Homologous sequences in proteins with different functions

Data on the primary structure of approximately 250 proteins and regulatory peptides are presented. It was shown that functionally different proteins contain homologous sequencies. Growth hormone molecule contains homologous sequencies to several proteins. On the whole, polypeptide hormones more frequently, as compared to other proteins, contained sequencies, which are homologous to fragments of proteins with various functions. Evolutionary aspects of multiple relations between proteins are discussed.     

Evolutionary significance of the phylogenetic distribution of the mammalian hypothalamic releasing hormones

The hypophysiotrophic hormones isolated from the mammalian hypothalamus are distributed throughout the nervous system of vertebrate species. Although their role in regulating pituitary hormone secretion in mammals is clear, a similar function in lower species has not been established. Thyrotropin-releasing hormone is unable to stimulate thyroid function in amphibia and fish, despite being present in the hypothalamus and brain of these species of high concentration. The tripeptide is also found in high concentration in frog skin, a tissue derived from (or programed by) primitive neuroectoderm that is also a rich source of other peptides structurally related to neural peptides located in mammalian brain and gut. Luteinizing hormone-releasing hormone (LHRH) is able to activate gonadotropin secretion in submammalian species but there is evidence that the LHRH material present in avian, reptilian, and piscine brain is not identical to the mammalian decapeptide. An LHRH-like material present in frog sympathetic ganglia appears to function as a neurotransmitter in this location. Somatostatin is present in high concentrations in the hypothalamus, brain, pancreas, and gastrointestinal tract of all vertebrates and chromatographically is identical to the mammalian material, suggesting that this peptide is an "ancient" molecule with an important role in neuronal pancreatic and digestive function. The hypothalamic releasing hormones are part of a family of neural peptides that have a widespread anatomic and phylogenetic distribution and form a diffuse neuroendocrine system. It an material, suggesting that this peptide is an "ancient" molecule with an important role in neuronal pancreatic and digestive function. The hypothalamic releasing hormones are part of a family of neural peptides that have a widespread anatomic and phylogenetic distribution and form a diffuse neuroendocrine system. It an material, suggesting that this peptide is an "ancient" molecule with an important role in neuronal pancreatic and digestive function. The hypothalamic releasing hormones are part of a family of neural peptides that have a widespread anatomic and phylogenetic distribution and form a diffuse neuroendocrine system. It appears likely that the releasing hormones initially arose with a neurocrine or paracrine function, and that only later in evolution did they acquire the role of regulating adenohypophysial secretion.     

A new member of the Balbiani ring multigene family in the dipteran Chironomus tentans consists of a single-copy version of a unit repeated in other gene family members

The known Balbiani ring (BR) multigene family members in the dipteran Chironomus tentans encode salivary gland secretory proteins in the size range between 38 and 1,000 kDa. The proteins interact to form protein fibers used by the aquatic larvae to spin feeding and protective larval tubes or pupation tubes. Here, we describe a new BR multigene family member, the spl7 gene, which codes for an 89-amino-acid-long protein with a relative mobility of 17k. The gene has a high content of charged amino acid residues and consists of two structurally different halves. Five regularly spaced cysteine codons are present in the 5 half while the 3 half contains five proline codons. These two different halves exhibit similarities to the C and SR regions, respectively, which form the tandemly repeated units in the about 40-kb-long BR genes and which also, in different versions, are the building blocks of all genes in the BR multigene family.In this multigene family, encoding interacting structural proteins, the long BR genes with their 125–150 tandemly arranged repeat units as well as the short sp17 gene with its single-copy version of such a repeat unit, have therefore evolved from a common ancestor.Correspondence to: L. Wieslander     

Lambda H-lambda T 80 hybrid study of the DNA structural gene region in lambda and phi 80 phages

Hybrids lambda H lambda T80 are formed due to recombination of the phage lambda att80 and phi 80 prophage partially deleted in the region of structural genes. Genetic structure of 22 independently isolated lambda H lambda T80 hybrids was determined by the restriction method and it was shown that recombination took place in the genes A, C, D and H. The frequencies of hybrid formation diminish from 1.10(-3) to 4.10(-5) for this gene order, which suggests that the polar divergence of nucleotide sequencies in the region of structural genes exists. It was found that formation of hybrids with recombination in the region of "weak" homology (gene H) was possible only when the region of "strong" homology was present in the deleted phi 80 prophage to initiate recombination.     

Delta-endotoxins form cation-selective channels in planar lipid bilayers.

Delta-endotoxins CryIA(c) and CryIIIA, two members of a large family of toxic proteins from Bacillus thuringiensis, were each allowed to interact with planar lipid bilayers and were analyzed for their ability to form ion-conducting channels. Both of these toxins made clearly resolved channels in the membranes and exhibited several conductance states, which ranged from 200 pS to about 4000 pS (in 300 mM KCl). The channels formed by both toxins were highly cation-selective, but not ideally so. The permeability ratio of K+ to Cl- was about 25 for both channels. The ability of these proteins to form such channels may account for their toxic action on sensitive cells, and suggests that this family of toxins may act by a common mechanism.     

Carotenoids in fish. XXIII. Syngnathidae family

The author investigated the presence of various carotenoids in three species of the Syngnathidae family by means of columnar and thin-layer chromatography. The investigations revealed the presence of the following carotenoids: canthaxanthin, lutein, lutein epoxide, zeaxanthin, astaxanthin (free and ester form) and 4-hydroxy-4-keto--carotene. Ketocarotenoids (astaxanthin and canthaxanthin) comprised the greatest part     

Biological problems of origin and development of various physiological functions (theory and application)

The author presents some idea about origin and development of some physiological functions: outer breathing, breath function of blood, blood circulation, thermoregulation, energy supply. The conclusions about main directions of evolution of these functions and duration of their development in phylogeny were drawn. The author gave some examples of abrupt changes of development of these functions in different groups of animals and discussed possible reasons of such changes. General quantitative estimation of the results of evolution of these functions from the position of their summArized efficiency was done. Quantitative characteristics of optimization and efficiency limits of physiological functions were suggested on the base of new data in general biology and comparative physiology. The author put toward the hypothesis about conventional "mistakes" of evolution and showed deep biological reasons of some seriOus illness. The examples of some applied problems in biology, physiology and medicine that can be solved with the data on evolution of physiological functions are presented.     

What Do Abelam Images Want from Us?: Plato's Cave and Kwatbi's Belly

In this paper I compare two origin myths, one from the Abelam speaking area of the Sepik region, Papua New Guinea, the other, the allegory of Plato's Cave found in The Republic. I explore the effects which each of these different conceptions of iconography and aesthetics has on the other when they intersect. I argue that fieldwork itself can be looked at as a hybrid form in the sense that it brings into juxtaposition different systems of thought and contrasting cultural tropes. At the moment of intersection a new cultural form, a hybrid, is produced in that someone may ask a question which has never been asked before and respondents may think about something they have never consciously thought about before. I attempt to imaginatively reconstruct one such moment when Anthony Forge questioned Abelam painters in the Sepik region of Papua New Guinea about their iconographic system. By comparing the two origin myths we can better comprehend why Forge received particular and, from his viewpoint, problematic answers to questions about the meaning of particular painting designs. The comparison reveals that the myths are inversions of one another and imply radically differing conceptions of space and iconography. The paper ends by demonstrating that Abelam painters in their turn have questions about systems of representation different from their own. This can be seen in their interrogation of the author about the labels on perfume bottles and their response to an art gallery in Sydney, Australia, which they visited with the author.     

Cancer initiating cells or cancer stem cells in the gastrointestinal tract and liver

It has been suggested that cancer stem cells population within the solid tumor with indefinite proliferation potential drives the growth and metastasis of cancer. In literature, these malignant stem cells also named Cancer initiating cells. Cancer stem cells exhibit low rate of division and proliferation in their niche that help them to avoid chemotherapy and radiation. Epithelial cancers are believed to originate from transformation of tissue stem cells. Bone marrow-derived cells, which are frequently recruited to sites of tissue injury and inflammation, might also represent a potential source of malignancy in the gastrointestinal tract. Pancreatic cancer is one of most common cause of cancer-related death. Pancreatic cancer stem cells have been characterized recently through serial transplantation of human pancreatic cancer cells. The phenotype of Pancreatic cancer stem cells has been defined as CD24(+)CD44(+)CD326 (ESA)(+). CD133 antigen has been also suggested as a potential marker for cancer stem cell in gastrointestinal tract but recently there is also debate in this regard. More recently, other cancer stem cells in gastrointestinal tract, such as colon cancer stem cells, liver cancer stem cells, have been also characterized in their phenotype. These advances clearly will bring the new strategy in cancer treatment and control in the gastrointestinal tract. In this review, the author will discuss the current status and progress about cancer stem cell research in gastrointestinal tract and liver.     

Ecological study of the saddle backed tamarin (Saguinus fuscicollis) in Northern Bolivia

The author carried out an ecological survey of the saddle backed tamarin (Saguinus fuscicollis) in the Pando, northern Bolivia, from July to December 1979. It was found thatS. fuscicollis formed a family group consisting of two to seven individuals and spent almost all the daytime in moving to forage insects, although it fed mainly on fruits of the family Moraceae. Primary forest was preferred for sleeping sites, whereas the animals spent more hours in secondary forest than in primary forest in their home range. Marking sites were concentrated in the center of the home range but encounter behaviors tended to take place near the borderlines of the home range. It was also found that infants began feeding on fruit at about 5 weeks of age, whereas they shared insects obtained by their mothers until about 10 weeks of age.     

Effects of shift changes on female workers at a dish factory

This study investigated the effects of working night shifts on social and family life by examining changes in workers' daily life before and after a change in their shifts. Subjects were 40 women aged 27-59 years, working at a dish factory. During the health examination of night workers in autumn of 2000, the subjects were directly interviewed about changes in their lives induced by the shift change. Question parameters consisted of 8 items including 30 sub-items related to social and family life, such as sleep, rest, meals, sports, family time, hobbies, neighborhood association and social activities. The subjects selected one of four response categories: "becoming worse", "no change", "becoming better" and "difficult to determine." With regard to the percentage of "becoming worse", meal-related items ranked high in all of the shift types. "Family time" and "hobbies" showed high percentages in the subjects transferring from day shifts to night shifts, and in those transferring from early-morning shifts to night shifts. "Rest", "sports" and "hobbies" showed high percentages in the subjects transferring from night shifts to midnight shifts. Decreased sleeping hours were confirmed in all of the shift types, while the subjects tended to sleep more soundly. As the workers transfer to shifts at earlier hours, they were obliged to make sacrifices in various aspects of their social and family life. Therefore, much assistance in this regard should be given to them.     

A serpin from the gut bacterium Bifidobacterium longum inhibits eukaryotic elastase-like serine proteases

Serpins form a large class of protease inhibitors involved in regulation of a wide spectrum of physiological processes. Recently identified prokaryotic members of this protein family may provide a key to the evolutionary origins of the unique serpin fold and the associated inhibitory mechanism. We performed a biochemical characterization of a serpin from Bifidobacterium longum, an anaerobic Gram-positive bacterium that naturally colonizes human gastrointestinal tract. The B. longum serpin was shown to efficiently inhibit eukaryotic elastase-like proteases with a stoichiometry of inhibition close to 1. Porcine pancreatic elastase and human neutrophil elastase were inhibited with the second order association constants of 4.7 x 10(4) m(-1) s(-1) and 2.1 x 10(4) m(-1) s(-1), respectively. The B. longum serpin is expected to be active in the gastrointestinal tract, because incubation of the purified recombinant serpin with mouse feces produces a stable covalent serpin-protease adduct readily detectable by SDS-PAGE. Bifidobacteria may encounter both pancreatic elastase and neutrophil elastase in their natural habitat and protection against exogenous proteolysis may play an important role in the interaction between these commensal bacteria and their host.     

Cytoangioarchitectonics of the parasympathetic ganglion of the frog bladder according to findings from studies during life]

The form of neuronal bodies and their interarrangement with capillaries was studied in prevital parasympathetic ganglia in the bladder of the frog (Rana temporaria). The size of the neurons and the diameter of the capillaries were measured. Most of the neurons were stated to have oval form and they are oriented by their long axis along the capillaries, about 20% neurons have contacts with 2--3 capillaries; some neurons have no contacts and their distance from the nearest capillary is 32--26 mkm. Intermediate structure may be either a connective tissue or neuroglia, or (seldom) other neuronal cells. Unequal conditions of neuronal blood supply, as the author believes, demonstrate their different metabolism and various levels of their functional activity.     

Fas and Fas ligand in gut and liver

Apoptosis (programmed cell death) has been shown to play a major role in development and in the pathogenesis of numerous diseases. A principal mechanism of apoptosis is molecular interaction between surface molecules known as the "death receptors" and their ligands. Perhaps the best-studied death receptor and ligand system is the Fas/Fas ligand (FasL) system, in which FasL, a member of the tumor necrosis factor (TNF) family of death-inducing ligands, signals death through the death receptor Fas, thereby resulting in the apoptotic death of the cell. Numerous cells in the liver and gastrointestinal tract have been shown to express Fas/FasL, and there is a growing body of evidence that the Fas/FasL system plays a major role in the pathogenesis of many liver and gastrointestinal diseases, such as inflammatory bowel disease, graft vs. host disease, and hepatitis. Here we review the Fas/FasL system and the evidence that it is involved in the pathogenesis of liver and gastrointestinal diseases.     

The Spanish woman and birth control

The author presents in this article just a small part of the results obtained in national survey of 1.902 married women, carried out in 1972, on "fertility and family planning in Spain". More specifically, attitudes of this sample of Spanish married women towards family planning are explained. It is pointed out, in the first place, that eight out of every ten interviewed women say that all married couples who can have children ought to have them. Younger women and those with a higher socio-econimic status, however, are less in favor of that statement. Trough several questions it is also evident that the number of interviewees who think that other women control their fertility is higher the more distant from the respondent is the social circle about which the question is formulated. In other words, interviewees resist to admit that persons with whom they are more intimately related control their fertility. Approximately half the women in the sample say that married couples should have as many children as may come, but the other half say that couples should decide the number of children they want to have and when they want to have them. This last opinion is relatively more important among younger and higher status women. Along with the previous finding, almost half of the interviewees are very much in favor or rather in favor of family planning, that proportion being even higher among younger and higher status women. Finally, seven ou of every ten respondents say that there should be wide and complete information about all family planning methods, leaving it up to each individual to use or not to use them according to its own conscience. This opinion, of course, is also more common among younger and higher status women.     

Forty years of cytochrome P450

The term "cytochrome P450" first appeared in literature in 1962. It was a microsomal membrane-bound hemoprotein without known physiological functions at that time and was characterized by a unique 450-nm optical absorption peak of its carbon monoxide-bound form, which was originally reported as the spectrum of a novel "microsomal carbon monoxide-binding pigment" in 1958. Elucidation of its function as the oxygenase in 1963 triggered a rapid expansion of research on this hemoprotein. Annual numbers of the published papers dealing with cytochrome P450, which were listed in Biological Abstracts, increased from 60 in 1970 to 500 in 1980, 900 in 1990, and 1500 in 1997. Cytochrome P450 is now regarded as the collective name of a large family of hemoproteins, "cytochrome P450 superfamily, "which seems to have diversified from a single ancestral protein to many forms during the course of biological evolution and is distributed widely among various forms of life from animals and plants to fungi and bacteria. Multicellular eukaryotic organisms including animals and plants have about 100 or more P450 genes in their genomes, and those many P450 genes are expressed tissue specifically and developmental stage specifically, indicating their diverse physiological functions. In mammals, various P450s participate in the biosynthesis and metabolism of sterols and steroid hormones and the metabolism of various lipid biofactors including eicosanoids, vitamin D3, and retinoids. Oxidative metabolism of foreign hydrophobic compounds as the first step of their excretion from the animal body is apparently another major function of cytochrome P450, which protects animals from noxious foreign compounds, man-created and natural.     

Changing Minds? Implications of Conceptual Change for Teaching and Learning about Biological Evolution

Learning about biological evolution presents particular challenges for students. Barriers to learning come in the form of students’ prior conceptions that conflict with the scientific perspective of biological change. Theory and research from developmental and educational psychology provide insight into these barriers. Helping students understand evolution is not simply a matter of adding to their existing knowledge, but rather, it means helping them to see the world in new and different ways. Theoretical perspectives on creating change in students’ conceptions have implications for teaching about biological evolution. The material is based upon work supported by the National Science Foundation: Grant #0635629 to all three authors, #0133446 to the second author, and #0540152 to the third author.     

A review of the ethnomedicinal uses,phytochemistry and pharmacology of the <Emphasis Type="Italic">Pleiocarpa</Emphasis> genus

Pleiocarpa genus is a flowering plant from the Apocynaceae family which are rich sources of phytochemicals and have been reported to be useful in the treatment of gastrointestinal ailments, fever, malaria, pain, diabetes and cancer. The aim of this review is to present the past and current ethnomedicinal uses, phytochemistry and the pharmacology of Pleiocarpa genus which are underexploited as revealed through this review in order to enhance its potential source of phytochemical leads in medicine. Some pharmacological activities of these plants based on their acclaimed ethnomedicinal uses have been investigated by various researchers. The chemical profile of the genus is limited to alkaloids and triterpenoids, where indole alkaloids may be considered as important taxonomical markers.     

Ethical issues and the family doctor

After noting several contemporary societal factors that contribute to increasing concern about bioethical issues in general, the author focuses on special problems that confront the general or family practitioner. These problems arise from the family physician's large number of potentially conflicting roles and relationships.