Emerging Data Support Switching Biologics

2012 ◽  
Vol 43 (2) ◽  
pp. 1-9
Author(s):  
MIRIAM E. TUCKER
Keyword(s):  
Author(s):  
George C. Ruben ◽  
Kenneth A. Marx

In vitro collapse of DNA by trivalent cations like spermidine produces torus (donut) shaped DNA structures thought to have a DNA organization similar to certain double stranded DNA bacteriophage and viruses. This has prompted our studies of these structures using freeze-etch low Pt-C metal (9Å) replica TEM. With a variety of DNAs the TEM and biochemical data support a circumferential DNA winding model for hydrated DNA torus organization. Since toruses are almost invariably oriented nearly horizontal to the ice surface one of the most accessible parameters of a torus population is annulus (ring) thickness. We have tabulated this parameter for populations of both nicked, circular (Fig. 1: n=63) and linear (n=40: data not shown) ϕX-174 DNA toruses. In both cases, as can be noted in Fig. 1, there appears to be a compact grouping of toruses possessing smaller dimensions separated from a dispersed population possessing considerably larger dimensions.


2006 ◽  
Vol 40 (3) ◽  
pp. 39
Author(s):  
SHARON WORCESTER

2009 ◽  
Vol 2 (8) ◽  
pp. 8
Author(s):  
BRUCE JANCIN
Keyword(s):  

2012 ◽  
Vol 42 (14) ◽  
pp. 28
Author(s):  
SUSAN LONDON
Keyword(s):  

2014 ◽  
Vol 0 (3) ◽  
Author(s):  
Viktor K. Partas ◽  
Alona Yu. Pavlenko

Author(s):  
Giuseppe Lisco ◽  
Vito A. Giagulli ◽  
Giovanni De Pergola ◽  
Anna De Tullio ◽  
Edoardo Guastamacchia ◽  
...  

Background: The novel pandemic of Coronavirus disease 2019 (COVID-19) has becoming a public health issue since March 2020 considering that more than 30 million people were found to be infected worldwide. Particularly, recent evidences suggested that men may be considered as at higher risk of poor prognosis or death once the infection occurred and concerns surfaced in regard of the risk of a possible testicular injury due to SARS-CoV-2 infection. Results: Several data support the existence of a bivalent role of testosterone (T) in driving poor prognosis in patients with COVID-19. On one hand, this is attributable to the fact that T may facilitate SARS-CoV-2 entry in human cells by means of an enhanced expression of transmembrane serine-protease 2 (TMPRSS2) and angiotensin-converting enzyme 2 (ACE2). At the same time, younger man with normal testicular function compared to women of similar age are prone to develop a blunted immune response against SARS-CoV-2, being exposed to less viral clearance and more viral shedding and systemic spread of the disease. Conversely, low levels of serum T observed in hypogonadal men predispose them to a greater background systemic inflammation, cardiovascular and metabolic diseases, and immune system dysfunction, hence driving harmful consequences once SARS-CoV-2 infection occurred. Finally, SARS-CoV-2, as a systemic disease, may also affect testicles with possible concerns for current and future testicular efficiency. Preliminary data suggested that SARS-CoV-2 genome is not normally found in gonads and gametes, therefore sex transmission could be excluded as a possible way to spread the COVID-19. Conclusion: Most data support a role of T as a bivalent risk factor for poor prognosis (high/normal in younger; lower in elderly) in COVID-19. However, the impact of medical treatment aimed to modify T homeostasis for improving the prognosis of affected patients is unknown in this clinical setting. In addition, testicular damage may be a harmful consequence of the infection even in case it occurred asymptomatically but no long-term evidences are currently available to confirm and quantify this phenomenon. Different authors excluded the presence of SARS-CoV-2 in sperm and oocytes, thus limiting worries about both a potential sexual and gamete-to-embryos transmission of COVID-19. Despite these evidence, long-term and well-designed studies are needed to clarify these issues.


Genetics ◽  
1997 ◽  
Vol 146 (2) ◽  
pp. 619-628 ◽  
Author(s):  
Muriel Boube ◽  
Corinne Benassayag ◽  
Laurent Seroude ◽  
David L Cribbs

Mutations of the Drosophila homeotic proboscipedia gene (pb; the Hox-A2/B2 homologue) provoke dose-sensitive defects. These were used to search for dose-sensitive dominant modifiers of pb function. Two identified interacting genes were the proto-oncogene Ras1 and its functional antagonist Gap1, prominent intermediaries in known signal transduction pathways. Ras1+ is a positive modifier of pb activity both in normal and ectopic cell contexts, while the Ras1-antagonist Gap1 has an opposite effect. A general role for Ras1 in homeotic function is likely, since Ras1+ activity also modulates functions of the homeotic loci Sex combs reduced and Ultrabithorax. Our data suggest that the modulation occurs by a mechanism independent of transcriptional control of the homeotic loci themselves, or of the Ras1/Gap1 genes. Taken together our data support a role for Ras1-mediated cell signaling in the homeotic control of segmental differentiation.


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