More convincing evidence of the absence of true regeneration, however, is the argument from malformation and the phenomenon known as " pseudo-scolex.
" It has long been known that proglottides of the same species often exhibit sporadic malformation from the normal shape, and the evidence goes to show that the variation was due to arrested growth or some unusual stress or pressure which, acting upon the young strobila, produced a deformation, and that the proglottides so affected could not regain their normal form.
arteriovenous malformation of brain.
Only inoculated N. clevelandii plants showed symptoms: systemic stem necrotic spots and leaf malformation.
Some very curious details are observable in these cases of malformation, For instance, the Aecidium eta/mum first referred to causes the new shoots to differ in direction, duration and arrangement, and even shape of foliage leaves from the normal; and the shoots of Euphorbia infected with the aecidia of Uromyces Pisi depart so much from the normal in appearance that the attacked plants have been taken for a different species.
The soft body of the Brachiopod is in all cases protected by a shell composed of two distinct valves; these valves are always, except in cases of malformation, equal-sided, but not equivalved.
pulmonic stenosis, aortic stenosis is a congenital heart defect in which a malformation impedes the flow of blood through the heart.
Like pulmonic stenosis, aortic stenosis is a congenital heart defect in which a malformation impedes the flow of blood through the heart.
This is a malformation of the jaw bone that leads to further scrambling of the teeth.
Treatment options for hemorrhagic stroke may include surgery, sterotactic radiotherapy, or interventional neuroradiology to treat the underlying aneurysm or arteriovenous malformation.
Telangiectasia is an arterial-venous malformation (AVM) composed of small blood vessels.
In most cases, spina bifida is obvious at birth because of malformation of the spine.
Like its parents, a Miniature Labradoodle may suffer from hip dysplasia, a genetic malformation of the hip socket.
A widespread disease known as pocket-plums or bladderplums is due to an ascomycetous fungus, Exoascus pruni, the mycelium of which lives parasitically in the tissues of the host plant, passes into the ovary of the flower and causes the characteristic malformation of the fruit which becomes a deformed, sometimes curved or flattened, wrinkled dry structure, with a hollow occupying the place of the stone; the bladder plums are yellow at first, subsequently dingy red.
cavernous malformation usually occurs on its own, in these families they are often multiple.
Jaundice can result from a congenital (present at birth) malformation of the liver, bile ducts, or gall bladder.
Pectus excavatum is a malformation of the chest in which the child's breastbone, or sternum, is sunken inward.
This may occur for many reasons, including Chiari malformation, abnormal cysts within the brain, and infections such as meningitis.
Truncus arteriosus is a complex malformation in which only one artery comes from the heart and forms the aorta and pulmonary artery.
Spina bifida is usually readily apparent at birth because of the malformation of the back and paralysis below the level of the abnormality.
The term meningocele is used when the spine malformation contains only the protective covering (meninges) of the spinal cord.
The other terms indicate involvement of the spinal cord and nerves in the malformation.
As an isolated abnormality, spina bifida is caused by the combination of genetic factors and environmental influences that bring about malformation of the spine and spinal column.
In rare instances, the spinal cord malformation may occur internally, sometimes with a connection to the gastrointestinal tract.
In spina bifida, many complications arise, dependent in part on the level and severity of the spine malformation.
As a rule, the nerves below the level of the abnormality develop in a faulty manner and fail to function, resulting in paralysis and loss of sensation below the level of the spine malformation.
At least one of every seven cases develops findings of Chiari II malformation, a condition in which the lower part of the brain is crowded and may be forced into the upper part of the spinal cavity.
If the spine malformation is not skin covered, alpha-fetoprotein from the fetus's circulation may leak into the surrounding amniotic fluid, a small portion of which is absorbed into the mother's blood.
After direct closure of the spine malformation, the fetus is returned to the womb.
Although complications from paralysis, hydrocephaly, Chiari II malformation, and urinary tract deterioration threaten the well-being of the survivors, the outlook for normal intellectual function is good.
Congenital cystic adenomatoid malformation (CCAM) occurs when one or more lobes of the lungs develop into fluid-filled sacs called cysts rather than into normal lung tissue.
Congenital cystic adenomatoid malformation (CCAM)-A condition in which one or more lobes of the fetal lungs develop into fluid-filled sacs called cysts.
Spina bifida-A birth defect (a congenital malformation) in which part of the vertebrae fail to develop completely so that a portion of the spinal cord, which is normally protected within the vertebral column, is exposed.
Cleft palate-A congenital malformation in which there is an abnormal opening in the roof of the mouth that allows the nasal passages and the mouth to be improperly connected.
Glaucoma can be caused by another eye disorder, such as a tumor or congenital malformation, or can appear without obvious cause, but if untreated it generally leads to blindness.
Anencephaly-A genetic defect resulting in the partial to complete absence of the brain and malformation of the brainstem.
In children, cystic fibrosis, aspiration problems, immunodeficiencies, and congenital or acquired lung malformation may increase the risk of pneumonia from S. pneumoniae.
Transposition of the great arteries is a complex congenital malformation; however, open heart surgery is highly effective in correcting it.
Boys are slightly more likely to have this malformation than girls.
Tetralogy of Fallot is a complex congenital malformation; however, open heart surgery is highly effective in correcting it.
Arnold-Chiari syndrome-A congenital malformation of the base of the brain.
Sturge-Weber syndrome (SWS) is a rare, congenital (present at birth), noninherited disorder characterized by the vascular malformation (birthmark) called a port wine stain, usually seen on an infant's face.
In addition, normal brain formation requires proper development of the surrounding skull, and skull defects may lead to brain malformation.
Anencephaly is the most common severe malformation seen in stillborn births.
Some cases of spina bifida are accompanied by another defect at the base of the brain, known as the Arnold-Chiari malformation or Chiari II malformation.
The Dandy-Walker malformation is a brain defect marked by incomplete formation or absence of the central section of the cerebellum and the growth of cysts within the lowest of the brain's ventricles.
Trisomy of chromosome 9 can cause some cases of Dandy-Walker and Chiari II malformation.
Chiari II malformation: Impaired swallowing and gag reflex, loss of the breathing reflex, facial paralysis, uncontrolled eye movements (nystagmus), impaired balance and gait.
Dandy-Walker malformation: Symptoms of hydrocephalus, lack of muscle tone or floppiness, seizures, spasticity, deafness, irritability, visual impairment, deterioration of consciousness, paralysis.
Many children with congenital brain anomalies, such as Chiari I malformation and nearly 50 percent of those affected by hydrocephalus, have normal intellectual functioning, and some have unimpaired physical mobility.
See also Chiara malformation; Spina bifida.
Chiari malformation is a congenital anomaly (a condition that is present at birth), in which parts of the brain protrude through the opening in the base of the skull into the spinal column.
In order to explain the various components of Chiari malformation, it is helpful to describe a few parts of the brain and their functions.
There are four major regions of the brain affected in Chiari malformation: the cerebellum, the brain stem, the ventricles, and the cerebrum.
In Chiari malformation, one or more of these parts of the brain function improperly or are malformed.
In addition to brain anomalies, Chiari malformation can also involve defects in the base of the skull and in the bony part of the spine.
There are four types of Chiari malformation.
In Type I malformation, the lower portions of the cerebellum, known as the cerebellar tonsils, protrude through the opening in the skull known as the foramen magnum and into the spinal cord canal.
Type II malformation, sometimes called Arnold Chiari malformation, is more severe than Type I and involves herniation of a more significant part of the cerebellum, part of the fourth ventricle, and parts of the brain stem.
Approximately 80-90 percent of children with Chiari malformation Type II also have hydrocephalus, a condition in which one or more of the ventricles becomes enlarged due to an accumulation of CSF.
Type II Chiari malformation may be diagnosed prenatally by ultrasound or shortly after birth during medical evaluation of the accompanying spina bifida.
In Type III malformation, parts of the cerebellum and the brain stem protrude into a spina bifida defect located at the base of the skull, on the neck.
Some neurologists do not consider it a Chiari malformation but rather a specific type of spina bifida called an encephalocervical meningocele.
Type IV malformation consists of an underdevelopment of the cerebrum and involves no herniation of brain tissue into the spinal area.
As with Type III malformation, many neurologists do not consider this a Chiari malformation but rather cerebellar hypoplasia (underdevelopment).
The remainder of this entry only discusses Chiari malformation Types I and II.
The true incidence of Chiari malformation is unknown.
Some researchers believe that there may be far more cases of Type I malformation, in particular, than reported since many individuals with Type I malformation experience few if any symptoms.
Most researchers agree that the rate of both Type I and Type II Chiari malformation is approximately 1 percent of all live births.
Of those with Type I malformation, approximately 25 percent also have syringomyelia.
As access to imaging testing such as MRI has increased, so has the number of children diagnosed with Chiari malformation Type I.
Therefore, the incidence of known Type I Chiari malformation is anticipated to increase.
Other possible causes for this malformation include exposure to harmful substances during fetal development or genetic factors.
Similarly, studies of families and identical twins with Chiari malformation show that the malformation occurs more often in these families than in families in which no member is affected.
Another proposed cause for Chiari malformation is an abnormality in bone development.
Chiari malformation may result because the cerebellum is of normal size, but the bones at the base of the skull are too small.
Symptoms of Chiari malformation vary according to the type of malformation.
In Type I Chiari malformation, symptoms may begin anytime between infancy and early adulthood.
Symptoms of Type II Chiari malformation include those that occur in Type I malformation.
Type II malformation occurs almost exclusively with spina bifida, which causes symptoms that may include paralysis of the lower extremities (and less often, the upper limbs), and bowel and bladder dysfunction.
In some children Chiari malformation is evident at birth, especially Type II malformation.
If the doctor suspects a Chiari malformation, magnetic resonance imaging (MRI) is the most helpful diagnostic tool.
This procedure is most helpful in assessing abnormalities of the skull and backbone associated with Chiari malformation.
The prognosis for Chiari malformation varies depending on which type of malformation is present.
Some patients may continue to experience neurological symptoms, but the long term prognosis for children with this type of Chiari malformation is excellent, including normal development and intellectual functioning.
Children with Chiari II malformation have a much poorer prognosis than those with Type I malformation.
Chiari malformation is a congenital anomaly, and no method of prevention is known.
Chiari malformation can have a significant impact on both the child and the family.
The full extent of problems associated with Chiari malformation may not be evident at birth, especially for children with Type I malformation.
Children with Type I malformation may experience months of subtle but progressive symptoms before a diagnosis is made.
The symptoms of Chiari Type I malformation when observed individually may not seem significant.
The first step for diagnosing Chiari malformation Type I is an accurate and detailed history and physical examination.
The prognosis for children with Chiari malformation Type I is very good.
Over 70 percent of those who have surgery to correct Type I malformation experience a significant reduction in symptoms; however, there are some symptoms that may not resolve.
The availability of MRI technology has led to diagnosis of younger children with Type I malformation and improved the quality of life for these children.
When discussing Chiari malformation and surgery with their child, parents should use words the child can understand.
Children with Chiari II malformation have a much poorer prognosis than those with Type I malformation and will usually be quite ill.
Parker, James N., et al. The Official Parent's Sourcebook on Chiari Malformation.
Cleft lip without cleft palate is the third most common congenital malformation among newborns in the United States and is estimated to occur roughly twice as often in males than in females.
Syndactyly of the fingers is the most common malformation affecting the hand.
Postaxial polydactyly, or an extra pinky finger, is the second most common malformation of the hand, occurring in approximately one in 3,000 births.
Polydactyly of the toes, especially of the little toe, is also a common malformation, occurring in approximately two in 1,000 births.
Syndactyly is an equally common malformation and runs in families as well.
Children with more severe polydactyly and syndactyly will have surgery to correct the malformation.
Prenatal diagnosis of congenital brain malformation is often possible, offering the option of family planning.
Down syndrome is the most common cause of mental retardation and malformation in a newborn.
The most common malformation is a narrowed, obstructed duodenum (the part of the intestine into which the stomach empties).
In Smith's Recognizable Patterns of Human Malformation. 5th edition Philadelphia: W.B.
The study hypothesizes that women who have a history of intrauterine device expulsion are likely to have "unfavorable uterine conditions," which may include poor positioning, small size, and subtle malformation.
The gem should be spherical and symmetrical, though slightly elongated pearls can often be set into rings to disguise the malformation.
The old Duke really had a slight malformation of the ear, which really was more or less hereditary.
Click below for more images of interest arteriovenous malformation of brain.
Although a cavernous malformation usually occurs on its own, in these families they are often multiple.
These features all indicate that DNT arises on a background of cortical malformation.
Termination or fetal malformation is legal up to 24 weeks gestation.
The two points thus meeting, the bill is 1 This peculiarity is found as an accidental malformation in the crows (Corvidae) and other groups; it is comparable to the monstrosities seen in rabbits and other members of the order Glires, in which the incisor teeth grow to an inordinate length.
The word usage examples above have been gathered from various sources to reflect current and historial usage. They do not represent the opinions of YourDictionary.com.