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Biomedical subjects

L Sierrasesúmaga

Publications and source records attributed to L Sierrasesúmaga.

At least 19 recordsLinked to original sources
PubMed2004

[Vascular malformations as syndromic markers].

Vascular malformations are static lesions, generally present at the moment of birth, formed by displasic vessels that grow in proportion to the growth of the child. They show normal cell replacements that constitute genuine mistakes of morphogenesis. The absence of regression of these malformations implies that they remain throughout the lifetime. The terminology describing this type of lesions gave rise to confusion in the medical literature until the International Society for the Study of Vascular Anomalies adopted a classification based on the dominant vessel of the malformation in 1996. This classification distinguishes between simple and complex forms depending on whether they affect one or several types of vessel. Vascular malformations can show themselves as isolated lesions or can be associated with other lesions, constituting the guide sign or being the principal marker of some syndromic complexes. This paper describes the principal signs and symptoms of those syndromes in which a vascular malformation is the key that raises suspicion about the existence of other associated lesions.

Blood Vessels↗
PubMed2001

Transient posterior encephalopathy induced by chemotherapy in children.

The cases of three children, 16, 12, and 12 years of age, who suffered sudden confusional state and cortical blindness lasting 12 to 30 minutes while under treatment with high-dose methotrexate, cyclophosphamide, and dactinomycin for a lower limb osteosarcoma are reported. Transient neuropsychologic deficits arose after the acute phase of treatment: left hemispatial neglect and constructive apraxia (Patient 1); constructive apraxia (Patient 2); and constructive apraxia and alexia without aphasia (Patient 3). The three patients recovered completely from all their deficits within the time frame of 3 hours to 2 weeks. Arterial hypertension and hypomagnesemia were found during the acute phase in all patients. In Patients 2 and 3, magnetic resonance imaging revealed increased parieto-occipital T(2) signal involving gray and white matter. In Patients 1 and 2, HmPAO-SPECT revealed parieto-occipital hypoperfusion that resolved a few days later. The alterations detected by neuroimaging were concurrent with the appearance and disappearance of the clinical symptoms. Such transient acute episodes have been named occipital-parietal encephalopathy. On the basis of our clinical, laboratory, and neuroimaging findings, an explanation for the origin of this syndrome, a migrainelike mechanism, triggered by chemotherapy-induced hypomagnesemia, is proposed.

Acute Disease↗
PubMed2000

Nonclonal chromosomal aberrations induced by anti-tumoral regimens in childhood cancer: relationship with cancer-related genes and fragile sites.

Cytogenetic studies were performed on 80 pediatric cancer patients to observe the chromosomal damage, both quantitative and qualitative, induced by chemotherapy. Peripheral blood lymphocytes (PBL) (n = 127) were obtained at diagnosis, during treatment, at remission, and at relapse, and chromosome analysis performed utilizing G-banding standard procedures. The results show a significant increase in the number of altered karyotypes (P = 0.03) in the samples during treatment, returning to values that were similar to those at diagnosis at 2-year remission. Most of the chromosomal aberrations (CA) detected during the chemotherapy regimens were nonclonal, unbalanced (75%), and involved chromosomes 1, 3, 5, 6, 11, 12, 16, and 17 most frequently. There was also a marked increase of CA in samples at relapse with very similar features (type and distribution) to those detected during treatment. There was a good correlation between the chromosomal breakpoints in our series and fragile sites (58%), oncogene (75%), and tumor suppressor gene (33%) loci described in the literature. The results obtained suggest that cytostatic drugs induce a transient increase in chromosome fragility occurring at several cancer-associated breakpoints.

Antineoplastic Agents↗
PubMed1999

Screening of the human tumor necrosis factor-alpha (TNF-alpha) gene promoter polymorphisms by PCR-DGGE analysis.

We have designed a new PCR-DGGE technique that enables detection of base changes in the TNF-alpha gene promoter. Screening of 130 samples from Spanish children has shown that this technique accurately detects the altered band patterns induced by the presence of the polymorphisms at positions -376, -308, -238 and -163 of the promoter sequence. Although further analysis are needed to fully characterise the alterations detected, we believe that this PCR-DGGE technique is a rapid and sensitive first approach to the genetic characterisation of the TNF-alpha promoter.

Child↗
PubMed1999

Combined surgical approach for sarcoma lung metastasis with atrial involvement.

A 20-year-old patient, who had been treated for a femur sarcoma with pulmonary metastases 8 years before, arrived at our institution with a new metastatic hilar lung nodule. During the standard lobectomy procedure an unexpected atrial invasion by the tumor was discovered. Intraoperative transesophageal echocardiography (TEE) showed a big pediculated tumor in the atrium. Cardiopulmonary bypass (CPB) was required in order to safely resect the atrial wall with the tumor. The atrial defect was repaired with a pericardial patch. Postoperative course was uneventful. After 14 months, the patient is asymptomatic and free of disease.

Adult↗
PubMed1998

Recombinant human erythropoietin for the treatment of anemia in children with solid malignant tumors.

BACKGROUND: Cancer is often associated with chronic anemia which frequently requires blood transfusions. This study was performed to assess the efficacy and safety of r-HuEPO therapy in children with cancer. PATIENTS AND METHODS: Twenty-five patients under 18 years of age with solid malignant tumors were treated with 150 U/kg/day of r-HuEPO 5 times weekly for 12 weeks. Response was defined as an increase of the baseline hemoglobin level by at least 2 g/dl. r-HuEPO patients were compared to 25 matched historical controls. RESULTS: Response was achieved in 72% of r-HuEPO patients. Hemoglobin level increased from 9.8 +/- 0.6 g/dl at baseline to 12.4 +/- 1.7 g/dl at the end of treatment in the r-HuEPO group and increased from 9.5 +/- 0.7 g/dl to 9.6 +/- 1.4 g/dl in the control group (P < .001, Student's t-test). Only 16% of patients receiving r-HuEPO required blood transfusions vs 96% of control patients (P < .001, Student's t-test), with mean units of blood transfused per patient being 0.35 in the r-HuEPO group and 3.56 in controls (P < .001, Student's t-test). There was a statistically significance improvement in Karnofsky's index in r-HuEPO patients. No adverse reaction related to r-HuEPO therapy was observed. CONCLUSIONS: r-HuEPO is a safe and effective means of increasing hemoglobin level and reducing blood requirements in children with solid malignant tumors receiving chemotherapy.

Adolescent↗
PubMed1998

Molecular features in a biphenotypic small cell sarcoma with neuroectodermal and muscle differentiation.

We report a case of a 13-year-old girl with soft tissue sarcoma of the hand, which showed muscle and neuroectodermal immunophenotypes. Molecular studies were performed on RNA collected from fine-needle aspiration (FNA) cytology and peripheral blood samples by nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. This biphenotypic tumor showed simultaneous expression of EWS-FLI1 and PAX3-FKHR transcripts, specific of Ewing family tumors and alveolar rhabdomyosarcoma, respectively. Although childhood sarcomas with simultaneous muscle and neural differentiation have been described to have EWS-FLI1 transcripts, there are no reports of tumors with both transcripts. Cytological specimens are a good source of RNA for molecular studies.

Adolescent↗
PubMed1998

Ewing family tumors: potential prognostic value of reverse-transcriptase polymerase chain reaction detection of minimal residual disease in peripheral blood samples.

In more than 95% of patients, the Ewing family of tumors (ET) has chimeric transcripts caused by fusion of the EWS gene to either FLI1 or ERG. The presence of specific EWS-FLI1 or EWS-ERG transcripts in peripheral blood (PB) samples of patients being treated for ET was prospectively evaluated, and these data were correlated to their clinical status. The authors studied 113 PB samples from 28 patients with ET. Treatment included chemotherapy, radiotherapy, and surgical excision of tumor after induction therapy. PB samples were taken prospectively at least 2 weeks after resection of tumor. Nested reverse-transcriptase polymerase chain reaction (RT-PCR) followed by Southern blot was performed in all samples. Resected tumors were reviewed for the degree of response to chemotherapy and volume. Seventy-seven PB samples from 28 patients had EWS-FLI1/ERG transcripts. In 11 patients, PB samples became negative with treatment, and, in 5 of them, the samples remained negative throughout the study. Samples taken during progression were always positive and, in 4 patients, became positive before progression was clinically evident. All patients with transcripts other than EWS-FLI1 type 1 (n = 3) died from tumor progression. This is a sensitive assay to monitor circulating tumor cells in Ewing tumors. The preliminary data suggest that progression is preceded by positive samples and may be related to specific transcript types.

Adolescent↗
PubMed1998

Differential polymerase chain reaction: a technical comparison of three methods for the detection of CDK4 gene amplification in glioblastomas.

Among the different techniques used to detect oncogene amplification in tumor DNA, Southern blot and differential PCR have been the most frequently used. We report on a technical comparison of three different methods to detect gene amplification by differential PCR: ethidium bromide staining, silver staining (both after standard differential PCR), and fluorescent differential PCR. We explored the relative densitometric measure of a 119 bp fragment of the CDK4 gene versus an 82 bp fragment of the IFNG gene. In total agreement with previous studies carried out by Southern blot and differential PCR by other authors, we were able to detect CDK4 amplification in 3 of the 21 glioblastomas (14%), but only by the fluorescent differential PCR method. In conclusion, fluorescent differential PCR is more sensitive than standard differential PCR for detection oncogene amplification in tumor DNAs.

Brain Neoplasms↗
PubMed1997

Analysis of the p16INK4 and TP53 tumor suppressor genes in bone sarcoma pediatric patients.

Recent data suggest that deletion of p16INK4 and mutation of TP53 are among the most common genetic events in the development of human cancer, since the codified proteins act as brakes of the abnormal cell cycle. As the molecular events leading to the development of pediatric bone sarcomas remain unclear, we analyzed 75 osteosarcoma and Ewing sarcoma samples from 43 pediatric patients to search for alterations at the TP53 or p16INK4 tumor suppressor genes. By means of PCR-DGGE (polymerase chain reaction and denaturing gradient gel electrophoresis) we detected TP53 point mutations in 18.6% of the tumor samples, but no constitutional mutations. In the analysis of p16INK4, 7% of the samples harbored deletions of the gene but no point mutations were detected by SSCP (single strand conformation polymorphism) analysis, just the polymorphism Ala-->Thr at codon 148. These data support the hypothesis that TP53 alterations may play a role in the development of pediatric bone tumors and that the primary mechanism of inactivation of p16INK4 seems to be homozygous deletion rather than point mutation.

Bone Neoplasms↗
PubMed1997

Growth and growth hormone secretion in children with cancer treated with chemotherapy.

OBJECTIVE: To evaluate the effect of chemotherapy on growth and growth hormone (GH) secretion. METHODS: We analyzed growth and GH secretion in 60 children in complete remission after treatment by chemotherapy and surgery for malignant solid tumors. None of them received cranial radiotherapy. Growth hormone reserve was assessed by at least two stimulation tests (clonidine, L-dopa, growth hormone-releasing hormone). In 12 children the reserve of GH pretreatment was also evaluated. RESULTS: Growth hormone deficiency (GHD) was observed in 27 of 60 patients (45%). At diagnosis, mean standing height was +0.23 +/- 0.11 standard deviation score (SDS) in the GHD group and +0.16 +/- 0.10 SDS in the non-GHD group. After chemotherapy, mean standing height in the GHD group was -0.28 +/- 0.15 SDS and -0.14 +/- 0.11 in the non-GHD group (p < 0.05), and the growth rate was +0.13 +/- 0.07 SDS in the GHD group and +0.22 +/- 0.18 SDS in the non-GHD group. For a mean follow-up of 30 months, the mean standing height was -0.46 +/- 0.29 SDS in the GHD group and -0.24 +/- 0.16 SDS for the non-GHD group (p < 0.05), and the growth rate was -0.27 +/- 0.19 SDS in the GHD group and -0.16 +/- 0.12 SDS in the non-GHD group (p < 0.05). The GH response to clonidine was significantly less than that found with the other stimuli. There was correlation between the dose intensity of some drugs and the subsequent GH response to stimulation tests. The GHD group was found to have received significantly higher doses of actinomycin D than the non-GHD group (p < 0.05). Growth impairment and GHD were not found to be correlated with duration of treatment and follow-up, tumor type, sex, or age. CONCLUSIONS: Chemotherapy as the sole form of treatment in children with cancer interferes with growth. The observed impairment of growth depends, at least in part, on a GHD related to chemotherapy. The growth rate in conjunction with the GH response to clonidine provides a sensitive measure of GHD associated with chemotherapy.

Adolescent↗
PubMed1996

Megestrol acetate therapy for anorexia and weight loss in children with malignant solid tumours.

BACKGROUND: Malnutrition is very frequent in childhood cancer. Its main cause is inadequate intake for energy demands owing to lack of appetite. Megestrol acetate is a synthetic progestin that has been used for reversing anorexia in adult cancer. OBJECTIVE: To assess megestrol acetate efficacy and side-effects in treating anorexia in childhood cancer. METHODS: Thirty-five children with solid tumours were receiving antitumour therapy. Nutritional assessment was by anthropometry. Megestrol acetate efficacy was assessed by evaluating grade of appetite, energy intake and well-being. Side-effects were evaluated by means of clinical history, physical examination, lipid profile, coagulation tests and cortisol rhythm. RESULTS: When compared to baseline all the anthropometric measurements increased (P < 0.05) from the first month of megestrol acetate therapy, as well as appetite and energy intake. No significant side-effects were found. CONCLUSION: Megestrol acetate therapy is a powerful appetite stimulant which led to weight gain, composed of both fat mass and fat-free mass. Megestrol acetate is well tolerated, with few and mild side-effects. If megestrol acetate therapy is started at the onset of anorexia, the use of more expensive, invasive and complicated techniques of nutritional support may be avoided.

Adolescent↗
PubMed1995

Chemotherapy-induced growth hormone deficiency in children with cancer.

BACKGROUND: Chemotherapy (CT) may produce growth impairment, however, the pathogenesis is still unclear. METHODS: A series of 25 patients mean age 13.3 years (6.3-19.8), previously treated for malignant solid tumours with only CT and surgery were studied. Growth hormone (GH) reserve was assessed by two different provocative stimuli (Clonidine and L-Dopa). Mean time between completion of treatment and GH evaluation was 18.5 months (2-74 months). At that time, all patients were in complete remission. RESULTS: GH deficiency (GHD), defined by an impaired GH response to both provocative tests was observed in 11 out of 25 patients (44%). At diagnosis, mean standing height was +0.23 +/- 1.42 SDS in the GHD group (GHD-g) and +0.18 +/- 1.23 SDS in the non-GHD group (n-GHD-g). At the end of therapy, the mean standing height in the GHD-g was -0.31 +/- 1.22 SDS and -0.17 +/- 1.41 in the n-GHD-g, differing from the former group (P = 0.05). For a mean follow-up of 30 months from the end of treatment, the mean standing height was -0.48 +/- 1.23 SDS in the GHD-g and -0.24 +/- 1.51 SDS for the n-GHD-g (P = 0.03). Growth rate at the end of treatment was +0.13 +/- 1.54 in the GHD-g and +0.21 +/- 1.75 in the n-GHD-g. For a mean follow-up of 30 months from the end of treatment, the growth rate was different between GHD-g and n-GHD-g (-0.31 +/- 2.72 vs. -0.21 +/- 1.93, P < 0.05). CONCLUSIONS: 1) Growth impairment in children treated because of malignant diseases has a multifactorial etiology, but CT-induced GH deficiency is one potential adverse factor. 2) An endocrine follow-up should be introduced in order to detect and treat hormonal deficiencies as early as possible.

Adolescent↗
PubMed1995

Mutational activation of ras genes is absent in pediatric osteosarcoma.

Activation of ras oncogenes is found in human cancers; overall it is observed in 15% of all neoplasms. The purpose of this study was to assess the extent of involvement of ras oncogenes in osteosarcoma. Tumor samples from a series of 49 pediatric patients diagnosed with osteosarcoma and treated at our institution were evaluated. Paraffin-embedded tumor samples from diagnostic biopsies, from tumor en bloc resection tissue after neoadjuvant chemotherapy, and samples from metastases were examined in search of point mutations in H, K, and N-ras genes at codons 12 and 61 by means of polymerase chain reaction (PCR), slot-blotting, and radioactive labeled specific DNA probes. A total of 92 archival samples were studied. No point mutations activating these genes were found. These findings suggest that the activation by point mutations at codons 12 and 61 of the H, K, and N-ras genes does not play a role in the pathogenesis of human osteosarcoma. Since no point mutations in codons 12 and 61 were detected, it was not possible to establish any correlation between the ras genes and clinical or histologic findings.

Base Sequence↗