最新研究
Chest Nov, 2001
(http://www.findarticles.com/cf_0/m0984/5_120/80677275/print.jhtml)
Relationship between Craniofacial (顱顏)
abnormalities and sleep-disordered breathing (睡眠窒息症) in Marfan's
syndrome *. (clinical investigations).
Author/s: Peter A. Cistulli
Objectives: To examine the prevalence and nature of craniofacial
abnormalities in patients with Marfan's syndrome and to investigate
the relationship between craniofacial abnormalities and obstructive
sleep apnea (OSA) severity in these patients.
Design: Cross-sectional.
Setting: Marfan's syndrome clinic in a tertiary teaching hospital.
Patients: Fifteen consecutive adult patients (7 men and 8 women;
mean [[+ or -] SD] age, 34.8 [+ or -] 13.2 years) who had Marfan's
syndrome.
Measurements and results: Apneic status was determined from standard
overnight polysomnography testing. Measurements from standardized
lateral cephalometric radiographs were compared to normative data.
Thirteen patients had OSA, which was defined as an apnea/hypopnea
index (AHI) of > 5 episodes per hour (mean AHI, 22 [+ or -]
15 episodes per hour). A high prevalence of craniofacial abnormalities
was found with significant gender differences for some of the
variables. Significant abnormalities for the entire group were
bimaxillary retrusion, a reduced maxillary length, an increased
total anterior face height, a long lower anterior face height,
an obtuse gonial angle, a steep mandibular plane, a reduced posterior
nasal airway height, a reduced posterior airway space, and an
increased distance from the mandibular plane to the hyoid bone.
Univariate analysis revealed significant correlations among the
total anterior face height, the upper anterior and posterior face
heights, the mandibular length, and AHI. There was a significant
correlation between the rank of the number of cephalometric abnormalities
per patient and AHI in those patients with OSA.
Conclusions: Craniofacial abnormalities are common in patients
with Marfan's syndrome. The relationship between some cephalometric
parameters and apnea severity suggests a potential role of craniofacial
structure in the pathogenesis of OSA in these patients. (CHEST
2001; 120:1455-1460)
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Business Wire April
30, 1999 http://www.findarticles.com/cf_0/m0EIN/1999_April_30/54513300/print.jhtml
Early Diagnosis and Intervention Are Key
to Lifesaving Heart Treatment for Marfan Syndrome.
STANFORD, Calif.--(BW HealthWire)--April 29, 1999--
A new multi-center study has found that early diagnosis and
surgical treatment are the key to correcting a common heart complication
of Marfan syndrome, a connective tissue disorder that affects
the bones, eyes, heart and blood vessels.
The findings were published Thursday, April 29, in The New
England Journal of Medicine.
In the study, researchers examined the records of 675 Marfan
syndrome patients from 10 internationally prominent medical centers
-- including Stanford Hospital -- to determine the benefits and
risks of early surgical interventions. They found that the death
rate was 1.5 percent for patients who underwent surgery early,
compared to 12 percent for patients who required emergency surgical
treatment.
D. Craig Miller, MD, Doelger Professor in Cardiovascular Surgery
at Stanford, and a co-author of the paper, said physicians have
sometimes faced a dilemma when deciding when to perform surgery
to correct ascending thoracic aortic aneurysms -- the ballooning
of the large blood vessel that leads away from the heart and a
common complication for Marfan sufferers.
While the procedure has been successful for more than three decades
in improving health and longevity for Marfan patients, physicians
must decide at what point the dangers of the aneurysm -- which
can rupture without warning -- outweigh the risks of a complex
surgery with its own set of risks and complications, Miller said.
"Based on the clear difference in mortality between elective
and emergency surgery, the answer is the operation should be performed
sooner rather than later," Miller said.
Specifically, among 455 patients who underwent elective surgery
between October 1968 and March 1996, seven patients (1.5 percent)
died. By contrast, among the 117 patients who underwent urgent
repair (defined as being medically able to wait seven days for
surgery to be scheduled), the mortality rate was 2.6 percent,
and among the 103 patients who underwent emergency repair within
24 hours after surgical consultation, it rose to 12 percent.
While all patients had some risk for approximately 60 days following
surgery, 93 percent of patients were still alive a year later,
and 59 percent were still alive 20 years later, the study noted.
"The fact that mortality rates rose so rapidly and similarly
at the 10 centers, which are all highly experienced in performing
this procedure under emergency circumstances, sends an additional
message that patients would be well advised to seek this procedure
at a center with special expertise and vast experience in thoracic
aortic surgery," said Miller. (While Miller noted the 10
centers had similar results, the mortality data was not broken
down by center.)
Marfan syndrome normally makes blood vessels and other organs
strong and elastic. Usually inherited, it affects the skeleton,
eyes, heart and blood vessels and is often characterized by excessive
height and abnormally long and slender fingers and toes, Miller
noted. Marfan and related connective tissue disorders affect some
200,000 people in the United States.
"It's unfortunate that untold thousands of cases of Marfan
syndrome go undiagnosed until fatal symptoms, such as aneurysm
rupture, cause death or create a need for an emergency operation.
This latest study really points to the benefits of an early diagnosis
and appropriately aggressive surgical treatment," Miller
said.
Miller said patients diagnosed with Marfan syndrome should receive
regular echocardiograms to check for signs of an aneurysm before
life-threatening symptoms emerge. The 10 centers typically recommend
replacement of the aortic root with a prosthetic graft and valve
in patients whose aneurysms reach twice the diameter of the normal
aorta (5.5 to 6.0 diameter), according to the NEJM article.
Newer aortic valve-sparing procedures are available for appropriate
patients at specialty centers such as Stanford, Miller said.
The study was led by Vincent L. Gott, MD, professor of surgery
at Johns Hopkins. Collaborating centers, in addition to Stanford
and Johns Hopkins, include Hannover University Hospital, Hannover,
Germany; Hopital La Pitie, Paris; Texas Heart Institute, Houston;
Methodist Hospital, Houston; Toronto Hospital, Canada; Mt. Sinai
Hospital, New York; Jewish Hospital, St. Louis; and University
Hospital, Zurich, Switzerland.
The research was supported in part by the National Institutes
of Health, the National Marfan Foundation, and the Dana and Albert
"Cubby" Broccoli Center for Aortic Diseases at Johns
Hopkins.
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Source:
http://www.columbiasurgery.org/news/new_research.html
Ultrasound Proves Cost-Effective
in Screening for Abdominal Aortic Aneurysm
In a study published in the medical journal Surgery in fall 2002,
researchers at NYP (NewYork-Presbyterian Hospital) have shown
that an ultrasound procedure is a cost-effective way to screen
for abdominal aortic aneurysm (AAA). In addition, ultrasound has
proven to be completely reliable in detecting AAAs. The study
was led by K. Craig Kent, MD, Chief of Vascular Surgery at NYP.
It is estimated that 2.7 million Americans have AAA, but only
50 percent of these individuals have been diagnosed. Known as
a 'silent killer,' AAA is a sac-like enlargement of the aorta,
the largest artery in the body. Over time the pressure of circulating
blood can slowly push out the vessel wall. Like an inflating balloon,
the larger the aneurysm gets the greater the chances that it will
burst. A ruptured AAA results in internal bleeding so severe that
only 20 percent of victims survive. Ultrasound screening could
be an effective way of reducing mortality from AAA.
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美國企業新聞社 2002-07-19
First Case of Periodontitis(牙週炎)
in Marfan's Syndrome Patient
TO NATIONAL AND MEDICAL EDITORS: Researchers Identify
First Case of Periodontitis in Marfan's Syndrome Patient
CHICAGO, July 18 /PRNewswire/ -- Researchers from the Eastman
Dental Institute at the University College in London identified
the first case of severe periodontitis in a person with Marfan's
Syndrome, a rare heredity disorder that causes connective tissues
to be weaker than normal. The case report is published in the
July issue of the Journal of Periodontology.
"Reports of oral findings in Marfan's syndrome patients
have focused mainly on skeletal abnormalities. This case is notable
since the detected periodontal breakdown was severe and could
be only partly explained by known risk factors, such as cigarette
smoking and inadequate oral hygiene," said Maurizio Tonetti,
D.M.D., PhD, professor and chair of the department of periodontology
at the University College London. "It also supports our hypothesis
that a variety of connective tissue disorders may increase susceptibility
to periodontal tissue breakdown."
Severe periodontitis is an advanced form of a chronic bacterial
infection (periodontal disease) that inflames the supporting tissues
of the teeth and destroys attachment fibers (periodontal ligaments)
and supporting bone that hold teeth in the mouth. The main cause
of periodontal diseases are bacterial plaque, sticky, colorless
film that constantly forms on the teeth. Other factors that contribute
to the disease include the following: smoking/tobacco use; genetics;
hormonal changes; stress; certain medications; clenching or grinding
your teeth; poor nutrition; systemic diseases; and notably, diabetes.
An oral examination determined the 41-year-old patient had swollen
and receding gums, severe periodontal ligament attachment loss
on all teeth and bleeding gums at 76 percent of the areas examined.
The patient had no family history of periodontitis.
"It is important to note that this case report does not
show a causal relationship between Marfan's syndrome and periodontal
diseases," said Kenneth Bueltmann, D.D.S., president of the
American Academy of Periodontology. "More research needs
to be conducted to determine if there is an association between
the diseases."
However, Dr. Tonetti recommends that Marfan patients follow a
preventive oral program based on professional tooth cleaning and
daily brushing and flossing. And that they receive regular periodontal
screenings by a periodontist.
Marfan syndrome is a heritable disorder of the connective tissue
that affects many organ systems, including the skeleton, lungs,
eyes, heart and blood vessels. The condition affects both men
and women of any race or ethnic group. Scientists estimate that
as many as 1 million people in the United States may have a heritable
disorder of connective tissue, according to the National Institute
of Arthritis and Musculoskeletal and Skin Diseases.
Periodontal diseases are serious bacterial infections that destroy
the attachment fibers and supporting bone that hold your teeth
in your mouth. When the attachment fibers are destroyed, gums
separate from the teeth, forming pockets that fill with plaque
and even more infection. As the disease progresses, these pockets
deepen even further, more gum tissue and bone are destroyed and
the teeth eventually become loose. Approximately 15 percent of
adults between 21 and 50 years old and 30 percent of adults over
50 have the disease.
A referral to a periodontist and free oral health brochures are
available by calling 800-FLOSS-EM or visiting the AAP's Web site
at www.perio.org.
The American Academy of Periodontology (AAP) was established
in 1914 to focus on the prevention, diagnosis and treatment of
diseases affecting the gums and supporting structures of the teeth
and in the placement and maintenance of dental implants. Currently,
more than 7,500 dental professionals are members of AAP.
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重度牙周炎(Sever Periodontitis):
這種程度的牙周炎，齒槽骨已大量流失，牙周組織嚴重的遭受破壞 並造成牙齒大幅度的動搖，甚至牙齒的位置產生明顯的移位，牙縫變大
，造成發音口齒不清的問題。患者口內常會有不定期的化膿腫大，口臭 的味道加劇最後牙齒遭到拔除或自動脫落。在 X 光片上可見到牙齒
周圍的齒槽骨被破壞僅剩1/4或已全部吸收殆盡。
有關牙週病之資料，詳見：http://home.kimo.com.tw/h2608860/perio.htm
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生物通訊 2002.7.15 (http://www.ebiotrade.com/newsf/readnews.asp?recordno=L2002716121543)
馬凡氏綜合症發病機理新理解－外顯子跳讀
在2002年7月15日出版的《基因與發育》(Genes & Development)上，約翰•霍普金斯大學的Massimo
Caputi, Raymond Kendzior Jr. and Karen Beemon博士報道，他們確定了馬凡氏綜合症(Marfan
Syndrome)發病機理的分子機制，這一發現有可能結束10多年來關於這種比較普遍的遺傳疾病是如何發生的爭論。
馬凡氏綜合症又稱蜘蛛足樣綜症、指趾過長綻合症、先天性中胚層營養不良。該病最早發現於1896年，是一種遺傳性結締組織疾病，為常染色體顯性遺傳。患者的父親或母親及兄弟姊妹間可有此病，但亦有個別散發病例並無家族史，係染色體突變所致，無性別差異。該病通常會影響到骨骼、呼吸、心血管和視覺系統，一般症狀表現為身材高大，四肢明顯長於常人。1991年，科學家發現，馬凡氏綜合症是由原纖蛋白1(fibrillin1,
FBN1)基因的突變引起的。
10多年後的今天，Beemon和他的同事進一步揭示了FBN1基因突變導致馬凡氏綜合症的分子機制。
FBN1基因編號原纖蛋白，原纖蛋白是組成結締組織的棒狀微細纖維(microfibrils)的一個組件。控制原纖蛋白活動的FBN1基因的突變就會影響結締組織的完整性，引起馬凡氏綜合症相關症狀。
FBN1共有65個外顯子，即編碼區，外顯子之間被沒有編碼功能的內含子隔斷，內含子在DNA轉錄過程中被從前體mRNA轉錄體中除去，即所謂的剪接。在20世紀90年代初，發現一名馬凡氏綜合症病人FBN1第51個多顯子上隱匿一個突變，該突變使得細胞核內的剪接機器完全跳讀外顯子51。而外顯子51的僥幸逃脫就會引起問題，外顯子51突變版的FBN1基因會變成一個"危險分子"，這是外顯子51編碼的部分正是保證原纖蛋白正常活動的關鍵。
Beemon博士和他的同事證明，外顯子51的跳讀是一個外顯子剪接增加子(exonic splicing
enhancer, ESE)遭到破壞的結果，這個外顯子剪接增強子是FBN1內一段增強剪接效率的DNA片段。科學家發現，其他類型ESE破壞的突變也會導致外顯子51跳讀。研究人員因而得出結論：FBN1的外顯子51的跳讀取決於ESE的損壞。
這項研究最絡將有助於我們進一步了解馬凡氏綜合症以及其他與外顯子跳讀有關的遺傳疾病的發病機理。
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Johns
Hopkins Medicine August 10, 1995
DIAGNOSIS OF MARFAN SYNDROME
AT EARLIEST STAGE
原文：http://www.hopkinsmedicine.org/press/1995/AUGUST/19957.HTM
Media Contact: Jo Martin
Phone: (410) 223-1736
E-mail: jmartin@welchlink.welch.jhu.edu
Researchers at the Johns Hopkins Children's Center have devised
a method that should allow the reliable diagnosis of Marfan syndrome
at the eight-cell stage of fetal development. Used in combination
with in vitro fertilization, carriers of this inherited disease
may now have the means to bear only unaffected, healthy children,
they say.
Traditionally, scientists waited 10 to 12 weeks after conception
to diagnose Marfan syndrome, says Hal Dietz, M.D., lead investigator
of the study, which appears in the August issue of Nature Medicine.
Because it can be severe, and pregnancy is taxing to women with
the disorder, quick findings are especially important to carriers.
For the first time, Dietz and others effectively amplified RNA
taken from an eight-celled fertilized egg not yet implanted in
the womb. Their method allowed them to make many copies of genetic
material -- enough to find a specific alteration in the genetic
code.
In the past, this "preimplantation diagnosis" was used
to detect other genetic disorders, like cystic fibrosis, by amplifying
DNA. But that method proved unreliable for Marfan syndrome.
Marfan syndrome is an autosomal dominant, heritable disorder
affecting connective tissue. Each offspring of a carrier has a
50-50 chance of inheriting the disease. It affects nearly one
in every 10,000 people and is characterized by skeletal deformity,
dislocation of the ocular lens of the eye, and expansion and ultimate
rupture of the aorta, often resulting in death.
Hopkins scientist Victor A. McKusick, M.D., began establishing
the clinical definitions of Marfan syndrome in the 1950s, but
its molecular roots were not known until the late 1980s when Dietz
and other researchers demonstrated that the primary defect was
in the gene encoding fibrillin. Fibrillin is found in the body's
connective tissue.
Mutations are permanent changes in DNA (deoxyribonucleic acid),
where genetic information is stored. To find a mutation, researchers
often "amplify" or make many copies of DNA using a technique
called polymerase chain reaction or PCR.
During this process, the twisted ladder of DNA is split into
two separate strands. A new half is rebuilt on each old half,
then the ladder is split again and the process repeated over and
over. Millions of copies of the DNA molecule that houses a gene
are reproduced, providing enough material for scientists to quickly
find a specific mutation.
To test PCR applicability for Marfan syndrome, Dietz and his
colleagues studied single skin cells from a patient with a known
mutation in the gene that encodes fibrillin. Problems arose, however.
In contrast to expectations, the PCR amplification technique copied
only one or the other of the two fibrillin genes present in any
given cell. If only the normal gene copied, misdiagnosis of Marfan
syndrome was likely, since only one of the two genes needs to
be defective for the syndrome to appear.
"DNA amplification gave us only two copies of each fibrillin
gene to start with," explains Dietz. "Because each gene
makes many copies of RNA (ribonucleic acid), we asked whether
PCR could be used to reliably amplify RNA."
Again using single skin cells from a Marfan patient, they showed
not only that they could amplify RNA, but also that both the normal
and altered genes were present.
Hereditary information flows from DNA to messenger RNA (mRNA).
Millions of copies of the skin cell's mRNA were reproduced, forming
a blueprint that allowed the researchers to work backward and
rebuild the DNA sequence of the coding region of the fibrillin
gene.
"We found consistent evidence of the mutated fibrillin gene,"
says Dietz. "But this information came from an adult. We
still needed to know if an embryo, only eight-cells old, could
produce the same information. It was a long-shot proposal,"
he says. "But it worked."
In conjunction with researchers from Cornell University's Center
for Reproductive Medicine, the study was repeated with information
from eight-celled embryos that were generated for other clinical
indications, but were no longer viable for artificial implantation.
"We successfully amplified the RNA each time," says
Dietz. "And we proved that this fibrillin RNA was derived
from copies of the fibrillin gene that were inherited from both
parents."
Because of that success, researchers are now prepared to offer
this form of diagnosis to those who request it. A preimplantation
diagnosis facility is currently being developed at Hopkins, says
Dietz, and should be available in the near future. The Hopkins
team is studying whether their technique for preimplantation diagnosis
can be applied to other potentially fatal genetic disorders.
Other researchers are Zayd Eldadah, an M.D., Ph.D. student at
the Johns Hopkins University School of Medicine, and Jamie Grifo,
M.D., Ph.D., from the Center for Reproductive Medicine, Cornell
University.
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