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Biomedical subjects

J M Aguilera

Publications and source records attributed to J M Aguilera.

12 recordsLinked to original sources
PubMed2003

Plug migration and cement mantle assessment in total hip replacement.

We reviewed a series of consecutive total hip replacements with cemented femoral components. Modern cementing techniques were followed in all cases, but two different medullary plugs were used-one was polyethylene and the other bioabsorbable gelatin. Cement mantle quality and plug migration were assessed by three different observers (X, Y, and Z); their findings did not agree. This was particularly evident when the cement mantles were assessed. There was a better cement mantle grading and less distal migration with polyethylene plugs, although there was no significant statistical difference between the two groups.

Absorbable Implants↗
PubMed2001

[Consensus conference on consultation times in neurology. Recommendations on consultation times in neurology outpatients care in Spain].

INTRODUCTION: Developing recommendations about consultation times in neurology helps plan the endowment of human resources and can contribute to homogenize and improve quality of health-care. OBJECTIVES: To elaborate recommendations on the consultation times needed to obtain enough quality neurology visits. MATERIAL AND METHOD: We used consensus search techniques, in particular the Community Impression technique. An ad hoc committee developed a preliminary proposal which was later discussed during a unlimited attendance working meeting and eventually voted by members of the Spanish Society of Neurology. The committee drew up a final consensus report after analysing the debate results and counting the ballots. FINAL RECOMMENDATION: "It is necessary that the Spanish Society of Neurology establishes and recommends standardized consultation times for neurology outpatients visits in Spain. These standardized values refer to consultation time per patient, both in the first and follow-up visits, in a General Neurology Outpatients Clinic. Moreover, there must be considered 'recommendable times' on one hand, and 'minimal required times' on the other hand. Any time value below the minimal required time means that the consultation duration does not fulfill the minimal requirements needed to warrant a care with acceptable quality for the patient". These recommendations are: Time for first consultation. Recommendable time: 45 minutes (Minimal required time: 25 minutes). Time for follow-up consultation. Recommendable time: 20 minutes (Minimal required time: 15 minutes).

Humans↗
PubMed2000

Apoptotic chondrocytes from osteoarthrotic human articular cartilage and abnormal calcification of subchondral bone.

OBJECTIVE: Osteoarthrosis (OA) is accompanied by altered subchondral bone remodeling. We investigated the role of chondrocytes in the mechanism of abnormal cartilage calcification. METHODS: Knee articular cartilage samples from OA and normal tissue were studied. Macroscopic and microscopic observations, alkaline phosphatase staining for light and electron microscopy (bright and dark fields). TUNEL technique, electron diffraction, and x-ray microanalyses were performed. RESULTS: Chondrocytes from patients displayed a morphology of apoptosis and showed abundant alkaline phosphatase (ALP)-rich matrix vesicles (MV) budding from the plasma membrane with hydroxyapatite microcrystals on their surface. Farther from the cells, hydroxyapatite crystals were detected on the MV surface and increased as they approached the subchondral bone. The concentration of Ca and P and their ratio increased inside the ALP-rich MV in relation to the proximity to subchondral bone. In the OA subchondral bone the ratio Ca/P varied from 3.936 to 0.974. In normal tissue the ratio was very homogeneous (maximum 1.973, minimum 1.781). CONCLUSION: In situ, apoptotic chondrocytes correlate with factors known to be involved in the calcification of the extracellular matrix. This suggests that apoptosis is involved in the abnormal calcification of OA cartilage, and consequently in the altered remodeling of the subchondral bone.

Aged↗
PubMed1997

Preservation of biological materials under desiccation.

A number of life forms, including seeds, certain nematodes, bacterial and fungal spores, and cysts of certain crustaceans, show an ability to survive desiccation. The present article reviews the literature available on this subject and critically evaluates the evidence for various mechanisms that may be responsible for these phenomena. Specific mechanisms considered include vitrification (glass formation) by sugars and other polyhydroxy compounds that are accumulated by the desiccated structures, specific effects of polyhydroxy compounds on membranes, effect of "compatible solutes" on conformation of key proteins, as well as other biochemical mechanisms. The article presents potential applications relevant to food technology and to biotechnology and reviews the research required to materialize more effective use of desiccation in food and biopreservation.

Animals↗
PubMed1994

[Chronic cluster headache: course and outcome of treatment].

We analyze the results of treatment and the course of disease in 20 patients suffering from chronic cluster headache. Patients were followed for an average of 5 years. Sumatriptan provided the most effective relief of symptoms in those who used that medication. The results of surgical and medical prophylaxes were poor. The disease either remitted or changed to an episodic variety after several months or years in most patients. There is no evidence to suggest that these changes were related to any particular treatment.

Adrenal Cortex Hormones↗
PubMed1994

[Cluster headache with a familial presentation].

Four out of 190 patients suffering from cluster headache (CH) were of familial presentation. In three families the affected relative was either the brother or the father of the proband. In the other family the disorder affected the father, two brothers, and perhaps the grand mother of the patient. The prevalence of the disease seems to be higher among relatives of CH patients compared to general population. It is unclear whether this familial aggregation depends up on genetic factors.

Adolescent↗
PubMed1993

Food, agricultural and marine biotechnology in Chile.

Economic segments with highest growth rates in Chile are those based on renewable resources like agriculture (fruits and vegetables), marine and forest products. Opportunities for biotechnology are based on a sound scientific base at universities, adequate funding and incipient industry-academia relationships. However, there is an urgent need to develop the engineering capabilities required to scale-up processes and to design, build and operate industrial biotechnology plants.

Agriculture↗
PubMed1993

[Benign amaurosis fugax].

In young patients episodes of amaurosis fugax usually correspond to processes not related with atherosclerosis of the extracranial vessels such as migraine, cardiac embolism, vasospasm, vasculitis, oral contraceptives or hematologic disease. In 11% of the cases, however, no cause can be found. These idiopathic cases generally have a benign course and their frequency decreases spontaneously allowing them to be described as benign amaurosis fugax. We describe four cases of amaurosis fugax in which no responsible cause was found despite extensive clinical, laboratory ultrasonographic and angiographic studies. The episodes progressively remitted. In these cases of benign amaurosis fugax the risk of a permanent deficit is exceptional and treatment is not necessary.

Adolescent↗
PubMed1986

[Various foods of intermediate humidity on the Chilean market].

Water activity, moisture content, pH, total sugars and sodium chloride content of commercial foods with reduced water content found in Chilean supermarkets were determined. The sample included meat, dairy, fruits and confectionary products. Principles involved in the reduction of water activity are discussed for each case.

Chile↗
PubMedDate not supplied

Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices.

The thermal stability of enzymes lactase and invertase in dried, amorphous matrices of sugars (trehalose, maltose, lactose, sucrose, raffinose) and some other selected systems (casein, PVP, milk) was studied. The glass transition temperature (Tg) was limited as a threshold parameter for predicting enzyme inactivation because (a) enzyme inactivation was observed in glassy matrices, (b) a specific effect of enzyme stabilization by certain matrices particularly trehalose was observed, and (c) enzyme stability appeared to depend on heating temperature (T) "per se" rather than (T-Tg). For these reasons, a protective mechanism by sugars related to the maintenance of the tertiary structure of the enzyme was favored. A rapid loss of enzyme (lactase) activity was observed in heated sucrose systems at T > Tg, and this was attributed to sucrose crystallization since it is known that upon crystallization the protective effect of sugars is lost. Thus, the stabilizing effect could be indirectly affected by the Tg of the matrix, since crystallization of sugars only occurs above Tg. Trehalose model systems (with added invertase) showed an exceptional stability toward "darkening" (e.g., non-enzymatic browning) when heated in the dried state to elevated temperatures and for long periods of time.

Animals↗
PubMedDate not supplied

[Cerebral infarct in systemic lupus erythematosus].

INTRODUCTION AND OBJECTIVE: Systemic lupus erythematosus is a syndrome of variable clinical and immunological expression, which may affect any organ. Stroke is an uncommon complication of systemic lupus erythematosus, attributed to many different etiopathogenic mechanisms such as early atherosclerosis, coagulopathy, vasculitis, cardiogenic embolism, etc. Our objectives were to analyze the incidence, clinical and immunological characteristics of this condition and to evaluate the therapeutic approach and evolution. CLINICAL CASES: We present the cases of six patients with cerebral infarcts who also had systemic lupus erythematosus. The frequency of cerebral infarct in our series of systemic lupus erythematosus was 6%. The average age was 45 years (range 13-67). All the cerebral infarcts occurred whilst the systemic lupus erythematosus was active. There were positive antiphospholipid antibodies in three of the patients and two patients had potentially embologenic cardiopathy (33%). Fifty percent of the patients required treatment with cyclophosphamide for their severe systemic disease and 66% received anticoagulants for an antiphospholipid syndrome and/or suspected thromboembolism. The clinical course was satisfactory in all cases but the one who died. CONCLUSIONS: The incidence of cerebral infarct in relation to systemic lupus erythematosus is low, and generally appears during advanced, active phases of the disease. The many etiopathogenic mechanisms involved generally act together so that it is difficult to say which is the main cause, especially in elderly patients. Amongst these mechanisms is the presence of antiphospholipid antibodies, detection of which is essential in this condition, and cardiogenic embolism. The evolution depends mainly on the multi-organ involvement and how early immunosuppressive and/or anticoagulant treatment is started.

Adolescent↗