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PubMed2025

Migration strategies, connectivity and corridor features of the partial migrant little bustard (Tetrax tetrax) across the Iberian Peninsula.

The study of migration ecology is crucial for understanding the factors and pressures affecting migratory species. Here, we studied the migratory ecology of the little bustard (Tetrax tetrax), a steppe bird that has suffered a sharp decline over recent decades, mainly due to agricultural intensification. Using 105 adult birds tagged across the main Iberian regions where the species is present (Alentejo, Extremadura, Ebro Valley, Northern Plateau, Southern Plateau and Guadalquivir Valley), we analysed the ratio of migratory and resident birds in each population and assessed their connectivity during the three main migratory periods (summer, winter and pre-breeding). Additionally, we describe the features of the migrations recorded in terms of length, duration and day period. Our results corroborate that little bustards can be considered partial migrants across Iberia, although the proportion of residents versus migrants varied between populations: the Alentejo (94.74%) and Northern Plateau (93.75%) had the highest proportion of migrants, followed by Guadalquivir Valley (81.82%), Extremadura (65.38%), Southern Plateau (55.56%) and Ebro Valley (25.93%). Migratory connectivity varied between periods: the pre-breeding and summering migrations showed a trend to move northwards, while birds moved southwards for winter. Regarding the migratory corridors obtained from the 253 migrations identified, we found three main routes: one corridor that connects the Northern Plateau with the western part of the Southern Plateau and Extremadura, another one that connects the Southern Plateau, Extremadura, Alentejo and Guadalquivir Valley, and one corridor that concentrates migrations within the Ebro Valley, and between the Ebro Valley and the Southern Plateau. Finally, analyses showed that little bustards migrate at night through areas dominated by herbaceous cover (avoiding tree-covered land and water bodies) and of low elevation and terrain roughness. Our results highlight the importance of developing an international and inter-regional conservation strategy to protect not only the breeding and wintering quarters, but also this endangered species' migratory corridors, thus supporting the viability of the metapopulation.

Brownian bridge kernel↗
PubMed1977

Association of a low molecular weight helper factor(s) with thymocyte proliferative activity.

Human mixed leukocyte supernatants contain thymocyte proliferative activity (TPA) and a low m.w. helper factor, designated HP-1, which is capable of partially restoring the antibody response of T-cell-deficient adherent murine spleen cells to the thymic-dependent antigen, SRC. TPA and HP-1 appear to have a comparable m.w. (14,000 to 14,500 daltons) by Sephadex gel filtration column chromatography. Furthermore, HP-1 and TPA exhibit similar patterns of heterogeneity on DEAE-cellulose chromatography, elute together on CM-cellulose chromatography, and manifest identical patterns of migration on polyacrylamide gel electrophoresis. These data suggest that the TPA and HP-1 activities reside in either the same molecule(s) or in different molecules with identical charge/mass ratios. Furthermore, the results support the hypothesis that the helper activity of HP-1 is derived from its capacity to activate T and/or pre-T cells.

Animals↗
PubMed1977

Migrating myoelectrical complex of the small intestine. An intrinsic activity mediated by the vagus.

In healthy conscious parenterally fed dogs and in sheep on their usual diet, the basic motor profile on the small intestine consists of recurring cycles of action potential activity. This cyclic pattern called the migrating myoelectrical complex comprises two distinct phases termed irregular, and regular spiking activity and is followed by a period of quiescence. The pattern persists after bilateral transthoracic vagotomy and in animals rendered diabetic by alloxan. In dogs, feeding disrupts the migrating myoelectrical complex pattern by obliterating the phases of regular spiking activity and quiescence for 6 to 12 hr, depending upon the amount of dry matter intake. After vagotomy a latency in the disruption of the migrating myoelectrical complex pattern with feeding occurs and in vagotomized dogs rendered diabetic, the duration of disruption is strongly reduced. In sheep, the duration of irregular spiking activity of a jejunal segment increased or decreased corresponding to the bulk of digesta, a phenomenon damped after vagotomy. The results indicate that the role of the vagus is limited to (1) prompting prandial disruption, which is then maintained by hormonal effect; (2) regulating the irregular spiking activity duration in relation to the bulk of digesta.

Action Potentials↗
PubMed1979

Rapid change of chromomeric and pairing patterns of polytene chromosome tips in D. melanogaster: migration of polytene-nonpolytene transition zone?

The high variability of chromomeric patterns in near-terminal regions of polytene chromosome arms has been explored in a number of races, strains and hybrids of Drosophila melanogaster. Traditional explanations for tip differences between strains (differential compaction of chromatin, somatic or germinal deletion) are examined and, in the light of the reported observations, rejected. The range of polytene tip variability and rates of change in wild races are greater than has been supposed: strains formerly considered to be terminally deleted appear to gain terminal bands; others, formerly considered normal, appear to have lost them. Strains with high cell-to-cell tip variability are also described. Cell-to-cell variations, as well as much of the observed rapid changes in tip appearance, are probably due to heritable differences in the location of an abrupt transition zone between polytene and nonpolytene chromatin. A quantitative relationship between the amount of certain subterminal bands present and the frequency of tip association of nonhomologous chromosomes is shown and its possible significance for chromosome is shown and its possible for chromosome pairing discussed.

Animals↗
PubMed1977

[Migration of transformed fibroblast-like cells on substrates with patterned relief-work (quantitative study)].

The quantitative estimation of migration ability of transformed fibroblast-like cells of various epecies (mouse , rat, hamster, man) cultured on the substratum with grooves of various depth (5--40 mcm) was performed. Of the majority of 11 cell lines examined, a reduced migration capacity up to its total disappeanance was registered as compared with the homological normal embryonic cells. A more pronounced reduction of migration ability was shown in mouse and rat transformed cells and less in human ones. Migration of transformed hamster cells was just equal to the weak migrtion of normal hamster embryonis cells. These data shown a weak response of the analysed transformed cells to the relief of underlying substratum.

Animals↗
PubMedDate not supplied

[Effect of prolonged unidirectional migration of the sleep--wakefulness rhythm phase on human physiological functions, mental productivity and sleep].

The paper gives the results of three 30-day experiments carried out to study the effect of migration of the sleep--alertness cycle on physiological functions, psychic productivity and sleep of man. The migration was agravated by the initial change of the cycle which varied from +/- 7 to +/- 11 hours. All test subjects showed a counter-clockwise migration which amounted to a 1.5 hour shift every 4-5 days. All test subjects demonstrated functional cerebral changes, decline of psychic productivity and sleep disorders. The level of those disturbances depended on the value of the initial shift of the sleep--alertness cycle and on the cumulation of the migration effect. Those disorders were noted even when the prechanged sleep--alertness cycle approximated the normal pattern as a result of migration. The results indicate that the migrating day--night pattern, particularly in combination with the initial shift of the sleep--alertness cycle, cannot be recommended for manned space missions. Good health condition and high work capacity of cosmonauts can be maintained, only if a 24-hour sleep--alertness cycle with a normal sleep pattern is provided.

Adult↗
PubMed1978

Development of the interpeduncular nucleus in the midbrain of Rhesus monkey and human.

The development of the interpeduncular nucleus (IPN) in primates was studied in rhesus monkey with 3H-thymidine autoradiographic, Nissl and Golgi methods and in humans in histological preparations from embryos and fetuses of different ages. Autoradiographic analysis demonstrated that the neurons of the monkey IPN underwent their final cell division between postconception day 36 (E36) and E42, which corresponds to Stages 17 through 21 of Hendrickx and Sawyer. Autoradiograms of monkeys sacrificed at various short intervals following exposure to a pulse of 3H-thymidine showed that IPN neurons were generated in the proximity of the ventricular surface near the confluence of the 3rd ventricle and cerebral aqueduct, migrated ventrally along the midline and then spread laterally after reaching the ventral midbrain, where IPN was first recognized at E45 (Stage 23). The distribution of successively generated neurons in autoradiograms revealed caudal to rostal and lateral to medial spatiotemporal gradients. Differentiation of IPN neuronal size and development of Nissl substance began in rhesus monkey only after postmitotic cells had reached their destination and seemed to be pronounced mainly through E104. However, growth of the dendrites and elaboration of their side branches as seen in Golgi impregnations progressed gradually from E81 to birth (E165) and perhaps even later. Analysis of histological preparations of a series of human embryos and fetuses was used to derive similar information indirectly, since the autoradiographic method cannot be applied to man. It was found that IPN neurons in human probably underwent their final division between Carnegie Stage 17 and 21. Similarly, as in monkey, postmitotic cells in human IPN displayed an inverted fountain pattern of cellular migration. IPN could first be delineated at Stage 23. There was evidence for both caudal to rostral and lateral to medial spatiotemporal gradients in the human, as in the monkey. Thus, in monkey and human, all IPN neurons are generated within the first quarter of intrauterine life and there is remarkable similarity in the timing, tempo and pattern of IPN neuronal differentiation in both species, indicating the validity of using nonhuman primates as an experimental model for understanding the development of this structure in man.

Animals↗
PubMed1975

Characterization of human alpha-galactosidase A and B before and after neuraminidase treatment.

It has been previously reported that following neuraminidase treatment alpha-galactosidase A is converted into the B form, as revealed by electrophoresis. By a variety of techniques such as isoelectrofocusing, DEAE-chromatography and by enzyme kinetic parameters, no conversion of alpha-galactosidase A into B, or the reverse, could be detected after neuraminidase treatment. Only an apparent transformation of alpha-galactosidase A into B was revealed by Cellogel electrophoresis. In addition, a discrepancy was noticed between the pattern of electrophoretic migration on starch gel and Cellogel and the net electrical charges of the two alpha-galactosidases as deduced by isoelectrofocusing and DEAE-cellulose. Neuraminidase treatment did not affect the activity of alpha-galactosidase A towards the natural substrate, ceramidetrihexoside, but the activity of alpha-galactosidase B decreased by about 30% under the same conditions. The two forms of alpha-galactosidases A and B used in this study were extensively purified by classical procedures.

Animals↗
PubMed1975

Effect of antithymocyte globulin pretreatment on immunological reconstitution of lethally irradiated animals.

Clinical and experimental studies have shown that antithymocyte globulin pretreatment will reduce the severity of the graft-versus-host reaction after allogeneic bone marrow transplantation. To determine whether this was attributable to a persisting cytotoxic factor in the recipients' sera or a result of the "masking" of foreign antigens by the antihymocyte globulin, an experimental schema utilizing a syngeneic transfer of immunocompetent cells was devised. Lethally irradiated mice that had been pretreated with rabbit antimouse thymocyte globulin (RAMTG) were injected with syngeneic spleen or bone marrow cells and their immunological competence was measured by the response to a test antigen, sheep red blood cells. It was found that such pretreatment had an adverse effect on the immunological potential of the infused cells. Thus, the plaque-forming cell response to sheep red blood cell antigen in RAMTG-pretreated recipients injected with spleen cells was reduced when compared to the saline or normal rabbit globulin-treated controls. The immunological recovery of lethally irradiated animals protected with syngeneic bone marrow was also delayed, but not permanently impaired, when the recipients had been pretreated with RAMTG. These effects were evident although the spleen or bone marrow cells had been injected into the RAMTG-pretreated recipients at a time when their sera were devoid of any cytotoxic antibodies. It is speculated that two mechanisms may contribute to this alteration in immune function of the infused cells: (1) that RAMTG exists in the serum in amounts sufficient to attach to receptor sites on lymphocytes or their precursors but insufficient to kill the cells, interfering with the antigen recognition mechanism or migration and homing patterns, or (2) that the RAMTG treatment creates a temporary defect in the microenvironment of the spleen and other hemopoietic tissues, thereby affecting the transplantation and proliferation kinetics of the infused cells.

Animals↗
PubMed1977

The role of cell-mediated immunity in the induction of inflammatory responses. Parke-Davis Award Lecture, 1977.

Reactions of cell-mediated immunity fall into two broad categories: those that involve direct participation of intact lymphocytes in the effector mechanism of the reaction and those that involve mediation by soluble lymphocyte-derived factors known as lymphokines. The first kind of reaction is essentially limited to lymphocyte-dependent cytotoxicity, although certain aspects of T cell-B cell cooperation may fall into this category as well. The second category appears to comprise the bulk of the so-called cell-mediated immune response and provides a link between this system and the inflammatory system. Various lymphokines have been shown to exert profound influence upon inflammatory cell metabolism, cell surface properties, patterns of cell migration, and the activation of cells for various biologic activities involved in host defense. Although substantial information is now available about various physicochemical as well as biologic properties of lymphokines, purification and characterization data are as yet too incomplete to allow us to ascribe all of these activities to discrete mediator molecules. Current work involving the development of antibody-based techniques for mediator assay may shed light on this issue. Information on the kinds of cells capable of lymphokine production is now available. Contrary to prior expectation, T cells are not unique in their capacity for lymphokine production. Under appropriate circumstances, B cells and even nonlymphoid cells can do so as well. The unique property of lymphocytes in this regard appears to relate to their ability to respond to certain specialized signals such as specific antigen or an appropriate mitogen. Mediator production per se may represent a general biologic phenomenon. Although lymphokines have been defined mainly in terms of in vitro assays, early speculations about their in vivo importance are proving correct. Evidence for the role of lymphokines comes from studies involving detection of lymphokines in tissues, studies involving injection of exogenous lymphokines, and studies involving suppression of in vivo reactions by various techniques. The use of antilymphokine antibodies has proven useful in the latter kinds of experiments. Work in many laboratories is beginning to relate these findings to clinically relevant situations. A major unsolved problem relates to the regulation and control of lymphokine production and activity. At present only a limited body of information is available on this point. This is a potentially fruitful area for future investigation since it may provide techniques for manipulating the immune system in ways that are clinically useful.

Animals↗
PubMed1979

The changing impact of white migration on the population compositions of origin and destination metropolitan areas.

Increased migration to the sunbelt and the metropolitan-nonmetropolitan "turnaround" represent departures from long-standing redistribution trends. Although these patterns have been examined from a number of perspectives, their consequences for individual metropolitan areas have not yet been brought to light. In the present study, stream-disaggregated data for the late 1950s and late 1960s are employed to assess the impact of recent migration on the sizes and compositions of white populations in thirty-one large metropolitan areas. Most large northern SMSAs have been experiencing the "new" migration patterns since the late 1950s. They have incurred net out-movements of whites to both metropolitan and nonmetropolitan areas. In their exchanges with nonmetropolitan areas, however, they have managed to retain greater numbers of college graduates and professional workers. Southern and western SMSAs did not sustain losses to nonmetropolitan areas during either period. They did appear to gain both total and high status population as a result of interregional metropolitan redistribution.

Educational Status↗
PubMed1979

Migratory history as a factor influencing dietary habit.

A traditional concept of staple food is present in the dietary habits of Japanese, and the prominent role of rice as a staple food has changed since the end of World War II. The influence of migration on staple food patterns was studied using Hayashi's method of multivariate analysis for the quantification of qualitative data. The result of the study suggested that migration clearly influences the choice of a staple food, and that the influence of migration is more conspicuous in comparatively younger generations.

Adult↗
PubMed1979

Lipoprotein abnormalities in cholestasis. I. Electrophoretic and ultracentrifugal analyses.

The alterations of lipid composition in sera of patients with liver diseases, particularly intrahepatic cholestasis and biliary obstruction, were studied by ultracentrifugation and polyacrylamide-gel disc-electrophoresis of lipoproteins and apoproteins. The elevation of serum cholesterol in intrahepatic cholestasis was greater than in biliary obstruction. The appearance of lipoprotein X in obstructive disease accounted for most of the increased cholesterol. The level of non-lipoprotein X cholesterol in intrahepatic cholestasis was significantly elevated, this being in part ascribed to the appearance of a new class of cholestatic lipoprotein, Slow-migrating HDL. The electrophoretic pattern of lipoprotein in cholestasis was generally characterized by a decrease in alpha band intensity and, in some types of cholestasis, by the appearance of Slow-migrating HDL. In addition, other abnormal lipoproteins exhibiting the characteristics of triglyceride-rich LDL (LP-Y), LP-X-like HDL and LDL-like HDL were found in some cases of intrahepatic cholestasis and biliary obstruction.

Apolipoproteins↗
PubMed1977

A new variant of glucosephosphate isomerase deficiency: GPI-Kortrijk.

A new case of glucosephosphate isomerase deficiency in a Belgian family is described. The activity of the enzyme was decreased to about 25-30% of the normal value. Characterization of the defect enzyme showed a decreased thermostability. Heating of the enzyme at 45 degrees C showed a loss of activity of 50% after 90 min. The pH-optimum and the KM-value for fructose 6-phosphate were normal. The electrophoretic pattern showed a faster migration. The variant described here differs from all known variants. Therefore we propose to give to this new variant the name GPI-Kortrijk.

Anemia, Hemolytic, Congenital Nonspherocytic↗
PubMed2025

The new frontier in understanding human and mammalian brain development.

Neurodevelopmental disorders that cause cognitive, behavioural or motor impairments affect around 15% of children and adolescents worldwide1, with diagnoses of profound autism and attention deficit hyperactivity disorder increasing in the USA and contributing to a major economic burden2,3. Yet the origins and mechanisms of these conditions remain poorly understood, limiting progress in therapies. Comprehensive cell atlases of the developing human brain, alongside those of model organisms such as mice and non-human primates, are now providing high-resolution measures of gene expression, cell-type abundance and spatial distribution. In this Perspective, we highlight recent studies that have identified novel developmental cell populations, revealed conserved and divergent patterns of cell genesis, migration and maturation across species, and begun testing hypotheses that link them to processes ranging from transcriptional control of cell fate specification to the emergence of complex behaviours. We present remaining conceptual and technical challenges and provide an outlook on how further studies of human and mammalian brain development can empower a deeper understanding of neurodevelopmental and neuropsychiatric disorders. Future efforts expanding to additional developmental stages, including adolescence, as well as whole-brain, multimodal and cross-species integration, will yield new insights into how development shapes the brain. These atlases promise to serve as essential references for unravelling mechanisms of brain function and disease vulnerability, and for advancing precision medicine.

Humans↗
PubMed1975

[Different forms of hyperlipoproteinemia in diabetics (author's transl)].

Plasma lipoprotein patterns currently employed in attempts to identify different forms of hyperlipoproteinemia have been investigated in 113 hospitalized diabetics. For classification two methods have been compared: The first is based on lipid electrophoresis pattern in agarose gel coupled with the measurement of triglycerides and cholesterol. The second is based on plasma lipoprotein pattern obtained by separation of lipoproteins on cellulose acetate and following densitometry combined with estimation of cholesterol and beta-cholesterol and triglycerides in plasma. It could be demonstrated, that the results obtained in agarose system are not convertible to data obtained with the method for quantifying lipoproteins. By quantitative analysis only 4 p.c. of diabetics had type IIa, 4 p.c. type V, the others type IIb or IV. Graphic plots and calculated concentrations of lipoproteins gave differences in lipoprotein profiles between compensated and acidotic diabetics. In diabetes stage 1 most values are in the normal range, in stage 2 prebetalipoproteins increase and betalipoproteins decrease. In some case betalipoproteins are elevated and prebetalipoproteins diminished. In stage 3 with metabolic acidosis we observed an altered lipoprotein profile with confluence of beta- and prebeta-peak. The calculated concentration profile was also different from the others and revealed no certain quantitative information described for other electropherograms containing alpha, beta- and prebeta-bands. This phenomenon was frequently observed in patients with acute viral hepatitis and severe chronic liver disease. The pattern in diabetics is representative for patients with an excess of plasma lipids (the 2.5 fold of normal values in the mean). It is characterised as a broad beta band on the electropherogram similar to type III pattern. Presence of beta migrating lipoproteins in the ultracentrifugal supernatand fraction of d = 1006 could not be demonstrated.

Acute Disease↗
PubMed1978

Evaluation of cytotoxic responses caused by selected organophosphorus esters in chick sympathetic ganglia cultures.

Ten day old chick sympathetic ganglia cultured in a microslide assembly were treated with a selected group of organophosphate pesticides to evaluate their cytotoxicity ranges, and the usefulness of such a model for screening pesticides. Examination by phase contrast and light microscopy for chemically-induced morphological alteration of nerve fibers, glial cells and neurons provided the criteria for quantitation and assessment of the toxic effects. Concentrations that produced half-maximal effects ranged from 1 x 10(-6)M (severely toxic) for methylparathian, diazinon, paraoxon, mevinphos, diisopropylfluorophosphate, tri-o-tolyl phosphate and its mixed isomers to a 1 x 10(-3)M (intermediate) for malathion, leptophos, coumaphos, mono- and dicrotophos. Some or no effects were evident at 1 x 10(2-)M for O'ethyl-O-p-nitrophenyl phenyl phosphonothioate, tri-m-tolylphosphate, chlorpyriphos and triphenyl phosphate. In all instances, nerve fibers were more sensitive than neurons or glial cells to insecticides. All cellular growth was inhibited at 1 x 10(-2)M (except triphenyl phosphate). Below 1 x 10(-7)M, no inhibitory effects were evident. The secondary abnormalities included decreased cellular migration, diffuse cellular growth pattern, increased vacuolization, nerve fiber swelling and cellular degeneration. The cytotoxic effects of these chemicals do not appear to be related to in vivo toxicity or cholinesterase inhibition potential.

Animals↗