[Application of a universal system of epitesis fixation in the rehabilitation of patients with maxillofacial defects]. / Proizvodstvo i primenenie universal'noi sistemy fiksatsii epitezov pri reabilitatsii patsientov s defektami litsa.

OBJECTIVE: The aim of the study was the creation of a universal epithesis fixation system that increases the reliability of its functioning in prosthetics of patients with maxillofacial defects of various genesis. MATERIAL AND METHODS: After the surgical preparation of patients, in accordance with the indications of the underlying disease, epithesis was made from rigid silicone elastomers using CAD/CAM technologies. For the production of attachments, the VT1-0 titanium alloy common in medicine was used. RESULTS: A universal epithesis fixation system was used for prosthetics of various parts of the patient's face. Depending on the clinical situation and the size of the prosthetics area, an intermediate lattice plate (mesostructure) of the appropriate size and configuration was selected. Two types of attachments were used to fix epithets: magnetic with a counterpart and non-magnetic mushroom-shaped. The universal epithesis attachment system is distinguished by the possibility of using each hole of the lattice, both for attaching it to the bone structure and for installing attachments, which makes it easy to fix the lattice to residual bone fragments and center the position of the transition elements and attachments depending on the aesthetic and functional needs of the structure in whole. CONCLUSION: The success of prosthetics largely depends on the epithesis attachment system. The proposed universal epithesis fixation system allows its use in various clinical situations and also reduces the cost of prosthetics for patients with maxillofacial defects.

The role of citizen science in addressing grand challenges in food and agriculture research.

The power of citizen science to contribute to both science and society is gaining increased recognition, particularly in physics and biology. Although there is a long history of public engagement in agriculture and food science, the term 'citizen science' has rarely been applied to these efforts. Similarly, in the emerging field of citizen science, most new citizen science projects do not focus on food or agriculture. Here, we convened thought leaders from a broad range of fields related to citizen science, agriculture, and food science to highlight key opportunities for bridging these overlapping yet disconnected communities/fields and identify ways to leverage their respective strengths. Specifically, we show that (i) citizen science projects are addressing many grand challenges facing our food systems, as outlined by the United States National Institute of Food and Agriculture, as well as broader Sustainable Development Goals set by the United Nations Development Programme, (ii) there exist emerging opportunities and unique challenges for citizen science in agriculture/food research, and (iii) the greatest opportunities for the development of citizen science projects in agriculture and food science will be gained by using the existing infrastructure and tools of Extension programmes and through the engagement of urban communities. Further, we argue there is no better time to foster greater collaboration between these fields given the trend of shrinking Extension programmes, the increasing need to apply innovative solutions to address rising demands on agricultural systems, and the exponential growth of the field of citizen science.

Laparoscopy shows superiority over endoscopy for early detection of malignant atrophic papulosis gastrointestinal complications: a case report and review of literature.

BACKGROUND: The malignant form of atrophic papulosis (Köhlmeier-Degos disease) is a rare thrombo-occlusive vasculopathy that can affect multiple organ systems. Patients typically present with distinctive skin lesions reflective of vascular drop out. The small bowel is the most common internal organ involved, resulting in considerable morbidity and mortality attributable to ischemic microperforations. Determination of the presence of gastrointestinal lesions is critical in distinguishing systemic from the benign, cutaneous only disease and in identifying candidates for treatment. CASE PRESENTATION: We describe an 18 year old male who first presented with cutaneous atrophic papulosis but became critically ill from small bowel microperforations. He had an almost immediate and dramatic response to treatment. Prior to his presentation with acute abdomen he had upper and lower endoscopy showing areas of nonspecific patchy erythema. At laparotomy, innumerable characteristic lesions with central pearly hue and erythematous border were seen. PubMed was used for a literature search using the keywords malignant atrophic papulosis, Degos disease, endoscopy, laparoscopy and laparotomy. This search yielded 200 articles which were further analyzed for diagnostic procedures and findings. Among the 200 articles we identified only 11 cases in which endoscopy was performed. Results of endoscopy and laparotomy in our patient with malignant atrophic papulosis were compared to those in the literature. Endoscopy of the gastrointestinal tract has shown gastritis and non-specific inflammation whereas laparoscopy shows white plaques with red borders on the serosal surface of the small bowel and the peritoneum. From personal communications with other physicians worldwide, we identified three additional unpublished cases in which endoscopy revealed only minimal changes while laparoscopy showed dramatic lesions. From our experience the endoscopic findings are often subtle and nonspecific, whereas laparascopy or laparotomy will reveal pathognomic lesions on the serosal surface of the intestine. CONCLUSION: Our report contrasts the endoscopic and laparoscopic findings in malignant atrophic papulosis which suggest laparoscopy is the more powerful means of detecting gastrointestinal involvement. Imaging studies may serve as a key indicator of systemic progression. Based on our experience, laparoscopy should be performed when there is a high index of suspicion for gastrointestinal malignant atrophic papulosis, even if endoscopic examination is non-diagnostic or normal.

The ontology of craniofacial development and malformation for translational craniofacial research.

We introduce the Ontology of Craniofacial Development and Malformation (OCDM) as a mechanism for representing knowledge about craniofacial development and malformation, and for using that knowledge to facilitate integrating craniofacial data obtained via multiple techniques from multiple labs and at multiple levels of granularity. The OCDM is a project of the NIDCR-sponsored FaceBase Consortium, whose goal is to promote and enable research into the genetic and epigenetic causes of specific craniofacial abnormalities through the provision of publicly accessible, integrated craniofacial data. However, the OCDM should be usable for integrating any web-accessible craniofacial data, not just those data available through FaceBase. The OCDM is based on the Foundational Model of Anatomy (FMA), our comprehensive ontology of canonical human adult anatomy, and includes modules to represent adult and developmental craniofacial anatomy in both human and mouse, mappings between homologous structures in human and mouse, and associated malformations. We describe these modules, as well as prototype uses of the OCDM for integrating craniofacial data. By using the terms from the OCDM to annotate data, and by combining queries over the ontology with those over annotated data, it becomes possible to create "intelligent" queries that can, for example, find gene expression data obtained from mouse structures that are precursors to homologous human structures involved in malformations such as cleft lip. We suggest that the OCDM can be useful not only for integrating craniofacial data, but also for expressing new knowledge gained from analyzing the integrated data.

High frequency de novo alterations in the long-range genomic structure of the mouse pseudoautosomal region.

The pseudoautosomal region (PAR) is a segment of shared homology between the X and Y chromosomes. Here we report physical linkage of three mouse PAR probes: DXYHgu1, DXYMov15 and (TTAGGG)n. Steroid sulphatase (Sts) maps distal to these probes, indicating that there is an internal array of the telomere sequence (TTAGGG)n in the PAR. Pseudoautosomal PacI restriction fragments, up to 2 Mb in size, are unstable in C57BL/6 x C57BL/6 crosses. New alleles, often several hundred kilobases different in size, occur at a sex-averaged rate of approximately 30% per allele. Such frequent large-scale germline genome arrangements are without precedent in mammals.

Expression of the X-inactivation-associated gene XIST during spermatogenesis.

Mammalian X-chromosome inactivation is thought to be controlled by the X inactivation centre (XIC, X-controlling element -Xce-in mice). A human gene, XIST and its mouse counterpart, Xist, which map to the XIC/Xce, are expressed exclusively from inactive X chromosomes, suggesting their involvement in the process of X-inactivation. We now report the presence of Xist/XIST transcripts in newborn and adult mouse testes, and in human testicular tissue with normal spermatogenesis, but not in the testes of patients who lack germ cells. Our results indicate that while the X chromosome in males is active in somatic cells, it undergoes inactivation during spermatogenesis.

Cloning and expression of the mouse pseudoautosomal steroid sulphatase gene (Sts).

Steroid sulphatase (STS) is an important enzyme in steroid metabolism. The human STS gene has been cloned and mapped to Xp22.3, proximal to the pseudoautosomal region (PAR). Using quantitative differences in STS activity among various mouse strains, a segregation pattern consistent with autosomal linkage was first reported, but more recent studies have linked Sts to the mouse PAR. Failed attempts to clone the mouse Sts gene using human reagants (STS cDNA and anti-STS antibodies) suggest a substantial divergence between these genes. However, partial amino-terminal sequence from purified rat liver Sts is very similar to its human counterpart, and several domains are conserved among all the sulphatases. We followed a degenerate-primer reverse transcriptase-PCR (RT-PCR) approach to amplify a conserved fragment of the rat Sts cDNA that was then used to clone the mouse Sts cDNA. This 2.3-kb cDNA revealed 75% similarity with rat Sts cDNA, while it was only 63% similar to human STS cDNA. Transfection of STS(-) A9 cells with the mouse Sts cDNA restored STS enzymatic activity. Sts was also mapped physically to the distal end of the mouse sex chromosomes, and our backcross studies placed Sts distal to the 'obligatory' cross-over in male meiosis.

The murine Xe169 gene escapes X-inactivation like its human homologue.

Among a number of genes that escape X-chromosome inactivation in humans, three have been evaluated in mice and unexpectedly all three are subject to X-inactivation. We report here the cloning and expression studies of a novel mouse gene, Xe169, and show that it escapes X-inactivation like its human homologue. Xe169 was assigned to band F2/F3 on the mouse X chromosome by fluorescent in situ hybridization and Southern analysis indicates that the gene is located outside the pseudoautosomal region. Homologous, but divergent, sequences exist on the Y chromosome. In vitro and in vivo studies show that Xe169 is expressed from both the active and the inactive X chromosomes. Xe169 is the first cloned non-pseudoautosomal gene that escapes X-inactivation in mice.

MRI of weight bearing and movement.

Conventional, static magnetic resonance imaging (MRI) is able to provide a vast amount of information regarding the anatomy and pathology of the musculoskeletal system. However, patients, especially those whose pain is position dependent or elucidated by movement, may benefit from more advanced imaging techniques that allow for the acquisition of functional information. This manuscript reviews a variety of advancements in MRI techniques that are used to image the musculoskeletal system dynamically, while in motion or under load. The methodologies, advantages and drawbacks of stress MRI, cine-phase contrast MRI and real-time MRI are discussed as each has helped to advance the field by providing a scientific basis for understanding normal and pathological musculoskeletal anatomy and function. Advancements in dynamic MR imaging will certainly lead to improvements in the understanding, prevention, diagnosis and treatment of musculoskeletal disorders. It is difficult to anticipate that dynamic MRI will replace conventional MRI, however, dynamic MRI may provide additional valuable information to findings of conventional MRI.

Linking molecular affinity and cellular specificity in cadherin-mediated adhesion.

Many cell-cell adhesive events are mediated by the dimerization of cadherin proteins presented on apposing cell surfaces. Cadherin-mediated processes play a central role in the sorting of cells into separate tissues in vivo, but in vitro assays aimed at mimicking this behavior have yielded inconclusive results. In some cases, cells that express different cadherins exhibit homotypic cell sorting, forming separate cell aggregates, whereas in other cases, intermixed aggregates are formed. A third pattern is observed for mixtures of cells expressing either N- or E-cadherin, which form distinct homotypic aggregates that adhere to one another through a heterotypic interface. The molecular basis of cadherin-mediated cell patterning phenomena is poorly understood, in part because the relationship between cellular adhesive specificity and intermolecular binding free energies has not been established. To clarify this issue, we have measured the dimerization affinities of N-cadherin and E-cadherin. These proteins are similar in sequence and structure, yet are able to mediate homotypic cell patterning behavior in a variety of tissues. N-cadherin is found to form homodimers with higher affinity than does E-cadherin and, unexpectedly, the N/E-cadherin heterophilic binding affinity is intermediate in strength between the 2 homophilic affinities. We can account for observed cell aggregation behaviors by using a theoretical framework that establishes a connection between molecular affinities and cell-cell adhesive specificity. Our results illustrate how graded differences between different homophilic and heterophilic cadherin dimerizaton affinities can result in homotypic cell patterning and, more generally, show how proteins that are closely related can, nevertheless, be responsible for highly specific cellular adhesive behavior.

Chromosome segregation during the prokaryotic cell division cycle.

Recent work has dramatically changed our view of chromosome segregation in bacteria. Rather than being a passive process, it involves rapid movement of parts of the circular chromosome. Several genes involved in chromosome segregation have been identified, and the analysis of their functions and intracellular localization are beginning to shed light on the mechanisms that ensure efficient chromosome segregation.

Monoclonal antibody characterization of a unique immune response control locus between H-2S and D.

The primary in vitro antibody response to the type 2 antigen, trinitrophenyl (TNP)-Ficoll, is controlled by two complementing loci in the H-2 region of the mouse major histocompatibility complex (MHC). High responder alleles at both loci are necessary for a high responder phenotype. Previous studies mapped one locus of control to the I-A subregion. In this report we demonstrate by recombinant analysis that the second locus of control is located between the H-2S and D regions. A comparison of responses in the B10.BAR6, B10.BAR10, and B10.BAR11 strains defined a locus controlling the response to TNP-Ficoll in a single haplotype, bounded on the left by the crossover event in the B10.BAR10 and on the right by the crossover event in the B10.BAR6 strain. A monoclonal antibody directed against this right-hand region of control has been produced (48.21.7) that blocks the response to TNP-Ficoll at the level of the antigen-presenting cell. The monoclonal antibody 48-21.7 is specific for the high responder b allele at the right-hand locus and did not inhibit responses to other protein antigens tested. The immune response to TNP-Ficoll was not inhibited by monoclonal antibodies that react with H-2Db or Qa-2 specificities, suggesting that the TNP-Ficoll response is controlled by a unique locus located between H-2S and D. Finally, 48-21.7 recognizes and precipitates a unique product of approximately 40,000 mol wt that is distinct from the H-2D region product recognized by the monoclonal antibody B22/249.

Three-dimensional head shape quantification for infants with and without deformational plagiocephaly.

OBJECTIVE: The authors developed and tested three-dimensional (3D) indices for quantifying the severity of deformational plagiocephaly (DP). DESIGN: The authors evaluated the extent to which infants with and without DP (as determined by clinic referral and two experts' ratings) could be correctly classified. PARTICIPANTS: Infants aged 4 to 11 months, including 154 with diagnosed DP and 100 infants without a history of DP or other craniofacial condition. After excluding participants with discrepant expert ratings, data from 90 infants with DP and 50 infants without DP were retained. MEASUREMENTS: Two-dimensional (2D) histograms of surface normal vector angles were extracted from 3D mesh data and used to compute the severity scores. OUTCOME MEASURES: Left posterior flattening score (LPFS), right posterior flattening score (RPFS), asymmetry score (AS), absolute asymmetry score (AAS), and an approximation of a previously described 2D measure, the oblique cranial length ratio (aOCLR). Two-dimensional histograms localized the posterior flatness for each participant. ANALYSIS: The authors fit receiver operating characteristic curves and calculated the area under the curves (AUC) to evaluate the relative accuracy of DP classification using the above measures. RESULTS: The AUC statistics were AAS = 91%, LPFS = 97%, RPFS = 91%, AS = 99%, and aOCLR = 79%. CONCLUSION: Novel 3D-based plagiocephaly posterior severity scores provided better sensitivity and specificity in the discrimination of plagiocephalic and typical head shapes than the 2D measurements provided by a close approximation of OCLR. These indices will allow for more precise quantification of the DP phenotype in future studies on the prevalence of this condition, which may lead to improved clinical care.

Rethinking interleukin-6 blockade for treatment of COVID-19.

Interleukin-6 (IL-6) is a pleiotropic cytokine with effects in immune regulation, inflammation, and infection. The use of drugs that inhibit IL-6 biological activity has been proposed as a treatment for patients with Coronavirus Disease 2019 (COVID-19). The rationale for this approach includes commitment to the concept that inflammation is a cause of lung damage in COVID-19 and belief that IL-6 is a pro-inflammatory molecule. Observational data thought to support IL-6 inhibition include elevated circulating IL-6 levels in COVID-19 patients and association between elevated IL-6 and poor clinical outcomes. However, IL-6 has significant anti-inflammatory properties, which calls into question the rationale for employing IL-6 blockade to suppress inflammation-induced tissue injury. Also, studies suggesting a beneficial role for IL-6 in the host response to infection challenge the strategy of using IL-6 blockade to treat COVID-19. In studies of recombinant IL-6 injected into human volunteers, IL-6 levels exceeding those measured in COVID-19 patients have been observed with no pulmonary adverse events or other organ damage. These observations question the role of IL-6 as a contributing factor in COVID-19. Clinical experience with IL-6 receptor antagonists such as tocilizumab demonstrates increase in severe and opportunistic infections, raising concern about using tocilizumab and similar agents to treat COVID-19. Trials of drugs to inhibit IL-6 activity in COVID-19 are ongoing and will shed light on the role of IL-6 in COVID-19 pathogenesis. However, until more information is available, providers should exercise caution in prescribing these therapies given the potential for patient harm.

Proteins on the move: dynamic protein localization in prokaryotes.

Despite their small size and lack of obvious intracellular structures, bacteria have a complex and dynamic intracellular organization. Recent work has shown that many proteins, and even regions of the chromosome, are localized to specific subcellular regions that can change over time, sometimes extraordinarily fast. Protein function can depend on cellular position, so the analysis of the intracellular location of a protein can be crucial for understanding its activity. Because regulatory proteins are among those that reside at specific cellular sites, it is now necessary to consider three-dimensional organization when describing the genetic networks that control bacterial cells.

Making memories stick: cell-adhesion molecules in synaptic plasticity.

Synapses are adhesive junctions highly specialized for interneuronal signalling in the central nervous system. The strength of the synaptic signal can be modified (synaptic plasticity), a key feature of the cellular changes thought to underlie learning and memory. Cell-adhesion molecules are important constituents of synapses, with well-recognized roles in building and maintaining synaptic structure during brain development. However, growing evidence indicates that cell-adhesion molecules also play important and diverse roles in regulating synaptic plasticity and learning and memory. This review focuses on recent advances in understanding the molecular mechanisms through which adhesion molecules might regulate synaptic plasticity.

Functional cis-heterodimers of N- and R-cadherins.

Classical cadherins form parallel cis-dimers that emanate from a single cell surface. It is thought that the cis-dimeric form is active in cell-cell adhesion, whereas cadherin monomers are likely to be inactive. Currently, cis-dimers have been shown to exist only between cadherins of the same type. Here, we show the specific formation of cis-heterodimers between N- and R-cadherins. E-cadherin cannot participate in these complexes. Cells coexpressing N- and R-cadherins show homophilic adhesion in which these proteins coassociate at cell-cell interfaces. We performed site- directed mutagenesis studies, the results of which support the strand dimer model for cis-dimerization. Furthermore, we show that when N- and R-cadherins are coexpressed in neurons in vitro, the two cadherins colocalize at certain neural synapses, implying biological relevance for these complexes. The present study provides a novel paradigm for cadherin interaction whereby selective cis-heterodimer formation may generate new functional units to mediate cell-cell adhesion.

Polar location of the chemoreceptor complex in the Escherichia coli cell.

The eukaryotic cell exhibits compartmentalization of functions to various membrane-bound organelles and to specific domains within each membrane. The spatial distribution of the membrane chemoreceptors and associated cytoplasmic chemotaxis proteins in Escherichia coli were examined as a prototypic functional aggregate in bacterial cells. Bacterial chemotaxis involves a phospho-relay system brought about by ligand association with a membrane receptor, culminating in a switch in the direction of flagellar rotation. The transduction of the chemotaxis signal is initiated by a chemoreceptor-CheW-CheA ternary complex at the inner membrane. These ternary complexes aggregate predominantly at the cell poles. Polar localization of the cytoplasmic CheA and CheW proteins is dependent on membrane-bound chemoreceptor. Chemoreceptors are not confined to the cell poles in strains lacking both CheA and CheW. The chemoreceptor-CheW binary complex is polarly localized in the absence of CheA, whereas the chemoreceptor-CheA binary complex is not confined to the cell poles in strains lacking CheW. The subcellular localization of the chemotaxis proteins may reflect a general mechanism by which the bacterial cell sequesters different regions of the cell for specialized functions.

Circuit simulation of genetic networks.

Genetic networks with tens to hundreds of genes are difficult to analyze with currently available techniques. Because of the many parallels in the function of these biochemically based genetic circuits and electrical circuits, a hybrid modeling approach is proposed that integrates conventional biochemical kinetic modeling within the framework of a circuit simulation. The circuit diagram of the bacteriophage lambda lysislysogeny decision circuit represents connectivity in signal paths of the biochemical components. A key feature of the lambda genetic circuit is that operons function as active integrated logic components and introduce signal time delays essential for the in vivo behavior of phage lambda.