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Biomedical subjects

E Ferrer

Publications and source records attributed to E Ferrer.

At least 91 records · Page 5Linked to original sources
PubMed1994

Stereotactic radiosurgery of deeply seated low grade gliomas.

The authors report the results of a series of 16 cases of low-grade gliomas in whom radiosurgery was performed. This series started in 1977. All the tumours received a single radiosurgical session (with a mean dose of 21.7 Gy, 5-10 mm. collimator; one patient received two sessions and in another patient two different targets were irradiated in the same session). Prior to radiosurgery, six patients received conventional external fractionated radiotherapy, with two lateral fields of up to 10 x 10 cm. and a mean dose of 55.1 Gy and another six patients with tumours less than 5 cm. in diameter, received stereotactic radiotherapy using four fields of up to 5 x 5 cm. and a mean dose of 53.1 Gy. In both cases, conventional fractionation was used, giving a dose of 1.8 to 2 Gy/day. The tumour disappeared in 8 cases (50%) and shunk or ceased its growth in 5 additional cases (31%). In 3 cases of brainstem gliomas in which the clinical condition was previously very poor there was no evolutional change and the patients eventually died. We conclude that radiosurgery is effective in the treatment of deeply seated low-grade gliomas, where it may become the treatment of choice in the absence of other more definitive choices.

Adolescent↗
PubMed1994

Fuch's heterochromic cyclitis and HLA histocompatibility antigens.

Genetic typing of class I major histocompatibility complex (MHC) antigens (HLA-A, -B and -C) was performed in 22 patients with Fuch's heterochromic cyclitis (FHC) and in a control group of 339 healthy subjects in order to ascertain whether there are any genetic factors that protect against or increase the risk of developing this disease. The frequency of only one HLA-antigen was found to differ significantly in the patients with FHC as compared with the normal subjects: HLA-A2 had a negative association with FHC (9.09% in FHC verus 47.47% in the control group; p < 0.01, Fisher's exact test with correction for the number of antigens studied) with an odds ratio of 0.11 (95% confidence limits 0.03 and 0.50). Other HLA antigens also showed a negative or positive association with FHC but not to a statistically significant level. Our results suggest a possible role for HLA genetic factors in the pathogenesis of FHC.

Gene Frequency↗
PubMed1994

Study of the retinal fiber layer in patients with acquired immunodeficiency syndrome.

A study using the monochromatic photography technique to examine the retina of a group of patients with human immunodeficiency virus (HIV) infections in different degrees of evolution and with no history of opportunistic retinal infection revealed the existence of lesions on the level of the retinal nerve fiber layer. The lesions detected included wide, slit-like defects; sector defects; and generalized diffuse atrophies. Both the sector defects and the diffuse atrophies appeared at times to be related to retinal cotton-wool exudates, but at other times they occurred in eyes with no observable retinal pathology. The results of this study can be interpreted as "in vivo" confirmations of the findings obtained by other authors in the postmortem study of optic nerves of patients with acquired immunodeficiency syndrome (AIDS), presenting a generalized degenerative process of the optic nerve with a loss of up to 40% of the axons of the retinal ganglion cells. In some cases, the results obtained in our study directly related the presence of cotton-wool exudates to the production of lesions in the retinal nerve fiber layer, whereas in other cases, the fiber lesions did not appear to be secondary to the cotton-wool exudates. Therefore, a primary lesion of the retinal ganglion cells or of the optic nerve fibers could be considered, as studies by other authors have suggested.

Acquired Immunodeficiency Syndrome↗
PubMed1993

[Surgical treatment combined with radiotherapy and chemotherapy in an unselected population of patients with malignant glioma].

BACKGROUND: Malignant gliomas are tumors of bad prognosis with a mean survival of 12 months. In the present report 74 patients diagnosed of malignant glioma were studied with the following aims: 1) evaluate how many could receive combined radiotherapy (RT) and chemotherapy (BCNU) treatment following surgery and 2) analyze whether the patients treated presented a survival similar to that described in the literature. METHODS: The records of 74 patients operated on for malignant glioma between 1987-1990 and consecutively included in a protocol of treatment with RT and BCNU were reviewed. RESULTS: Out of the total of 74 patients, 29 (39%) were considered evaluable. The medians of progression free interval and survival were of 10 and 16 months, respectively in these patients. Forty-five (61%) patients could not fulfill the protocol mainly because of tumoral progression prior to completion of RT and severe post surgical complications. The evaluable patients were significantly younger (p = 0.004) and tumoral exeresis wider (p = 0.0003) than in those who were not evaluable. CONCLUSIONS: Most of the patients operated on for malignant glioma may not receive treatment considered as standard, principally due to tumor progression in the first weeks following surgery and the presence of severe post surgical complications.

Adult↗
PubMed1993

A structural and evolutionary analysis of a dispersed repetitive sequence.

A family of dispersed repetitive sequences (Hch1) which is present in the genome of the wild barley Hordeum chilense was studied in detail. Hch1 sequences are found both as part of short tandem arrays and dispersed throughout the H. chilense chromosomes. Subcloning of sections of the sequence reveals that it is composed of unrelated classes of sequences which can also be found separately in other genomic locations. Analysis of these sequences in the genomes of wheat and two other wild barley species strongly suggests that specific amplifications and arrangements of the repeated sequences have taken place during speciation. Nucleotide sequence analysis fails to detect, in their entirety, the features shown by plant transposons.

Base Sequence↗
PubMed1991

[Digestive manifestations and metabolic acidosis secondary to intravenous administration of cotrimoxazol].

BACKGROUND: Digestive features and metabolic acidosis have been observed in patients with Pneumocystis carinii pneumonia treated with intravenous high dose co-trimoxazole. METHODS: To evaluate this phenomenon, a retrospective study of 22 patients (group A) and a prospective study of 12 patients (group B) were carried out. Group B patients were investigated following a protocol lasting for the 21 days of treatment. RESULTS: Metabolic acidosis developed in 23 (67%) of the overall number of study patients, and it was associated with digestive features such as nausea, vomiting and epigastralgia in 12. One patient had digestive features without metabolic acidosis. Metabolic acidosis developed early, between the days 4 and 7 of administration of the drug. The mean value of bicarbonate at the onset of therapy was 24,55 mEq; the mean value in the patients with metabolic acidosis was 16,43 mEq. The overall mean value of base excess at the onset of therapy was -2,39, and it was -8,46 in the patients who developed metabolic acidosis. CONCLUSIONS: As in all patients other causes of metabolic acidosis were ruled out, it became obvious that intravenous co-trimoxazole was directly related to the development of digestive features and metabolic acidosis, which disappeared with bicarbonate administration or with cessation of therapy.

Acidosis↗
PubMed1991

[Efficacy of sucralfate in the prophylaxis of diarrhea secondary to acute radiation-induced enteritis. Preliminary results of a double-blind randomized trial].

BACKGROUND: Pelvic radiation therapy is usually associated with intestinal symptoms, especially diarrhea. Sucralfate has been demonstrated to be effective in peptic ulcers, and seems to provide some benefits in chemotherapy induced mucositis and radiogenic rectitis and enteritis. METHODS: Thirty-four patients between 20-80 years of age, without diarrea and with a Karnofsky index greater than 60%, undergoing whole pelvic irradiation (46 Gy total dose, 2 Gy/day, 5 days/week) have been randomized to receive: sucralfate (1g/6h) (18 patients) or placebo (16 patients) during the treatment period and 3 weeks later. RESULTS: The statistical analysis of the clinical records show that patients receiving sucralfate do better during the whole treatment period (p = 0.03), and they need other complementary measures against diarrhea, as diet (p = 0.03) or pharmacologic support (p = 0.002), later in the course of the radiotherapy. Nevertheless, the incidence and severity of diarrea and other associated simptoms show no differences between both groups. CONCLUSIONS: Sucralfate increases the enteric tolerance during pelvic irradiation in cancer patients.

Acute Disease↗
PubMed1991

Dosimetry and use of an immobilization system for head and neck radiotherapy treatments.

The day-to-day reproducibility of planned radiotherapy treatment is an important precondition for achieving good clinical results and reducing toxic effects. This reproducibility is difficult to achieve in the irradiation of head and neck malignancies because of the mobility of this anatomical area. This paper presents a dosimetric study and analysis of the utility of a facial mask immobilization system prepared from an orthopedic glass-fiber bandage. The dosimetric study conducted on a lucite phantom shows that the interposition of one, two, or three layers of the bandage reduces the deep absorbed dose by about 1% at 0.5 cm2, while increasing the absorbed surface dose by 12% (for a field of 15 X 15 cm2 and one layer of bandage) to 46% (for a field of 5 X 5 cm and three layers of bandage). The dosimetric study conducted on a Rando Anderson manikin shows an average increase in the skin dose of about 8% and a maximum increase of about 20%. The good dosimetric results and the practicality of this system of immobilization have persuaded us to propose it as an alternative to the systems currently on the market, which, although rather more sophisticated, are also more expensive.

Head and Neck Neoplasms↗
PubMed1991

Catabolism of 3- and 4-hydroxyphenylacetic acid by Klebsiella pneumoniae.

Klebsiella pneumoniae catabolizes both 4-hydroxyphenylacetic acid and 3-hydroxyphenylacetic acid via meta-cleavage of 3,4-dihydroxyphenylacetic acid, ultimately yielding pyruvate and succinate. The organism can synthesize two hydroxylases catalysing 3,4-dihydroxyphenylacetic acid formation, which differ in substrate specificity, cofactor requirement, kinetics and regulation. Five enzymes sequentially involved in the catabolism of 3,4-dihydroxyphenylacetic acid are encoded on a 7 kbp fragment of the K. pneumoniae chromosome that has been isolated in a recombinant plasmid.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1990

Fractionated total body irradiation for bone marrow transplantation: clinical results on 66 patients.

Short term clinical results of bone marrow transplantation on 66 patients conditioned with fractionated total body irradiation (12 Gy in 6 fractions and 3 days) are presented here. An acute toxic effects incident, similar to that obtained previously, a 27.6% interstitial pneumonitis associated with acute severe graft versus host disease in 77% of cases, 19.2% relapses, and 41% total crude survival with an actuarial probability of surviving for more than two years of 46% for ALL, 64% for AML and 28% for CML, are the results obtained since now.

Adolescent↗
PubMed1989

Total body irradiation in bone marrow transplantation: fractionated vs single dose. Acute toxicity and preliminary results.

The usefulness of total body irradiation (TBI) plus chemotherapy as a preparative regimen prior to bone marrow transplantation has been widely documented. However, the procedure can be highly toxic. Fractionated and low dose rate TBI has been said to enhance therapeutic ratio by increasing normal tissue tolerance and increasing leukemic cell kill. We report here the acute toxic effects and preliminary results on 2 consecutively groups of patients, treated with bone marrow transplantation (BMT) for leukemia or multiple myeloma, and conditioned by 2 TBI regimens. Group A patients received 10 Gy-Co-60 single dose of TBI plus 120 mg/kg of cyclophosphamide over a period of 2 days (8 Gy lungs). Group B received 12 Gy Co-60 of TBI in 6 fractions (2/day), (8 Gy lungs) plus 120 mg/kg of cyclophosphamide over a period of 3 days. The acute toxic effects recorded were similar in both groups. Only a 40% vs 0% (P = 0.02) incidence of parotiditis in groups A and B favors fractionation. Other results obtained to date are as follows: an incidence of interstitial pneumonitis of 39% and 31% (ns); relapses of 10% and 20% (ns), and mortality of 55% and 60% for each group respectively. An interesting finding was that IP was associated with acute grade II-IV graft vs host disease in 87% and 100% of cases of group A and B, respectively. We conclude that fractionated TBI is at least as effective as single dose TBI as a conditioning regimen; however, only randomized trials would allow definitive conclusions.

Adolescent↗
PubMed1988

Partitioning behaviour in aqueous two-phase systems and fractionation by counter-current distribution of chick-embryo erythrocytes with numerical resolution of distribution curves.

The partition of chick-embryo and young-chick erythrocytes in dextran-poly-(ethylene glycol) two-phase systems depends on the interfacial tension and electrical potential differences between the phases. Counter-current distribution with charged 5% dextran-poly(ethylene glycol) systems has proved to be an adequate method for the separation of primitive and definitive erythrocytes present in chick embryos when a phase settling time of 20 min is used. The computer-aided numerical resolution of experimental curves has shown the existence of subpopulations which could not have been detected by using conventional methods.

Animals↗
PubMed1988

Lumbar microdiscectomy: analysis of 100 consecutive cases. Its pitfalls and final results.

100 consecutive microsurgically operated patients suffering lumbar prolapsed disc are analyzed in the present work. Three different groups have been distinguished. Under and over forty years of age, and patients operated on after chemonucleolysis failure. General results after all treatments have been 76% good result, 17% improvement and 7% worsening. Special remark should be given about the chemonucleolysis group, that has a highest worsening percentage which raises 25% of the group patients.

Adult↗
PubMed1987

Separation by counter-current distribution of young-chick erythrocyte populations and numerical resolution of distribution curves.

The presence of two red cell populations in young chicks has been demonstrated after increasing the settling time used during counter-current distribution with charged 5% Dextran--4% poly(ethylene glycol) two-phase systems. A Fortran program using statistical methods was applied to show the resolution in two peaks (with two or three subpopulations assumed) of the counter-current distribution curves.

Animals↗