can be considerably improved.

Animals↗
PubMed1976

Similarities and differences in the structure of X and Y chromosome rRNA genes of Drosophila.

In Drosophila melanogaster, the rRNA genes (rDNA) are clustered at single sites on two non-homologous chromosomes, the X and Y. Examination of the structure of X and Y rDNAs with restriction endonucleases reveals that the X rDNA contains repeating units not present in the Y. Such observations, as well as genetic evidence, illustrate difficulties with the hypothesis that recombination is the predominant mechanism preserving similarities between these two clusters maintained on different chromosomes. This raises the possibility that selection pressure has a significant role in maintaining the parallel evolution of these two separate but homologous redundant gene clusters.

Animals↗