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Biomedical subjects

C Robles

Publications and source records attributed to C Robles.

At least 19 recordsLinked to original sources
PubMed2003

Phenolic compounds content in Pinus halepensis Mill. needles: a bioindicator of air pollution.

Foliar phenol concentrations (total and simple phenols) were determined in Aleppo pine (Pinus halepensis Mill.) needles collected in June 2000, from 6 sites affected by various forms of atmospheric pollutants (NO, NO(2), NO(x), O(3) and SO(2)) monitored during two months. Results show an increase in total phenol content with exposure to sulphur dioxide and a reduction with exposure to nitrogen oxide pollution. p-Coumaric acid, syringic acid and 4-hydroxybenzoic acid concentrations increase with exposure to nitrogen oxide pollution, whereas gallic acid and vanillin decrease in the presence respectively of sulphur dioxide and ozone. This in situ work confirms the major interest of using total and simple phenolic compounds of P. halepensis as biological indicators of air quality.

Air Pollutants↗
PubMed2000

Infraspecific variability in the essential oil composition of Cistus monspeliensis leaves.

The leaf essential oils of Cistus monspeliensis plants growing wild on calcareous and siliceous soils in Provence (South of France) were analysed by GC and GC-MS. Qualitative and quantitative differences are noted in the essential oil composition between the Cistus populations from the two soil types. For chemotaxonomic purposes, a characterisation of the two types of oil is proposed.

France↗
PubMed2000

Cancer screening in the elderly population.

This article reviews the current state of knowledge regarding cancer screening in the geriatric population. Care of the elderly requires knowledge of underlying physiologic changes, comorbidities, quality-of-life factors, and life expectancies. There is always the danger that ageism may prevent elderly cancer patients from receiving the proper treatment. On the other hand, overzealous treatment can lead to adverse results if elderly patients are not properly targeted based on current evidence of the benefits and risks of specific screening practices.

Age Factors↗
PubMed2000

Low-dose cytarabine maintenance therapy vs observation after remission induction in advanced acute myeloid leukemia: an Eastern Cooperative Oncology Group Trial (E5483).

The Eastern Cooperative Oncology Group (ECOG) conducted a prospective phase III study in patients with relapsed/refractory acute myeloid leukemia (AML) to evaluate whether administration of repeated courses of low-dose cytarabine (LDAC) maintenance therapy after induction of complete remission in advanced AML would improve disease-free and overall survival. Patients with AML in second/later relapse or refractory disease were first treated with a combination of high-dose cytarabine and amsacrine. Those who achieved complete remission were then randomized to observation or to receive LDAC, 10 mg/m2 subcutaneously twice a day x2 21 days every 2 months until relapse occurred. Of 86 patients eligible for randomization, 41 patients were assigned to receive LDAC and 45 patients to observation. The median disease-free survival was 7.4 months for patients assigned to LDAC compared to 3.3 months for patients receiving no additional therapy, P= 0.084. The median survival from randomization was 10.9 months and 7.0 months for patients receiving LDAC maintenance chemotherapy and observation, respectively (P= 0.615). The data from this study suggest that LDAC maintenance therapy given to patients with advanced AML who achieve complete remission can increase disease-free survival compared to observation, but does not improve overall survival. Nevertheless, because of the ineffectiveness and toxicity of intensive post-remission chemotherapy in this circumstance, LDAC maintenance therapy, a tolerable outpatient regimen, offers the potential for improved quality of life.

Acute Disease↗
PubMed2000

Follow-up of transmission of hepatitis C to babies of human immunodeficiency virus-negative women: the role of breast-feeding in transmission.

BACKGROUND: The studies on hepatitis C virus (HCV) vertical transmission, the effect of potential risk factors and the role of breast-feeding have reported conflicting results. PATIENTS AND METHODS: Seventy-three infants of 63 anti-HCV-positive and anti-HIV-negative mothers were studied from 1993 to 1999 in the south of Spain. The mean period of follow-up in children was 29.2 +/- 19 months (range, 8 to 76 months); 6 (8%) children were lost to follow-up. Breast milk was studied for HCV-RNA in 68 samples of 35 mothers. RESULTS: Alanine aminotransferase was high in 19 (26%) and HCV-RNA was positive in 46 (63%) pregnant woman. Breast milk HCV-RNA was negative in nonviremic mothers and positive in 20% of the viremic mothers. The overall rate of vertical HCV transmission was 11.9% (n = 8) (95% confidence interval, 6 to 23%) if HCV-RNA was positive one or more times, but only 1.5% (n = 1) (95% confidence interval, 0.1 to 9%) if HCV-RNA was permanently positive. Seven HCV-infected children did not develop antibodies to HCV, and they had a spontaneous clearance of the virus. A 10-month-old baby was HCV-RNA-positive from birth to the end of the follow-up. The genotype in each of the infants was consistent with that of their mother. The rate of HCV transmission was higher for infants of mothers with higher HCV viremia (P < 0.01) and also for infants whose mothers were HCV-RNA-positive in breast milk (P < 0.05). There were no statistically significant differences between other risk factors. CONCLUSION: The presence of transitory viremia without seroconversion indicates that the vertical transmission of HCV is not important. This could be related to the viral charge and ingestion of milk of HCV-RNA-positive mothers. However, to advise avoidance of maternal breast feeding, it would be necessary to conduct larger studies.

Adult↗
PubMed1999

[In Process Citation]

This study focuses on how allelopathic mechanisms may be involved in the floristic composition and dynamics of Cistus albidus shrubbery. Allelopathic potential of essential oils was measured for Lactuca sativa (toxicity for other species) and Cistus albidus (self-toxicity). These oils have little effect on germination but significantly increase, even in low quantities, the number of unviable seedlings and inhibit normal seedling growth. These results explain, at least partially, the existence of monospecific stands over several years and the lack of natural regeneration of the Cistus albidus populations. Bioassays performed using natural aerial leachates of Cistus albidus revealed no significant effects on the above-mentioned parameters. Leaching does not seem to be an important means of allelochemicals release. Nevertheless, essential oils have been quantified in litter and soil, indicating a possible occurrence of allelopathy in such ecosystems.

Journal Article↗
PubMed1998

Low-dosage prophylactic vancomycin in central-venous catheters for neonates.

Neonatal infectious pathology remains one of the main causes of morbidity and mortality in this age group. The introduction of plasticized catheters for the administration of medication, fluidotherapy and parenteral nutrition was a significant advance in treatment of patients at risk, but also led to the appearance of infectious complications. Negative coagulase staphylococcus is the principal pathogen in most neonatal intensive care units. Recent studies have examined the prophylactic use of vancomycin in preterm babies receiving parenteral nutrition. We have evaluated the efficacy of this procedure, applied via the central venous catheters employed for all neonates, within the intensive care unit over a period of one year. Prophylactic vancomycin administered via the catheters significantly reduced the incidence of Gram-positive infections, despite the presence within this group of a greater number of septic risk factors than in the control group.

Anti-Bacterial Agents↗
PubMed1997

[High- and low-risk molecular sequences in autoimmune diseases. An analysis of type I diabetes in Latin America].

Type I diabetes is an autoimmune and a polygenic disease, in which MHC-class II genes contribute to 48% of the disease. The aim of the present study, is to provide a guideline to understanding the molecular association of these genes, through the immunogenetic analysis of 3 Latin american mestizo populations. We included 606 individuals, 349 patients with DMDI and 257 healthy controls coming from 3 geographical areas: Mexico City, Mexico; Caracas, Venezuela and Medellin, Colombia. The results clearly indicate that in mestizo groups, the diabetogenic haplotypes are from mediterranean ancestry, while protection is due to Amerindian genes. It was demonstrated that the relevant sequences for IDDM expression are located to DRB1 and DQB1 loci with a minimal contribution of DQA1 residues. The sequences determining peptide recognition and the induction of TH1 cells mediating the cellular autoimmune response are in positions DRB1-57 and 74 (an aspartic acid and a glutamic acid respectively, confer protection), modulated by D-57 in the DQ, 8 chain. These data show that DRB1-DQB1 haplotypes are central for IDDM expression and open new pathways for the disease management.

Adolescent↗
PubMed1994

New subdivision schema for the avian torus semicircularis: neurochemical maps in the chick.

Chemoarchitectonic subdivisions in the chicken torus semicircularis were mapped by means of acetylcholinesterase histochemistry and immunocytochemical labeling of leucine-enkephalin, choline acetyltransferase, neuropeptide Y, and calbindin/calretinin in adjacent sections. The torus semicircularis was found to consist of three main divisions: intercollicular area, toral nucleus, and preisthmic superficial area. All three appear variously subdivided. The intercollicular area is a mid-mesencephalic ventral periventricular region and appears subdivided into core and shell intercollicular regions. The toral nucleus is formed by a large caudal periventricular cytoarchitectonic complex, consisting of a periventricular lamina subdivided into core and shell regions, a pericentral, diffuse external nucleus, a central nucleus subdivided into core and shell regions, a caudomedial shell nucleus, a paracentral nucleus, and a posterior hiliar nucleus, apart from other minor parcellations. The preisthmic superficial area extends superficially at the caudomedial end of the toral nucleus, reaching the paramedian dorsal brain surface just rostral to the isthmo-optic nucleus. It is subdivided into core and shell regions. This previously unnoticed area is distinguished here from the intercollicular area and from the caudomedial shell and paracentral nuclei, all of which are frequently mixed in the literature under the concept "intercollicular nucleus." The revised terminology and subdivision for the avian torus clarifies many chemoarchitectonic and hodological mappings reported in the literature. It also suggests new research subjects and eliminates some causes of confusion.

Acetylcholinesterase↗
PubMed1993

Bronchogenic cancer in patients under 40 years old. The experience of a Latin American country.

Lung cancer in young patients is increasing in frequency, as documented by data from the United States, Canada, Japan, and European countries. However, to date and to our knowledge, there have not been any reports from Latin America on this topic. The published reports show that lung cancer in young patients is associated with smoking habit and family history of lung cancer. Its clinical course seems to be more aggressive than in older patients and the histologic type is less often squamous type. We describe 48 patients, aged 40 years or younger, who were diagnosed as having lung cancer in the Instituto Nacional de Cancerología from 1980 to 1990. The patients were equally divided between men and women. Smoking was documented for only 46 percent of the cases. The histologic type most frequently diagnosed was adenocarcinoma (N = 26) followed by squamous cell carcinoma (N = 12). Almost all the cases (46 cases) were staged IV according to the TNM classification. A group of 33 patients older than 40 years (56 to 82 years) were used for comparison. The differences in sex ratio that were higher for men in the elder (m/f, 2.7:1) were family history for cancer in six patients elder; positive smoking habit in all the aged patients (100 percent) compared with only 43.7 percent in the younger group; histologic type (26 adenocarcinomas and 4 squamous in the younger compared with 14 and 12, respectively, in the elder).

Adult↗
PubMed1987

Long-term results of praziquantel therapy in neurocysticercosis.

The long-term results of praziquantel therapy in 141 patients with neurocysticercosis are presented. Seventy-five patients (53%) were considered to be cured because the cysts or nodules disappeared or became calcified following praziquantel treatment and the patients were asymptomatic at the end of a 5-year follow-up period. An additional 35 patients (24.8%) improved clinically and radiographically. The intraventricular Cysticercus cysts of five patients in this group were not affected by praziquantel and had to be surgically removed. The remaining 31 patients (21.9%) were unchanged or became worse probably because, prior to therapy, Cysticercus larvae had caused tissue damage. The fact that praziquantel did not affect intraventricular cysts suggests a low concentration of the drug in the cerebrospinal fluid. Surgery continues to be an important tool in the treatment of cysticercosis to remove parasites that do not respond to praziquantel therapy as well as for the relief of intracranial hypertension.

Adolescent↗
PubMed1985

Endocrine and biochemical studies in a 46,XY phenotypically male infant with 17-ketosteroid reductase deficiency.

A 46,XY phenotypically male patient with 17-ketosteroid reductase deficiency is described. The patient was a 6-month-old infant who presented with micropenis and bilateral cryptorchidism. Baseline plasma levels of testosterone (T), delta 4-androstenedione (delta 4A), and 5 alpha-dihydrotestosterone (5 alpha-DHT) were within the normal range [patient: 0.17 (T), 0.12 (delta 4A), and 0.032 (5 alpha-DHT) ng/ml; normal infants: 0.03-0.55 (T), 0.14-0.45 (delta 4A), and 0.01-0.23 (5 alpha-DHT) ng/ml]. hCG administration induced a significant rise in plasma delta 4A levels (up to 8.39 ng/ml) and a slight increase in T and 5 alpha-DHT levels. The delta 4A/T ratios before and during the hCG challenge were 0.86 and 55.61, respectively (controls: 0.83 and 0.13). Incubation of genital skin-derived fibroblasts from the patient with either [3H]T or [3H] delta 4A revealed normal formation of delta 4A from T and diminished conversion of delta 4A to T. The development of a male phenotype despite both a testicular and peripheral 17-ketosteroid reductase deficiency is difficult to explain. It is possible that the fetal testes were the source of sufficient amounts of T during the early periods of embryonic life, and that late onset of the enzyme deficiency prevented the development of completely normal male genitalia. The in vitro finding of normal T to delta 4A conversion by the mutant fibroblasts suggests that in this particular tissue 17 beta-reduction and dehydrogenation of androgens are mediated by two isoenzymes with distinct substrate and/or cofactor specificities.

17-Hydroxysteroid Dehydrogenases↗
PubMed1981

[Coma states induced by craniocerebral injuries in children. Review of 20 cases].

From a total of three-hundred and fifty-six children admitted into the Department of Pediatrics at the Hospital Clínico of the University of Granada during of period of two years, twenty cases that needed admittance in critical pediatrics care unit are revised. Organic etiology that provoked coma, time of appearance, intensity, evolution, complications and short term outcome are analysed. A comparison is made of the incidences and prognosis of this type of coma with that of other authors presenting therapeutic outline carried. Two large evolutive groups; one which consisted of nine patients which entered into coma immediately after injury. The second group includes those patients which had lucid period before entering into coma. Following conclusions have been withdrawn: Severity and duration of coma does not have a definite relationship with the existence of a mass-lesion. Presence of an associated--mass-lesion is a sign of grave prognosis. For a good therapeutic response the following approaches are necessary: Immediate assistance monitoring and periodic or systematic maintenance of extracranial variants diagnostic, and treatment of the primary causing factor.

Brain Injuries↗