Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CALCIFICATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources
PubMed1980

Stereospecific inhibition of alkaline phosphatase by L-tetramisole prevents in vitro cartilage calcification.

To clarify the role of alkaline phosphatase (ALP) and ATPase in skeletal mineralization, we studied the effect of the anthelmintic drug, l-tetramisole (levamisole), a stereospecific inhibitor of ALP activity, and its inactive isomer, d-tetramisole (dexamisole), on in vitro calcification of rachitic rat cartilage. ALP activity in homogenized rachitic rat proximal tibiae was inhibited by l-tetramisole in a dose-dependent manner. Histochemical and electron microscopic cytochemical analysis of intact epiphyseal plate rachitic rat cartilage showed that 5 x 10(-2) M and greater concentrations of l-tetramisole (1) virtually abolished ALP activity, (2) moderately reduced ATPase activity, and (3) prevented in vitro cartilage calcification, while preserving the structural integrity of the matrix vesicles. Concentrations of d-tetramisole as high as 1 x 10(-1) M failed to inhibit ALP activity in tibial homogenates by more than 10 per cent and did not alter histochemical staining of enzyme activity or calcification in intact cartilage slices. Heating the cartilage slices destroyed ALP activity, prevented calcification, and disrupted matrix vesicle integrity. These data show that there is a close association between ALP activity and in vitro calcification of rachitic rat cartilage. In the absence of ALP activity, intact matrix vesicles do not promote calcification. Our data also suggest that some ATPase activity of rachitic rat cartilage may be distinct from ALP activity.

Adenosine Triphosphatases↗
PubMed1984

[Cerebral schistosomiasis with a huge calcification. A case report].

A case of cerebral schistosomiasis with a huge calcification and with a long clinical course was reported. A 39-year-old male developed ataxic gait gradually associated with headache and general fatigability. According to the past history, the patient had suffered from severe meningitis with disturbance of consciousness for 2 weeks when he was 10 years of age. Neurological examination revealed positive Romberg's sign and left homonymous hemianopsia. Plain craniogram showed a large calcification occupying the whole right occipital region. This calcification was lobulated in shape and was 11 X 9 X 9 cm in size. CT scan demonstrated calcification and remarkable hydrocephalus. This calcification had no mass effect. Left vertebral angiogram revealed the right parieto-occipital artery to be stretched and slightly displaced toward midline. Hematological analysis disclosed no abnormality except for eosinophilia (10%). Pre-operative diagnosis was an old calcified granuloma of unknown origin. For the purpose of biopsy, a right occipital craniotomy was performed. On reflecting the dura, fibrous adhesion and vascular network were seen between the inner table of the dura and the arachnoid. Subarachnoid space was enlarged and all cortical vessels were narrow in their diameters. By a corticotomy, a whitish-yellow calcified mass was seen in the depth of 2 mm. The yellowish gelatinous content poured out of the mass. A piece of calcification and a small amount of content were taken as specimen. Microscopic study of the calcified tissue showed many egg shells of schistosoma japonica, necrotic tissues and infiltration of small round cells.

Adult↗
PubMed1984

Techniques for prevention of calcification of valvular bioprostheses.

Calcification of valvular bioprostheses in children is a major problem that has stimulated extensive research in our laboratory. In previous reports, we have shown that the rate of calcification could be reduced by decreasing the phosphate content in the tissue or by blocking calcification binding sites with Mg++ and/or with a surfactant (Tween 80). Since then, we have systematically investigated incorporation of numerous other surfactants and of polyacrylamide within the tissue, and these investigations form the basis of this report. The methods of investigation included subcutaneous implantation of treated tissues in growing rabbits, stability tests, and intracardiac implantation in sheep. Results showed that surfactants differed in their efficacy in mitigating calcification, with N-lauroylsarcosine and triton X-100 being the most efficient. Polyacrylamide incorporation was also efficient in calcification mitigation, but this effect was lost after flexibility testing in vitro or implantation in vivo, a drawback that suggests further research is necessary into stabilization of this polymer. This report not only brings attention to new alternatives in calcification mitigation treatment of bioprosthetic tissues but also underlines important points of methodology.

Acrylic Resins↗
PubMed1978

A comparative study of physiologic intracranial calcifications.

It has been the impression of clinicians that pineal calcification is infrequent in Shiraz, Iran. In order to evaluate this clinical impression 2000 consecutive skul X-rays taken at Saadi Hospital, Shiraz, Iran, were reviewed for the presence of physiologic intracranial calcifications. The incidence of these clasifications in male and female in consecutive age groups of 10 years from 0 to over 70 years of age were assessed and compared with previous reports from other countries. The average incidence of pineal calcification for those over 20 years of age was 18.29% in this study compared with 55% in the U.S.A. The incidence of calcification in the choroid plexus and the falx cerebri was also considerably less than previously reported. The literature is reviewed and the possible causes for the geographical differences in the reported frequency of physiologic intracranial calcifications is discussed. It is possible that racial and dietary factors may be significant in the variation in the incidence of pineal and other cranial calcifications noted in different countries. Within a population group, age and sex are additional factors.

Adolescent↗
PubMedDate not supplied

[Intraspinal calcifications. Symptomatology. Pathologic value].

Calcifications in the spinal canal on plain films are not an unusual finding. The authors present 22 such cases. Identification and pathological value depend on the topography and morphology of these calcifications. The calcifications have been classified in three groups: anterior, median and posterior. The most common etiologies for the anterior ones were calcifications of the posterior longitudinal ligament and calcified discal hernias; meningiomas were the most common cause of the median calcifications; ligamentum flavum calcifications accounted for must of the posterior ones.

Adult↗
PubMed1980

Calcification of aortic homografts used for reconstruction of the right ventricular outflow tract.

Calcification of aortic homografts used for reconstruction of the right ventricular outflow tract was studied in assess the frequency of occurrence, location, extent, speed of progression, and clinical and hemodynamic implications. Radiologic follow-up by means of penetrated posteroanterior and lateral radiograms ranged from 2 to 10 years in two groups of patients. Group 1 comprised 40 patients with cyanotic congenital heart disease in whom an aortic homograft was used to restore continuity between the right ventricle and pulmonary arteries. Results from this group were correlated with those from Group 2, which included 80 patients who had a homograft implanted as a substitute for their own pulmonary valve, which had been used as an autograft for replacing the diseased aortic or mitral valve. In Group 1, 92% of the grafts were calcified 6 months to 4 years after operation. Calcification was severe in two cases, moderate in 33, and mild in two. One of the grafts had to be removed in the tenth postoperative year for progressive obstruction. In Group 2, 27% showed signs of calcification, never before the second year after implantation. Calcium development was severe in two, moderate in 12, and mild in eight. Two obstructed homografts were removed. Aortic homograft calcification has been more common, developed earlier, and been more severe in patients operated upon for congenital lesions. The lower age, the peculiar metabolism, the distorted anatomy, and the development of pulmonary hypertension in this group may account for this fact. In 96% of the patients who were followed, calcification has not yet meant clinical disability or hemodynamic dysfunction. Use of "fresh," antibiotic-sterilized homografts has reduced the incidence of calcification in Group 2 and is expected to decrease its severity in all cases.

Adolescent↗
PubMed1994

[Non-calcified line in calcification of the globus pallidus].

In recent years, high resolution X-ray CT has provided detailed information on calcification of the basal ganglia. At this institution, a review of 30 patients with 57 globus pallidus calcifications revealed curvilinear non-calcified lines in 19 calcifications. These were considered to be the medial medullary lamina of the globus pallidus. An attempt was made to classify calcifications of the globus pallidus into calcifications of the medial and lateral segments by the non-calcified line or location of the calcification, and to assess the tendency to calcify of both the medial and lateral segments. The results of this assessment revealed that the lateral segment tended to calcify more than the medial segment.

Adult↗
PubMed1995

[Progression of senile aortic valve calcification: echocardiographic and clinical assessment].

Factors involved in the progression of senile aortic valve calcification were evaluated by analyzing the clinical and echocardiographic characteristics of patients older than 69 years with senile aortic valve calcification. The patients were divided into three groups; group 1: 46 male and 40 female patients with calcification of one cusp and almost normal pliability of three cusps, group 2: 48 males and 55 female patients with calcification of two or three cusps, mildly reduced pliability of calcified cusps, and aortic valve area (AVA) > or = 2.0 cm2, group 3: 26 male and 31 female patients with calcification of two or three cusps, significantly reduced pliability of calcified cusps, and AVA < or = 1.5 cm2. There were no significant differences in age, weight, height, left ventricular dimension, or left ventricular wall thickness between these three groups. For male patients, the end-diastolic maximum left ventricular outflow tract dimensions (LVOT) in groups 1, 2, and 3 were 20 +/- 2 mm, 19 +/- 2 mm (p < 0.01 vs group 1), and 17 +/- 3 mm (p < 0.001 vs group 1, p < 0.01 vs group 2), respectively. For female patients, the LVOTs of groups 1, 2, and 3 were 18 +/- 2 mm, 16 +/- 2 mm (p < 0.001 vs group 1), and 16 +/- 2 mm (p < 0.001 vs group 1), respectively. Reduction in LVOT was not associated with left ventricular hypertrophy or decrease in dimension of aortic annulus. In female patients, the frequency of mitral annular calcification of group 3 was 61% [p < 0.05 vs group 1 (35%), p < 0.01 vs group 2 (25%)].(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Reliability of electron beam computed tomography to detect coronary artery calcification.

Electron beam computed tomography (CT) provides a safe, rapid, and noninvasive means to detect the presence and quantitate the deposition of calcium in the coronary arteries. To examine the reproducibility of a coronary calcification screen using electron beam CT, 50 subjects underwent two studies, averaging 12 minutes between studies. The number, volume, and calcification scores were determined for each artery as well as a total score of coronary calcification. Thirty-four of the 50 subjects had evidence of coronary calcification. The reliability score for total coronary artery calcification was 0.99. The reliability score for the total number of lesions and total volume was at or above 0.98. There were 8 cases in which a negative calcium score on retest was positive or where a positive calcium score on retest was negative. In both instances, the amount of calcium detected was very small. Therefore, evidence suggests that electron beam CT is reliable in the detection of coronary artery calcification and may be a useful tool for the early detection of coronary atherosclerosis before flow impairment.

Calcinosis↗
PubMed1994

Calcification of porcine bioprosthesis implanted into human heart: high resolution scanning electron microscopic and scanning tunneling microscopic investigation.

High-resolution scanning electron microscopy (HR-SEM) combined with scanning tunneling microscopy (STM) was used to investigate the calcification mechanism occurring in the porcine bioprostheses implanted into the human heart. Eleven explanted porcine heart valves obtained during open heat surgery were prepared for HR-SEM and STM observations. HR-SEM examinations of all explanted valves with secondary and backscattered electron imaging revealed abnormal accumulation of calcium in various shapes and sizes on the defective valve surface and in the underlying basement membrane. Calcific deposits were consistently observed within the pinhole defects on the valve surface and in the subsurface structures of the valve tissues along the surface defects. In addition, calcium-containing crystals were often present just underneath the disrupted valve surface. STM examinations also showed that calcific deposits were frequently accumulated in or around the pinhole defects on the valve surface. Thus, STM findings were compatible with HR-SEM observations. In view of the occurrence of calcific deposits in the vicinity of the surface defects on the valve tissue and frequent observation of calcific spots and crystals in the subsurface structures just beneath the defective valve surface, our results prove the hypothesis that alteration of the valve surface is an important factor for calcification occurring in the implanted bioprosthetic heart valves.

Animals↗
PubMed1993

Aortic and renal atherosclerotic calcifications seen on computed tomography of the spine. A positive predictor of hypertension.

RATIONALE AND OBJECTIVES: This study was undertaken to determine if there is an association between hypertension and aortic or renal atherosclerotic calcifications seen on computed tomography (CT) of the spine. METHODS: The lumbar CTs of 93 sequential patients were evaluated without knowledge of their blood pressures. Aortic and renal atherosclerosis was graded on a scale of 0-3. The patients' charts were reviewed for the presence of hypertension and diseases that might cause hypertension. RESULTS: Sixty-five patients had atherosclerotic calcifications. Forty-four of these were hypertensive. Logistic regression analysis revealed that calcifications in the left renal artery (P = .003), the right renal artery (P = .010) and the abdominal aorta (P = .001) are statistically significant positive predictors of hypertension. Renal artery calcifications are better predictors of hypertension than aortic calcifications. CONCLUSIONS: Renal and abdominal aortic calcifications are significant radiographic findings in lumbar spine CT examinations and their presence should be routinely included in the radiographic report.

Adult↗
PubMed1993

[Study on vascular calcification in patients on continuous ambulatory peritoneal dialysis (CAPD): special reference to active vitamin D (VD) treatment].

Cardiovascular complications, such as vascular calcification (VC), have been a major concern in patients undergoing chronic dialysis. The pathogenesis of this VC has been attributed to the altered calcium and phosphate metabolism, but the contributing factors have not been clarified. In order to investigate these factors, 38 CAPD patients were divided into two sub-groups according to the absence of aortic calcification (Group-A; n = 18) or the presence of aortic calcification (Group-B; n = 20). The number of elderly patients was larger and the duration of CAPD was longer in Group-B than in Group-A. Calcium and phosphate metabolism and serum lipids levels did not differ significantly between groups and the number of patients given VD was 8/18 in Group-A and 14/20 in Group-B. In order to explore the progression of VC in CAPD patients given long-term treatment with VD, 22 patients who were matched for the duration of CAPD were analyzed. These were divided into two sub-groups according to whether they were treated with VD (Group-C; n = 11) or not treated with VD (Group-D; n = 11). Radiological findings (such as the degree of aortic calcification), bone mineral content, divalent ions, parathyroid hormone levels and lipid profiles were examined. The prevalence of patients with aortic calcification was significantly higher in Group-D than in Group-C (7/11 v. s. 2/11, P < 0.05). However, lipids, mineral and endocrinological parameters did not differ between the sub-groups. No significant difference in the calcium and phosphate balance was observed. The bone mineral content revealed no difference between both of the sub-groups. VD administration by conventional mode, even without significant suppression of PTH or increase of bone mineral content, may enhance vessel calcification in patients on long-term CAPD.

Adult↗
PubMed1977

Soft tissue calcification in chronic dialysis patients.

Autopsy protocols and microscopic slides of 56 dialyzed and 18 nondialyzed chronically uremic patients were reviewed to assess the presence, extent, and severity of extraosseous soft tissue calcification. Calcification was identified in 79% of the dialysis patients and 44% of the nondialysis patients (P iss less than .025). Soft tissue calcification most frequently involved the heart, lungs, stomach, and kidneys. Lesions were severe in 36% of the dialysis patients and, when strategically located within the myocardium, were life-threatening. The deaths of 6 dialysis patients were attributed to severe calcification of the cardiac conduction system and/or myocardium. The presence and severity of soft tissue calcification was not related to duration of dialysis, patients' age, degree of parathyroid gland hyperplasia, radiographic evidence of soft tissue calcification, serum calcium and phosphate levels, Ca X P products, or type or severity of metabolic bone disease.

Adolescent↗
PubMed1996

A case of calcification of the cervical ligamentum flavum.

We report a case of cervical myelopathy caused by the calcification of the cervical ligamentum flavum. A 42-year-old woman with gait disturbance and an episode of dysuria was transferred to our hospital on June 30, 1994. Neurological examination revealed only a mild right hemiparesis. A plain neck X-ray and a tomogram revealed a nodular calcification in the posterior part of the spinal canal at the level of C5/6. Three dimensional computed tomography clearly demonstrated that the mass consisted of three nodular structures on the vertebral lamina. Magnetic resonance images demonstrated severe compression of the spinal cord by the mass whose intensity was low. The mass was removed en bloc together with the ligamentum flavum and C5 and C6 lamina. The mass showed no continuity to the dura mater. The calcification was confined within the ligament. The patient's neurological deficits were resolved two weeks after the surgery. X-ray diffraction study demonstrated the component of the mass was found to be pure hydroxyapatite. Clinical features of calcification of the ligamentum flavum are reviewed from 85 reported cases including ours, and the difference between this calcification and the ossification of the ligament is emphasized. Calcification of the ligamentum flaum is a distinct clinical entity.

Adult↗
PubMed1995

[Analysis of deposits in calcific periarthritis].

Analysis was conducted on calcific deposits from 5 patients with calcific periarthritis. These calcific deposits were dried, immersed in hydrazine, or heated to 1000 degrees C for 1 hour, to prepare 3 kinds of samples. The samples were classified as dried samples, hydrazine-deproteinated samples, or as heated samples. All samples were analyzed by X-ray diffraction (XRD). Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (Raman), and by electron probe microanalysis (EPMA). Although the XRD patterns of the dried samples and of the deproteinated samples were similar to that of hydroxyapatite (HAp), it was still unclear whether or not the calcific deposits were HAp. FTIR then revealed that the dried samples contained carbonate. Raman showed that the dried samples and the deproteinated samples do not have an OH-group. The dried samples were then heated to 1000 degrees C for one hour and analyzed by all 4 methods. The heated samples were found to be HAp. From these results, the calcific deposits from the 5 patients with calcific periarthritis were found to be carbonate apatite: Ca10-x-y/2 (PO4)6-x (CO3) x (OH) 2-y (CO3)y/2.nH2O.

Apatites↗
PubMed1996

Are there gender differences regarding coronary artery calcification.

This article reviews the current knowledge about coronary artery calcification in women, concentrating on the pathophysiology of atherosclerotic calcification, the gender and age differences in the detection of calcification by electron beam computed tomography (EBCT), and the clinical significance of detected coronary calcium. The effects of estrogen and vitamin D on vascular calcification are examined with respect to data that point to similarities between the processes of calcification and bone matrix formation. Gender and age differences in EBCT coronary calcium detection, with emphasis on differences and consequences of calcium prevalence, are also examined. Lastly, the diagnostic and prognostic significance of coronary calcification is discussed, noting that it is more significant in symptomatic, older, and high-risk adults than it is in younger individuals of either gender.

Age Factors↗
PubMed1996

[Calcification in atherosclerotic plaque as one of the types of complicated atherosclerotic lesions].

Calcifications of the atherosclerotic plaque is the form of a complicated atherosclerotic lesion. It is characterized by granular or massive deposits of calcium chloride inside the atherosclerotic plaque. It was found in at least one of the three main coronary arteries in 43 (86.00%) out of 50 autopsy cases. In all three, coronary arteries calcifications were found in 8 (18.60%) cases, in two coronary arteries in 19 (44.19%), and one coronary artery in 16 (37.21%) cases. Calcifications of atherosclerotic changes which contain fats were statistically significantly more frequently established than those which did not contain fats. In three fourths of cases calcifications were present in segments with significant narrowing of the arterial lumen (group 3 and 4). In 59.61% of calcificated atherosclerotic changes the residual lumen was of eccentric shape, in 20.51% of concentric shape, in 7.69% it was semilunar, and in 12.18% a few lumens were detected (channeled and organized thrombi). Granular deposits of calcium were established 63.46%, while massive in 36.54% of segments of atherosclerotic lesions, but no statistically significant difference in distribution of these two types of calcifications was established in regard to the type of atherosclerotic change.

Aged↗
PubMed1997

[An autopsied case of atypical presenile dementia which shows lobar atrophy, severe neurofibrillary tangles and calcification].

We report an autopsy case of atypical presenile dementia. Shibayama, Kosaka and others had reported similar autopsy cases. These cases had the following common pathologic characteristics: circumscribed cerebral atrophy, diffuse neurofibrillary tangles (NFTs) noted in the cerebral cortex with few senile plaques (SPs), and pathological calcification. We propose the term "dementia with cerebral calcification and tangles" (DCCT) for this atypical presenile dementia. Our patient, who was female and died at the age of 65 years, also exhibited these characteristics. Her clinical diagnosis was Alzheimer's disease. She had developed apparent dementia at the age of 55. Psychological and neurological symptoms such as memory impairment, speech disturbance and abnormal behavior slowly progressed. Gradually, she had become bedridden in her own home. When she was 65 years old, she was admitted because of pneumonia, and died soon after. In the pathologic examination of our patient, the brain weight was 850 g, and severe cerebral atrophy predominant in the temporal lobe was noted. Microscopically, diffuse and numerous NFTs were also found in the cerebral cortex and brain stem. Some NFTs were observed in the dentate nucleus of the cerebellum. However, SPs were seldom noted. Calcifications were also found in the putamen, globus pallidus and cerebellar cortex. NFTs in our case had developed without the formation of SPs. The degree of the NFT formation was correlated to the extent of cerebral cortical atrophy and neuron loss. Therefore, we suspect that NFTs with neuron loss strongly contribute to clinical symptoms such as dementia. The distribution of NFTs resembles that in patients with Alzheimer's disease, they are more prominent in the temporal lobe in our case. Although there has not been any discussion about the findings of glial cells and neuropils in DCCT, our detailed examination showed argyrophilic structures in glial cells and in neuropils. Most of the glial cells appeared to be oligodendrocytes. Calcification is also a prominent characteristic of DCCT. Using analytical electron microscopy, we examined the area of calcification in the globus pallidus and cerebellum, and found an accumulation of both Fe and Ca. The role of calcification in the pathogenesis, however, remains unclear. It is very important to examine cases of atypical presenile dementia clinicopathologically, in order to study the correlation between NFTs and SPs in neurological disease, and to understand their pathogenetic significance.

Aged↗