Gene therapy, in short. They would infect you with a virus (probably a retrovirus, ironically enough) that carries a mutant copy of the HIV-1 Tat gene. Normal Tat is a gene that drastically increases HIV production. HIV hijacks the machinery of human T-cells to make copies of its own genes. The protein that Tat codes for has a nasty trick- it binds to transcription factors in your cells and and increases their output- more HIV production, which includes more Tat production, which causes more HIV production, and the disease explosively progresses. It is thought that reaching a critical mass of Tat is a key element in the transition from HIV infection to AIDS. But if you had a mutant Tat that counteracted this activity, HIV production would only occur at a baseline rate- you'd never get that Tat-HIV-Tat positive feedback.
Here's the article abstract which has some of the technical details. MLV is the murine (mouse) leukemia virus.
This would be a gene therapy treatment- using viral vector to express a mutant protein in your cells. Last year, the European Medicines Agency approved a gene therapy treatment for the first time (no approvals in the US currently). Glybera is indicated for lipoprotein lipase deficiency, a rare disorder that affects fatty acid metabolism. Glybera uses a viral vector to deliver a working copy of the LPL gene to cells; this proposed AIDS treatment would deliver a nonworking copy of TAT to infected cells in a similar fashion. I bring up Glybera for comparison purposes because it is expected to cost over 1 million dollars a patient for a course of treatment. Eventually, gene therapy may become such a routine way of creating treatments that costs will be very low. That is not the present situation.
This coating is actually not just silicone, but a blend of silicone and " liquid-resisting nanoscale cubes developed by the Air Force that contain carbon, fluorine, silicon and oxygen," which is apparently supposed to be layman's terms for fluorodecyl polyhedral oligomeric silsequioxane (POSS). Those are cubic networks of silica that have a fluorocarbon chain at each vertex, sort of a three-dimensional Teflon. The very low chemical reactivity plus the nanoscale roughness of the surface causes the lotus effect. The mixture with silicone helps the POSS adhere to materials, though they state in their paper that the POSS preferentially segregates to the surface and is responsible for the coating's properties:
"A wide range of organic chemicals including toluene and chloroform, which readily wet/swell cross-linked PDMS, are also easily repelled. Even when our surfaces are immersed in a liquid bath of PDMS (Mn = 800 Da, lv = 19.8 mN/m), a plastron (air pockets) layer that is indicative of a robust Cassie–Baxter state is formed. The plastron layer was stable and remained unchanged even upon extended exposure to un-cross-linked PDMS. Note that PDMS is a major constituent of the electrospun beads. The observation of a stable plastron layer even when the surface is submerged under PDMS is extremely unique and indicates that the surface does not reconfigure, even when exposed to an enthalpically favorable solvent."
HIV isn't the only retrovirus or the only virus that targets T-cells. I will admit that the crisis that AIDS has posed has greatly accelerated research into retroviruses, but the development of retroviruses as gene therapy vectors is only tangentially connected to research on AIDS as a disease.
AIDS as a pandemic has from the start been as much or more about public health measures as it has virology, and if we had been far more fortunate, HIV would have remained a fearsome but rare curiosity. Research on it might have remained a backwater of the academic world, and yes, the pace of treatments like this might have been slowed, though I strongly doubt by 50 years. When you ask if success against cancer means AIDS could have been "worth it," I believe that we would have had ample opportunity to obtain this knowledge without the cost of thirty million lives.
The researchers involved used a disease called experimental autoimmune encephalomyelitis (EAE). This is a disease with many general similarities with multiple sclerosis (being autoimmune responses against myelin), but there are differences in the course of the disease versus MS. EAE is considered to be closer to a rarer human disease, acute disseminated encephalomyelitis (ADEM) than to MS. Nevertheless, EAE has been used for decades as a model for autoimmune diseases, as it has the major advantage of being able to be reliably induced in animals. The method of immune system modulation used in this study seems general enough to apply to similar autoimmune disorders, but that has not been actually established with studies yet.
True, the particles used are an inert support for the proteins, not a treatment in themselves. The idea was to present the proteins as if they were cell-surface proteins which the immune system would recognize and build tolerance for. The original paper's authors performed earlier work with the same proteins attached to white blood cells. This was successful, but in terms of developing a clincal treatment, manufacturing engineered cells presents far more complexity, risk, stability issues, and cost than the manufacture of polymer microparticles coated with the protein. Microparticles, rather than nanoparticles, is the term consistently used throughout the paper, coincidentally. The particles are 500 nanometers in diameter, which is larger than what are usually considered nanoparticles 100 nm).
That's not necessarily true of pharmaceuticals, and in fact, quite a few other blockbuster drugs have come about as re-purposed molecules: Merck originally developed Proscar (finasteride) as a prostate enlargement treatment. Then it submitted finasteride to the FDA again as Propecia for male pattern baldness. Wikipedia tells me, "Merck's patent on finasteride for the treatment of BPH expired on June 19, 2006. Merck was awarded a separate patent for the use of finasteride to treat MPB. This patent is set to expire in November 2013."
Bupropion was developed as an antidepressant (Wellbutrin), but there's a separate patent covering Zyban, which is the same molecule when prescribed for smoking cessation. Latisse is the glaucoma drug Lumigan, repurposed when they found it makes your eyelashes grow.
For that matter, Viagra itself is also sold in a different dose as Revatio for pulmonary hypertension- I'm pretty sure that Pfizer's "treatment of erectile dysfunction" patent expiring in 2019 does not apply to that product. I will note that these "use patents" are much more likely to be invalidated in court challenges compared to the "composition of matter" patent (it was considered surprising by many observers when Pfizer won their case with Teva in the US last year), but they are out there.
Yes, Teva's central argument in the challenge was that in the patent in question, Pfizer never specifically establishes the relationship between sildenafil and the treatment of ED. From the judgement:
As required by s. 2 of the Act, an invention must be novel. In the instant case, the invention is not sildenafil, per se, because this compound was already known. In fact, Pfizer had been investigating sildenafil as a cardiovascular drug when it first suspected that the compound would be useful in treating ED (R.F., at para. 13). The invention is therefore not sildenafil, but the use of sildenafil to treat ED.(italics theirs)
The court ruled that the patent never concretely established this relationship:
Although Patent ’446 includes the statement that “one of the especially preferred compounds induces penile erection in impotent males” (A.R., vol. X, at p. 173), the specification does not indicate that sildenafil is the effective compound, that Claim 7 contains the compound that works, or that the remaining compounds in the patent had been found not to be effective in treating ED. The claims were structured as “cascading claims”, with Claim 1 involving over 260 quintillion compounds, Claims 2 to 5 concerning progressively smaller groups of compounds, and Claims 6 and 7 each relating to an individual compound.
The disclosure in the specification would not have enabled the public “to make the same successful use of the invention as the inventor could at the time of his application”, because even if a skilled reader could have narrowed the effective compound down to the ones in Claim 6 and Claim 7, further testing would have been required to determine which of those two compounds was actually effective in treating ED. As the trial judge stated, at para. 146, “[a] skilled reader would then conduct tests on those two compounds and determine which of those compounds worked.” And as he also stated, at para. 135, “the skilled reader must undertake a minor research project to determine which claim is the true invention”.
Pfizer had the information needed to disclose the useful compound and chose not to release it. Even though Pfizer knew that the effective compound was sildenafil at the time it filed the application, it limited its description to the following statement:
In man, certain especially preferred compounds have been tested orally in both single dose and multiple dose volunteer studies. Moreover, patient studies conducted thus far have confirmed that one of the especially preferred compounds induces penile erection in impotent males. [Emphasis added; A.R., vol. X, at p. 173.]
It chose a method of drafting that failed to clearly set out what the invention was. Even now, in its factum to this Court, Pfizer offers no explanation as to why — knowing that Claim 7 contained the tested and thus, the useful, compound — it elected to withhold that information.
Just to follow on, the Canadian Supreme Court decision is here and the invalidated patent is here. What caused the patent to be invalidated was that the patent is basically written to cover a wide array of similar molecules, all derivatives of a central molecular skeleton. Often, minor alterations to a molecule can be made that do not change the behavior of the molecule as a drug. What it appears Pfizer was looking to do here was prevent competitors from developing ED drugs that were simple derivatives of sildenafil (Viagra) (like adding a methyl group or a fluorine atom somewhere it would have no significant effect). That's considered acceptable strategy, and as a result, other ED drugs like vardenafil (Levitra) and tadalafil (Cialis) have differences in their core structures that keep them from infringing.
However, the Canadian court found that Pfizer had failed to essentially zero in on sildenafil with their claims. When it came down to actually stating that this molecule is the one that lab studies have found treats ED, Pfizer only ever mentions the core skeleton (known as "formula I") and never uniquely identifies sildenafil. It mentions sildenafil (not even by name, only by its R groups) in one claim, but never connects it and only it to ED. The court judgement notes that "formula I" represents 260 quintillion possible compounds, and therefore rejected the patent for vagueness.
This particular patent fight is also occurring in other places. In the US, there was a decision last year between Pfizer and Teva that was ruled the opposite way, and if no other challenge is successful, I believe Viagra will continue to exist under patent for Pfizer until 2019. At issue is that Viagra really has two patents- one for sildenafil and its formulation into a drug and one for the use of sildenafil to treat erectile dysfunction. Sildenafil was originally developed for blood pressure and cardiovascular disease, so the application for the ED indication patent trailed the formulation patent by several years. The formulation patent expired this year, but the indication patent lasts until 2019. In the US, a regulatory framework known as a Paragraph IV challenge exists for generic drug manufacturers to either argue that their proposed generic does not violate the existing patents, or that the patents themselves are invalid. This potentially allows them to open up the generic market years before the patent was originally set to expire, so this sort of legal action is not uncommon, particularly for blockbuster drugs.
These happen to only be "adult stem cells" in the sense that they are not totipotent embryonic stem cells (cells from the very earliest stages after fertilization that can differentiate into any cell type), but I'd like to point out that doesn't mean they come from an adult brain. They're only "adult" by the meaning of having matured to the multipotent stage (neuronal stem cells can differentiate into neurons or glia, but not muscle cells or liver cells, for instance). The biotech company that provided these cells, StemCells, Inc. cultures them from donated fetal brain tissue.
The first production step comprises a proprietary method for purification of HuCNS-SC cells from donated fetal brain tissue procured from an FDA-registered, not-for-profit agency, in compliance with Good Tissue Practice (GTP) and all other applicable state and federal regulations. As part of the purification process, cells from the tissue are “tagged” with a monoclonal antibody that recognizes human neural stem cells. High-speed Fluorescence Activated Cell Sorting (FACS) is then used to isolate the cells tagged by the monoclonal antibody. The FACS-isolated HuCNS-SC cells are then placed in cell culture.
The stem cells aren't turning into neurons, actually, despite coming from "neuronal stem cells." The intent of the treatment is for the stem cells to differentiate into oligodendrocytes, which are a type of glial cell (which in turn are several types of cells that provide support functions to neurons). Oligodendrocytes are interesting cells because they wrap around neurons like insulation around a wire (which is exactly their purpose). These cells play an important role in nerve conduction and in overall brain function, but they're just tubes filled with fat.
Anyone here teaching a course might be interested in the comprehensive new textbook I'm writing. It has an attractive hard cover, a quality binding, and a single page inside which lists the URLs for Google and Wikipedia. My planned retail price is $499, but I'm willing to offer a volume discount.
Well, they shouldn't, if they're drinking out of 2L bottles, most of which are polyethylene terephthalate and generally do not contain BPA, which is why the focus here is on the epoxy liners of many aluminum cans. They did try to control for caloric intake in the study:
Controlling for race/ethnicity, age, caregiver education, poverty to income ratio, sex, serum cotinine level, caloric intake, television watching, and urinary creatinine level, children in the lowest urinary BPA quartile had a lower estimated prevalence of obesity (10.3% [95% CI, 7.5%-13.1%]) than those in quartiles 2 (20.1% [95% CI, 14.5%-25.6%]), 3 (19.0% [95% CI, 13.7%-24.2%]), and 4 (22.3% [95% CI, 16.6%-27.9%]).
However, they also admit in the conclusions, "Explanations of the association cannot rule out the possibility that obese children ingest food with higher BPA content or have greater adipose stores of BPA."
From further down in that link you posted, "it appears to have a surface of basaltic rock -- frozen lava -- which oozed out of the asteroid's presumably hot interior shortly after its formation 4.5 billion years ago, and has remained largely intact ever since." So no volcanic activity anymore, though meteorites believed to originate from Vesta are believed to have been formed in the impact that produced the Rheasilivia crater, which possibly ejected material as deep as the mantle.
Yes, those speeds are backwards. The chart in the article gives 20 down and 5 up. The rankings also set up an interesting debate about value and what customers consider an acceptable data rate. Is 20/5 at $25.47 (cost of living adjusted USD) a better deal than 50/50 at 32.74 or 100/50 at 34.47? And how do the television offerings really compare? There are quality of service factors beyond having the most channels
The prices are weighted by the World Bank's Purchasing Power Parity metrics "which adjust for differences in costs of living, price levels, and other factors that affect a consumer’s purchasing power."
The article gets that wrong-- the 3.5% improvement is not something that's been specifically observed in this shoe. From the designer's site, "Scientific investigations have shown that tuning the mechanical properties of a sprint shoe to the physical abilities of an athlete can improve performance by up to 3.5%...." Which is to say, some sort of study has been done to demonstrate that custom-made track spikes can deliver that kind of improvement, but no data exists for this shoe specifically. The release on that site even goes on to note,"Fusaro continues to fine-tune the shoe: The upper is still too stiff to offer optimum speed. More flexibility and comfort needs to be added to the shoe, using a combination of different material or additive manufacturing processes that can offer different flexibilities in the same product."
Drug laws vary widely of course, but as an example, the US DEA drug schedules both directly specify molecules, including derivatives and precursors in some cases, and also have some entries like "barbiturates not specifically listed." In addition, they include the statement, "This document is a general reference and not a comprehensive list. This list describes the basic or parent chemical and does not describe the salts, isomers and salts of isomers, esters, ethers and derivatives which may also be controlled substances."
The structure of the vein isn't a major issue in this particular case- the procedure was a bypass, so all that was needed was a tube of tissue that could take blood from one vein to another. This procedure, called a meso Rex bypass, has been done with a variety of vein sources already. The cadaver donor vein used here was an iliac vein, which normally returns blood from the legs. Issues of structure or size do come into play when other types of grafts or transplants are considered, but I think, as other comments have noted, that in this case generation of the vein from stem cells was done for immunological reasons, as even decellularized animal tissue can provoke an immune response.
I think this is a non-aqueous system. I don't have access to this paper, but in an earlier paper from the same group (using a silicon nitride cell) mentions that a "stock solution for synthesis was prepared by dissolving Pt(acetylacetonate)2 (10 mg/mL)
in a mixture of o-dichlorobenzene and oleylamine (9:1 in volume ratio). About 100 nanoliters of the growth solution was loaded into the reservoir of a liquid cell and the
solution was drawn into the cell by capillary force."
Imidacloprid is considered neonicotinoid, but its biochemical effects should not be compared to natural nicotine. Just as humans do, insects have a couple of different types of receptors for the neurotransmitter acetylcholine, including a nicotinic receptor. Insect physiology favors the nicotinic receptor pathway such that some insectides which are mildly toxic to humans are extremely poisonous to insects. Nicotine can activate these receptors temporarily, which is responsible for its physiological effects. However, imidacloprid irreversibly binds to the nicotinic receptor, which blocks acetylcholine transmission and leads to the insect's death. It appears that sublethal concentrations may still cause significant impairment, similar to myasthenia gravis.
Slashdot Mirror
Gene therapy, in short. They would infect you with a virus (probably a retrovirus, ironically enough) that carries a mutant copy of the HIV-1 Tat gene. Normal Tat is a gene that drastically increases HIV production. HIV hijacks the machinery of human T-cells to make copies of its own genes. The protein that Tat codes for has a nasty trick- it binds to transcription factors in your cells and and increases their output- more HIV production, which includes more Tat production, which causes more HIV production, and the disease explosively progresses. It is thought that reaching a critical mass of Tat is a key element in the transition from HIV infection to AIDS. But if you had a mutant Tat that counteracted this activity, HIV production would only occur at a baseline rate- you'd never get that Tat-HIV-Tat positive feedback.
Here's the article abstract which has some of the technical details. MLV is the murine (mouse) leukemia virus.
This would be a gene therapy treatment- using viral vector to express a mutant protein in your cells. Last year, the European Medicines Agency approved a gene therapy treatment for the first time (no approvals in the US currently). Glybera is indicated for lipoprotein lipase deficiency, a rare disorder that affects fatty acid metabolism. Glybera uses a viral vector to deliver a working copy of the LPL gene to cells; this proposed AIDS treatment would deliver a nonworking copy of TAT to infected cells in a similar fashion. I bring up Glybera for comparison purposes because it is expected to cost over 1 million dollars a patient for a course of treatment. Eventually, gene therapy may become such a routine way of creating treatments that costs will be very low. That is not the present situation.
This coating is actually not just silicone, but a blend of silicone and " liquid-resisting nanoscale cubes developed by the Air Force that contain carbon, fluorine, silicon and oxygen," which is apparently supposed to be layman's terms for fluorodecyl polyhedral oligomeric silsequioxane (POSS). Those are cubic networks of silica that have a fluorocarbon chain at each vertex, sort of a three-dimensional Teflon. The very low chemical reactivity plus the nanoscale roughness of the surface causes the lotus effect. The mixture with silicone helps the POSS adhere to materials, though they state in their paper that the POSS preferentially segregates to the surface and is responsible for the coating's properties:
"A wide range of organic chemicals including toluene and chloroform, which readily wet/swell cross-linked PDMS, are also easily repelled. Even when our surfaces are immersed in a liquid bath of PDMS (Mn = 800 Da, lv = 19.8 mN/m), a plastron (air pockets) layer that is indicative of a robust Cassie–Baxter state is formed. The plastron layer was stable and remained unchanged even upon extended exposure to un-cross-linked PDMS. Note that PDMS is a major constituent of the electrospun beads. The observation of a stable plastron layer even when the surface is submerged under PDMS is extremely unique and indicates that the surface does not reconfigure, even when exposed to an enthalpically favorable solvent."
AIDS as a pandemic has from the start been as much or more about public health measures as it has virology, and if we had been far more fortunate, HIV would have remained a fearsome but rare curiosity. Research on it might have remained a backwater of the academic world, and yes, the pace of treatments like this might have been slowed, though I strongly doubt by 50 years. When you ask if success against cancer means AIDS could have been "worth it," I believe that we would have had ample opportunity to obtain this knowledge without the cost of thirty million lives.
The researchers involved used a disease called experimental autoimmune encephalomyelitis (EAE). This is a disease with many general similarities with multiple sclerosis (being autoimmune responses against myelin), but there are differences in the course of the disease versus MS. EAE is considered to be closer to a rarer human disease, acute disseminated encephalomyelitis (ADEM) than to MS. Nevertheless, EAE has been used for decades as a model for autoimmune diseases, as it has the major advantage of being able to be reliably induced in animals. The method of immune system modulation used in this study seems general enough to apply to similar autoimmune disorders, but that has not been actually established with studies yet.
True, the particles used are an inert support for the proteins, not a treatment in themselves. The idea was to present the proteins as if they were cell-surface proteins which the immune system would recognize and build tolerance for. The original paper's authors performed earlier work with the same proteins attached to white blood cells. This was successful, but in terms of developing a clincal treatment, manufacturing engineered cells presents far more complexity, risk, stability issues, and cost than the manufacture of polymer microparticles coated with the protein. Microparticles, rather than nanoparticles, is the term consistently used throughout the paper, coincidentally. The particles are 500 nanometers in diameter, which is larger than what are usually considered nanoparticles 100 nm).
That's not necessarily true of pharmaceuticals, and in fact, quite a few other blockbuster drugs have come about as re-purposed molecules: Merck originally developed Proscar (finasteride) as a prostate enlargement treatment. Then it submitted finasteride to the FDA again as Propecia for male pattern baldness. Wikipedia tells me, "Merck's patent on finasteride for the treatment of BPH expired on June 19, 2006. Merck was awarded a separate patent for the use of finasteride to treat MPB. This patent is set to expire in November 2013." Bupropion was developed as an antidepressant (Wellbutrin), but there's a separate patent covering Zyban, which is the same molecule when prescribed for smoking cessation. Latisse is the glaucoma drug Lumigan, repurposed when they found it makes your eyelashes grow.
For that matter, Viagra itself is also sold in a different dose as Revatio for pulmonary hypertension- I'm pretty sure that Pfizer's "treatment of erectile dysfunction" patent expiring in 2019 does not apply to that product. I will note that these "use patents" are much more likely to be invalidated in court challenges compared to the "composition of matter" patent (it was considered surprising by many observers when Pfizer won their case with Teva in the US last year), but they are out there.
The court ruled that the patent never concretely established this relationship:
However, the Canadian court found that Pfizer had failed to essentially zero in on sildenafil with their claims. When it came down to actually stating that this molecule is the one that lab studies have found treats ED, Pfizer only ever mentions the core skeleton (known as "formula I") and never uniquely identifies sildenafil. It mentions sildenafil (not even by name, only by its R groups) in one claim, but never connects it and only it to ED. The court judgement notes that "formula I" represents 260 quintillion possible compounds, and therefore rejected the patent for vagueness.
This particular patent fight is also occurring in other places. In the US, there was a decision last year between Pfizer and Teva that was ruled the opposite way, and if no other challenge is successful, I believe Viagra will continue to exist under patent for Pfizer until 2019. At issue is that Viagra really has two patents- one for sildenafil and its formulation into a drug and one for the use of sildenafil to treat erectile dysfunction. Sildenafil was originally developed for blood pressure and cardiovascular disease, so the application for the ED indication patent trailed the formulation patent by several years. The formulation patent expired this year, but the indication patent lasts until 2019. In the US, a regulatory framework known as a Paragraph IV challenge exists for generic drug manufacturers to either argue that their proposed generic does not violate the existing patents, or that the patents themselves are invalid. This potentially allows them to open up the generic market years before the patent was originally set to expire, so this sort of legal action is not uncommon, particularly for blockbuster drugs.
The stem cells aren't turning into neurons, actually, despite coming from "neuronal stem cells." The intent of the treatment is for the stem cells to differentiate into oligodendrocytes, which are a type of glial cell (which in turn are several types of cells that provide support functions to neurons). Oligodendrocytes are interesting cells because they wrap around neurons like insulation around a wire (which is exactly their purpose). These cells play an important role in nerve conduction and in overall brain function, but they're just tubes filled with fat.
Anyone here teaching a course might be interested in the comprehensive new textbook I'm writing. It has an attractive hard cover, a quality binding, and a single page inside which lists the URLs for Google and Wikipedia. My planned retail price is $499, but I'm willing to offer a volume discount.
However, they also admit in the conclusions, "Explanations of the association cannot rule out the possibility that obese children ingest food with higher BPA content or have greater adipose stores of BPA."
According to Netcraft, it actually died 15 years ago.
From further down in that link you posted, "it appears to have a surface of basaltic rock -- frozen lava -- which oozed out of the asteroid's presumably hot interior shortly after its formation 4.5 billion years ago, and has remained largely intact ever since." So no volcanic activity anymore, though meteorites believed to originate from Vesta are believed to have been formed in the impact that produced the Rheasilivia crater, which possibly ejected material as deep as the mantle.
The syrup must flow! Flow very slowly, but flow nonetheless!
You can have my lightning gun when you pry it from my charred, tetanized hands!
Yes, those speeds are backwards. The chart in the article gives 20 down and 5 up. The rankings also set up an interesting debate about value and what customers consider an acceptable data rate. Is 20/5 at $25.47 (cost of living adjusted USD) a better deal than 50/50 at 32.74 or 100/50 at 34.47? And how do the television offerings really compare? There are quality of service factors beyond having the most channels
The prices are weighted by the World Bank's Purchasing Power Parity metrics "which adjust for differences in costs of living, price levels, and other factors that affect a consumer’s purchasing power."
The article gets that wrong-- the 3.5% improvement is not something that's been specifically observed in this shoe. From the designer's site, "Scientific investigations have shown that tuning the mechanical properties of a sprint shoe to the physical abilities of an athlete can improve performance by up to 3.5%...." Which is to say, some sort of study has been done to demonstrate that custom-made track spikes can deliver that kind of improvement, but no data exists for this shoe specifically. The release on that site even goes on to note,"Fusaro continues to fine-tune the shoe: The upper is still too stiff to offer optimum speed. More flexibility and comfort needs to be added to the shoe, using a combination of different material or additive manufacturing processes that can offer different flexibilities in the same product."
Drug laws vary widely of course, but as an example, the US DEA drug schedules both directly specify molecules, including derivatives and precursors in some cases, and also have some entries like "barbiturates not specifically listed." In addition, they include the statement, "This document is a general reference and not a comprehensive list. This list describes the basic or parent chemical and does not describe the salts, isomers and salts of isomers, esters, ethers and derivatives which may also be controlled substances."
The structure of the vein isn't a major issue in this particular case- the procedure was a bypass, so all that was needed was a tube of tissue that could take blood from one vein to another. This procedure, called a meso Rex bypass, has been done with a variety of vein sources already. The cadaver donor vein used here was an iliac vein, which normally returns blood from the legs. Issues of structure or size do come into play when other types of grafts or transplants are considered, but I think, as other comments have noted, that in this case generation of the vein from stem cells was done for immunological reasons, as even decellularized animal tissue can provoke an immune response.
I think this is a non-aqueous system. I don't have access to this paper, but in an earlier paper from the same group (using a silicon nitride cell) mentions that a "stock solution for synthesis was prepared by dissolving Pt(acetylacetonate)2 (10 mg/mL) in a mixture of o-dichlorobenzene and oleylamine (9:1 in volume ratio). About 100 nanoliters of the growth solution was loaded into the reservoir of a liquid cell and the solution was drawn into the cell by capillary force."
Imidacloprid is considered neonicotinoid, but its biochemical effects should not be compared to natural nicotine. Just as humans do, insects have a couple of different types of receptors for the neurotransmitter acetylcholine, including a nicotinic receptor. Insect physiology favors the nicotinic receptor pathway such that some insectides which are mildly toxic to humans are extremely poisonous to insects. Nicotine can activate these receptors temporarily, which is responsible for its physiological effects. However, imidacloprid irreversibly binds to the nicotinic receptor, which blocks acetylcholine transmission and leads to the insect's death. It appears that sublethal concentrations may still cause significant impairment, similar to myasthenia gravis.