Medical Physiology Online

Peer reviewed, open access journal. ISSN 1985-4811.

Can we use will power to negate effect of general anesthetics?

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ASK A QUESTION

Can we use will power to negate effect of general anesthetics?

Is it possible for an individual to consciously alter or negate the effect of a drug? For example, can an individual use his will power to remain conscious after being administered a general anaesthetic? Can an individual retain motor function using his will even after being administered skeletal muscular relaxants, eg succinyl choline?. Just out of curiosity..

Janarthan Rama Murti
Second Year Medical Student, AIMST University, Malaysia

E-mail: scientist768 at gmail dot com

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Written by E.S.Prakash

April 4, 2010 at 11:38 PM

To give or not to give lecture slides to students before I deliver the lecture?

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LETTER TO THE EDITOR

To give or not to give lecture slides to students before I deliver the lecture?

E.S.Prakash, Department of Physiology, Faculty of Medicine, AIMST University, 08100 Bedong, Kedah, Malaysia.

E-mail: dresprakash at gmail dot com

Download PDF of the Letter

Supplement 1 Slides of an entire lecture [Sample]

Supplement 2 Slides used for providing a Preview of an upcoming lecture [Sample]

Supplement 3 Post-test [Sample]

Submitted 25 Feb 2010; revised, accepted and published 22 Mar 2010

Acknowledgment: The author is the editor and publisher of Medical Physiology Online.

This manuscript was reviewed and accepted for publication as a letter by Dr David J Solomon, Professor of Medicine, Michigan State University, East Lansing, Michigan, USA. E-mail: dsolomon at msu dot edu

Dr Solomon is a member of Senior Advisory Board of Medical Physiology Online.

Please cite this article as: Prakash ES To give or not to give my lecture slides to students before I deliver the lecture? Medical Physiology Online 2010; available from http://www.medicalphysiologyonline.org

Prepublication Record: The prepublication record containing the original version of the manuscript, editor’s comments and author’s response can be accessed at https://medicalphysiologyonline.files.wordpress.com/2010/03/mpo-018-2010_prepublication-record.pdf

This is an open access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0/, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, is properly cited.

Written by E.S.Prakash

March 21, 2010 at 11:26 PM

Posted in 256080

Announcement: 8th Inter-Medical School Physiology Quiz, 2010

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At the 7th Inter-Medical School Physiology Quiz held on 2 and 3 October 2009 at the University of Malaya [for details, click here], over 30 teams participated including teams from medical schools in Malaysia, Thailand, Japan, China, Singapore, Srilanka, India, Philippines, and Indonesia. The team from National University of Singapore emerged the winner. The team from Chulalongkorn University, Bangkok came second, and the team from Monash University, Malaysia team came third.

Mc Graw Hill Inc., donated a  2 -volume set of ‘Harrison’s Principles of Internal Medicine’ to each member of the  winning team. Oxford-Fajar Malaysia also donated book prizes to the teams that came second and third. All the 30 plus University teams enjoyed another stimulating and memorable physiology quiz and new friends were made across states and nations.

The 8th Inter-Medical School Physiology Quiz (IMSPQ) will be hosted by University of Malaya in Kuala Lumpur, and is tentatively scheduled for the last week of September 2010. There is no registration fee for participants, and organizers will provide free food and accommodation arrangements to all student participants. For further information, kindly contact the programme chairperson Dr Cheng Hwee Ming at hmingcheng at gmail dot com

Contributed by

Dr Cheng Hwee Ming

Department of Physiology

Faculty of Medicine

University of Malaya

Kuala Lumpur, Malaysia

E-mail: hmingcheng at gmail dot com

Written by E.S.Prakash

March 11, 2010 at 3:41 AM

Posted in 256080

Question regarding “Choosing Sex”

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I refer to the article “Choosing Sex” by Professor Capel published recently in The Scientist http://www.the-scientist.com/2009/10/1/36/1/ [accessed 6 Oct 2009]

My question is what would happen if none of these signals (Wnt, SRY, FGF9) were present  in the first place. What would be the eventual fate of the bipotential gonad? Will both testes and ovaries develop or neither?

Ravivarma Panirselvam, 

Second Year Medical Student

AIMST University, 08100 Bedong, Kedah, Malaysia

E-mail: ravivarmarao at gmail dot com

Conflict of interests: none

__________

Posted in the “Ask a Question” Section by E.S.Prakash, Editor, MPO.

Written by E.S.Prakash

October 6, 2009 at 12:01 PM

Posted in 256080

Increasing kidney oxygenation as a potential therapeutic avenue for kidney disease

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Point of View

Increasing kidney oxygenation as a potential therapeutic avenue for kidney disease

Nikki R Adler, Department of Physiology, Monash University, PO BOx 13F, Melbourne, Victoria 3800, Melbourne, Australia. E-mail: nradl2 at student dot monash dot edu

Manuscript received 23 Jul 2009; first decision 5 Aug 2009; revised 3 Oct 2009; accepted and published 3 Oct 2009

Abstract:

It is important to investigate the mechanisms of chronic kidney disease as it is a public health problem worldwide. The unique architecture of the kidney vasculature underpins the kidney’s susceptibility to hypoxia. The countercurrent arrangement of arteries and veins in the renal cortex and of capillaries (ascending and descending) in the medulla contributes to decreased oxygen availability. Kidney disease is associated with loss of peritubular capillaries in the tubulointerstitium. Tissue hypoxia contributes to the progression and pathogenesis of chronic kidney disease. Hypoxia occurs in the tubulointerstitium prior to structural microvascular damage. Thus, hypoxia is a pathogenic factor in early stage renal disease. Approaches to increase intrarenal oxygenation form a potential therapeutic target. Presently, inhibition of the renin angiotensin system is used to treat chronic kidney disease. Angiotensin-II receptor antagonists and angiotensin-converting-enzyme inhibitors afford renoprotection in part by altering the balance between oxygen delivery and oxygen consumption, thereby treating chronic hypoxia in the tubulointerstitium. Erythropoietin (EPO) may confer renal cytoprotection and improve kidney oxygenation. However, its efficacy in the treatment of chronic renal disease in the human condition is yet to be established. Modulation of the hypoxia inducible factor (HIF) system, via prolyl hydroxylase inhibitors, is a potential therapeutic target for the treatment of chronic kidney disease. Additional research should be conducted to further elucidate the mechanisms of kidney oxygenation and the adaptive hypoxic response.

Conflict of interests: none

PDF of the full article

Some rights reserved, N.R.Adler. This is an open access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by-nc-sa/3.0/


Written by E.S.Prakash

October 3, 2009 at 3:05 PM

Posted in 256080

Letter regarding the article ‘Cold-activated brown adipose tissue in healthy men’ by Lichtenbelt et al.

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LETTER TO THE EDITOR

Using integrated 18F-fluorodeoxyglucose positron emission tomography and computed tomography, Lichtenbelt et al [1] have demonstrated cold induced brown adipose tissue activity in lean and overweight healthy men. The authors also find a significant negative correlation between body mass index and brown adipose tissue activity.

In this study, body mass index (BMI) was used to classify subjects as lean (BMI < 25 kg/m2) or overweight/obese (BMI ³ 25 kg/m2). However, the percentage of body fat in overweight/obese subjects varied from 16.9 – 41.8%, the lower limit of this being much lower than that in ‘lean’ subjects, indicating that at least some of the subjects who were classified as obese were not ‘excessively fat’. Indeed, for body fat percentage values between 10 and 20% (n = 10 in this study), the authors also found a steep inverse relationship between body fat percentage and brown adipose tissue activity (Figure 3B in Ref. 1). Although what is a healthy body fat percentage remains to be established from prospective studies [2] and obesity is not currently defined on the basis of body fat percentage or fat mass index (i.e., fat mass in kg divided by square of the height expressed in meters; Ref. 3), we are interested in knowing how the volume of brown adipose tissue and resting metabolic rate compared if subjects in this study were dichotomized on the basis of an arbitrary body fat percentage (say 20%) or fat mass index rather than BMI.

Secondly, since waist circumference, an estimate of abdominal adiposity, has been demonstrated to independently predict mortality, [4] we wonder if this was measured in this study and if so how it correlated with brown adipose tissue activity.

Conflict of interests: none

E.S.Prakash and K.R.Sethuraman,

Faculty of Medicine, AIMST University, 08100 Semeling, Kedah, Malaysia

E-mail: dresprakash at gmail dot com

Acknowledgment:

E.S.Prakash is the Editor and Dr K.R.Sethuraman is a member of the Senior Advisory Board of Medical Physiology Online.

Editor for this Submission: This letter was reviewed and accepted for publication by Dr Roger Evans, Department of Physiology, Monash University, Melbourne, Australia. e-mail: roger dot evans at med dot monash dot edu dot au. Dr Evans is a member of the Senior Advisory Board for Medical Physiology Online.

Submitted 15 June 2009, revised 16 Jun 2009, accepted and published 17 Jun 2009.

References:

[1] van Marken Lichtenbelt WD, Vanhommerig JW, Smulders NM, et al. Cold-activated brown adipose tissue in healthy men. New England Journal of Medicine 2009; 360:1500-8 [Abstract]

[2] Gallagher D, Heymsfield SB, Heo M, Jebb SA, Murgatroyd PR, and Sakamoto Y. Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index. American Journal of Clinical Nutrition 2000; 72: 694–701. [Full text]

[3] Schutz Y, Kyle UUG and Pichard C. Fat-free mass index and fat mass index percentiles in Caucasians aged 18 – 98 y. International Journal of Obesity 2002; 26: 953–960. [Abstract]

[4] Pischon T, Boeing H, Hoffmann K, et al. General and abdominal adiposity and risk of death in Europe. New England Journal of Medicine 2008; 359: 2105-2120. [Full text]

Please cite this letter as E.S.Prakash and K.R.Sethuraman. Letter regarding the article ‘Cold-activated brown adipose tissue in healthy men’ by Lichtenbelt et al. Medical Physiology Online 2009; available from http://www.medicalphysiologyonline.org

Some rights reserved © E.S.Prakash and K.R.Sethuraman, 2009. This is an open access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by-nc-sa/3.0/

Written by E.S.Prakash

June 17, 2009 at 11:19 AM

Cardiac inter-beat interval complexity is influenced by physical activity

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RESEARCH COMMUNICATION

Benjamin J. Wilson1, Gus L. W. Hart2, and Allen C. Parcell3

1Department of Recreation Management and Youth Leadership, Brigham Young University, Provo, Utah; 2Department of Physics and Astronomy, Brigham Young University, Provo, Utah; 3Human Performance Research Center, Department of Exercise Sciences, Brigham Young University, Provo, Utah.

Correspondence to: Benjamin J. Wilson, 3838 S 1860 E, Salt Lake City, UT 84106, USA.

E-mail: benjaminjameswilson at gmail dot com

Submitted 25 Oct 2008; time to first decision 25 days; revision accepted and published 1 Jan 2009.

Abstract:

The complexity of physiological signals may be a more sensitive indicator of health than standard or average measurements. We examined cardiac inter-beat intervals of healthy subjects who are either physically active or sedentary to determine whether measures of complexity are more sensitive to subtle cardiac changes than standard measures. Subjects were pre-screened by self-report, and qualifying subjects were placed in either the active group (n = 10) or sedentary group (n = 10). Cardiac inter-beat intervals were recorded and subsequently analyzed using standard time and frequency domain heart rate variability measurements as well as multiscale entropy and the detrended fluctuation analysis, both measures of complexity. Of the measurements, the detrended fluctuation analysis was the only tool that significantly (P = 0.04) differentiated between the active and sedentary groups. This suggests that the complexity of physiologic signals is a more sensitive indicator of cardiac health than standard measures.

 

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Please cite this article as: Wilson BJ, Hart GLW, Parcell AC. Cardiac inter-beat interval complexity is influenced by physical activity. Medical Physiology Online, 1 Jan 2009, available from http://www.medicalphysiologyonline.org

Written by E.S.Prakash

January 1, 2009 at 1:34 AM