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Biomedical subjects

L Muñoz

Publications and source records attributed to L Muñoz.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Potential developmental toxicity of anatoxin-a, a cyanobacterial toxin.

Some 2000 species of cyanobacteria (blue-green algae) occur globally in aquatic habitats. They are able to survive under a wide range of environmental conditions and some produce potent toxins. Toxin production is correlated with periods of rapid growth (blooms) and 25%-70% of blooms may be toxic. Anatoxin-a is an alkaloid neurotoxin that acts as a potent neuro-muscular blocking agent at the nicotinic receptor. Acute toxicity, following consumption of contaminated water, is characterized by rapid onset of paralysis, tremors, convulsions and death. Human exposures may occur from recreational water activities and dietary supplements, but are primarily through drinking water. The current studies were conducted to examine the effect of in utero exposure on postnatal viability, growth and neurodevelopment, to evaluate the potential of in vitro embryotoxicity, and to explore the synergistic relationship between anatoxin-a and the algal toxin microcystin-LR by the oral route. The results of preliminary studies on amphibian toxicity are also reported. Time-pregnant mice received 125 or 200 microg kg(-1) anatoxin-a by intraperitoneal injection on gestation days (GD) 8-12 or 13-17. Pup viability and weight were monitored over a 6-day period. Maternal toxicity (decreased motor activity) was observed at 200 microg kg(-1) in both treatment periods. There were no significant treatment-related effects on pup viability or weight on postnatal day (PND) 1 or 6. The GD 13-17 pups were evaluated on PND 6, 12 and 20 for standard markers of neurodevelopmental maturation (righting reflex, negative geotaxis and hanging grip time). No significant postnatal neurotoxicity was observed. In vitro developmental toxicity was evaluated in GD 8 mouse embryos exposed to 0.1-25 microm anatoxin-a for 26-28 h. Perturbations in mouse yolk sac vasculature were noted from the 1.0 microm concentration in the absence of significant embryonic dysmorphology. Potential algal toxin synergism was tested in mice receiving either 0, 500 or 1,000 microg kg(-1) microcystin-LR by gavage and approximately 50 min later receiving either 0, 500, 1,000 or 2,500 microg kg(-1) anatoxin-a by the same route. No deaths occurred at any dose and no definitive signs of intoxication were observed. Stages 17 and 25 toad embryos (Bufo arenarum) were exposed to 0.03-30.0 mg l(-1) of anatoxin-a for 10 days. Adverse effects included a dose-dependent transient narcosis, edema and loss of equilibrium. Most notable was the occurrence of 100% mortality at the high dose in both groups 6-13 days post-exposure. The observed delay between initial exposure and death is highly unusual for anatoxin-a.

Animals↗
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Rod myopathy with extensive systemic and respiratory muscular involvement.

A patient with both muscle weakness and progressively degenerating respiratory function became increasingly less responsive to therapeutic intervention. The diagnosis of the muscle disease was made through biopsy samples and confirmed as rod myopathy. Through autopsy samples, the patient was found to have had extensive centriacinar emphysema and widespread involvement of rod disease in the skeletal muscles. The most involved of the muscles sampled (anterior tibial, brachioradialis, rectus femoris, psoas, diaphragm, biceps) was the diaphragm. While the influence on diaphragmatic function has been reported in the juvenile form of rod disease, this is the first known report of the extensiveness of involvement in adult-onset disease. The diseased state of the diaphragm was appreciated as a contributing factor to the respiratory insufficiency.

Adult↗
PubMedDate not supplied

[Clinical and prognostic heterogeneity in Aicardi's syndrome: a description of two cases].

INTRODUCTION: Aicardi's syndrome is characterized by infantile spasms, agenesis of the corpus callosum and ocular lesions. Clinically it presents as severe mental retardation, severe limitation of motor development and of language, with a prognosis of survival for only a few months or years. We present two new cases of this uncommon syndrome and describe the heterogeneity of its clinical and prognostic severity. CLINICAL CASES: Case 1. A ten-month old patient had flexion spasms of the limbs at the age of 4 months, bilateral corioretinal lesions and generalized hypoplasia of the corpus callosum. During the clinical course of the disorder, the epileptic crises were controlled, there was mental retardation, the head was held steady and the baby could sit. Case 2. A nine year old patient had had flexion spasms when aged 2 months, had bilateral retinal lesions and generalized hypoplasia of the corpus callosum. During his clinical course the epileptic crises were controlled, there was severe mental retardation, the patient could pay attention and collaborate, articulate single words, walk on his own and manipulate objects. CONCLUSION: Aicardi's syndrome should be considered to be a syndrome in which the clinical findings and prognosis are heterogeneous, as seen from new cases with less clinical and functional limitation than the patients first described.

Agenesis of Corpus Callosum↗
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[Complementary chemotherapy of breast cancer; experience at the University Clinic of Navarra].

From 1982 to 1989, 68 patients were treated with the diagnosis of breast cancer. 57 were premenopausal and 11 postmenopausal. The most frequent stage was T2N1 (44.1%) followed by T1N1 (20.6%). The mean dosage of chemotherapy given were 91.2% for cyclophosphamide, 88% for methotrexate and 94% for 5-fluorouracil. The treatment was well tolerated and the most frequent toxicity encountered was leukopenia. The disease free survival were 89.4% at 96 month for premenopausal and 63.3% at 68 month for postmenopausal. We have not seen any differences in the disease free survival in relation to the size of the tumor or the status of the hormonal receptors of the tumor. The most important prognostic factor were the number of positive axilar nodes affected and the dosage of chemotherapy.

Adult↗
PubMedDate not supplied

[Discordance in the anatomy of the bronchial tree and atrial appendages].

It is well known, that in complex congenital heart disease, the bronchial anatomy reflects the atrial situs in the majority of patients. Few exceptions to this rule have been reported in the literature. We report four patients in whom we found discordance between the anatomy of the bronchial tree and the external aspect of the atrial appendages. Two patients had bronchial situs solitus with atrial levoisomerism, the third patient had bronchial levoisomerism with atrial situs solitus and in the fourth one we found inverted bronchial anatomy with levoisomerism of the atrial appendages. In three patients, broncho-atrial discordance was diagnosed clinically by bronchial tomography and selective atrial angiography, and in the other one the diagnosis was made by anatomical study. In this last patient, external atrial anatomy was found to be of levoisomerism, with an internal atrial aspect of situs inversus. Prediction of atrial arrangement by bronchial anatomy retains its diagnostic value. However, it is necessary to bear in mind that exceptions do exist. It is discussed how to suspect these exceptions, and the final diagnostic conduct is indicated.

Bronchi↗
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Papillary cystic neoplasm of the pancreas. Two cases treated by surgery.

The papillary cystic neoplasm of the pancreas is a rare tumor. Two cases are presented, one of a 38-year-old man and the other of a 23 year-old woman. Both had mild upper abdominal symptoms and were successfully resected with a distal pancreatectomy. Forty-five well documented cases informed in the literature are reviewed. The neoplasm has a striking preference for young women and a relatively benign course with only 10% of the reported cases presenting recurrence or distant metastases.

Adult↗