scholarly journals Turing's theory of morphogenesis of 1952 and the subsequent discovery of the crucial role of local self-enhancement and long-range inhibition

2012 ◽  
Vol 2 (4) ◽  
pp. 407-416 ◽  
Author(s):  
Hans Meinhardt

In his pioneering work, Alan Turing showed that de novo pattern formation is possible if two substances interact that differ in their diffusion range. Since then, we have shown that pattern formation is possible if, and only if, a self-enhancing reaction is coupled with an antagonistic process of longer range. Knowing this crucial condition has enabled us to include nonlinear interactions, which are required to design molecularly realistic interactions. Different reaction schemes and their relation to Turing's proposal are discussed and compared with more recent observations on the molecular–genetic level. The antagonistic reaction may be accomplished by an inhibitor that is produced in the activated region or by a depletion of a component that is used up during the self-enhancing reaction. The autocatalysis may be realized by an inhibition of an inhibition. Activating molecules can be processed into molecules that have an inhibiting function; patterning of the Wnt pathway is proposed to depend on such a mechanism. Three-component systems, as discussed in Turing's paper, are shown to play a major role in the generation of highly dynamic patterns that never reach a stable state.

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Pongsakorn Choochuen ◽  
Kitiwan Rojneuangnit ◽  
Thanitchet Khetkham ◽  
Sookkasem Khositseth

Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare skeletal disorder characterized by aggressive osteolysis associated with progressive nephropathy. The early clinical presentation can mimic polyarticular juvenile idiopathic arthritis. Since 2012, MAFB mutations have been discovered in all MCTO patients. Therefore, the early diagnosis can be made based on genetic confirmation. We report the clinical manifestation of mineral bone disease and the molecular genetic study of a Thai female adolescent with MCTO. She presented with end-stage renal disease, bilateral wrist and ankle joint deformities, and subtle facial dysmorphic features. We identified a heterozygous missense MAFB mutation at nucleotide 197 from C to G (NM_005461.4; c.197C>G), predicting the change of amino acid at codon 66 from serine to cysteine (p.Ser66Cys), and the mutation was absent in the parents, indicating a de novo mutation. This report confirms the previous link between MAFB mutation and MCTO. Her unexplained hypercalcemia after a regular dose of calcium and active vitamin D supported an important role of MafB in the negative regulation of RANKL-mediated osteoclast differentiation. Therefore, we would encourage the physicians who take care of MCTO patients to closely monitor serum calcium level and perform a genetic study as a part of the management and investigation.


Genetic variation is the basis of adaptive flexibility in populations and is the ultimate evolutionary basis of much species and community-level diversity. Accordingly, the preservation and maintenance of genetic diversity has a high priority in many conservation programmes. This paper discusses how genetic diversity is measured at the molecular level, including some newer measures made possible with restriction site or DNA sequence data as well as the development of a phylogenetic approach to assessing the significance of genetic variation within a species. These measures of genetic diversity are then used to re-examine the validity of the 50/500 rule of conservation biology; a rule that states that populations should have no fewer than 50 individuals for short-term maintenance of genetic variation and no fewer than 500 individuals for long-term maintenance. Both the 50 and 500 parts of this rule are found to be invalid and frequently misleading. Instead of invoking ‘universal’ rules, conservation biologists should recognize the role of biodiversity in management policies. Not all species are the same, and we need more research and a willingness to try novel approaches rather than naively apply a ‘rule’ that has no demonstrable generality.


2016 ◽  
Vol 04 (01) ◽  
pp. 4-10

AbstractImmunosuppression permits graft survival after transplantation and consequently a longer and better life. On the other hand, it increases the risk of infection, for instance with cytomegalovirus (CMV). However, the various available immunosuppressive therapies differ in this regard. One of the first clinical trials using de novo everolimus after kidney transplantation [1] already revealed a considerably lower incidence of CMV infection in the everolimus arms than in the mycophenolate mofetil (MMF) arm. This result was repeatedly confirmed in later studies [2–4]. Everolimus is now considered a substance with antiviral properties. This article is based on the expert meeting “Posttransplant CMV infection and the role of immunosuppression”. The expert panel called for a paradigm shift: In a CMV prevention strategy the targeted selection of the immunosuppressive therapy is also a key element. For patients with elevated risk of CMV, mTOR inhibitor-based immunosuppression is advantageous as it is associated with a significantly lower incidence of CMV events.


GYNECOLOGY ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 9-16
Author(s):  
Nataly I Frolova ◽  
Tatiana E Belokrinitskaya

Background. Miscarriage is a common complication in early pregnancy. Current studies have shown a higher prevalence of miscarriage, ranging from 10 to 20%. The review is devoted to modern concepts of etiology and pathogenesis of early pregnancy losses. Aim. Assess the role of epigenetic factors and molecular-genetic markers in the pathogenesis and prediction of early pregnancy losses Materials and methods. In order to write this review domestic and foreign publications were searched in Russian and international search systems (PubMed, eLibrary, etc.) for the last 10-15 years. Relevant articles from the peer-reviewed literature and clinical practice guidelines were included. Results. Many recent studies have proved the contribution of various epigenetic factors to the pathogenesis of spontaneous miscarriages, and the molecular-genetic determination such kinds of pregnancy complication has been confirmed. Conclusion. The miscarriage in early gestation is driven by combined impact of epigenetic and molecular-genetic factors, as well as the presence of intergenic interactions. It is may lead to deterioration of physiological functions, and maternal pathologenic pathways could be changed as during her periconceptional period as so during the pregnancy.


Author(s):  
Nikolai Petrov ◽  
Nikolai Petrov ◽  
Inna Nikonorova ◽  
Inna Nikonorova ◽  
Vladimir Mashin ◽  
...  

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.


2004 ◽  
Vol 52 (Suppl 1) ◽  
pp. S122.6-S123
Author(s):  
M. Garg ◽  
C. Bell ◽  
L. Rogers ◽  
S. Bassilian ◽  
W. N.P. Lee

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2431
Author(s):  
Natalia A. Shnayder ◽  
Marina M. Petrova ◽  
Tatiana E. Popova ◽  
Tatiana K. Davidova ◽  
Olga P. Bobrova ◽  
...  

Chronic pain syndromes are an important medical problem generated by various molecular, genetic, and pathophysiologic mechanisms. Back pain, neuropathic pain, and posttraumatic pain are the most important pathological processes associated with chronic pain in adults. Standard approaches to the treatment of them do not solve the problem of pain chronicity. This is the reason for the search for new personalized strategies for the prevention and treatment of chronic pain. The nitric oxide (NO) system can play one of the key roles in the development of peripheral pain and its chronicity. The purpose of the study is to review publications devoted to changes in the NO system in patients with peripheral chronical pain syndromes. We have carried out a search for the articles published in e-Library, PubMed, Oxford Press, Clinical Case, Springer, Elsevier, and Google Scholar databases. The search was carried out using keywords and their combinations. The role of NO and NO synthases (NOS) isoforms in peripheral pain development and chronicity was demonstrated primarily from animal models to humans. The most studied is the neuronal NOS (nNOS). The role of inducible NOS (iNOS) and endothelial NOS (eNOS) is still under investigation. Associative genetic studies have shown that single nucleotide variants (SNVs) of NOS1, NOS2, and NOS3 genes encoding nNOS, iNOS, and eNOS may be associated with acute and chronic peripheral pain. Prospects for the use of NOS inhibitors to modulate the effect of drugs used to treat peripheral pain syndrome are discussed. Associative genetic studies of SNVs NOS1, NOS2, and NOS3 genes are important for understanding genetic predictors of peripheral pain chronicity and development of new personalized pharmacotherapy strategies.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Feifei Zhang ◽  
Hui Wang ◽  
Jiang Yu ◽  
Xueqing Yao ◽  
Shibin Yang ◽  
...  

AbstractDe novo and acquired resistance, which are mainly mediated by genetic alterations, are barriers to effective routine chemotherapy. However, the mechanisms underlying gastric cancer (GC) resistance to chemotherapy are still unclear. We showed that the long noncoding RNA CRNDE was related to the chemosensitivity of GC in clinical samples and a PDX model. CRNDE was decreased and inhibited autophagy flux in chemoresistant GC cells. CRNDE directly bound to splicing protein SRSF6 to reduce its protein stability and thus regulate alternative splicing (AS) events. We determined that SRSF6 regulated the PICALM exon 14 skip splice variant and triggered a significant S-to-L isoform switch, which contributed to the expression of the long isoform of PICALM (encoding PICALML). Collectively, our findings reveal the key role of CRNDE in autophagy regulation, highlighting the significance of CRNDE as a potential prognostic marker and therapeutic target against chemoresistance in GC.


Sign in / Sign up

Export Citation Format

Share Document