Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Magnetic resonance imaging demonstrated coexistent central nervous system abnormalities in 30 of 40 patients with optic nerve hypoplasia. Based on their associated neuroradiological findings, these patients were placed into one of five categories: group 1, isolated optic nerve hypoplasia; group 2, absence of the septum pellucidum; group 3, posterior pituitary ectopia; group 4, hemispheric migration anomalies; and group 5, intrauterine/perinatal hemispheric injury. Posterior pituitary ectopia (group 3) and cerebral hemispheric abnormalities (groups 4 and 5) were found to be highly predictive of pituitary hormone deficiency and neurodevelopmental deficits, respectively. Isolated absence of the septum pellucidum (group 2) was associated with normal neurodevelopmental and endocrinologic function. Thinning or agenesis of the corpus callosum was predictive of neurodevelopmental problems only by virtue of its frequent association with cerebral hemispheric abnormalities. Magnetic resonance imaging can now be used to provide specific prognostic information regarding the likelihood of neurodevelopmental deficits and pituitary hormone deficiency in infants with optic nerve hypoplasia. The prevailing notion of septo-optic dysplasia as a distinct nosologic entity should be reconsidered.
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PMID:Optic nerve hypoplasia. Clinical significance of associated central nervous system abnormalities on magnetic resonance imaging. 842 27

Structural failure (fracture) is a problem in biomechanics. Its solution resides, in part, in identifying the material and structural properties of bone that determine its mechanical resistance to structural failure. Bones must be stiff so that they do not bend when loaded, otherwise movement against gravity would not be possible. However, bones must also be flexible, otherwise their ability to absorb energy by elastic and plastic deformation will decrease and the energy imparted will be dissipated only by microdamage or complete fracture. Thus, failure may occur if bones deform too much (exceeding their peak strain) or too little (exceeding their peak stress). Phylogeny and ontogeny make bone "just right" for the functions it is predicted to perform, but the genetic material was not warned about the increased longevity the female enjoys after ovarian failure. Age-related and menopause-related abnormalities in bone remodeling produce loss of the material and structural properties that no longer keep bone "just right". High remodeling reduces the mineral content of bone tissue resulting in loss of stiffness (resistance to shortening in compression and lengthening in tension when loaded). Sex hormone deficiency increases the volume of bone resorbed and reduces the volume of bone formed in each BMU. Solutions to the biomechanic problem will emerge provided that the material and structural properties of bone that determine its strength are measured and studied. Drugs are available to reduce remodeling rate so that there is more time for completion of secondary mineralization to restore bone stiffness. If remodeling is suppressed too much the production of microdamage may increase as homogeneous and highly mineralized bone is less resistant to microdamage progression while reduced remodeling targeted to microdamage may result in microdamage accumulation. Drugs are available to reduce osteoclastic bone resorption and increase osteoblastic bone formation, which together will restore bone balance in the BMU and so prevent further loss of bone mass, prevent thinning and loss of trabeculae, thinning of cortices, and progression of porosity. These approaches prevent the progression of fragility but will not restore bone architecture. Even if a positive BMU balance is achieved, drugs that reduce remodeling are unlikely to reverse the structure damage. Slow remodeling means there are too few remodeling foci depositing their small net positive bone volume to progressively thicken cortices or trabeculae. Agents that are anabolic, that increase bone formation on the periosteal and endosteal surfaces are needed to restore the structure of bone. Other articles in this volume address this challenge. We do not understand the proportional contributions made by differences in bone size, cortical thickness, trabecular number, thickness, connectivity, tissue mineral content, microdamage burden, osteocyte density, porosity, to differences in spine and hip fracture rates within a sex, between sexes, between races, or between treatment, and control arms in clinical trials. The challenge for the future is to measure these specific materials and structural determinants of bone strength. Whether a combination of these material and structural properties will more accurately identify women likely to sustain fractures, or improve approaches to drug therapy is unknown. The quest to eliminate fragility fractures is a distant horizon seen through a glass darkly at this time.
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PMID:The structural and biomechanical basis of the gain and loss of bone strength in women and men. 1269 91

Magnetic resonance imaging (MRI) in patients with congenital growth hormone deficiency (GHD) has revealed several morphological abnormalities of the hypothalamo-pituitary region which include hypoplasia of the anterior pituitary lobe, the absence or marked thinning of the pituitary stalk and ectopia of the posterior pituitary lobe (EPP). This triad of abnormalities is called pituitary stalk interruption syndrome (PSIS). Our study reports the imaging findings of 23 patients with idiopathic GHD and short stature who were examined by MRI. The majority of the patients had abnormal MR studies with findings indicating the presence of the pituitary stalk syndrome. The high correlation between the clinical profile and the MR findings in cases of pituitary dysfunction (most often GHD), defines the significant role of MRI as additional tool for the diagnosis of pituitary hormone deficiency.
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PMID:Pituitary stalk interruption syndrome: the role of MRI and review of the literature. 2414 82

The genetic causes of combined pituitary hormone deficiency remain elusive in most patients. Recently, incompletely penetrant heterozygous mutations in ROBO1 have been described in patients with pituitary stalk interruption syndrome. Herein, we identified a novel homozygous slice site mutation in ROBO1 (c.1342+1G>A) using a trio whole-exome sequencing strategy in a 5-year-old Japanese boy who had combined pituitary hormone deficiency, psychomotor developmental delay, severe intellectual disability, sensorineural hearing loss, strabismus, and characteristic facial features, including a broad forehead, micrognathia, and arched eyebrows. Magnetic resonance imaging delineated anterior pituitary hypoplasia, ectopic posterior pituitary, invisible pituitary stalk, thinning of the corpus callosum, and hypoplasia of the pons and midbrain. The phenotypically normal parents (first cousins) were heterozygous for the mutation. The results provide further evidence of ROBO1 being involved in the development of the pituitary gland. A recessive mutation of ROBO1 is a potential novel cause of a syndromic disorder associated with combined pituitary hormone deficiency.
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PMID:A homozygous splice site ROBO1 mutation in a patient with a novel syndrome with combined pituitary hormone deficiency. 3069 97