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Biomedical subjects

E Thomas

Publications and source records attributed to E Thomas.

At least 271 records · Page 15Linked to original sources
PubMed1992

Rapid development of giant aneurysm at the base of the brain in an 8-year-old boy with perinatal HIV infection.

An 8-year-old boy with perinatal HIV infection developed a large fusiform aneurysm in the circle of Willis two years prior to death which was confirmed by radiological studies. The postmortem examinations revealed a predominantly intimal, proliferative lesion, and partial destruction of the internal elastic lamina in the involved arteries. Within the intima hyperplasia of fibroblasts and smooth muscle cells was observed. No inflammatory alterations, no granulomas and no multinucleated giant cells could be noted in the vascular walls and in the cerebral parenchyma. A small ischemic infarct was present in the left thalamus. Cerebellum, brainstem and medulla showed multiple areas of progressive multifocal leukoencephalopathy (PML). Immunohistochemistry with anti-gp41, a monoclonal antibody against HIV envelope did not exhibit any positive results. These findings implicate that the vascular lesion might be attributed to primary infection of the brain by HIV which led to a defect of elastic lamina and consecutive intimal hyperplasia. A second hypothesis could be based on the effect of extremely high dose AZT therapy avoiding inflammatory reaction after HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Serum and erythrocyte magnesium concentrations and migraine.

Most people suffering from migraine present a hypersensitivity of the cervico-facial muscles, which may be linked to magnesium deficit. This paper describes a comparative study of serum and erythrocyte magnesium levels in 79 migraine patients and 55 controls. Serum magnesium did not differ significantly in either group, but some values were quite low. On the other hand, there was a significantly greater erythrocyte magnesium deficit in persons suffering from migraine than in controls (in both female and male subjects). This fact correlates with the improved state of migraine patients (already ascertained in earlier studies) following treatment consisting of the intake of magnesium-rich water. The findings support the hypothesis of a magnesium deficit in people suffering from migraine and raise the problem of the relationship between migraine and other pathologies, including chronic magnesium deficit, latent tetany due to magnesium deficit, mitral valve prolapse, and allergy.

Adolescent↗
PubMed1992

Difficult intubation: a prospective study.

Difficult intubation has been much discussed in the anaesthetic literature. The incidence of difficult intubation (11:560) was higher in obstetric patients (6:277) as compared to gynaecological patients (5:283) in our hospital. We tested the Mallampati's classification as a predictor of difficult intubation in 277 obstetric and 283 gynaecological patients. We recommend that Mallampati's classification can be used reliably (p less than 0.05) to predict difficult intubation in obstetric but not in gynaecological patients.

Adolescent↗
PubMed1992

Papillitis and the postcholecystectomy syndrome.

The importance of papillitis as a disease entity capable of producing significant symptoms is not well appreciated. Presenting symptoms are usually pain or cholestasis. The cholangiographic appearance of papillitis may mimic that of papillary tumor and small distal common bile duct stone; endoscopic papillotomy (EPT) with biopsy may help clarify the diagnosis. In patients with delayed drainage, EPT may be therapeutic. Two cases of papillitis that presented as difficult diagnostic and therapeutic problems are reported.

Ampulla of Vater↗
PubMed1992

A small proteoglycan isolated from human cartilage containing a nonfunctional hyaluronic acid binding region.

A low buoyant density fraction (A4) was isolated from human cartilage by CsCl density gradient ultracentrifugation. This fraction contained a hydrodynamically small proteoglycan (Kav, 0.74 on Sepharose CL-2B) that reacted with monoclonal antibody 12/20/1C6 specific for the hyaluronic acid binding region (G1 globe) of the large aggregating high-density proteoglycan isolated from many animal cartilages. Despite the presence of the hyaluronic acid binding region, this small proteoglycan did not form proteoglycan aggregates with hyaluronan, not even in the presence of link protein.

Binding Sites↗
PubMed1991

Septal unit activity during classical conditioning: a regional comparison.

Single unit activity was recorded from the lateral and medial septum of rats during aversive Pavlovian differential conditioning. One conditioned stimulus (CS+) was consistently paired with and another (CS-) was explicitly unpaired with a brief shock unconditioned stimulus (US). In the lateral septum single unit activity generally increased in the presence of a conditioned inhibitor of fear (CS-), while unit activity generally decreased in the presence of a conditioned excitor of fear (CS+). Responses in the medial septum were more heterogeneous. Many cells did not show plastic changes to the CSs, others showed responses to the conditioned stimuli opposite to that seen in the lateral septum. A small group of cells showed responses similar to that seen in the lateral septum. Finally, theta bursting cells were seen in the medial septum with some evidence of increased theta activity in the presence of a conditioned inhibitor of fear (CS-). The results were interpreted as consistent with the proposition that the lateral septum mediates the inhibition of aversive emotional states. The medial septum may have some involvement with the activation of fear or anxiety.

Action Potentials↗
PubMed1991

A computational model of the vertical anatomical organization of primary visual cortex.

A method for modeling anatomical connectivity for a vertically organized slab of cortical tissue in mammalian primary visual cortex has been developed. The modeled slab covers 500 x 500 microns of cortical surface and extends vertically throughout the full depth of the cortex. The model slab was divided into 6 laminae and neuronal somata were distributed in three dimensions through the slab in accordance with experimentally derived cell densities. Axonal and dendritic arborizations were modeled as line segments. A total of 17 morphological types of neurons were included. Connectivity was established based on proximity between axonal and dendritic arbors. There is good general agreement between the vertical distribution of connections generated by the model and the vertical distribution of synapses observed for cat area 17. In all layers, fewer connections were generated in the model than synapses in cat area 17. This is due, at least in part, to the exclusion of long range intracortical projections and sources of afferent input other than the dorsal lateral geniculate nucleus from the model. The connection scheme described here will be used in conjunction with a physiology model to model vertical signal flow, and will be expanded further to model receptive fields of cortical neurons.

Afferent Pathways↗
PubMed1991

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) lyase deficiency in Saudi Arabia.

Deficiency of 3-hydroxy-3-methylglutaryl-CoA lyase has been studied in 11 Saudi infants. The diagnosis was established by the measurement of enzyme activity in lymphocytes, in fibroblasts and, in seven patients, by the gas chromatography/mass spectrometer pattern of excreted organic acids in the urine. In seven infants the disease caused a devastating acidotic attack within the first day of life, while in two the crisis occurred by the third day of life. In two infants from one family the disease appeared later in infancy. The clinical presentation of an acidotic attack is lethargy, hyperpnoea, tachypnoea and seizures, either at birth (two infants), following first feeding (in five infants), or following vomiting or refusal of food in later infancy. The acidotic attacks recurred later in life following minor illness or refusal to eat. The acidosis of this enzyme deficiency progresses rapidly, leading to cardiopulmonary arrest and death within hours of onset unless treated promptly. In four surviving infants diagnosed and treated early, development is normal. Magnetic resonance and computerized tomography brain scans in these infants, however, show white matter lesions and mild atrophy.

Acidosis, Lactic↗
PubMed1991

Anxiolytic effects of benzodiazepines in amygdala-lesioned rats.

The role of the amygdala in the anxiolytic action of benzodiazepines was examined. Performance on a water-licking conflict paradigm was tested in rats with localized damage to the central nucleus of the amygdala (ACE) or with general damage to the entire amygdaloid complex. The effects of the benzodiazepine chlordiazepoxide (2.5-20.0 mg/kg) on conflict behavior in these animals was also examined. Electrolytic lesions of either ACE or of the entire amygdaloid complex resulted in a pronounced increase of punished responding, an effect that persisted for at least 12 sessions postoperatively. After shock levels were adjusted in the lesioned groups to match their baseline punished behavior to that of the controls, various doses of chlordiazepoxide were administered. Not only did the lesioned animals show an increase in punished behavior in response to the drug, they were more sensitive than controls to the lower drug doses. A complete model of anxiolytic action may have to include both mechanisms that block anxiogenic regions and those that activate anxiolytic regions.

Amygdala↗
PubMed1991

Mercuric chloride-induced inhibition of different ATPases in the intestine of mudskipper, Boleophthalmus dentatus.

This paper deals with the toxicity of mercuric chloride to different ATPases in the intestine of mudskipper (Boleophthalmus dentatus). Mudskippers were exposed to four sublethal concentrations of mercuric chloride for three durations. The specific activities of Na+, K(+)-ATPase, Ca(2+)-ATPase, Mg(2+)-ATPase, Ca2+, HCO3(-)-ATPase, and Mg2+, HCO3(-)-ATPase were estimated. There was linear inhibition of all the enzymes with increasing mercuric chloride concentration as well as exposure duration. The Na+,K(+)-ATPase was found to be the enzyme most affected, followed by other ion-dependent ATPases. Inhibition of all the enzymes indicates severe damage to the intestinal cells, resulting in a blockage of the transport of substances across the membrane.

Adenosine Triphosphatases↗
PubMed1991

Peptic ulcer disease. How to treat it now.

Options for treatment of peptic ulcer disease are becoming more diverse. Most new agents are effective yet offer no real advantage over more traditional therapy. However, omeprazole (Prilosec) may be of benefit owing to its potent inhibition of acid secretion, but it is not yet approved for this purpose. Whether treatment of Helicobacter pylori infection will prove beneficial is not yet known, but the answer should be forthcoming. Finally, as with any disease process, alleviation of risk factors is always important. Appropriate counseling regarding use of nonsteroidal anti-inflammatory drugs and cigarette smoking is a necessity.

Anti-Ulcer Agents↗
PubMed1991

Significance of CSF immunoglobulins in monitoring neurologic disease activity in Behçet's disease.

We examined the intrathecal production of immunoglobulins (Ig) G, A, and M in 16 patients with Behçet's disease, 13 of whom have CNS involvement, and in 40 neurologic controls. Oligoclonal IgA and IgM bands were mainly detected in CSF samples from patients with active neuro-Behçet's disease and were documented to disappear when neurologic manifestations remit. Oligoclonal IgG bands, however, were not related to disease activity and were also found in some neurologic controls. High immunoglobulin index values were detected in both active and quiescent diseases and were high in some patients with impaired blood-CSF barriers. The study presented here demonstrates that CSF oligoclonal IgA and IgM may be helpful in monitoring CNS disease activity in neuro-Behçet's and could be useful in understanding the pathogenesis of this disease.

Adult↗