The complex pictured, [(η6-Tha)Ru(bipy(OH)O)(9-EtG-N7)][PF6], contains the bipy(OH)O chelating ligand, and showed a large increase in the cytotoxicity toward human ovarian and human lung cancer cells. The tetrahydroanthracene (tha) “faces” protect the RuII against oxidation. Examining the crystal structures shows CH/π interactions between the bipyridine ligand and tetrahydroanthracene are important for stabilizing the interaction between [(η6-Tha)Ru(bipy(OH)O)(9-EtG-N7)][PF6] and proteins. Although this complex was not tested for activity against ovarian and lung cancer cell lines, A2780 and A549 respectively, other complexes with the tetrahydroanthracene (tha) moity were tested and proved to be most active against the ovarian cancer cell line. Ruthenium complexes such as [(η6-Tha)Ru(bipy(OH)O)(9-EtG-N7)][PF6] have been shown to mimic iron binding in the human body and the ligand, bipy(OH)O, helps the complex bind to DNA in ways that another antitumor compound, cisplatin, cannot. This shows extreme promise as a therapeutic as cisplatin tumor toxicity is not as high with some types of tumors.

As you search for relevant examples / topics for your MotW assignment, it is important to recognize that there is not a ‘correct’ way to search. Ultimately, the correct method is the one that leads to an answer or solution. Notice I didn’t say the answer, rather an answer, as the question will likely evolve during the search process (and it is a process). The more paths / methods you can employ for gathering information and ideas the better, and like most everything worth doing, deliberate practice is required.

If you are having difficulties finding appropriate examples, try using Google Scholar (http://scholar.google.com) to investigate a topic you have some interest in learning more about. I provide a couple examples below (all Scholar searches excluded patents were limited from 2009 to the present).

• Perhaps you have an interest in metal containing enzymes so you search Scholar using “metalloenzymes” and find a review paper on structure–function relationships in metalloenzymes. While the paper provides background, it doesn’t specifically include crystal structures. You do notice an interesting figure with several cool structures so you search again using the keywords “hydrogenase model” and find an interesting paper on iron-only hydrogenase active site models.
• Searching using the keywords “anticancer metal complex” would lead you to a paper on a Gold(I) complex with anticancer properties. While that might not be exactly what you wanted to find, you read the first several paragraphs and find a reference to “metal thiosemicarbazone complexes” and search Google Scholar again. Here you find a paper on Cu(II) and Ni(II) thiosemicarbazonates that you find completely fascinating.

Browse your ‘hit lists’ beyond the first page and then look at specific journals to narrow the range of your chosen topic. Is a transition metal involved? Is the compound molecular? Is a cif available for download or will you have to request it from the CCDC? While these are simple examples, you should take it as far as your interest, time, and patience allow!

One final tip for now. As soon as we have chosen an article for your MotW assignment, start writing. You may find it necessary to change topics only after you begin writing. Have a backup plan and please, have fun with it!

I don’t know about you, but I generally have a difficult time refocusing after an extended time away from the classroom. And while there are differences in expectations from the perspective of both the student and teacher, the strategies for getting (re)started are likely similar if not the same. I have tried the proverbial dipping of a toe into the shallow end and gently easing my way in to recklessly diving headlong into the deep end without testing the water first (as painful and shocking as it can be). In the spirit of jumping into the deep end, here are a few past posts to get your semester started.

1. Quick tips to improve your writing now
2. A few of my favorite books on writing
3. So you’re writing your first post
4. Commenting
5. More info on the Molecule of the Week assignment
6. Lists of some of my science related feeds
7. Student perspective – Impressions about the Molecule of the Week assignment
8. Student perspective – Why take it to the next level

And a few additional links you might find useful.

• Newbie’s Guide to Google Reader
• Getting good with Google Reader
• Google Reader Help
• Google Docs for Students
• Google Docs Blog
• Google Docs Help

Enjoy!

All stars start out using hydrogen as nuclear fuel. This hydrogen is fused together to form helium in a very explosive nuclear reaction that “powers” the star. As the hydrogen runs out, the star begins to collapse from a lack of radiative pressure from the core. The collapse of this much mass increases the temperature until the core is hot enough for Helium fusion. This process is repeated as the fuel continues to be consumed, from hydrogen to helium, helium to carbon, carbon to silicon, and silicon to iron. It is at this point that the already explosive reactions become even more cataclysmic. All of the previous fusion reactions release energy, but an iron fusion reaction actually requires energy. This process reverses the radiation pressure which causes a irreversible pull towards the center of mass. At its most compressed state, all electrons in the star are compressed into contact with the nucleus against the strong force. The resulting rebound causes one of the most powerful explosions in the universe a supernova.

Since Betelgeuse is near the end of its life as a super giant it is due to supernova in the next several years. When this happens, the resulting explosion will be approximately 10,000 times brighter than our sun, though it will be very distant. The supernova will last for several months, up to even a year. The brightness will block out every star in the night sky and will even be brighter than the moon. It will even be visible in the daytime. The extreme distance will limit any detrimental effects here on Earth (whether it be radiation or charged particles), preventing any poorly done future Hollywood movies. It won’t end the world, but having two suns in the sky will sure look cool.

See Also: http://stars.astro.illinois.edu/sow/betelgeuse.html

Surrogacy is a procedure in which sperm and egg fertilized in vitro are implanted into a female subject who has agreed to carry the pregnancy to term. She gives birth to the child and usually forfeits the child to the couple who has paid for the arrangement who then, for the most part, retain legal custody of the child.

For most surrogacy cases, the reason for pursuing this path usually is that the female of a heterosexual couple cannot carry her own child or the complication from her carrying term would most likely result in her expiration. This represents a little over 90% of all surrogacy cases. In these cases, for the most part, the legal proceedings have been clear: the male of the couple has provided the sperm and the female of the couple has provided the egg, and no one can challenge that the couple represents the legal characters of parents. For the most part, surrogate concerns have been sidelined as she has no legal connection to the child. Since the legal sphere has not as of yet gone to define what someone has to be involved in concerning the birth process to be considered a parent, surrogates usually find resistance and judicial scorn.

Another portion of the group paying for their children to be born of a surrogate are homosexual couples who provided the corresponding piece to the “child puzzle” from at least one partner. Here courts have been a little more uncertain and varied in decisions, but the rulings have still reflected the notion that sperm donor and egg donor, especially if the egg donor also carried the child to term, need to exist as legal guardians by current legal proceedings. If the egg was provided from another source, it becomes the choice of the women, individually, if they do or do not want to be involved in the child’s life.

The problem with the other 5% of cases not mentioned is that, quite frankly, it may turn babies into commodities. The Kehoes couple wanted to have a child but the female could not carry a child to term and it was very improbable that she could even conceive. The couple purchased their child from other people who had no known relation to them. They chose the route of surrogacy for the children they wanted much like someone picks between fine wines and strong spirits. The egg came from a medical school student at the University of Michigan and the sperm came from an athletic man who had maintained a 4.0 GPA throughout high school. They chose the surrogate mother based on a rating system that helped pick the “best” candidate for an easy delivery. Neither female nor male of the Kehoes couple had any part in the birth of the twins nor is there any genetic relation between the Kehoes and the children.

Legally, there truly is no answer for who are the parents of these children. The donors for the most part do not want to be involved and they usually view this procedure no more than people who donated blood for money. Legally, if those who provided genetic character to a child refuse to be legally responsible, the state needs to watch the children until foster parents adopt the children through the legal proceedings. The problem with the surrogate program is that while parents have to go through extensive screening for adoption, there is no standard for screening the parents who pay for surrogate procedures, and most couples are never screened aside from the question of whether or not their check clears. However, there is another problem: in these cases, the surrogate female is recognized, at least in some states, as an equal in legal rights to the children as the economically liable couple.

The surrogate female of the Kehoes case, Ms. Baker, challenged the couple in court for custody of the twins on the grounds that Ms. Kehoes was being treated for severe mental illness that would normally restrict her from adoption. Ms. Baker stated that had she known the mental state of Ms. Kehoes she would not have gone through with the surrogacy. The state of Michigan decided to rule with Ms. Baker and the children are now currently in her custody but the legal proceedings continue and the question of who will be considered legal guardians is still very much undecided. Similar cases have occurred in California, Oregon, New Jersey and Texas, all of which eventually ended in favor of the economically liable couple.

The question of whether or not any part needs to be played in the birth process as a requirement for parenthood still needs to be answered, as does the ethical implications behind “buying” your children. The miracles of fertilization now are to be met with the confines of law. What will occur from the encounter is still very much undecided.

For the original article please visit:
http://www.nytimes.com/2009/12/13/us/13surrogacy.html?_r=2&pagewanted=1

For the site that the Kehoes used to find their surrogate please visit:
http://surromomsonline.com/

For further references on foster care and the most up-to-date status of this and all cases please visit:
http://topics.nytimes.com/top/reference/timestopics/subjects/f/foster_care/index.html?inline=nyt-classifier

High amounts of fat in food, such as ice cream, not only affect a person’s stomach but also their brain. Some of the fat travels to the brain, which then causes the brain to send out signals to all of the cells in the body. These signals “tell” the cells to disregard the hormones leptin and insulin, which tell the body to “stop” eating to regulate body weight. When a human eats, these hormones send signals to the body to stop eating once the body is full, but these hormones do not always work when a human eats something enjoyable like “junk” food. Leptin is released to stop the feeling of hunger by fat tissue in the body and insulin slows the desire for food by increasing in the pancreas after detection of blood sugar from a meal.

In a study done at the University of Texas Southwestern Medical Center at Dallas, Dr. Deborah Clegg analyzed what kinds of fats affected the brain in this way. Dr. Clegg believes that the fat actually changed the chemical composition of the brain because the fat is incorporated into the brain. Dr. Clegg performed this study by looking at effects of different fats on the brain of animals after exposure by three different methods: injection directly into the brain, feeding the animal through a stomach tube, and infusion into the carotid artery a few times a day. Palmitic acid and oleic acid were the specific fats used. Palmitic acid is a saturated fatty acid and is found in foods such as butter and beef while oleic acid is an unsaturated fatty acid found in food such as olive oil. The results showed that palmitic acid affected the signaling pathways of the leptin and insulin over about three days while the oleic acid did not affect the hormones. These studies were done on animals but Dr. Clegg believes that the saturated fatty acids will affect a human’s brain in a similar way. In another study with rats, the saturated fats, especially palmitic acid, caused the insulin modulator to localize to the cell membranes in the hypothalamus, which slowed the insulin signaling in the brain. Dr. Clegg hopes to soon determine a way to reverse the effects of the palmitic acid on the brain signaling.

Many of the most successful drugs on the market today are being prescribed for ailments that are quite different from the ones they were originally designed to treat since many drugs have been found to bind to multiple targets. Sometimes these interactions lead to new uses for well established drugs. At other times, they may cause harmful side effects. Either way, knowing about these interactions allows for better use of drugs.

In the new method, drug receptors are not defined by structure or sequence but by the ligands that bind to them. This approach differs from structure-based approaches which usually use a receptor’s crystal structure as a starting point.

“This approach uncovered interactions between drugs and targets that we never could have predicted simply by looking at the chemical structures,” said senior study author Bryan Roth, M.D., Ph.D., professor of pharmacology and director of the National Institute of Mental Health Psychoactive Drug Screening Program at UNC. “We may now have a way to predict what side effects are likely to occur from treatment before we even put a drug into clinical testing.” internetchemistry.com

By using a modified version of an already established algorithm used to search gene-sequence databases, compounds were screened against a database of targets, asking how much the compounds looked like the ligands. The team compared 3,665 approved or investigational drugs with hundreds of targets which were defined by their ligands. The researchers predicted thousands of unanticipated interactions and experimentally tested 30 of them. Of these 30, they confirmed 23 of the interactions.

In one case, the team found  that Rescriptor, which inhibits the enzyme HIV reverse transcriptase, also inhibited the histamine H4 receptor. The scientists have linked Rescriptor binding to histamine H4 at physiologically relevant concentrations to some of the painful side effects that the drug has. In another example, the antidepressant Prozac, whose primary target is the serotonin transporter, bound the beta-1 adrenerfic receptor, a G-protein-coupled receptor (GPCR) that usually binds such compounds as epinephrine and norepinephrine.

Roth states that the power of their approach is that it can be used to uncover the real targets of pharmaceutical compounds quickly and efficiently, and will probably lead to a greater understanding of the many molecular targets of each drug. Consequently, this new method will be an important step forward for chemists to design drugs that act on multiple targets.