Puncturing the Myth (ZT) from The Scientist# Biology - 生物学
H*i
1 楼
因为某些原因，COE推迟，loan broker也不给我一个具体的计划出来，觉得很不爽。感
觉还不如换个loan broker重新申请。
请问，需要赔偿loan broker损失吗？有什么影响？谢咯
觉还不如换个loan broker重新申请。
请问，需要赔偿loan broker损失吗？有什么影响？谢咯
c*l
2 楼
用ATI Tray Tool，把显存频率降低到300
是不是附件这样就可以了？？
因为这是系统的默认设置，直接把显存频率设到300，我觉得系统出厂默认
把显存频率设置在下限有点不make sense
是不是附件这样就可以了？？
因为这是系统的默认设置，直接把显存频率设到300，我觉得系统出厂默认
把显存频率设置在下限有点不make sense
m*a
3 楼
Read it here: http://the-scientist.com/2011/08/31/puncturing-the-myth/
Puncturing the Myth
Purinergic signaling, not mystical energy, may explain how acupuncture works.
By Geoffrey Burnstock | August 31, 2011
4 Comments
According to traditional Chinese medical theory, acupuncture points are
situated on meridians along which qi, the vital energy, flows. However, I
have proposed a less mysterious neurophysiological mechanism to explain the
beneficial effects of this 2,000-year-old practice (Medical Hypotheses, 73:
470-72, 2009). In particular, my hypothesis is based on the surprising
finding that a hitherto unknown extracellular signalling system exists
between cells, including nerve cells.
Adenosine 5’-triphosphate (ATP) is well established as an intracellular
energy source that powers biochemical processes. In 1972 I proposed that ATP
has another biochemical role: it acts as an extracellular signalling
molecule between cells. The messages carried by ATP are received on the
surface of cells by specific receptors, which I termed purinoceptors,
because ATP belongs to a group of chemicals known as purines. Six years
later, two families of purinoceptors were identified—P1 receptors for
adenosine, the breakdown product of ATP, and P2 receptors for ATP. The
purinergic signaling concept was rejected by many for two decades. It wasn’
t until the early 1990s, when the chemical and molecular structure of the
plasma membrane receptors for ATP was characterized and other downstream
members of this primitive signalling pathway were identified, that the
concept of purinergic signalling between cells became widely accepted, and
it is now a rapidly expanding field of physiological and pathophysiological
study.
Two intriguing hints prompted me to consider that inserting and twisting a
needle might release ATP from the skin and form the physiological basis for
the effects of acupuncture: 1) Initially it was thought that the ATP acting
as an extracellular signalling molecule was merely a by-product released
when cells were damaged or dying. 2) A paper published 34 years ago reported
that ATP injected into the human skin stimulated sensory neurons (Pain, 3:
367-77, 1977).
It is now clear that ATP can be released from many cell types (e.g.,
osteoblasts and endothelial, epithelial, and glial cells) in response to
gentle mechanical stimulation that does not damage the cells. ATP is also
released in response to heat and electrical currents—techniques used today
in conjunction with acupuncture to enhance its effect. Recent evidence has
also confirmed the 1977 finding that sensory nerve terminals in the skin are
activated by ATP. In this way, messages can be relayed from the skin via
interneurons in the spinal cord to the brain stem. Furthermore, the well-
established reduction of pain by acupuncture may be explained by the
possibility that the binding of ATP to purinoceptors on sensory nerve
endings in the skin activates a signaling pathway which ultimately modulates
pain perception in the brain’s cortex. Acupuncture’s inhibition of pain
may also involve the release of endorphins.
ACUPUNCTURE AND PURINERGIC SIGNALING
Insertion and twisting of the needles employed in acupuncture mechanically
deforms the skin, leading to the release of ATP by skin keratinocytes (1).
ATP binds to specific receptors located on sensory nerve endings in the skin
known as P2X3 and P2X2/3 (2). The signaling message is then relayed via
dorsal root ganglia to the spinal cord (3) and subsequently through
interneuronal pathways (4) to the brain stem (5) which contains motor
neurons that control the functions of gut, lung, heart, arteries and
reproductive organs, all major targets for acupuncture. Signals also travel
to pain centers in the cortex, delivering a message to inhibit pain (6).
LUCY READING-IKKANDA
The ATP-activated sensory nerves also lead to modulation of the activity of
brain-stem neurons controlling autonomic nervous system functions of gut,
lung, urogenital, and cardiovascular systems—all of which have been
treatment targets for traditional acupuncture procedures. There is published
evidence for the release of ATP from keratinocytes, the major cell type in
the skin, during mechanical stimulation. Similarly, ATP is released from
urothelial cells lining the bladder and ureter in response to stretch, and
receptors for ATP are present on suburothelial sensory nerves, ready to
relay messages to the pain centers in the central nervous system. In
addition, release of ATP in response to mechanical stimulation (changes in
blood flow) from endothelial cells that line blood vessels leads to
vasodilatation. And further, ATP is released from epithelial cells lining
the airways in response to stretch, leading to activation of ATP receptors
on sensory nerves, in turn resulting in the activation of reflexes that
protect the lung against hyperventilation.
Immunohistochemical studies have shown that the specific ATP receptor
subtypes, P2X3 and P2X2/3, are located on sensory nerve endings in the skin.
The same subtypes are also especially abundant in the tongue, another site
where acupuncture needles are placed. An isolated preparation of tongue
tissue showed that the increased electrical activity in lingual general
sensory nerves in response to mechanical stimulation could be mimicked by
injecting ATP into the preparation and blocked by injecting antagonists to
the P2X3 receptor subtype. The cell bodies of the sensory nerve endings that
supply the skin are located in sensory ganglia, which then connect with
neurons in the dorsal spinal cord. A series of interneurons then mediate
modulatory pathways to the brain stem and hypothalamus, which are the
nervous control centers for the activities of visceral organs. (See
illustration.)
Suggested experiments
Many tools are available to test various aspects of this hypothesis
experimentally. Apyrase, a readily available enzyme that breaks down ATP,
could be applied to the skin to see whether the enzyme diminishes the
benefits of acupuncture. In contrast, inhibitors of ATP breakdown, such as
ARL-67156, could be employed to see whether this would enhance the
beneficial effects of acupuncture. There are also very sensitive assay
methods for measuring ATP release, which could be used in skin subjected to
mechanical deformation, heat, and electrical current. Selected blockers (
antagonists) of P2X3 and P2X2/3 receptors are available, which should block
the beneficial effects of acupuncture. It seems likely from experiments on
the bladder and intestine that ATP-sensitive low-threshold sensory fibers
mediate physiological events, while high-threshold fibers mediate pain. This
will need to be clarified for the sensory nerves supplying the skin and
tongue before approaches to enhancing the ATP-related responses to
acupuncture are carried out, in case the enhancement results in pain.
I hope that this hypothesis will provoke some scientists interested in
acupuncture to investigate further.
Geoffrey Burnstock is Emeritus Professor and President of the Autonomic
Neuroscience Centre of University College Medical School in London. He is
editor-in-chief of Autonomic Neuroscience, Purinergic Signalling, and the
journals Open Neuroscience and Open Pharmacology.
Puncturing the Myth
Purinergic signaling, not mystical energy, may explain how acupuncture works.
By Geoffrey Burnstock | August 31, 2011
4 Comments
According to traditional Chinese medical theory, acupuncture points are
situated on meridians along which qi, the vital energy, flows. However, I
have proposed a less mysterious neurophysiological mechanism to explain the
beneficial effects of this 2,000-year-old practice (Medical Hypotheses, 73:
470-72, 2009). In particular, my hypothesis is based on the surprising
finding that a hitherto unknown extracellular signalling system exists
between cells, including nerve cells.
Adenosine 5’-triphosphate (ATP) is well established as an intracellular
energy source that powers biochemical processes. In 1972 I proposed that ATP
has another biochemical role: it acts as an extracellular signalling
molecule between cells. The messages carried by ATP are received on the
surface of cells by specific receptors, which I termed purinoceptors,
because ATP belongs to a group of chemicals known as purines. Six years
later, two families of purinoceptors were identified—P1 receptors for
adenosine, the breakdown product of ATP, and P2 receptors for ATP. The
purinergic signaling concept was rejected by many for two decades. It wasn’
t until the early 1990s, when the chemical and molecular structure of the
plasma membrane receptors for ATP was characterized and other downstream
members of this primitive signalling pathway were identified, that the
concept of purinergic signalling between cells became widely accepted, and
it is now a rapidly expanding field of physiological and pathophysiological
study.
Two intriguing hints prompted me to consider that inserting and twisting a
needle might release ATP from the skin and form the physiological basis for
the effects of acupuncture: 1) Initially it was thought that the ATP acting
as an extracellular signalling molecule was merely a by-product released
when cells were damaged or dying. 2) A paper published 34 years ago reported
that ATP injected into the human skin stimulated sensory neurons (Pain, 3:
367-77, 1977).
It is now clear that ATP can be released from many cell types (e.g.,
osteoblasts and endothelial, epithelial, and glial cells) in response to
gentle mechanical stimulation that does not damage the cells. ATP is also
released in response to heat and electrical currents—techniques used today
in conjunction with acupuncture to enhance its effect. Recent evidence has
also confirmed the 1977 finding that sensory nerve terminals in the skin are
activated by ATP. In this way, messages can be relayed from the skin via
interneurons in the spinal cord to the brain stem. Furthermore, the well-
established reduction of pain by acupuncture may be explained by the
possibility that the binding of ATP to purinoceptors on sensory nerve
endings in the skin activates a signaling pathway which ultimately modulates
pain perception in the brain’s cortex. Acupuncture’s inhibition of pain
may also involve the release of endorphins.
ACUPUNCTURE AND PURINERGIC SIGNALING
Insertion and twisting of the needles employed in acupuncture mechanically
deforms the skin, leading to the release of ATP by skin keratinocytes (1).
ATP binds to specific receptors located on sensory nerve endings in the skin
known as P2X3 and P2X2/3 (2). The signaling message is then relayed via
dorsal root ganglia to the spinal cord (3) and subsequently through
interneuronal pathways (4) to the brain stem (5) which contains motor
neurons that control the functions of gut, lung, heart, arteries and
reproductive organs, all major targets for acupuncture. Signals also travel
to pain centers in the cortex, delivering a message to inhibit pain (6).
LUCY READING-IKKANDA
The ATP-activated sensory nerves also lead to modulation of the activity of
brain-stem neurons controlling autonomic nervous system functions of gut,
lung, urogenital, and cardiovascular systems—all of which have been
treatment targets for traditional acupuncture procedures. There is published
evidence for the release of ATP from keratinocytes, the major cell type in
the skin, during mechanical stimulation. Similarly, ATP is released from
urothelial cells lining the bladder and ureter in response to stretch, and
receptors for ATP are present on suburothelial sensory nerves, ready to
relay messages to the pain centers in the central nervous system. In
addition, release of ATP in response to mechanical stimulation (changes in
blood flow) from endothelial cells that line blood vessels leads to
vasodilatation. And further, ATP is released from epithelial cells lining
the airways in response to stretch, leading to activation of ATP receptors
on sensory nerves, in turn resulting in the activation of reflexes that
protect the lung against hyperventilation.
Immunohistochemical studies have shown that the specific ATP receptor
subtypes, P2X3 and P2X2/3, are located on sensory nerve endings in the skin.
The same subtypes are also especially abundant in the tongue, another site
where acupuncture needles are placed. An isolated preparation of tongue
tissue showed that the increased electrical activity in lingual general
sensory nerves in response to mechanical stimulation could be mimicked by
injecting ATP into the preparation and blocked by injecting antagonists to
the P2X3 receptor subtype. The cell bodies of the sensory nerve endings that
supply the skin are located in sensory ganglia, which then connect with
neurons in the dorsal spinal cord. A series of interneurons then mediate
modulatory pathways to the brain stem and hypothalamus, which are the
nervous control centers for the activities of visceral organs. (See
illustration.)
Suggested experiments
Many tools are available to test various aspects of this hypothesis
experimentally. Apyrase, a readily available enzyme that breaks down ATP,
could be applied to the skin to see whether the enzyme diminishes the
benefits of acupuncture. In contrast, inhibitors of ATP breakdown, such as
ARL-67156, could be employed to see whether this would enhance the
beneficial effects of acupuncture. There are also very sensitive assay
methods for measuring ATP release, which could be used in skin subjected to
mechanical deformation, heat, and electrical current. Selected blockers (
antagonists) of P2X3 and P2X2/3 receptors are available, which should block
the beneficial effects of acupuncture. It seems likely from experiments on
the bladder and intestine that ATP-sensitive low-threshold sensory fibers
mediate physiological events, while high-threshold fibers mediate pain. This
will need to be clarified for the sensory nerves supplying the skin and
tongue before approaches to enhancing the ATP-related responses to
acupuncture are carried out, in case the enhancement results in pain.
I hope that this hypothesis will provoke some scientists interested in
acupuncture to investigate further.
Geoffrey Burnstock is Emeritus Professor and President of the Autonomic
Neuroscience Centre of University College Medical School in London. He is
editor-in-chief of Autonomic Neuroscience, Purinergic Signalling, and the
journals Open Neuroscience and Open Pharmacology.
A*M
4 楼
不用赔偿什么，本来和loan broker签的也都不是binding contract，无所谓的，但是
也可能要损失你的appraisal fee，也可能还有一些processing fee
也可能要损失你的appraisal fee，也可能还有一些processing fee
c*l
5 楼
up
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