Alistair Grant<[log in to unmask]> wrote:
<< I am afraid that an important epidemic, such as CHD, deserves more than
what amounts to un-referenced speculation and comment (although
interesting!). I also strangely feel compelled to apologise a priori to Mel
Siff's 'fans' (those who faithfully post messages to the list congratulating
him on his own posts) as no doubt they will be appalled at my criticism of
his latest posting. However, treat this as my attempt to bring a modicum of
scientific credibility to the list, at least for this important disease area,
that of course Dr Siff has had experience of as a patient.
More careful consideration of the epidemiological, pathological and clinical
literature will reveal that 'infection' has been suspected as being
associated with heart disease since the beginning of this century. However,
as rightly pointed out in the posting, it is in the last decade that has seen
a resurgence of interest, particularly in the respiratory pathogen Chlamydia
pneumoniae, and the enteric pathogen Helicobacter pylori. ...
One thing that is interesting in the post was the reference to the ecological
theory. I'm not sure about portraying it as a 'struggle' however thankfully
the 'ecological fallacy' is now being rejected by many who supported it in
the last decade and research into the contribution of population level
determinants of CHD are making a comeback.
I welcome constructive discussion however I plead that opinion be supported
by the appropriate 'evidence' to improve the credibility of our profession!>>
Mel Siff:
*** Coincidentally, the latest issue of Scientific American featured an
article on much the same topic this week:
<http://www.sciam.com/2001/0501issue/0501profile.html>
Here are a few excerpts from this article:
<Newton had a falling apple. Darwin mused on finches. Paul W. Ewald's
inspiration was diarrhea. "I wish I had something more romantic," says the
Amherst College evolutionary biologist. It gets uglier: Ewald, then a
graduate student studying bird behavior, was camped near a Kansas garbage
dump. As he waged a three-day battle against his sea of troubles, he
contemplated the interactions between a host—himself, in this case—and a
pathogen. "There's some organism in there," Ewald remembers thinking during
that 1977 experience, "and this diarrhea might be my way of getting rid of
the organism—or it might be the organism's way of manipulating my body" to
maximize its chances of passage to the next victim by, for example,
contaminating the water supply. "If it's a manipulation and you treat it,
you're avoiding damage," he notes. "But if it's a defense and you treat it,
you sabotage the host."
Host-pathogen relationships have dominated Ewald's thoughts ever since,
leading to numerous articles, two books and, depending on whom you talk to,
the respect or scorn of scientists and physicians. The admiration comes from
those who think he was on to something really big in his earlier
publications, which he summed up in his 1994 book Evolution of Infectious
Disease. "I think that Paul Ewald has been a pioneer in using evolutionary
theory to attack hard questions in pathogenesis," comments Stephen Morse, a
virologist and epidemiologist at Columbia University. "His work has, for the
first time, shown a way to generate testable hypotheses to study such
questions as the evolution of virulence—once thought intractable—and
infectious causes of chronic diseases." Indeed, the Atlantic Monthly referred
to Ewald as "the Darwin of the microworld" (to which Ewald responds, "No,
Darwin is Darwin of the microworld, too").
Any antipathy is the result of his latest research, outlined in last year's
Plague Time. The 47-year-old Ewald argued in the book that infection may play
a role in cancer, atherosclerosis, Alzheimer's and other chronic conditions
ordinarily thought of as inevitable consequences of genetics, lifestyle or
aging. "Some of his recent work is controversial," Morse states. "I'd
personally prefer to reserve judgment for now on those questions, at least
until more data are in." Others are less gracious..........
When Ewald wanders into the fields of chronic disease, however, he steps into
some eight-letter castigation. Given evolutionary principles and the
available evidence, he argues in Plague Time, infectious agents should be
considered as at least part of the etiology of apparently noninfectious
conditions. Of course, the connection between Helicobactor pylori and peptic
ulcers is now taken for granted, although medical texts of 20 years ago were
mute on the subject. Associations between infections and some ca
ncers—hepatitis virus with liver cancer, papillomavirus with
cervical cancer—have become accepted in only the past few decades. Ewald
thinks that more cancers, perhaps the majority, as well as numerous other
common, widespread and ancient chronic diseases, will eventually become
linked with various infections: for atherosclerosis and Alzheimer's disease,
he points to studies showing associations with Chlamydia pneumoniae. He even
holds that schizophrenia may be related to infection with the protozoan Toxopl
asma gondii..... >
*** In addition, here are some research publications of the many hundreds
relating to the same topic (you can easily find all of these articles via
Medline):
Cochran GM, Ewald PW, Cochran KD. Infectious causation of disease: an
evolutionary perspective. Perspect Biol Med. 2000 Spring;43(3):406-48.
Siscovick D, Alexander R, et al Collaborative multidisciplinary workshop
report: the role of epidemiology studies in determining a possible
relationship between Chlamydia pneumoniae infection and atherothrombotic
diseases. J Infect Dis. 2000 Jun;181 Suppl 3:S430-1.
Ewald PW, Cochran GM. Chlamydia pneumoniae and cardiovascular disease: an
evolutionary perspective on infectious causation and antibiotic treatment. J
Infect Dis. 2000 Jun;181 Suppl 3:S394-401. Review.
Ewald PW, Sussman JB, et al Evolutionary control of infectious disease:
prospects for vectorborne and waterborne pathogens. Mem Inst Oswaldo Cruz.
1998 Sep-Oct;93(5):567-76.
Ewald PW. The evolution of virulence and emerging diseases. J Urban Health.
1998 Sep;75(3):480-91.
Ewald PW. Guarding against the most dangerous emerging pathogens. Emerg
Infect Dis. 1996 Oct-Dec;2(4):245-57. Review.
Ewald PW. The evolution of virulence: a unifying link between parasitology
and ecology. J Parasitol. 1995 Oct;81(5):659-69. Review.
Ewald PW. Evolution of mutation rate and virulence among human retroviruses.
Philos Trans R Soc Lond B Biol Sci. 1994 Nov 29;346(1317):333-41; discussion
341-3.
Ewald PW. The evolution of virulence. Am. 1993 Apr;268(4):86-93. Review.
Ewald PW. Evolution of HIV in Africa. Science. 1992 Jul 3;257(5066):10.
Ewald PW. Waterborne transmission and the evolution of virulence among
gastrointestinal bacteria. Epidemiol Infect. 1991 Feb;106(1):83-119. Review.
Siscovick D, Alexander R, et al Collaborative multidisciplinary workshop
report: the role of epidemiology studies in determining a possible
relationship between Chlamydia pneumoniae infection and atherothrombotic
diseases. J Infect Dis. 2000 Jun;181 Suppl 3:S430-1.
Grayston JT. What is needed to prove that Chlamydia pneumoniae does, or does
not, play an etiologic role in atherosclerosis? J Infect Dis. 2000 Jun;181
Suppl 3:S585-6.
Grayston JT. Background and current knowledge of Chlamydia pneumoniae and
atherosclerosis.
J Infect Dis. 2000 Jun;181 Suppl 3:S402-10.
Orfila JJ. Seroepidemiological evidence for an association between Chlamydia
pneumoniae and atherosclerosis.
Atherosclerosis. 1998 Oct;140 Suppl 1:S11-5.
Sumarokov AB, Liakishev AA. Chlamydia pneumoniae infection and
atherosclerosis. Klin Med (Mosk). 1999;77(7):4-10. [Russian]
Byrne GI, Skarlotos SI, Grunfeld C, Kalayoglu MV, Libby P, Saikku P,
Summersgill JT, Wyrick P.
Collaborative multidisciplinary workshop report: interface of lipid
metabolism, atherosclerosis, and Chlamydia infection. J Infect Dis. 2000
Jun;181 Suppl 3:S490-1.
Sullivan JL, Weinberg ED. Iron and the role of Chlamydia pneumoniae in
heart disease. Emerg Infect Dis. 1999 Sep-Oct;5(5):724-6.
Gupta S, Camm AJ. Chronic infection in the etiology of atherosclerosis--the
case for Chlamydia pneumoniae.
Clin Cardiol. 1997 Oct;20(10):829-36. Review.
Latorre G, Girala M, Gomez F, Lucas I. Chlamydia pneumoniae pneumonia Rev
Med Univ Navarra. 1998 Jan-Mar;42(1):14-7. Spanish.
Arain GM. Chlamydia pneumoniae: can it cause atherosclerosis? J Pak Med
Assoc. 1997 Oct;47(10):242.
Wong Y, Ward ME. Chlamydia pneumoniae and atherosclerosis. J Clin Pathol.
1999 May;52(5):398-9.
Gupta S, Leatham EW. The relation between Chlamydia pneumoniae and
atherosclerosis. Heart. 1997 Jan;77(1):7-8.
Grayston JT, Campbell LA. The role of Chlamydia pneumoniae in
atherosclerosis. Clin Infect Dis. 1999 May;28(5):993-4.
Moller K, Skinhoj P. Chlamydia pneumoniae and atherosclerosis--the hen, the
egg or five feathers? Ugeskr Laeger. 1999 Sep 13;161(37):5173-4. Danish.
Siscovick DS, Schwartz SM, Caps M, Wang SP, Grayston JT. Chlamydia pneumoniae
and atherosclerotic risk in populations: the role of seroepidemiology. J
Infect Dis. 2000 Jun;181 Suppl 3:S417-20. Review.
Shor A, Phillips JI. Chlamydia pneumoniae and atherosclerosis. JAMA. 1999
Dec 1;282(21):2071-3. Review.
Veller M, Shor A. The role of Chlamydia pneumoniae in the pathogenesis of
atherosclerosis. Eur J Vasc Endovasc Surg. 1998 Dec;16(6):459-61.
Leinonen M. Chlamydia pneumoniae and other risk factors for atherosclerosis.
J Infect Dis. 2000 Jun;181 Suppl 3:S414-6. Review.
Gleichmann U, Gleichmann S. Arteriosclerosis--a Chlamydia pneumoniae
infection? Dtsch Med Wochenschr. 1998 Jan 23;123(4):98-100. German.
Mockel M. Persistence of Chlamydia pneumoniae in coronary plaque tissue
Dtsch Med Wochenschr. 2000 May 19;125(19):645. German.
--------------------------------------
Dr Mel C Siff
Denver, USA
http://groups.yahoo.com/group/Supertraining/
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