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Biomedical subjects

A Casasco

Publications and source records attributed to A Casasco.

At least 19 recordsLinked to original sources
PubMed2004

Differential distribution of elastic tissue in human natural skin and tissue-engineered skin.

Tissue-engineered skins (TES), manufactured by epidermal and dermal equivalents, are now being used in biological, pharmacotoxicological and clinical applications. It is thus interesting to know to what extent artificial organs are similar to natural counterparts. Elastic fibres are important constituents of the extracellular matrix of natural skin (NS). The aim of our study was to investigate the possible occurrence and distribution of elastic tissue in a model of human TES using different histochemical techniques, including classical Orcein and Fuchsin-Resorcin methods and immunohistochemistry, at both light and electron microscopical levels. Immunoperoxidase and high resolution immunogold methods were used. In NS, classical staining techniques and elastin-immunohistochemistry revealed a well-organized network of elastic fibres. High resolution immunocytochemistry revealed an intense labelling in the amorphous component of elastic fibres. Fibres of different diameters were immunostained. In TES, no stained elastic fibres were observed using classical staining techniques, and the interpretation of immunoperoxidase observations was not clear-cut. In contrast, immunogold staining at the electron microscopical level provided specific labelling of elastin-like immunoreactive material in the dermal equivalent. However, ultrastructural immunocytochemistry revealed that elastic tissue organization in TES was poor compared to that in NS. This study demonstrates that elastic fibres are a component of the extracellular matrix in this model of TES and suggests that fibroblasts of the dermal equivalent are engaged in matrix secretion. Nevertheless, the level of extracellular matrix organization in TES is low compared to NS. Moreover, this study also suggests that different models of bilayered TES may differ with respect to extracellular matrix organization. These aspects should be considered when TES is used in biological and pharmacotoxicological studies. A better understanding of the factors influencing extracellular matrix formation in TES is necessary to achieve further development of skin generation in vitro.

Cells, Cultured↗
PubMed2002

[Hemangiomas and superficial vascular malformations of the face and neck].

Hemangiomas and superficial vascular anomalies of the head and neck form what usually calls the angiomas. Many terms exist in the literature for that reason the classification of the ISSVA, admitted by most of the doctors, helps us in naming the different anomalies. The processing of this pathology needs a multidisciplinary collaboration with doctors of different specialties. The evolution of the radiological, surgical techniques of laser, and who knows, of the research, allows to hope us to cure some of the particularly dangerous anomalies like the arteriovenous malformations. We presented here the different technics used in 2001 in the management of hemangioma and superficial vascular anomalies insisting on a multidisciplinary approach.

Adult↗
PubMed2001

Cell proliferation and differentiation in a model of human skin equivalent.

Recent advances in culturing technology has permitted the production of organotypic models that may be referred to as human skin equivalents (HSE). We have studied histochemical, ultrastructural, and kinetic aspects of an HSE composed by an epidermal equivalent and a dermal equivalent separated by a basement membrane. Only keratinocytes and fibroblasts were present in the epidermal and dermal equivalents, respectively; cells of other lineages were lacking. Keratinocyte stratification and differentiation seemed similar to natural skin. Evidence is shown that such an HSE may also release growth factors such as vascular endothelial growth factor that are believed to play a role in skin grafting. The distribution of cycling cells as well as the values of the growth fraction are comparable to those observed in natural skin. Although the absence of several cells populations that reside in natural skin is a remarkable feature of this HSE, the high levels of tissue organization and cell differentiation lead us to believe that such an HSE may be considered a candidate substitute of human skin in biological, pharmacologic, and clinical applications.

Cell Differentiation↗
PubMed2001

Cell kinetics in a model of artificial skin. An immunohistochemical and flow cytometric analysis.

Bioengineered organs raised in vitro are candidate substitutes for natural organs in biological, pharmacological and clinical applications. We have studied cell kinetics in a human skin equivalent (HSE) using a combined immunohistochemical and flow cytometric approach. Morphological analysis has shown that, relative to unstimulated natural skin, cell proliferation mainly occurs in the basal layer of the epidermal equivalent. Immunohistochemical and flow cytometric measurements of the growth fraction suggested a cell turnover comparable to that of natural skin. Immunohistochemical labelling indices matched well with flow cytometric data. These observations are consistent with morphological and histochemical data demonstrating normal cell differentiation and tissue architecture in HSE and suggest that such HSE may be a usefull substitute for human skin.

Biocompatible Materials↗
PubMed2000

[3D-CT angiography with volume rendering technique in the intracerebral aneurysms].

PURPOSE: Many techniques of 3D reconstruction (MIP, SSD) permit a good evaluation of the circle of Willis in order to detect cerebral aneurysms. More recently, the advent in the clinical practice of a calculation algorithm (VRT) adapted to the workstations for images treatment seems to improve evaluation of the characteristics regarding these aneurysms. MATERIALS AND METHODS: We report 4 cases with cerebral aneurysms studies with CT-angiography using the technique MIP and VRT. RESULTS: The VRT, using the totality of image informations, allows a better understanding than MIP about the intracranial cerebral aneurysms including their constitution and 3D localization. CONCLUSION: The VRT reconstruction permits to obtain quickly good quality and reproductive images, without relationship with threshold.

Adult↗
PubMed2000

Cerebral aneurysms treated by Guglielmi detachable coils: evaluation with diffusion-weighted MR imaging.

BACKGROUND AND PURPOSE: The most frequent and serious complications of endovascular treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs) are ischemic lesions caused by thromboembolic events. Diffusion-weighted MR imaging appears to be the most sensitive technique for detecting early ischemic phenomena. We evaluated this technique for the detection of brain changes in patients who underwent GDC treatment of aneurysms. METHODS: Twenty patients with a cerebral aneurysm were studied with diffusion-weighted imaging before and after endovascular treatment with GDCs. Aneurysms were located in the anterior (n = 16) or posterior (n = 4) circulation. Bleeding had occurred in 11 patients. MR studies, including fast fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted sequences, were scheduled before, 2 to 4 hours after, and 48 hours after treatment. MR images, including apparent diffusion coefficient (ADC) maps, were assessed for the presence of acute ischemic stroke lesions. RESULTS: In all patients, the aneurysm was excluded without neurologic worsening. In 18 patients, diffusion-weighted and FLAIR images showed no evidence of recent ischemic lesions after treatment. In one patient, an asymptomatic frontobasal hyperintense signal on diffusion-weighted images with a drop of ADC values corresponding to an acute ischemic lesion was observed. In another patient, multiple silent lesions were seen on diffusion-weighted images after embolization. These silent lesions were not all located in the vascular territory of the aneurysm's parent artery. CONCLUSION: This preliminary study suggests that diffusion-weighted MR imaging is a potentially useful tool for monitoring patients after endovascular treatment of a cerebral aneurysm. While small asymptomatic lesions can be observed on these images after embolization, their exact prevalence should be evaluated in a larger series.

Adult↗
PubMed1999

Combined management of intracranial aneurysms by surgical and endovascular treatment. Modalities and results from a series of 395 cases.

The selective occlusion of saccular intracranial aneurysms may be achieved by two techniques: microsurgical clipping and endovascular coiling. Each of them have particular indications which need to be defined. We report on a series in which both techniques were applied. From September 1992 to June 1996, 395 consecutive patients with small or large aneurysm were treated either by surgery (N = 102) or by endovascular coiling (N = 293). Coiling was chosen each time the shape of the aneurysm seemed to be appropriate for this treatment: narrow neck and ratio neck diameter by sac diameter less than one third. Satisfactory results with complete or subtotal obliteration and no recanalization on the following controls at 1, 6, 12 and 36 months, were obtained in 92% before retreatment and in 98.8% after retreatment. Unsatisfactory results were observed after surgery in 7 cases and in 25 cases after embolization. After retreatment, it remains 3 post-surgical and 2 post-endovascular cases. In the overall series, good and excellent clinical outcome was noted in 90% for small aneurysms and in 86.5% for large ones; mortality was of 4.8%. In a series in which were applied both types of treatment, surgery in 25% and endovascular technique in 75%, good results in terms of aneurysm occlusion and clinical results were achieved. These results are as good as the best series in which surgery was the only choice. Therefore with appropriate selection, endovascular treatment is a good alternative for treatment of the majority of saccular aneurysms.

Adult↗
PubMed1999

Stenting of the extracranial internal carotid artery for dissecting aneurysm.

Symptomatic dissecting aneurysms of the extracranial internal carotid artery are not frequent. Medical treatment of these lesions can be ineffective and surgical options present high morbidity. We describe a case successfully treated with endovascular therapy, using a self-expanding stent. The advantages of the endovascular treatment and the rationale of the use of self-expanding stents are discussed.

Adult↗
PubMed1999

Immunolocalization of gelatinase-A (matrix metalloproteinase-2) in damaged human temporomandibular joint discs.

The fibrous tissue of the articular disc of the dysfunctional temporomandibular joint undergoes deep and variable structural modifications. Here the concurrence of morphological changes and the expression of matrix metalloproteinase-2 (MMP-2) in damaged discs from individuals suffering joint dysfunction was investigated. Microscopic, ultrastructural and immunocytochemical investigations were made on variously damaged articular discs and on one control sample. Disaggregation of collagen fibres, an increase in cellular components and calcification of large areas of tissue were observed in the damaged discs. These modifications were accompanied by a positive immunoreaction pattern for MMP-2. Fibroblast-, chondroblast- and osteoblast-like cells displayed a positive cytoplasmic reaction. In samples displaying evidence of synovial hyperplasia, some cells of the synovial protrusions were MMP-2 immunoreactive. No MMP-2 staining was observed in the control sample. These findings demonstrate that structural modifications of the articular disc could be specific responses to changes in the function of the temporomandibular joint. Variations in extrinsic stimuli may activate intrinsic factors, such as MMPs, that induce structural modifications in the discal tissue.

Adult↗
PubMed1999

[Evolution of angiographic signs of venous hypertension and clinical signs of intracranial hypertension in intracranial dural arteriovenous fistulas].

Dural arteriovenous fistulas (dAVFs) can cause cerebral venous hypertension (VHT). The most common mechanism is due to the fact that some dAVFs can drain retrogradelly in cortical (better defined as leptomeningeal) veins (directly or after drainage in a dural sinus) causing venous engorgement and consequently an impairment of the cerebral venous drainage. However, more rarely, dAVFs without a cortical venous drainage can also be responsible for VHT probably due to dAVF shunts causing insufficient antegrade cerebral venous drainage. In addition, dAVFs are often associated with stenosis and/or thrombosis of dural sinus(es) which can worsen the VHT. Raised pressure within the superior sagittal sinus causes impeded cerebrospinal reabsorption in the arachnoid villi allowing increased intracranial pressure. The venous engorgement in the cortical veins can cause a venous congestive encephalopathy analogous to the venous congestive myelopathy of the spinal dural AVFs. Clinically VHT can cause not only symptoms related to increased intracranial pressure but also seizures, neurological deficits, impairment of the cognitive functions and dementia. An important aspect is the risk of hemorrhage in dAVFs with a leptomeningeal venous drainage leading to VHT. Although the term VHT sensu strictu should be used if venous pressure measurements are performed, angiographic criteria for VHT such as delayed circulation time, venous engorgement and abnormal visualization of the cerebral veins are well established. The purpose of our study was to evaluate the angiographic signs of VHT in patients with dAVF and to study the course of the VHT and of the clinical signs of increased intracranial pressure before and after dAVF endovascular treatment. A retrospective chart analysis of 22 patients (13 males, 9 females) ranging in age from 20 to 87 years (mean: 53 ys.) with a dAVF associated with angiographic signs of VHT was performed. Ten dAVFs were located on the transverse/sigmoid sinus(es), 6 on the superior sagittal sinus, 3 on the petro-tentorial incisura, 1 on the inferior petrosal sinus, 1 on the anterior ethmoidal region and 1 on the Galen vein region. All dAVFs had a retrograde leptomeningeal venous drainage. Stenosis or thrombosis of the dural AVF sinus was observed in 17 cases and stenosis or thrombosis of another sinus(es) and/or of the jugular vein in 8 cases. In 11 patients, the angiographic signs of VHT were global affecting the entire cerebral venous drainage and, in the other 11 patients, the VHT was focal. The VHT caused clinical symptoms of increased intracranial pressure in 18 patients. Other clinical findings included: bruit (11 cases), seizures (3 cases), vertigo (3 cases), visual deficits (2 cases) and impairment of cognitive functions (4 cases). Three patients presented hemorrhage (one parenchymal hematoma, one hemorrhagic infarction and one subarachnoid hemorrhage). The 4 patients without clinical symptoms of increased intracranial pressure presented only bruit in 2 cases, bruit and vertigo in 1 case, bruit and hemorrhagic infarction in another one. The dAVFs were treated by endovascular therapy (arterial approach: 3 cases, venous approach: 6 cases and both arterial and venous approach: 13 cases). Endovascular sessions ranged from 1 to 7 (mean: 2.8) for each patient. After the endovascular treatment, in 12 patients with complete occlusion of the dAVF, the disappearance of angiographic signs of VHT and clinical cure were observed. In 8 patients with partial occlusion of the dAVF, the disappearance of angiographic signs of VHT and clinical cure were observed in 4 cases (almost complete dAVF occlusion in 2 cases); in the other 4 cases, only reduction the angiographic signs of VHT and clinical improvement were obtained. In all 16 patients who were clinically cured angiographic signs of VHT disappeared despite the persistence of dAVF shunts as observed in 4 cases. (ABSTRACT TRUNCATED)

Adult↗
PubMed1999

[The value of MRI for the diagnosis of meningeal hemorrhage during vasospasm].

Retrospectively, subarachnoidal hemorrhage can be misdiagnosed when the acute event did not bring the patient to medical attention, when clinical history is unclear and the CT scan is normal. Moreover, days after subarachnoid hemorrhage, cerebral vasospasm can result in neurological deficits that are indistinguishable from that produced by other causes of stroke. We report our experience with two patients who presented with symptoms of ischemia due to an arterial vasospasm that followed unrecognized rupture of an intracranial aneurysm. In both cases, CT scan failed to detect subarachnoid hemorrhage while MR detected the presence of signal changes in the subarachnoidal spaces associated with an ischemic stroke in one case. Neurological symptoms resolved completely after aneurysm treatment. MR can be a critical for the diagnosis of stroke secondary to vasospasm in order to prescribe an adapted treatment, avoid anticoagulant or thrombolytic therapy, and rapidly exclude the recently ruptured aneurysm to protect the patient from the risk of rebleeding.

Adult↗
PubMed1999

Spinal vascular malformations: endovascular therapy

Over the past 30 years, the development of diagnostic spinal angiography has led to effective endovascular techniques for treatment of spinal vascular malformations. Specific locations, size, rapidity of shunt, and clinical presentation determine the best treatment and prognosis.

Journal Article↗
PubMed1999

Major complications of percutaneous embolization of skull-base tumors.

The technique of direct intratumoral injection of permanent liquid polymerizing agent was initially described in 1994 and has evolved significantly with experience. We report complications that occurred in two patients during injection of Histoacryl and offer suggestions to prevent such complications in the future. In one patient, the glue settled in the right middle cerebral artery; in the second, the glue entered the left ophthalmic artery through a collateral branch. Although the fundamental injection technique has not changed, we suggest additional precautions and modifications to make this procedure a safer and more valuable element in the overall management of patients with difficult skull-base tumors.

Adolescent↗
PubMed1998

Therapeutic approach to arteriovenous malformations of the tongue.

Arteriovenous malformations (AVM) are developmental errors with a high complication rate because they are hemodynamically active. The aim of our study is to evaluate management of the rare subgroup of tongue AVM. From 1982 to 1994, 25 patients with AVM of the tongue presented to our department. All patients were discussed in our multidisciplinary staff consultation and were treated by embolization, surgery, or were followed-up clinically with no intervention. Thirteen patients were asymptomatic in a hemodynamically quiescent phase and did not require any kind of intervention. The 12 others underwent embolization procedures following which 6 became stable, 2 had complementary surgery, 1 was lost to follow-up, 1 had two minor bleeding episodes without the need for hospitalization, and 2 were improved. Arteriovenous malformations of the tongue must be followed clinically and treated only if they become active. Permanent embolization with a polymerizing liquid administered through supra-selective catheterization or by direct puncture of the malformation is recommended.

Adolescent↗
PubMed1998

In search of biological markers of high-risk carotid artery atherosclerotic plaque: enhanced LDL oxidation.

The oxidation of low density lipoprotein (LDL) is a key event in the development and progression of atherosclerosis because it generates molecular epitopes that are more atherogenic than parent LDL. We found previously that patients with carotid atherosclerosis have a significantly higher titer of autoantibodies against oxidatively modified LDL than normal subjects. The aim of this study is to correlate biological markers of in vivo LDL oxidation with the degree of carotid stenosis and of plaque ulceration (PU) in a series of patients undergoing carotid endoarteriectomy (CEA). Ninety-four consecutive patients (68M and 26F, aged 67.3 +/- 8.2 years) who underwent CEA at our institution between June 1993 and January 1994 were included in the study. The degree of carotid stenosis and the presence and extent of PU were correlated with the level of autoantibodies (IgG) against oxidatively modified LDL (Cu++-oxidized [oxLDL] or malondialdehyde derivatized LDL [MDA-LDL]), that consistently mirrors the occurrence of oxidative modifications in vivo. A statistically significant correlation (r = 0.23, p = 0.039) was found between the degree of carotid stenosis and antiMDA-LDL specific ratio (a parameter that describes the specificity of LDL towards other proteins as target for oxidative modification). A statistically significant correlation was also found between the PU score and antioxLDL IgG (r = 0.32, p = 0.011), antiMDA-LDL IgG (r = 0.25, p = 0.045) and antiMDA-LDL IgG specific ratio (r = 0.38, p = 0.002). None of the classical biochemical parameters (total, LDL and HDL cholesterol and triglycerides) correlated with the above-mentioned plaque characteristics. The results shown, support the use of biological markers of in vivo LDL oxidation (antioxidatively modified LDL autoantibody titers) to evaluate the clinical setting of high-risk carotid atherosclerosis both in screening and in follow-up studies.

Aged↗
PubMed1998

Dural arteriovenous fistulas as a cause of intracranial hypertension due to impairment of cranial venous outflow.

OBJECTIVES: A retrospective study was carried out on 13 patients with intracranial dural arteriovenous fistulas (DAVFs) who presented with isolated or associated signs of intracranial hypertension. METHODS: Nine patients presented with symptoms of intracranial hypertension at the time of diagnosis. Ocular fundoscopy available in 12 patients showed bilateral papilloedema in eight and optic disk atrophy in four. Clinical evolution was particularly noticeable in five patients because of chronic (two patients) or acute (after lumbar shunting or puncture: three patients, one death) tonsillar herniation. RESULTS: Two patients had a type I fistula (drainage into a sinus, with a normal antegrade flow direction). The remaining 11 had type II fistulas (drainage into a sinus, with abnormal retrograde venous drainage into sinuses or cortical veins). Stenosis or thrombosis of the sinus(es) distal to the fistula was present in five patients. The cerebral venous drainage was abnormal in all patients. CONCLUSION: Type II (and some type I) DAVFs may present as isolated intracranial hypertension mimicking benign intracranial hypertension. Normal cerebral angiography should be added as a fifth criterion of benign intracranial hypertension. The cerebral venous drainage pattern must be carefully studied by contralateral carotid and vertebral artery injections to correctly evaluate the impairment of the cerebral venous outflow. Lumbar CSF diversion (puncture or shunting) may induce acute tonsillar herniation and should be avoided absolutely. DAVF may induce intracranial hypertension, which has a poor long term prognosis and may lead to an important loss of visual acuity and chronic tonsillar herniation. Consequently, patients with intracranial hypertension must be treated, even aggressively, to obliterate the fistula or at least to reduce the arterial flow and to restore a normal cerebral venous drainage. The endovascular treatment may associate arterial or transvenous embolisation and/or surgery. Patients in whom the fistula is not obliterated after an endovascular therapeutic procedure, need continuous clinical and angiographical follow up.

Adult↗
PubMed1998

Management of intracranial aneurysms by surgical and endovascular treatment--modalities and results from a series of 395 cases.

The selective occlusion of saccular intracranial aneurysms may be achieved by two techniques: microsurgical clipping and endovascular coiling. Each of them have particular indications which need to be defined. From September 1992 to June 1996, 395 consecutive patients with small or large aneurysms were treated either by surgery (n = 102) or by endovascular coiling (n = 293). Coiling was chosen each time the shape of the aneurysm seemed to be appropriate for this treatment: narrow neck and ratio neck diameter by sac diameter less than one third. Satisfying results with complete or subtotal obliteration and no recanalization on the following controls at 1, 6, 12, and 36 months were obtained in 92% before retreatment and in 98.8% after retreatment. Unsatisfying results were observed after surgery in seven cases and in 25 cases after embolization. After retreatment, it remains three post-surgical and two post-endovascular cases. Good and excellent clinical outcome was noted in 90% for small aneurysms and in 86.5% for large ones. Mortality is of 4.8% in the overall series. In a series in which were applied both types of treatment, surgery in 25% and endovascular techniques in 75%, good results in terms of efficiency and clinical results were achieved. These results are as good as the best series in which surgery was the only choice. Therefore with appropriate selection, endovascular treatment is a good alternative for treatment of the majority of saccular aneurysms.

Adult↗