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Biomedical subjects

B Lucas

Publications and source records attributed to B Lucas.

14 recordsLinked to original sources
PubMed1992

TNF-alpha production by U937 promonocytes is enhanced by factors released from HIV-infected T4 lymphocytes: TNF-alpha is one of the mediators causing lysis of HIV-infected T4 cells.

In the present study, we have shown that the addition of culture supernatants from HIV-infected SupT1 cells (T4) but not from noninfected cells markedly increased the production of TNF-alpha by U937 promonocytic cells after stimulation with phorbol 12-myristate 13-acetate (PMA). Pretreatment of supernatants with the antibodies to granulocyte/macrophage colony-stimulating factor (GM-CSF) or TNF-alpha, but not interferon-gamma, significantly diminished this enhancing effect. These results suggest that HIV may play an indirect role by producing cytokines from infected T4 cells that can lead to an increased production of TNF-alpha by monocytic cells. Further, TNF-alpha produced by U937 cells following stimulation with PMA plus lipopolysaccharide or with phytohemagglutinin induced lysis of HIV-infected T cells. TNF-alpha-induced cytotoxicity was markedly higher toward HIV-infected than toward noninfected T4 cells. Addition of antibody to TNF-alpha during the cytotoxic phase of response resulted in a reduction of about 50% in the percentage of cytotoxicity, indicating TNF-alpha as one of the lytic mediators.

Antibodies↗
PubMed1992

A note on the occurrence of unusual electroencephalographic sleep patterns in selected normal children.

Polysomnographic recordings were performed in 50 children free from any familial or personal history of seizure or neurologic diseases to evaluate the frequency of epileptiform and unusual electroencephalographic patterns in a normal population. A 9-year-old boy exhibited focal spikes that became bilateral with a density of 24% to 32% during slow wave sleep, and another boy showed a few spikes during slow wave sleep. In seven cases, 14- and 6-Hz rhythms were recorded, mostly in rapid eye movement sleep. A right rhythmic and temporal discharge was observed in one girl. Epileptiform electroencephalographic patterns are not infrequent, and 14- and 6-Hz rhythms during rapid eye movement sleep are common in normal children.

Adolescent↗
PubMed1990

The influence of vigilance states on paroxysmal EEG activities and clinical seizures in children.

We studied the relationships between clinical variables and those related to the states of vigilance in 18 cases of benign partial epilepsy with centro-temporal spike-waves, 22 cases of definite symptomatic partial epilepsy, and 16 cases of undetermined partial epilepsy. The time of day during which the seizures appeared and the paroxysmal activity densities during non-REM and REM sleep are not distributed differently among the 3 electro-clinical types. However, the benign epilepsy with centro-temporal spikes group had more patients with sleep-sensitive paroxysmal activities. Patients who mainly had nocturnal seizures were found to have more frequent generalized seizures and a greater sleep-sensitive paroxysmal activity. Three cases demonstrated continuous spike-waves during sleep. The patients who had little or no paroxysmal activity during sleep were the youngest. This study illustrates that sleep-sensitive seizures and paroxysmal activities are not specific to benign childhood epilepsy with centro-temporal spikes, and that seizures and paroxysmal activities are two manifestations associated with epilepsy, affected in different ways by states of vigilance.

Adolescent↗
PubMed1990

Are frequent spike-waves during non-REM sleep in relation with an acquired neuro-psychological deficit in epileptic children?

In a population of 11 children with frequent spike waves during non REM sleep who had no neurological symptoms between birth and their first symptom, 3 groups were compared according to their neuropsychological performances. In the first group, the children had no intellectual deficit, in the second group, they had an acquired aphasia as in the Landau-Kleffner syndrome and in the third they had severe behavioural disorder and mental deterioration. The non REM sleep paroxysmic activity density tended to be highest in the third group, variable in the second group and moderate in the first group, and their topography was always generalized in the acute phase in groups II and III but asymmetrical in group I. The EEG anomalies disappeared during adolescence but in group II and III children a moderate to severe delay in school work persisted.

Aphasia↗
PubMed1987

Two distinct classifications of adult epilepsies: by time of seizures and by sensitivity of the interictal paroxysmal activities to sleep and waking.

Two hundred and thirty-six adult epileptic outpatients were classified twice: firstly according to the time of seizures reported by the patient or his family in diurnal, nocturnal, awaking and diffuse epilepsies (Es) and secondly according to the sensitivity to sleep or waking of the interictal paroxysmal activities (PA) observed during a polysomnographic night session with a sleep PA increase, with a waking PA increase, with PA indifferent to sleep and waking or with few or no PA. The stability of the sensitivity of the PA to sleep and waking was 84%. Patients with diurnal epilepsy have more frequently myoclonic attacks and a lower seizure frequency. Patients with a sleep PA increase have less frequently generalized motor seizures, more frequently partial complex seizures, a higher seizure frequency, higher total night PA density and more frequently the appearance of new PA during sleep. Patients with a waking PA increase had more frequently massive myoclonus, rarely the appearance of new PA during sleep and a high total night PA density. There is no significant relationship between the two classifications. Neither classification succeeds in discriminating the electro-clinical type of the epilepsies.

Adolescent↗
PubMed1977

Nutrient intake and stimulant drugs in hyperactive children.

Recent studies have demonstrated suppressed growth of height and weight in children receiving stimulant drugs for hyperactivity. For approximately twelve months, growth data and food records were collected on two subjects receiving different types and dosages of stimulant drugs. The two cases demonstrated that dextroamphetamine levels of 10 mg. or more and methylphenidate levels of 30 mg. or more decreased caloric intake significantly. This decrease may be limiting for long-term growth. Both subjects had a variety of feeding problems due to poor appetite. Careful nutritional evaluation and planning are important to insure optimal energy and nutrient intake in these children receiving stimulant drugs.

Ascorbic Acid↗
PubMed1976

Multichambered bladder anomalies.

This report reviews multichambered bladder conditions, offers a workable classification of them, presents a detailed case report, and discusses the possible causes of these anomalies. We wish to stress the importance of careful examination of the genital area in the newborn and early roentgenologic evaluation of the genito-urinary system when an anomaly is found.

Diverticulum↗
PubMed1976

Prevalence of hypertension in a renal transplant population on alternate-day steroid therapy.

A study of the prevalence of hypertension in a group of renal transplant patients on alternate-day maintenance steroid therapy was conducted. Twenty-four percent of the transplant clinic population was hypertensive. The factors that were associated with a lower prevalence of hypertension were good graft function, bilateral nephrectomy of the patients' own diseased kidneys (although the majority of our patients without bilateral nephrectomy are normotensive), and use of a living related donor. We conclude that the prevalance of hypertension in transplant patients on alternate-day steroid therapy is low. In the presence of all these favorable factors, only 6% of allograft recipients were hypertensive.

Adolescent↗
PubMedDate not supplied

[Ocular damage caused by industrial lasers. Apropos of 3 accidents].

We report three cases of ocular injury caused by industrial lasers when safety precautions are not observed. These three cases concern engineers working in a research institute and using YAG laser alignment procedure. Damages observed are: a) Macular hole; b) Subretinal hemorrhage; c) Intravitreous hemorrhage. An absolute central scotoma occurred in two cases.

Accidents, Occupational↗