Re: Rat Monty Pythons fare?

[Guest guest]

Hi folks:

In case anyone missed it, an astonishing stat from Al's post:

" Friedman showed that overweight mice with defective ob genes — and

who cannot make leptin — respond to injections of leptin by losing up

to 30% of their body weight in two weeks. "

Rodney

--- In , " old542000 " <apater@m...>

wrote:

>

> Hi All,

>

> There is an article in the new issue of Nature Med that

> piqued interest regarding the use of " sumo " .

>

> Previously, it has been somewhat humorously

> noted that:

>

> " Sumo wrestlers, football players, and basketball players play

an

> important role in our world, their small numbers do not pose a

threat

> to our survival. However, their body habitus should not be the goal

> for the average male of the future. "

>

> This was previously subject of our grist mill, and is from:

>

> http://tinyurl.com/4me67 ,

>

> which is

>

> Samaras TT, Elrick H.

> Less is better.

> J Natl Med Assoc. 2002 Feb;94(2):88-99.

> PMID: 11853051 [PubMed - indexed for MEDLINE]

>

> Another background paper Medline abstract that

> has not been shared among us is, from the actively

> exercising overweight group suggests that the above

> paper is correct:

>

> Nippon Eiseigaku Zasshi. 1995 Aug;50(3):730-6.

> Risk factors for mortality and mortality rate of sumo wrestlers

> Hoshi A, Inaba Y.

>

> We compared the mortality rate of sumo wrestlers with that of

the

> contemporaneous Japanese male population, and inferred the

usefulness

> of an

> index for predicting longevity in sumo wrestlers. The standardized

> mortality

> ratios (SMR) for sumo wrestlers were very high in each period, and

> also high for

> ages from 35 to 74. 's proportional hazards model analysis

> revealed that the

> variables in " nyuumaku " entry year and BMI were statistically

> significant (p <

> 0.05) factors in mortality. In the survival curves, the lower BMI

> group had good

> life expectancy compared with the higher BMI group. In conclusion,

> the higher

> rate of mortality in sumo wrestlers seems to be due to the markedly

> higher rate

> of mortality from 35 to 74 years old. In sumo wrestlers, also, this

> study

> provides evidence that the higher overweight groups have

> substantially higher

> risks for mortality.

> PMID: 7474495 [PubMed - indexed for MEDLINE]

>

> And, here is the preview of prospective studies for

> using a new rat model of human obesity. It was of

> interest, I believe, that the rats die early, but

>

> " their infertility is fully reversible with simple

> measures such as diet restriction " .

>

> Need we search further to generate interest in aging research

> investment, as well as humor.

>

> 'Sumo' rats set researchers on hunt for obesity genes

> Nature Medicine Feb 2005 11, 108

> K. S. Jayaraman

>

> " We are ready to start the project right away and hopefully

> clone the gene in two years. " - Friedman, Rockefeller

> University

>

> The world's fattest rats are the focus of a new joint project

for

> scientists from India and the US. The researchers hope to identify

> and clone the genes responsible for the 'sumo' rats that weigh in

at

> about 1.4 kilograms (3.1 pounds), about four times the standard

> weight for a rat.

> " If, as we believe, this is a new obesity gene, it could have

> major implications, " says Nappan Veettil Giridharan, deputy

director

> of India's National Institute of Nutrition (NIN) in Hyderabad. The

> NIN maintains a colony of about 400 sumo rats in their twenty-first

> generation. Giridharan says all evidence indicates that the genes

may

> differ from all obese rat models currently available.

> Like other rodent models, the sumo rats serve as good paradigms

> for human disorders such as diabetes and infertility. But unlike

the

> other models, these rats also develop cataracts and tumors, and

their

> infertility is fully reversible with simple measures such as diet

> restriction. The rats also have kinky tails, not seen in any other

> obese models.

> From day 35 on, the rats rapidly gain weight and their body

shape

> gradually becomes rotund. Too fat to move, they lie supine with

their

> heads close to the food pellets. They also show signs of rapid

aging

> and die in about 18 months, compared with the normal three years,

> Giridharan says.

> To map the mutation, Giridharan and his colleagues plan to cross

> the Indian rat with unrelated strains such as the Brown Norway and

> Fischer-344 strains. Genetic analysis on the resulting progeny will

> then help localize the mutation and ultimately clone it. DNA

analysis

> will be carried out by the US collaborators, led by

Friedman,

> at Rockefeller University in New York.

> In 1994, Friedman and his colleagues cloned the obese gene and,

in

> 1995, identified its product, leptin. Friedman showed that

overweight

> mice with defective ob genes—and who cannot make leptin—respond to

> injections of leptin by losing up to 30% of their body weight in

two

> weeks.

> The $500,000 cost of the project is to be shared by the US

> National Institutes of Health and the Indian Council of Medical

> Research (ICMR).

> " We are ready to start the project right away and hopefully

clone

> the gene in two years, " says Friedman. The ICMR is planning another

> large study to use the NIN rat to screen for potential obesity and

> diabetes drugs.

>

> Cheers, Al Pater.

[Guest guest]

Note the dates on those abstracts: '95 and 2002. At one time they thought

leptin showed promise, but IIRC, that promise has not been borne out.

Also of course (as we often forget) CRON is not about weight (although

surely losing weight can help make one healthier)

on 2/4/2005 11:27 PM, Rodney at perspect1111@... wrote:

>

> Hi folks:

>

> In case anyone missed it, an astonishing stat from Al's post:

>

> " Friedman showed that overweight mice with defective ob genes — and

> who cannot make leptin — respond to injections of leptin by losing up

> to 30% of their body weight in two weeks. "

>

> Rodney

>

>

[Guest guest]

Hi All,

Thank you for your comments, Francesca.

This aspect that you have difficulty with may be rebutted effectively

in Friedman's more recent report that can be found in Medline by

searching for 15644325 to identify the freely avaialble to all paper,

http://www.jbc.org/cgi/reprint/M413684200v1

, which explains in Fig. 1 clearly that leptin not only decreases

weight but also depresses the calories that are consumeed. And,

there is an adequate discussion of how leptin can be used for human

obesity, I believe, in the introduction at least, of

http://www.jbc.org/cgi/reprint/M413684200v1

Cheers, Al Pater.

>

> >

> > Hi folks:

> >

> > In case anyone missed it, an astonishing stat from Al's post:

> >

> > " Friedman showed that overweight mice with defective ob genes —

and

> > who cannot make leptin — respond to injections of leptin by

losing up

> > to 30% of their body weight in two weeks. "

> >

> > Rodney

> >

> >