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Biomedical subjects

E Ferrer

Publications and source records attributed to E Ferrer.

At least 127 records · Page 7Linked to original sources
PubMed1977

A new approach to quantitative analysis of somatic association.

A formula is proposed for estimating statistically the degree of somatic chromosome association during metaphase. Standard chi-square tests can then be used to determine the presence or absence of somatic association between homologous chromosomes in selected species. The method requires that the chromosomes be morphologically distinguishable and that their circular arrangement on the metaphase plate has not been distorted by the squash used during their preparation.

Chromosomes↗
PubMed1975

[Chronic glomerulonephritis with Hb antigen].

The authors report nine cases of chronic glomerulonephritis with positive hepatitis B antigen (AgHB) (8 cases) and positive anti-AgHb (1 case). Five patients had membranous glomerulonephritis. The sub-type was ad in 6 cases and ay in 2. In 3 members of two families of patients, AgHB was positive with the same sub-type as the subject studied. In 5 cases, liver biopsy showed signs of chronic hepatitis. According to the authors, a positive AgHB in glomerulonephritis is often associated with clinically latent chronic hepatitis.

Adolescent↗
PubMedDate not supplied

Towards a method for automated classification of 1H MRS spectra from brain tumours.

Recent studies have shown that MRS can substantially improve the non-invasive categorization of human brain tumours. However, in order for MRS to be used routinely by clinicians, it will be necessary to develop reliable automated classification methods that can be fully validated. This paper is in two parts: the first part reviews the progress that has been made towards this goal, together with the problems that are involved in the design of automated methods to process and classify the spectra. The second part describes the development of a simple prototype system for classifying 1H single voxel spectra, obtained at an echo time (TE) of 135 ms, of the four most common types of brain tumour (meningioma (MM), astrocytic (AST), oligodendroglioma (OD) and metastasis (ME)) and cysts. This system was developed in two stages: firstly, an initial database of spectra was used to develop a prototype classifier, based on a linear discriminant analysis (LDA) of selected data points. Secondly, this classifier was tested on an independent test set of 15 newly acquired spectra, and the system was refined on the basis of these results. The system correctly classified all the non-astrocytic tumours. However, the results for the the astrocytic group were poorer (between 55 and 100%, depending on the binary comparison). Approximately 50% of high grade astrocytoma (glioblastoma) spectra in our data base showed very little lipid signal, which may account for the poorer results for this class. Consequently, for the refined system, the astrocytomas were subdivided into two subgroups for comparison against other tumour classes: those with high lipid content and those without.

Brain Neoplasms↗
PubMedDate not supplied

Assessment of diurnal tensional curve in early glaucoma damage.

We know very little about the relationship between the diurnal intraocular pressure variations and the progression of visual field loss. A prospective study of 149 eyes of 149 patients suffering from intraocular hypertension has been carried out through a minimum period of five years. At least 4 years before the appearance of field defects, we detected significant oscillations of IOP in the 64% of the cases prone to develop visual field loss. Likewise, we have found a statistically significant relationship between the presence of defects in the RNFL (retinal nerve fiber layer) and the existence of significant oscillations of IOP.

Circadian Rhythm↗
PubMedDate not supplied

Preparation and properties of oligodeoxynucleotides containing 5-iodouracil and 5-bromo- and 5-iodocytosine.

The behavior of oligonucleotides containing 5-iodouracil, 5-bromocytidine, and 5-iodocytidine in concentrated ammonia is described. 5-Aminouracil and 5-aminocytidine are obtained as side products when deprotection is performed at 60 degrees C. Small amounts, if any, of side products are obtained when ammonia deprotection is performed at room temperature. The base-pairing properties of these 5-halopyrimidines including triple helix are described.

Ammonia↗
PubMedDate not supplied

Effect of prophylactic brimonidine on bleeding complications after cataract surgery.

PURPOSE: To evaluate the effect of prophylactic brimonidine on bleeding complications after cataract surgery. METHODS: The authors performed a prospective, double-masked, two-surgeon study of 137 patients (137 eyes) who underwent phacoemulsification and intraocular lens implantation with or without prophylactic brimonidine before cataract surgery. The authors also compared the effect of brimonidine among patients with systemic diseases such as diabetes mellitus (types I and II), hypertension, and anticoagulant or antiplatelet treatment. RESULTS: Subconjunctival hemorrhage was observed in 73.70% of the patients not treated with brimonidine before surgery and in only 23.75% of the patients who were given prophylactic brimonidine (p<0.001, chi2). The grade of hemorrhage was also statistically significant (p<0.001, Mann-Whitney). No statistically significant difference with regard to the presence of hemorrhage in diabetic patients or in the anticoagulant or antiplatelet treatment group was observed. However, a statistically significant difference (p<0.027, chi2) was found between hypertensive patients treated and not treated with prophylactic brimonidine before cataract surgery. CONCLUSIONS: This study suggests that brimonidine administered before cataract surgery may significantly reduce subconjunctival hemorrhage in the general population. It has been shown to be beneficial in hypertensive patients. A strong statistical trend, but not significance has been found in diabetic patients or in patients treated with antiplatelet or anticoagulant drugs, but further studies are needed to reach conclusive results.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

Diode laser photocoagulation in retinopathy of prematurity.

We used diode laser photocoagulation to treat 22 eyes of 12 patients with retinopathy of prematurity. Three infants were followed for at least six months and nine for at least one year. We treated 14 eyes with threshold disease and 8 eyes with prethreshold disease. The treatment was administered within 72 hours of diagnosis and topical anesthesia and sedation were used. No evidence of lesions of the anterior segment of preretinal or vitreous hemorrhages was found after the treatment. External inflammatory signs were neglibible. Systemic complications occurred only in three treatment sessions. Eight of the 14 eyes with threshold disease (57%) and all eight eyes with prethreshold disease had favorable outcomes. In total 73% with ROP had favorable outcomes. Treatment with the diode laser is easily performed, effective essentially in cases of prethreshold disease but in threshold disease too, with minimal ocular or systemic complications.

Anesthesia, Local↗
PubMedDate not supplied

Response to liposomal doxorubicin and clinical outcome of HIV-1-infected patients with Kaposi's sarcoma receiving highly active antiretroviral therapy.

PURPOSE: HIV-associated Kaposi's sarcoma (KS) may not resolve despite highly active antiretroviral therapy (HAART). Moreover, the therapeutic goal has shifted from palliative care to long-term durable complete remission. The objective of the study was to assess the impact of liposomal doxorubicin in the treatment of HIV-associated KS in the HAART era. METHOD: In this prospective, noncomparative, multicenter study, patients with more than 10 cutaneous lesions or visceral disease were treated with 20 mg/m(2) of liposomal doxorubicin (Caelyx) every 3 weeks in addition to their antiretroviral therapy. In addition to tumor measurements and laboratory tests, human herpes virus 8 (HHV-8) polymerase chain reaction (PCR) in peripheral blood mononuclear cells (PBMC) was performed. RESULTS: Out of 79 participants enrolled in the study, 47 (59%) had stage T(1), 41 (52%) I(1), and 32 (40%) S(1). Nine individuals were not evaluable for response, 32 (40%) had complete response, 30 (38%) partial response, 5 (6%) stable disease, and 3 (4%) progression. Regression analysis did not find any statistically significant factor predicting response. HHV-8 PCR was positive in 37/53 (70%) patients with available PBMC samples, and HHV-8 viremia cleared in 14/27 (52%) without correlation with clinical response. Eleven (14%) participants experienced a relapse of KS, while at the last update of data, 49 (62%) remained stable. The only risk factor for recurrence identified was the follow-up time (odds ratio [OR] 1.21, 95% CI 1.07-1.36; p =.002). CONCLUSION: The response rate of AIDS-associated KS to liposomal doxorubicin administered with HAART was high, and most often the response was durable. HHV-8 viremia did not correlate well with clinical outcome.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Health-related quality of life in HIV-infected naive patients treated with nelfinavir or nevirapine associated with ZDV/3TC (the COMBINE-QoL substudy).

PURPOSE: The aim of the study was to assess differences in health-related quality of life (HRQoL) in HIV-infected naive patients treated with two HAART regimens at 12 months. METHOD: The MOS-HIV questionnaire was used to measure HRQoL in a subgroup of 127 patients included in the COMBINE study, which was an open-label, randomized, multicenter study comparing zidovudine (ZDV) and lamivudine (3TC) plus nelfinavir (NFV) or nevirapine (NVP) regimens in HIV-infected naive patients. 63 patients were included in the ZDV/3TC/NFV arm and 64 in the ZDV/3TC/NVP arm. RESULTS: No statistically significant differences were observed at baseline in demographic and clinical variables and HRQoL scores between treatment groups, except that the proportion of homosexual men was higher in the ZDV/3TC/NVP arm. There were no statistically significant differences in HRQoL scores between arms at 12 months and over time; only ZDV/3TC/NVP patients showed statistically significant improvement in Physical Health Summary score (p <.01) and a trend toward a better profile in Mental Health Summary score (p =.07). Overall, patients who were treated with ZDV/3TC/NVP showed greater changes in physical dimensions and patients who were treated with ZDV/3TC/NFV showed greater changes in mental health. CONCLUSION: Differences in HRQoL between study groups at 1 year follow-up were not detected. Nevertheless, a trend toward improvement was observed in summary health scores in ZDV/3TC/NVP-treated patients.

Adult↗
PubMedDate not supplied

[Advantages of neuroendoscopy in the management of non-communicating hydrocephalus].

INTRODUCTION: Non-communicating hydrocephalus is defined as a blockade of the physiological cerebrospinal fluid (CSF) flow from the choroid plexus to the subarachnoid space. Usually, a ventricle peritoneal shunt with a valve is employed as treatment but this does not provide a physiological restoration on the CSF flow. OBJECTIVE: The aim of the study is to introduce a more physiological solution by means of endoscopic technique. We also pretend to find out some prognostical factors related to successful treatment. PATIENTS AND METHODS: We present a prospective non-randomized series of 32 endoscopic III ventriculostomies performed in patients with non-communicating hydrocephalus. When the blockade was due to a tumor, an endoscopic biopsy was performed at the same surgical time. In the same way, if the cause was a ventricular hematoma, an endoscopic aspiration was performed. The patients follow-up was two years. RESULTS: The procedure was considered successful (83.8% of the cases) when the clinical symptoms resolved without ventricle-peritoneal shunt. We study the relationship of the blockade level and the highest value of intracranial pressure during endoscopy with the results of the procedure in terms of success and morbidity. We have found significant relation between high pressure during endoscopy and the practice of a complementary biopsy or hematoma evacuation. CONCLUSIONS: Endoscopic third ventriculostomy provides an effective and physiological solution to non communicating hydrocephalus. Complementary endoscopic procedures can be associated at the same surgical time, however this association can be related to increased values of intracranial pressure during surgical performance.

Adolescent↗
PubMedDate not supplied

[Analysis of the survival of permanent vascular access ports].

Complications arising from vascular access are major causes of morbidity in patients on renal replacement therapy. They contribute to frustration of health care providers and to high medical cost. To prevent failures in the future it will be helpful to identify the factors that are related to vascular access, malfunction. In a retrospective analysis we analysed the types, duration and primary patency rate of 1,033 permanent vascular access in 544 consecutive patients established during a 13-year period in a tertiary care hospital. Patient characteristics, incidence and risk factors related to vascular access failure were registered. In addition vascular access outcomes in patients who started haemodialysis with a catheter and in whom initial vascular access failure occurred were analysed separately. Forty-five per cent of patients required a central catheter at the start of HD, but 92% of them were being dialysed with an a-v fistula at the last observation. The total number of complications was 0.24 episodes per patient per year at risk, and the rate of thrombosis 0.1. A total of 52% of patients were dialysed throughout the observation period with their initial a-v fistula; 9.3% had more than three episodes of vascular access failure. The radiocephalic a-v fistula was the access with the best median duration, exceeding 7 years, but also the type that had the highest initial failure rate, i.e. 25% of patients and 13% of events. The brachiocephalic a-v fistula was the second most frequent type of vascular access, with a median duration of function of 3.6 years, in contrast the humerobasilar a-v fistula, lasted on average over 5 years. Average patency of the different types of grafts did not exceed 1 year, with the exception of the autologous saphenous graft with a median duration of function of 1.4 years. Patients with glomerulonephritis had the best function rates for their access, the median duration exceeding the duration of the study, whereas in half of diabetic patients it was less than 1 year. The duration of patency of the vascular access was twice as long in patients below age 65 years and in elderly males compared to elderly females. Patients who start HD with a catheter, as well as those with initial vascular access failure, have a higher rate of access failure in the subsequent course on renal replacement therapy. In conclusion, the radiocephalic and the brachiocephalic a-v fistula are the two types of vascular access with the longest duration of function, although a high rate of initial failure is seen with the radiocephalic a-v fistula. Age, female gender, presence of diabetic nephropathy, start of dialysis with a catheter, and failure to wait for initial maturation of vascular access are risk factors, and account for the majority of vascular access failure during renal replacement therapy.

Adolescent↗
PubMedDate not supplied

[Thalamic neuro inhibition in the treatment of post traumatic tremor].

INTRODUCTION: Severe head trauma could be followed by a wide range of movement disorders. Usually, they appear as a moderate or severe intention tremor that causes great patient disability. Those movement disorders use to be refractary to medical treatment, although sometimes they would be spontaneusly controlled by a year. CLINICAL CASE: 14 year old boy who suffered severe head trauma at age of 8. One year after the injury he developed an action tremor and choreiform dyskinesia with hemibalistic features evocated by the movement. Medical treatment was ineffective. Due to the great patients disability, we chose the surgical treatment based on the placement of an stimulation electrode in thalamic Vop/Vim complex, obtaining a tremor abolition with an improvement in the scales of tremor and quality of life. DISCUSSION: Surgical treatment of postraumatic tremors tryes to improve in terms of function and activities of daily living, more than suppresion of a symptom. The aim of this treatment is cut the palidal thalamic cortical pathways. Anyway, target is defined by the tremor related cells and, it is more a functional target than an anatomical one. We prefer stimulation more than lesion, due to the lack of brain definitive injury because its reversibility and adjustability features.

Adolescent↗