part II the CAC-hålet theory

The etiology of Schizophrenia could be linked to endogenous Carbon disulfide CS2 production. The manufacture and exposure to endogenous CS2, could probably act in months after months before showing some of the symptoms of high CS2 exposure (Hallucinations, Psychosis and personality changes)

Suggestions

To ensure a proper analysis of earlier undetectable biomarkers one might consider gas-analysis from skin and breath as an biomarker and emission source, since the CS2 otherwise could leave undetected through the biggest organ -  the skin. I propose analysis of total air content in a closed chamber with subjects naked to avoid contamination with techniques for gas detection (59), (60) to reveal the biometrics of human endogenous CS2 production. Which has not been done to my knowledge.

By practising these suggestions it might be easier to understand and prevent the disease by detecting the prodromal and active  systems conditions besides the genetic vulnerability and map out what role CS2 play in the etiology of Schizophrenia.

References:

(1)
Wien Klin Wochenschr. 1958 Jun 13;70(24):445-6.
[Schizophreniform reactions in chronic carbon disulfide poisoning.]
[Article in German]
Petran V
(2)
Clin Pathol 1993;46:861-864
Increased pentane and carbon disulfide in the
breath of patients with schizophrenia
M Phillips, M Sabas, J Greenberg
(3)
Respiration. 1987;52(1):34-41.Links
Respiratory sensitivity to carbon dioxide in schizophrenia.
Verma R, Dewan M, Ashutosh K.
(4)
Acta Psychiatr Scand. 1990 Jun;81(6):497-506.
Cerebral blood flow responses to inhaled carbon dioxide in schizophrenia.
Mathew RJ, Wilson WH.
Department of Psychiatry, Duke University Medical Center, Durham, North Carolina 27710.
(5)
Am J Physiol Regul Integr Comp Physiol. 2009 May;296(5):R1473-95.
Integration of cerebrovascular CO2 reactivity and chemoreflex control of breathing: mechanisms of regulation, measurement, and interpretation.
(6)
Adv Exp Med Biol. 2006;588:65-73
Control of cerebral blood flow during sleep and the effects of hypoxia.
Corfield DR, Meadows GE
(7)
J Korean Med Sci. 1998 Dec;13(6):645-51. Cerebral vasoreactivity by transcranial Doppler in carbon disulfide poisoning cases in Korea. Lee E, Kim MH.
(8)
Br J Anaesth. 2008 Nov;101(5):673-9. Epub 2008 Sep 12.
Carbon dioxide negatively modulates N-methyl-D-aspartate receptors.
Brosnan RJ, Pham TL.
(9)
1994: Kumar M; Lu W P; Ragsdale S W
Binding of carbon disulfide to the site of acetyl-CoA synthesis by the nickel-iron-sulfur protein, carbon monoxide dehydrogenase, from Clostridium thermoaceticum.
Biochemistry 1994;33(32):9769-77.
(10)
Chin Med J (Engl). 2008 Dec 20;121(24):2553-6.
Effects of carbon disulfide on the expression and activity of nitric oxide synthase in rat hippocampus.
Guo XM, Tang RH, Qin XY,Yang J, Chen GY.
(11)
Yang KS, Choi HR, Kim JJ, et al. Study of carbon disulfide intoxication.
Seoul: Korean Ministry of Labor Press, 1999
(12)
Lee E, Kim MH. Cerebral vasoreactivity by transcranial Doppler in carbon disulfide poisoning cases in Korea. J Korean
Med Sci 1998;13:645-651
(13)
J Korean Med Sci. 1998 Dec;13(6):645-51. Cerebral vasoreactivity by transcranial Doppler in carbon disulfide poisoning cases in Korea. Lee E, Kim MH.
(14)
Biochem. J. (1980) 188, 107-1 12 107
The Effects of Carbon Disulphide on Rat Liver Microsomal Mixed-Function
Oxidases, in vivo and in vitro
Maria J. OBREBSKA,* Peter KENTISH and Dennis V. PARKE
(15)
Journal of Ncurochcmistru. 1971, Vol. 18, pp. 177 to 182. Pergamon Press.
Oxidation and phosphorylation processes in brain mithochondria of rats exposed to carbon disulfide.
S. Tarkowski Hanna Sobczak
(16)
Lefaux, R. 1968. Carbon disulphide. Pp. 117-119 in Practical Toxicology of Plastics. Cleveland, OH: Chemical Rubber Company
(17)
Gorny, R., Carbon disulfide-induced vitamin 96 deficiency in rats fed diets with different vitamin B6 contents, Bromarol. Chem. Toksykol., 13(3), 299, 1980.
(18)
Washuettl, J., Winker, N., and Steiner, I.,The effects of carbon disulfide on the vitamin BI content in the serum of exposed workers, Munch. Med. Wochenschr., 121(24), 819, 1979.
(19)
165. Miyagawa, K., Carbon disulfide poisoning – Effects of L-methionine and L-methionine
combined with vitamin B12 on carbon disulfide poisoning, Shikoku Acra Med., 6(3), I, 1955.
(20)
Wronska-Nofer,. T., Nofer, J., and Stanislaw, T., Disorders in excretion of niacin metabolites in carbon disulfide-poisoned animals, Med. Pr., 16, 77, 1965.
(21)
Wronska-Nofer, T., The influence of low doses of nicotinic acid upon the development
of lipid disturbances in rats chronically exposed to carbon disulphide, hi. Arch. Arbeitsmed., 29(4), 285, 1972.
(22)
Knobloch, K., Effect of nicotinamide on excitability of the vestibular nerve and some motor nerves in chronic carbon disulfide poisoning in guinea pigs, Med. Pr., 12, 355, 1961.
(23)
Kuljak, S. and Stern, P., Protective effect of glutathione and xanthinol nicotinate against carbon disulfide poisoning in the mouse, Arh. Hig. Rada Toksikol., 22(2), 137, 1971
(24)
Paine, A. J., Williams, L., and Legg, R. F., Apparent maintenance of cytochrome P450 by
nicotinamides in primary cultures of rat hepatocytes, Life Sci., 24, 2185, 1979.
(25)
Silvestroni, A. and Rimiani, R., Microcirculation in chronic experimental intoxication with carbon disulfide. Effects of nicotinic acid, Folia Med., 53, 1, 1970.
(26)
McKenna, M. J. and DiStefano, V., Carbon disulfide. I. The metabolism of inhaled carbon disulfide in the rat, J. Pharmacol. Exp. Ther., 202(2), 245, 1977
Reaction of carbon disulfide with blood in vitro, Prac. Lek., 6, 11, 1954.
(27)
Brieger, H., Carbon disulfide in the living organism-retention, biotransformation and
pathophysiologic effects, in Toxicology of Carbon Disulfide, Brieger, H., Ed., Excerpta Medica Foundation,
Amsterdam, 27, 1967.
(28)
Gadaskina, I. D. and Andreeva, N. B., Biochemical shifts occurring in the organism
following carbon disulfide poisoning (free SH groups and blood ceruloplasmin; copper and zinc metabolism), Gig. Tr. Prof. Zabol.. 13, 28, 1969.
(29)
Kotas, P., Obrusnik, I., Lukas, E., and Krivanek, M., Determination of zinc and copper in the
periphera nerves of rats with carbon disulfide-induced neuropathy, J. Radioanal. Chem., 19(2), 263, 1974.

(30)
(Scheel, 1967). ISBN 92 4 154070 2, World Health Organization 1979
COHEN AE, SCHEEL LD, KOPP JF, STOCKELL FR, Jr, KEENAN RG, MOUNTAIN JT, PAULUS HJ.
Biochemical mechanisms in chronic carbon disulfide poisoning. Am Ind Hyg Assoc J. 1959
Aug;20(4):303–323.
(31)
Wilmarth KR, Froines JR (November 1992). “In vitro and in vivo inhibition of lysyl oxidase by aminopropionitriles”. J Toxicol Environ Health 37 (3): 411–23. PMID 1359158
(32)
Csiszar K. Lysyl oxidases: a novel multifunctional amine oxidase family. Prog Nucleic Acid Res Mol Biol.
2001; 70: 1–32.
(33)
Chem Res Toxicol. 1998 May;(5):544-9.
Carbon disulfide and N,N-diethyldithiocarbamate generate thiourea cross-links on erythrocyte spectrin in vivo.
Erve JC, Amarnath V, Graham DG, Sills RC, Morgan AL, Valentine WM.
(34)
Volume 272, Number 51, Issue of December 19, 1997 pp. 32370-32377
Irreversible Inhibition of Lysyl Oxidase by Homocysteine Thiolactone and Its Selenium and Oxygen Analogues Implications for Homocystinuria
(35)
Arteriosclerosis, Thrombosis, and Vascular Biology. 2002;22:1409-1414
Low Density Lipoproteins Downregulate Lysyl Oxidase in Vascular Endothelial Cells and the Arterial Wall Cristina Rodríguez ; Berta Raposo ; José Martínez-González ; Laura Casaní ; and Lina Badimon
(36)
Madlo, Z. and Soucek, B., Absorption, metabolism, and action of carbon disulfide in the organism. VII. Inhibition of serum cholinesterase by carbon disulfide, Prac. Lek., 6, 312, 1953
Soucek, B. and Madlo, Z., Absorption metabolism, and action of carbon disulfide in the organism. VIII.
(37)
Acta Neuropathol. 1984;63(3):255-63.Links
Ultrastructure of carbon disulphie neuropathy.
Jirmanová I, Lukás E.
(38)
Ca2+ Calmodulin levels was increased in cerebral cortex, hippocampus and spinal cord. Volume 179, Issues 2-3, 15 May 2009, Pages 110-117 Changes of lipid peroxidation in carbon disulfide-treated rat nerve tissues and serum Da-Qing Suna, b Ai-Wu Lic, , Ju Lid, Dian-Guo Lib, Yi-Xin Lib, Hao-Fengb and
Ming-Zhi Gongb, Chemico-Biological Interactions.
(39).
Davidson M, Feinleib M. Carbon disulfide poisoning: A review.
Am Heart J 1972;83:100-114
(40).
Lee KB, Byoun HJ, Choi TS, Kim SS, Cho WY, Kim HK.
Clinical manifestation of chronic carbon disulfide intoxication.
Korean J Int Med 1990;39:245-251
(41).
Choi JW, Jang SH. A review of the carbon disulfide poisoning
experience in Korea. Korean J Occup Med 1991;3:11-20
(42).
Yang KS, Choi HR, Kim JJ, et al. Study of carbon disulfide intoxication.
Seoul: Korean Ministry of Labor Press, 1999
(43)
Aaserud O, Gierstad L, Nakstad P, et al. Neurological examination,
computerized tomography, cerebral blood flow and neurophysiological
examination in workers with long-term exposure
to carbon disulfide. Toxicology 1988;49:277-28
(44)
Aaserud O, Hommeren OJ, Tvedt B, et al. Carbon disulfide exposure
and neurotoxic sequelae among viscose rayon workers.
Am J Ind Med 1990;18:23-37
(45)
Sugimura K, Kabashima K, Tatetsu S. Computerized tomography
in chronic carbon disulfide poisoning. No to Shinkei 1979;
31:1245-1253
(46)
Huang CC, Chu CC, Chen RS, et al. Chronic carbon disulfide
encephalopathy. Eur Neurol 1996;36:364-368
(47)
Peters HA, Levine RL, Matthews CGM et al. Extrapyramidal
and other neurologic manifestations associated with carbon
disulfide fumigant exposure. Arch Neurol 1988;45:537-540
(48)
Ca2+ Calmodulin levels was increased in cerebral cortex, hippocampus and spinal cord. Volume 179, Issues 2-3, 15 May 2009, Pages 110-117 Changes of lipid peroxidation in carbon disulfide-treated rat nerve tissues and serum Da-Qing Suna, b Ai-Wu Lic, , Ju Lid, Dian-Guo Lib, Yi-Xin Lib, Hao-Fengb and
Ming-Zhi Gongb, Chemico-Biological Interactions.
(49)
Alterations of microtubule and microfilament expression in spinal cord of carbon disulfide intoxicated rats. Chinese journal of industrial hygiene and occupational diseases. Original title: Zhonghua lao dong wei sheng zhi ye bing za zhi Zhonghua laodong weisheng zhiyebing zazhi. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2007 Mar;25(3):148-51 Pan GB, Song FY, Zhao XL, Yu LH, Zhou GZ, Xie KQ.
(50)
Toxicological Sciences 94(2), 240–255. Richard M. LoPachin. David S. Barber
doi:10.1093/toxsci/k?066 Advance Access publication July 31, 2006
(51)
Chin Med J (Engl). 2008 Dec 20;121(24):2553-6.
Effects of carbon disulfide on the expression and activity of nitric oxide synthase in rat hippocampus.
Guo XM, Tang RH, Qin XY, Yang J, Chen GY.
(52)
Schizophr Res. 2000 Feb 14;41(3):405-15
Apoptosis and schizophrenia: is the tumour suppressor gene, p53, a candidate susceptibility gene?
Catts VS, Catts SV.
Schizophrenia Research Unit, South Western Sydney Area Health Service, Liverpool Hospital, Liverpool, NSW, Australia.
(53)
Int J Hyg Environ Health. 2007 Jan;210(1):69-77. Epub 2006 Sep 1.
Use of genotypic selection to detect P53 codon 273 CGT>CTT transversion: application to an
occupationally exposed population.
Carton T, Tan XD, Hartemann P, Joyeux M.
(54)
Forensic Sci Int. 2005 Oct 29;153(2-3):147-55. Epub 2004 Nov 25.
A study of volatile organic compounds evolved from the decaying human body.
Statheropoulos M, Spiliopoulou C, Agapiou A.
School of Chemical Engineering, National Technical University of Athens (NTUA)
(55)
(Purdon et al., 2002; Purdon and Rapoport, 2007).
(56)
Bartonicek V. The distribution of carbon disulfide in whole blood, the brain and the suprarenal gland over a given period in parenteral administration in white mice. Prac Lek 1957; 9:28-30.
(57)
The modification of genetic expression after CS2 exposure have been shown in humans with p53. Chem Biol Interact. 2009 May 15;179(2-3):110-7. Epub 2008 Nov 25.
Changes of lipid peroxidation in carbon disulfide-treated rat nerve tissues and serum.
Sun DQ, Li AW, Li J, Li DG, Li YX, Hao-Feng, Gong MZ.
Shandong University, Jinan, Shandong, China.
(58)
Schizophrenia Research Volume 62, Issue 3, 1 August 2003.
The niacin skin flush test in schizophrenia- a combined a quantitative dose–response study
(59)
MCCANN Patrick, NAMJOU Khosrow, ROLLER Chad, MCMILLEN Gina, KAMAT Pratyuma. IV-VI Semiconductor Lasers for Gas Phase Biomarker Detection
Proceedings of SPIE, the International Society for Optical Engineering ISSN 0277-786X
(60)
Mater. Res. Soc. Symp. Proc. Vol. 891 © 2006 Materials Research Society
Patrick J. McCann1 and Yurii Selivanov2 1 School of Electrical and Computer Engineering, University of Oklahoma, Norman, OK 73019 2 P. N. Lebedev Physical Institute, Russian Academy of Sciences, Leninskii Pr. 53, 119991, Moscow, Russia
(61)
Br J Anaesth. 2008 Nov;101(5):673-9. Epub 2008 Sep 12.
Carbon dioxide negatively modulates N-methyl-D-aspartate receptors. Brosnan RJ, Pham TL.
(62)
Am J Physiol Regul Integr Comp Physiol. 2009 May;296(5):R1473-95.
Integration of cerebrovascular CO2 reactivity and chemoreflex control of breathing: mechanisms of regulation, measurement, and interpretation.
(63)
Adv Exp Med Biol. 2006;588:65-73
Control of cerebral blood flow during sleep and the effects of hypoxia.
Corfield DR, Meadows GE
(64)
Activity of glutamate decarboxylase in the brain of rats exposed to carbon disulfide
International Archives of Occupational and Environmental Health Volume 33, Number 1 / March, 1974
Stanislstrokaw Tarkowski
(65)
Tarkowski S, Cremer JE. 1972. Metabolism of glucose and free amino acids in brain, studied with C-labelled glucose and butyrate in rats intoxicated with carbon disulfide. J Neurochem
19:2631-2640.
(66)
The Journal of Neuroscience, 1999, 19:RC16:1-9
RAPID COMMUNICATION Novel Injury Mechanism in Anoxia and Trauma of Spinal Cord White Matter: Glutamate Release via Reverse Na+-dependent Glutamate Transport Shuxin Li1, Geoff A. R. Mealing2, Paul Morley2, and Peter K. Stys1

This is my last project for my Anatomical Visualization class:

The assignment was to create an illustration to explain the sliding filament mechanism theory of muscle contraction at the molecular
level. It took a bit of research for me to understand how this process worked, and was challenging to represent in a static image.

I also finished a personal website for my computer applications class:

Troponin and tropomyosin bestow Ca2+ dependence on the productive interactions of actin and myosin: rapid ATPase activity, generation of force, and generation of movement. 

In the absence of Ca2+, much of the myosin-binding site on actin is obscured by tropomyosin. Calcium binding to troponin causes tropomyosin to shift position, exposing much of the myosin-binding site. Strong actinmyosin binding requires a further repositioning of tropomyosin. … The shifting position of tropomyosin on actin is always a critical aspect of regulation.

The thin filament not only undergoes kinetic transitions, but also can have spatial transitions. Any local shift in tropomyosin position on the actin surface, for example caused by a lone, strongly bound cross-bridge, implies spatial transition(s) between actins with tropomyosin in one position, and actins with tropomyosin in another. Thus, the flexibility of tropomyosin on the actin filament is significant for full appreciation of its regulatory function.

Heller, M.J., et al., Cardiomyopathic tropomyosin mutations that increase thin filament Ca2+ sensitivity and tropomyosin N-domain flexibility. J Biol Chem, 2003. 278(43): p. 41742-8

As a trimeric regulatory protein complex located on actin-tropomyosin filaments, troponin (Tn) together with tropomyosin (Tm), regulates cardiac muscle contraction in response to Ca²⁺.

Troponin I (TnI) is one of the subunits of Tn, which makes extensive contacts with the other subunits of the Tn trimer, troponin C (TnC) and troponin T (TnT), as well as actin-Tm.

In relaxed muscle at low intracellular Ca²⁺concentration, by virtue of its interaction with actin, TnI constrains Tm-Tn in a position on the actin filament that prevent myosin binding and subsequent crossbridge cycling.

Upon muscle stimulation, elevated intracellular Ca²⁺ triggers muscle contraction by binding reversibly to TnC. Ca²⁺ binding causes a region of TnI to switch from its binding site on actin to a site on TnC. This conformational change removes the positional constraint of Tn-Tm on actin and permits the interaction of myosin with actin and the subsequent hydrolysis of ATP (actin-activated myosin ATPase activity) that provides energy for force production.

Foster, D.B., et al., C-terminal truncation of cardiac troponin I causes divergent effects on ATPase and force: implications for the pathophysiology of myocardial stunning. Circ Res, 2003. 93(10): p. 917-24

If the two myosins propel actin at different velocities, then the velocity of an actin filament will depend on the relative propotions of the two myosins and the relative pulling strengths or kinetics of the two myosins;  in a mixture, filaments will tend to run dispropotionately cliser to the velocity of the stronger myosin. Myosin mixtures assays can therefore be used to estimate the relative difference in force or detachment kinetics of two different populations of myosin.

A flow cell (i.e., an open system that allows solution exchange during the experiment) is assembled from a glass slide and a nitrocellulose coated coverslip using silicon grease along the edges of the coverslip as spacer between the two surfaces.

A myosin solution is then allowed to flow into the cell. Within seconds, the myosin molecules bind to the coverslip. The nitrocellulose prevents myosin denaturation on the highly charged glass surface.

After a washing step to remove excess myosin, free binding sites in the flow cell are blocked to prevent actin filaments from sticking to the glass surface. Fluorescent derivatives of phalloidin (e.g., rhodamin-phalloidin) – a mushroom toxin that tightly binds to actin filaments – are used to fluorescently label actin filaments indirectly.

When added to the flow cell, these fluorescent actin filaments bind to the myosin molecules, and the motility assay system is ready for use. Adding “fuel” in the form of ATP produces a sliding movement of the actin filaments powered by the myosin motors attached to the coverslip.

http://www.mih.unibas.ch/Booklet/Booklet96/Chapter2/Chapter2.html ]]> http://muscletters.wordpress.com/2009/07/01/in-vitro-motility-assay-1-classical-paper/ Wed, 01 Jul 2009 19:41:28 +0000 muscletters http://muscletters.wordpress.com/2009/07/01/in-vitro-motility-assay-1-classical-paper/ The first quantitative measurement of rates of movement of purified myosin along actin in vitro were made by using the Nitella-based movement assay. That depends on the biochemically undefined actin cables of the Nitella cell, which are stabilized by unknown factors and may be contaminated by components of the Nitella cytoplasm.

The first approach to establish a purified movement system was use an array of polar, aligned actin filaments bound to the substrated by the Dictyostelium protein severin. These experiments provided quantitative in vitro measurement of movement of purified actin and myosin. However, this system has been difficult to develop into a practical myosin movement assay. Many beads attach to the substratum without moving, and those that move do so for relatively short distances.

Yanagida et al. observed single fluorescent actin filaments in solution by using a video light microscope. They found that the amplitude and frequency of bending of the filaments increased in the presence of soluble myosin fragments and ATP. We considered that we might observe linear movement of single fluorescent actin filaments along myosin filaments by inverting our movement system, immobilizing the myosin on the substrate, and allowing single actin filaments to attach to the bound myosin.

In this study, we report that, in the presence of ATP, myosin filaments attached to glass are indeed capable of supporting movement of single actin filaments labeled with rhodamine phalloidin. The rates of movement of these single actin filaments are consistent with those measured in our previous assays and depend on the concentration of ATP, the buffer pH, and the type of myosin.

The most important feature of this assay is that it gives rapid, quantitative, and reproducible myosin movement data from small samples of purified proteins. And this assay offers the opportunity to examine the direct effects of modifications of either actin or myosin or of added factors on the movement process.

Kron, S.J. and J.A. Spudich, Fluorescent actin filaments move on myosin fixed to a glass surface. Proc Natl Acad Sci U S A, 1986. 83(17): p. 6272-6.

Probably one of the better and less known Matt Costa songs.

One of the mental functions many of us take for granted is memory – that is – until we’re at the grocery store.  If you’re like me, you dart out of the house confident that you don’t need a list since you’re just going to “pick up a few things” – only to return home and discover (hours later when you’re comfortably ensconced on the couch) that you forgot the ice cream.  Damn, why can’t I have a more efficient working memory system ?  What’s the matter with my lateral frontal cortex ?  Can I (should I) blame it on my genes ? What genes specifically ?

One group recently reported the use of the so-called BOLD-response (blood oxygen level dependent) as a means to sift through the human genome and identify genes that mediate the level of brain activity in the lateral frontal cortex that occur during a working memory task – somewhat akin to remembering a list of groceries.  Steven Potkin and associates in their paper, “Gene discovery through imaging-genetics: identification of two novel genes associated with schizophrenia” [doi: 10.1038/mp.2008.127] examine the level of brain activity in 28 patients with schizophrenia (a disorder where mental function in the lateral frontal cortex is disrupted) and correlate this brain activity (difference between short and long list) with genetic differences at 100,000 snps spread across the autosomes.

They identify 2 genes (that pass an additional series of statistical hurdles designed to weed-out false positive results) RSRC1 and ARHGAP18, heretofore, never having been connected to mental function.  Although neither protein is neuron or brain-specific in its expression, ARHGAP18 is a member of the Rho/Rac/Cdc42-like GTPase activating (RhoGAP) gene family which are well known regulators of the actin cytoskeleton (perhaps  a role in synaptic plasticity ?) and RSRC1 is reported to bind to actin homologs. Also, RSRC1 may play a role in forebrain development since it is expressed in cdc34+ stem cells that migrate under the control of TGF-alpha (As an aside, yours truly co-published a paper showing that TGF-alpha is regulated by early maternal care – possible connection ? Hmm).  A last possibility is a role in RNA splicing which many SR-proteins like RSRC1 function in – which also could be important for synaptic function as many mRNA’s are stored in synaptic terminals.

The authors’ method is completely novel and they seem to have discovered 2 new points from which to further explore the genetic basis of mental disability.  It will be of great interest to see where the research leads next.

Image by sean dreilinger via Flickr

I was irked to see, in today’s New York Times, a picture of a young child having his cheek swabbed so that his parents could ascertain his status at the rs1815739 C/T variant .  T-alleles at this site give rise to a premature stop codon in the alpha 3 actinin (ACTN3) gene while the C-allele encodes a full-length protein that contributes to the fast twitching of muscle fibers.  Not surprisingly, it was found [PubMed Central ID: PMC118068] that folks who have achieved status as Olympic caliber sprinters are more likely to carry the C-allele than ethnically matched controls. The company, Atlas Sports Genetics is now marketing the test, for $149 as a means to “predict a child’s natural athletic strengths”.  Holy Crap !

Its sad to think of the myriad of ways in which genetic information can be misused and misrepresented – sadder still to think of using genetic tests to deny kids the simple joy of playing with each other.  Parents may be intersted to know that among europeans and asians, the C-allele is present at about 50%, making 75% of the population either a C/C or a C/T … which, taken alone, explains very little of why a handful of individuals achieve athletic success. Parents considering paying the $149 might also wish to read a recent article by Dr. Jerome Kagan, a well-regarded developmental psychologist on recent trends in overparenting.

My 23andMe profile shows a middling C/T which is on par with my middling soccer skills.  Nevertheless, I had a great experience learning and building relationships with my pals on the soccer field, many who remain friends decades hence.

I like to think of the myosin filaments as caterpillars…. that have 2 heads: so as you can see from the picture above, the myosin filaments have little ‘legs‘  sticking out at the 2 ends (but they like to call them heads….) and what those 2 pictures at the bottom are trying to say (and doing a crappy job at it..) is that these heads reach out to an actin filament and then attaches itself, then physically pulls the actin towards the middle over and over again (much like how animals walk), which makes the muscle shorten.

If you keep in mind the same image, then you can begin to understand the logic behind the length-force relationship of muscles:

all this says is that when the muscle is stretched or shortened to a point it will start to reduce its ability to produce force (so why it’s harder to do a squat or a push-up if you go lower, despite the fact you are moving the same weight). So back to the caterpillar metaphor: if the branch (actin) is too far but close enough for a leg or 2 to reach, it still really can’t pull itself up the other side and if anything it’ll have to keep scuttling just to stay attached (that vibration you get when you strain?…). And when your muscles are too short, the actin filaments will end up sliding past each other, which means that the ‘legs’ at each ends will actually be working against the contraction as they run along the actin going the opposite way, also when the actin overlaps it stops the myosin from connecting with the filaments it was suppose to; and also the myosin filaments will end up butting up against the ends of the sarcomere.

Anyways that’s my first in-a-nutshell post and I hope it was useful and didn’t confuse/bore you to death. I try to steer away from the molecular stuff for now since it can be extremely boring and extremely long and I want to try to keep these as simple and short as possible (hopefully I did alright this round), and I guess I’ll keep these post to things people can relate to (rather than your school stuff where you spend 2 months learning about how you make pee…. but if you really want to know….).

[Doing this is also beneficial to my study ]

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Hugh Hefner finally grew up:

[another fashion store in HK somewhere...]