The fallacy of the Principle of Procreative Beneficence

The claim that we have a moral obligation, where a choice can be made, to bring to birth the 'best' child possible, has been highly controversial for a number of decades. More recently Savulescu has labelled this claim the Principle of Procreative Beneficence. It has been argued that this Principle is problematic in both its reasoning and its implications, most notably in that it places lower moral value on the disabled. Relentless criticism of this proposed moral obligation, however, has been unable, thus far, to discredit this Principle convincingly and as a result its influence shows no sign of abating. I will argue that while criticisms of the implications and detail of the reasoning behind it are well founded, they are unlikely to produce an argument that will ultimately discredit the obligation that the Principle of Procreative Beneficence represents. I believe that what is needed finally and convincingly to reveal the fallacy of this Principle is a critique of its ultimate theoretical foundation, the notion of impersonal harm. In this paper I argue that while the notion of impersonal harm is intuitively very appealing, its plausibility is based entirely on this intuitive appeal and not on sound moral reasoning. I show that there is another plausible explanation for our intuitive response and I believe that this, in conjunction with the other theoretical criticisms that I and others have levelled at this Principle, shows that the Principle of Procreative Beneficence should be rejected.     

Stages of life: A new metaphysics of conceptionism

When a human being comes into existence is crucial in bioethics. Conceptionism is the view that a human being comes into existence at conception. The twinning argument is an influential objection to this view. All versions of the twinning argument rely on a metaphysics of material objects, namely, endurantism. Given this, a strategy for defending conceptionism against the twinning argument is to deny endurantism and adopt an alternative metaphysics of material objects. A version of this strategy which has been debated in this journal is to adopt perdurantism, or the ‘multiple occupancy view’, on which monozygotic twins share the zygote region as a temporal part. We present a novel version of this strategy: conceptionists can evade the twinning argument by adopting an exdurantist metaphysics of material objects. We suggest reasons for thinking that this is a plausible and, indeed, preferable way for conceptionists to avoid the twinning argument.     

Genetic aspects of the organization of legumin genes in pea

We have compared physical and genetic maps of the region around the legJ gene in pea. In this vicinity there are four B-type legumin genes, arranged as two close pairs. The detection of a recombination event within this gene cluster allows the orientation of this group of genes within the surrounding linkage group to be determined. The relationship between physical and genetic distances in this region is discussed, as are the implications of this for relating physical and genetic maps elsewhere in the pea genome.     

Genomics of the Bacillus cereus group of organisms

Members of the Bacillus cereus group of organisms include Bacillus cereus, Bacillus anthracis and Bacillus thuringiensis. Collectively, these organisms represent microbes of high economic, medical and biodefense importance. Given this significance, this group contains the highest number of closely related fully sequenced genomes, giving the unique opportunity for thorough comparative genomic analyses. Much of the disease and host specificity of members of this group can be attributed to their plasmids, which vary in size and number. Chromosomes exhibit a high level of synteny and protein similarity, with limited differences in gene content, questioning the speciation of the group members. Genomic data have spurred functional studies that combined microarrays and proteomics. Recent advances are reviewed in this article and highlight the advantages of genomic approaches to the study of this important group of bacteria.     

The Role of Surgery in the Treatment of Transposition of the Great Vessels

In 28 infants and children with complete transposition of the great vessels, atrial septal defects were created utilizing an open technique with inflow caval occlusion and moderate hypothermia. Of the 12 infants for whom operation was necessary during the first two weeks of life only two survived, suggesting that this technique is not adequate for infants at this age. Only four of the 16 children operated on between the ages of two weeks and three years failed to survive. Two of these died because of pre-existing non-cardiac conditions. Seven children with associated systemic-to-pulmonary shunts survived; the open technique may be preferable in this particular group. Despite the initial improvement afforded by this procedure, three sudden late deaths occurred. For this reason, and because of the danger of early development of pulmonary vascular disease, total operative correction of the malformation should be performed early.     

Geometric characterization of cell membrane of mouse oocytes for ICSI

Intracytoplasmic sperm injection (ICSI) is a broadly utilized assisted reproductive technology. A number of technologies for this procedure have evolved lately, such as the most commonly utilized piezo-assisted ICSI technique (P-ICSI). An important problem with this technique, however, is that it requires a small amount of mercury to stabilize the tip of the penetration micropipette. A completely different and mercury-free injection technology, called the rotationally oscillating drill (Ros-Drill) (RD-ICSI), was recently developed. It uses microprocessor-controlled rotational oscillations of a spiked micropipette after the pipette deforms the membrane to a certain tension level. Inappropriate selection of this initiation instant typically results in cell damage, which ultimately leads to unsuccessful ICSI. During earlier manual clinical tests of Ros-Drill, the technicians' expertise determined this instant in an ad hoc fashion. In this paper, we introduce a computer-vision-based tool to mechanize this process with the objective of maintaining the repeatability and introducing potential automation. Computer images are used for monitoring the membrane deformations and curvature variations as the basis for decision making. The main contribution of this paper is in the specifics of the computer logic to perform the monitoring. These new tools are expected to provide a practicable means for automating the Ros-Drill-assisted ICSI operation.     

Substrate specificity and kinetic properties of neutral maltase of human granulocytes

A neutral maltase immunologically similar to this of kidney exist in human granulocytes. We have studied some kinetic properties of this enzyme on a microsomal fraction of granulocytes. Its optimal pH is very closed of 6.8 and this enzyme, highly specific for maltose, hydrolysis very weakly the nigeriosis. Maltotriose, maltotetraose and maltopentanose are inhibitors of this enzyme, which is not inhibited by all disaccharides studied.     

静态荧光光谱法研究杜氏盐藻的生长规律

测量了杜氏盐藻不同生长期的静态荧光光谱,得出了杜氏盐藻生长规律曲线。通过与传统的分光光度计法和血球计数板法研究盐藻生长规律的比较发现,该方法反映的是活盐藻细胞浓度的变化情况,更能反映盐藻实际生长规律;不仅操作简便,灵敏度高,而且可以实现远距离非接触测量。     

Dynamics of mechanical properties of drying drops of biological liquids as a reflection of the features of self-organization of their components from nano- to microlevel

It has been shown that the dynamics of molecular self-organization of the components of liquids drying in the form of drops on a solid wettable surface contains information about their composition and structure. The physical mechanisms of this phenomenon have been considered. A method of recording this dynamics and retrieving useful information has been suggested. Examples of using this method in medical diagnosis and quality assessment of food products, drugs, and liquids of domestic appliance are given.     

Ontogenesis of animals from the position of absence of self-maintaining synthesis of regulatory proteins]

The starting point of this paper is that there is no self-maintenance of most tissue-specific regulatory proteins. There in only one cycle within regulatory genes hierarchy--"germ line" cycle ensuring the next generation ontogeny. The consequences of this are stage-specificity of gene expression and organism ageing. To explain the existence of long-living differentiated cells, we assume that certain genes cause specific repression of mRNAs encoding regulatory proteins, thereby stabilizing the mRNAs. On the contrary, the mRNAs encoding regulatory proteins necessary for proliferation are to be translated due to growth factors. If one of the genes encoding such mRNAs acquires a foreign (viral, for example) promoter, the cell will divide infinitely; this can explain a number of nuclear proto-oncogenes properties. From this view-point, cell proliferation and differentiation, ontogeny and regeneration are considered.     

Function of the lipopolysaccharide-binding protein of Periplaneta americana as an opsonin.

Previously, we reported the purification of an LPS-binding protein from the hemolymph of the American cockroach that was specific for E. coli LPS. In this study we found that this protein participated in the clearance of E. coli cells injected into the abdominal cavity of the cockroach, and that hemocytes ingested E. coli cells treated with this LPS-binding protein in vitro. These findings suggest that this LPS-binding protein acts as an opsonin.     

Axonal transport of [3H]serotonin in an identified neuron of Aplysia californica

The distribution of (Na+ + K+) ATPase over the plasma membranes of the proximal convoluted tubule from canine renal cortex has been determined. Ultrathin frozen sections of this tissue were stained with rabbit antibodies to this enzyme and ferritin-conjugated goat antirabbit gamma-globulin. It is demonstrated that high concentrations of this enzyme uniformly line the intercellular spaces of this epithelium. The consequences of this observation are discussed in terms of the low resistant tight junctions of these tubules and the isotonic fluid transport which they support. Furthermore, antibodies to (Na+ + K+) ATPase recognize an antigen on the luminal surfaces of the tubules within the brush border. It is proposed that the enzyme is present in this region of the plasma membrane as well, although at much lower concentration. To further substantiate this conclusion, a brush border fraction has been purified from rabbit kidney and been shown to contain significant (Na+ + K+) ATPase. These results contradict earlier conclusions about the location of (Na+ + K+) ATPase in this tissue.     

The role of a beta-bulge in the folding of the beta-hairpin structure in ubiquitin

It is known that the peptide corresponding to the N-terminal beta-hairpin of ubiquitin, U(1-17), can populate the monomeric beta-hairpin conformation in aqueous solution. In this study, we show that the Gly-10 that forms the bulge of the beta-turn in this hairpin is very important to the stability of the hairpin. The deletion of this residue to desG10(1-16) unfolds the structure of the peptide in water. Even under denaturing conditions, this bulge appears to be important in maintaining the residual structure of ubiquitin, which involves tertiary interactions within the sequence 1 to 34 in the denatured state. We surmise that this residual structure functions as one of the nucleation centers in the folding process and is important in stabilizing the transition state. In accordance with this idea, deleting Gly-10 slows down the refolding and unfolding rate by about one half.     

Theoretical study of fluorescence of photosynthetic pigments at complex dependence of intensity of exciting light on time

Now the methods using the radiance with complex dependence of light intensity on time are applied to research of photosynthesis by means of fluorescence, exciting photosynthetic pigments. One of these methods is applied in PAM-fluorometers--the commercial devices currently widely used to investigate a state of photosynthesizing systems. However, if excitation is performed in this way, the question, what components of fluorescence are registered at an output of such devices, remains to be open-ended. In this work an attempt to analyse this task has been made.     

The effects of temperature upon the toxicity of chemicals to aquatic organisms

Although rather extensive bibliographies give the impression that there is a vast amount of literature on the effects of temperature on aquatic organisms, when one tries to apply this information to specific interactions, such as the effects of temperature changes on chemical toxicity to aquatic organisms, often very little of the evidence is applicable. Although the most useful information on this relationship has been acquired in laboratory situations even this body of literature (which forms the bulk of this paper) is not adequate to make any scientifically justifiable generalizations. Field data on this relationship is almost non-existent and it is unlikely that much will become available unless specific studies are initiated which are directed toward this end. This is equally true of the laboratory information although it seems more likely that this will be generated as a spinoff from other research activities. In order to develop water quality management programs for steam-electric power plants one should understand the relationship between temperature and the response of aquatic organisms to toxic chemicals. Not only do some power plants discharge chlorine and other similar materials as well as heated waste water but those that discharge the latter only may be located near discharges of toxic chemicals. Since temperature and chemical stress to aquatic organisms are most commonly discussed independently we felt a paper covering this relationship would be useful.     

Ultimate Use of Two-Photon Fluorescence Microscopy to Map Orientational Behavior of Fluorophores

The orientational distribution of fluorophores is an important reporter of the structure and function of their molecular environment. Although this distribution affects the fluorescence signal under polarized-light excitation, its retrieval is limited to a small number of parameters. Because of this limitation, the need for a geometrical model (cone, Gaussian, etc.) to effect such retrieval is often invoked. In this work, using a symmetry decomposition of the distribution function of the fluorescent molecules, we show that polarized two-photon fluorescence based on tunable linear dichroism allows for the retrieval of this distribution with reasonable fidelity and without invoking either an a priori knowledge of the system to be investigated or a geometrical model. We establish the optimal level of detail to which any distribution can be retrieved using this technique. As applied to artificial lipid vesicles and cell membranes, the ability of this method to identify and quantify specific structural properties that complement the more traditional molecular-order information is demonstrated. In particular, we analyze situations that give access to the sharpness of the angular constraint, and to the evidence of an isotropic population of fluorophores within the focal volume encompassing the membrane. Moreover, this technique has the potential to address complex situations such as the distribution of a tethered membrane protein label in an ordered environment.     

Prospects for the involvement of cancer stem cells in the pathogenesis of osteosarcoma

Osteosarcoma (OS) is one of the most common bone tumors in children and adolescents that cause a high rate of mortality in this age group and tends to be metastatic, in spite of chemotherapy and surgery. The main reason for this can be returned to a small group of malignant cells called cancer stem cells (CSCs). OS-CSCs play a key role in the resistance to treatment and relapse and metastasis through self-renewal and differentiation abilities. In this review, we intend to go through the different aspects of this malignant disease, including the cancer stem cell-phenotype, methods for isolating CSCs, signaling pathways, and molecular markers in this disease, and drugs showing resistance in treatment efforts of OS.     

Ultimate Use of Two-Photon Fluorescence Microscopy to Map Orientational Behavior of Fluorophores

The orientational distribution of fluorophores is an important reporter of the structure and function of their molecular environment. Although this distribution affects the fluorescence signal under polarized-light excitation, its retrieval is limited to a small number of parameters. Because of this limitation, the need for a geometrical model (cone, Gaussian, etc.) to effect such retrieval is often invoked. In this work, using a symmetry decomposition of the distribution function of the fluorescent molecules, we show that polarized two-photon fluorescence based on tunable linear dichroism allows for the retrieval of this distribution with reasonable fidelity and without invoking either an a priori knowledge of the system to be investigated or a geometrical model. We establish the optimal level of detail to which any distribution can be retrieved using this technique. As applied to artificial lipid vesicles and cell membranes, the ability of this method to identify and quantify specific structural properties that complement the more traditional molecular-order information is demonstrated. In particular, we analyze situations that give access to the sharpness of the angular constraint, and to the evidence of an isotropic population of fluorophores within the focal volume encompassing the membrane. Moreover, this technique has the potential to address complex situations such as the distribution of a tethered membrane protein label in an ordered environment.