Functions and roles of IFIX,a member of the human HIN-200 family,in human diseases

Molecular and Cellular Biochemistry - Pyrin and hematopoietic expression, interferon-inducible nature, and nuclear localization (HIN) domain family member 1 (PYHIN1), also known as IFIX, belongs to...     

A, B, and H isoantigens in the human fetus

We studied the appearance of isoantigens A, B, and H during the fertilization age in human embryos and fetuses with the specific red cell adherence (SRCA) test. The first positive reaction was found in endothelial cells of a 4-wk-old embryo. In 6-wk-old embryos the isoantigens appeared on the luminal surface of the epithelium of the stomach and small intestine. In other organs the blood group isoantigens were detected at different stages of development; in 12-wk-old fetuses the distribution became identical with that of adults. In pancreatic exocrine glands from fetuses of all blood groups up to 5 mo old, H antigen alone was present. Brunner's glands of the duodenum reacted positively for both A and B blood group antigens of the fetus and also for H antigen, which supports the assumption that some secretory glands produce the precursor H substance throughout fetal and adult life.     

Pulmonary carbonic anhydrase in the human, monkey, and rat

The distribution of carbonic anhydrase in the human, monkey, and rat lung was studied by the histochemical method of Hansson. High activity of this enzyme was demonstrated in the endothelium of pulmonary capillaries. In the human and the monkey lung enzyme activity was exhibited in the whole circumference of the capillaries, but in the rat enzyme activity is confined to capillary segments having close contact with alveolar epithelium forming the blood-air barrier. Staining was inhibited by 10 microM acetazolamide, but was not affected by 10 microM Cl 13,850, an inactive acetazolamide analogue. The location of carbonic anhydrase in the lung supports the idea that pulmonary carbonic anhydrase promotes CO2 elimination from the blood into the alveolar space. Its possible functions may be to act upon plasma to accelerate the conversion of HCO-3 to CO2 and to facilitate CO2 transport through the lung tissue.     

Imitation,objects, tools,and the rudiments of language in human ontogeny

Human beings are imitative generalists. We can immediately imitate a wide range of behaviors with great facility, whether they be vocal maneuvers, body postures, or actions on objects. The ontogeny of this skill has been an enduring question in developmental psychology. Classical theory holds that the ability to imitate facial gestures is a milestone that is passed at about one year. Before this time infants are thought to lack the perceptual-cognitive sophistication necessary to match a gesture they can see with one they cannot see themselves perform. A second developmental milestone is the capacity for deferred imitation, i.e. imitation of an absent model. This is said to emerge at about 18 months, in close synchrony with other higher-order activities such as object permanence and tool use, as part of a general cognitive shift from a purely sensory-motor level of functioning to one that allows language. Research suggests that the imitative capacity of young infants has been underestimated. Human infants are capable of imitating facial gestures at birth, with infants less than one day old manifesting this skill. Moreover recent experiments have established deferred imitation well before the predicted age of 18 months. Studies discussed here show that 9-month-olds can duplicate acts after a delay of 24 hours, and that 14-month-olds can retain and duplicate as many as five actions over a 1-week delay. These new findings re-raise questions about the relation between nonverbal cognitive development and language development: What aspects, if any, of these two domains are linked? A hypothesis is delineated that predicts certain very specific relations between particular cognitive and semantic achievements during the one-word stage, and data are reported supporting this hypothesis. Specifically, relations are reported between: (a) the development of object permanence and the use of words encoding disappearance, (b) means-ends understanding (as manifest in tool use) and words encoding success and failure, and (c) categorization behavior and the onset of the naming explosion. This research on human ontogeny suggests close and highly specific links between aspects of early language and thought.     

Fear, faces, and the human amygdala

The amygdala's historical role in processing stimuli related to threat and fear is being modified to suggest a role that is broader and more abstract. Amygdala lesions impair the ability to seek out and make use of the eye region of faces, resulting in impaired fear perception. Other studies in rats and humans revive earlier proposals that the amygdala is important not only for fear perception as such, but also for detecting saliency and biological relevance. Debates about some features of this processing now suggest that while the amygdala can process fearful facial expressions in the absence of conscious perception, and while there is some degree of preattentive processing, this depends on the context and is not necessarily more rapid than cortical processing routes. A large current research effort extends the amygdala's putative role to a number of psychiatric illnesses.     

Neandertals,competition, and the origin of modern human behavior in the Levant

The East Mediterranean Levant is a small region, but its paleoanthropological record looms large in debates about the origin of modern humans and the fate of the Neandertals. For most of the twentieth century, the Levantine paleoanthropological record supported models of continuity and evolutionary transition between Neandertals and early modern humans. Recent advances in radiometric dating have challenged these models by reversing the chronological relationship between Levantine Neandertals and early modern humans. This revised chronostratigraphy for Levantine Middle Paleolithic human fossils raises interesting questions about the evolutionary relationship between Neandertals and early modern humans. A reconsideration of this relationship moves us closer to understanding the long delay between the origin of morphologically modern‐looking humans during the Middle Paleolithic (>130 Kyr) and the adaptive radiation of modern humans into Eurasia around the time of the transition from the Middle to Upper Paleolithic (50 to 30 Kyr).     

Falcon genomics in the context of conservation,speciation, and human culture

Here, we review the diversity, evolutionary history, and genomics of falcons in the context of their conservation and interactions with humans, and provide a perspective on how new genomic approaches may be applied to expand our knowledge of these topics. For millennia, humans and falcons (genus Falco) have developed unique relationships through falconry, religious rituals, conservation efforts, and human lifestyle transitions. From an evolutionary perspective, falcons remain an enigma. Having experienced several recent radiations, they have reached an unparalleled and almost global distribution, with an intrageneric species richness that is roughly an order of magnitude higher than typical within their family (Falconidae) and across other birds (Phylum: Aves). This diversity has evolved in the context of unusual genomic architecture that includes unique chromosomal rearrangements, relatively low chromosome counts, extremely low microdeletion rates, and high levels of nuclear mitochondrial DNA segments (NUMTs). These genomic peculiarities combine with high levels of ecological and organismal diversity and a legacy of human interactions to make falcons obvious candidates for evolutionary studies, providing unique research opportunities in common topics, including chromosomal evolution, the mechanics of speciation, local adaptation, domestication, and urban adaptation.     

Abundance, biology, and human exploitation of bats in the Palau Islands

Three species of bats, Pteropus pilosus, P. muriannus pelewensis , and Embullonura semicaudata palauensis , were surveyed by observations, systematic counts, and interviews with local residents in the Palau Islands of Micronesia during a one-month period in 1991. Pteropus pilosus is presumed extinct, with no observations made this century. Pteropus m. pelewensis occurred throughout the archipelago. It is less colonial than other subspecies of P. muriannus , with most of the population appearing to roost solitarily or in small groups of a few bats. Colonies were uncommon and typically ranged in size from about 30–200 animals. Evidence of two larger roosting concentrations, one of which may have held as many as 3,000 bats, was also found. These fruit bats forage and roost in a variety of forested habitats and have diverse diets known to contain the fruits of 54 species, the flowers of 28 species, and the leaves of one species. At dusk, most bats began foraging within several kilometres of their day roosts, but some flew at least 12 km to reach feeding sites. The largest numbers of P. m. pelewensis roosted on rugged and fairly inaccessible limestone islands near the centre of the archipelago, near where most people also lived. We were unable to estimate population size or determine population trend in the island chain. The bats are heavily harvested for commercial export, with more than 180,000 animals shipped to the Mariana Islands from 1975–1994. Smaller numbers are also killed as a local food source. Emballonura s. palauensis , the only insectivorous bat in the islands, was seen at 65% of the evening count locations and was also widespread in the archipelago. Recommendations for managing bats in Palau include a prohibition on the export of fruit bats and the establishment of several protected areas.     

Criticism,commitment, and the growth of human sociobiology

The fundamental unit of assessment in the sociobiology debate is neither a field nor a theory, but a framework of group commitments. Recourse to the framework concept is motivated, in general, by post-Kuhnian philosophy of scientific change and, in particular, by the dispute between E. O. Wilson and R. C. Lewontin. The framework concept is explicated in terms of commitments about problems, domain, disciplinary relations, exemplars, and performance evaluations. One upshot is that debate over such charges as genetic determinism, reductionism, adaptationism, and the biologization of human nature has been vexed. It has lost sight of human sociobiology's central problem, namely to help show that the modern synthesis is complete.     

Positive selection, relaxation, and acceleration in the evolution of the human and chimp genome

For years evolutionary biologists have been interested in searching for the genetic bases underlying humanness. Recent efforts at a large or a complete genomic scale have been conducted to search for positively selected genes in human and in chimp. However, recently developed methods allowing for a more sensitive and controlled approach in the detection of positive selection can be employed. Here, using 13,198 genes, we have deduced the sets of genes involved in rate acceleration, positive selection, and relaxation of selective constraints in human, in chimp, and in their ancestral lineage since the divergence from murids. Significant deviations from the strict molecular clock were observed in 469 human and in 651 chimp genes. The more stringent branch-site test of positive selection detected 108 human and 577 chimp positively selected genes. An important proportion of the positively selected genes did not show a significant acceleration in rates, and similarly, many of the accelerated genes did not show significant signals of positive selection. Functional differentiation of genes under rate acceleration, positive selection, and relaxation was not statistically significant between human and chimp with the exception of terms related to G-protein coupled receptors and sensory perception. Both of these were over-represented under relaxation in human in relation to chimp. Comparing differences between derived and ancestral lineages, a more conspicuous change in trends seems to have favored positive selection in the human lineage. Since most of the positively selected genes are different under the same functional categories between these species, we suggest that the individual roles of the alternative positively selected genes may be an important factor underlying biological differences between these species.     

Differential expression of the Quox-1 gene in normal human cells,early human embryo,and tumor cells

Quox-1 is the only gene in the hox family whose expression occurs throughout the developing central nervous system. The differential expression of the Quox-1 gene was studied in normal human tissues and tumor tissues. Marked expression of Quox-1 was detected in early human embryos, LCE cells, and HeLa cells, with weak to zero expression being detected in various normal human tissues. Immunocytochemistry analysis further confirmed that the Quox-1 protein was absent in normal human leukocytes. However, high levels of Quox-1 product were found in leukocytes of acute lymphocyte leukemia patients and in patients with a subtype of acute nonlymphocyte leukemia. In addition, Southern blot analysis showed that the genomic DNA of LCE, HeLa, and normal human leukocyte cells had a DNA rearrangement of the Quox-1 gene, suggesting that the rearrangement of genomic DNA might be the cause of differential expression in normal human tissues and tumor tissues. The data implied that the overexpression of Quox-1 was associated with tumors, and that there may be links between the processes of embryogenesis and carcinogenesis.     

Blowing in the wind? Identity, materiality, and the destinations of human ashes

This article asks whether the recent UK-based practice of removing ashes from crematoria has led to entirely new, innovative rituals of disposal, or whether contemporary practice is an appropriation of late nineteenth-century Romantic values and beliefs. Drawing on findings from a major empirical study among both professionals and lay people involved in the removal of ashes, it explores the potentiality of ash remains as a mobile material residue of the corpse, and considers whether they enable disposal strategies which no longer reflect concerns with space and place – particularly those associated with traditional burial grounds.     

Function, expression, and characterization of the serotonin transporter in the native human intestine

The enteric serotonin transporter (SERT) plays a critical role in modulating serotonin availability and thus has been implicated in the pathogenesis of various intestinal disorders. To date, SERT expression and function in the human intestine have not been investigated. Current studies were designed to characterize the function, expression, distribution, and membrane localization of SERT in the native human intestine. Real-time PCR studies showed relatively higher SERT mRNA expression in the human small intestine compared with colon (ileum > duodenum > jejunum). Northern blot analysis revealed three mRNA hybridizing species encoding SERT (3.0, 4.9, and 6.8 kb) in the human ileum. Consistent with SERT mRNA expression, SERT immunostaining was mainly detected in the epithelial cells of human duodenal and ileal resected tissues. Notably, SERT expression was localized predominantly to the apical and intracellular compartments and was distributed throughout the crypt-villus axis. Immunoblotting studies detected a prominent protein band ( approximately 70 kDa) in the ileal apical plasma membrane vesicles (AMVs) isolated from mucosa obtained from organ-donor intestine. Functional studies showed that uptake of [(3)H]serotonin (150 nM) in human ileal AMVs was 1) significantly increased in the presence of both Na(+) and Cl(-); 2) inhibited ( approximately 50%) by the neuronal SERT inhibitor, fluoxetine (10 microM) and by unlabeled 5-HT; and 3) exhibited saturation kinetics indicating the presence of a carrier-mediated process. Our studies demonstrated differential expression of SERT across various regions of the human intestine and provide evidence for the existence of a functional SERT capable of removing intraluminal serotonin in human ileal epithelial cells.