Reflex pupillary dilatation in response to skin incision and alfentanil in children anaesthetized with sevoflurane: a more sensitive measure of noxious stimulation than the commonly used variables.

BACKGROUND: Estimation of analgesia in anaesthetized children is often imprecise, and consequently, anaesthesiologists commonly evaluate children's response to surgical stimulation by movement or haemodynamic changes. In adults reflex pupillary dilatation has been demonstrated to be a very sensitive measure of noxious stimulation, correlated with opioid concentrations. The autonomic nervous control changes with age, raising the hypothesis that mechanisms involved in pupillary autonomic functions regarding both sympathetic and parasympathetic components may also differ between adults and children. In this pilot study, we tested the hypothesis that the pupillary reflex dilatation might allow assessment of noxious stimulation and analgesic effect of alfentanil in children under sevoflurane anaesthesia, as an alternative to haemodynamic and bispectral measures. METHODS: After sevoflurane induction, 24 children were maintained in steady-state conditions at 1.5 MAC of sevoflurane in O(2)-N(2)O (50-50). An intense noxious stimulation was provided by standardized skin incision on the lower limb. A bolus of alfentanil (10 microg kg(-1)) was administered either 1 min (n=16) or 2 min (n=8) after skin incision. Haemodynamic values, bispectral index (BIS) and pupillary diameter (PD) were recorded just before stimulation and at 30-60 s intervals during 4 subsequent minutes. RESULTS: In all children PD increased significantly after noxious stimulation [+200 (40)%, at 60 s]. In contrast, mean heart rate and blood pressure increased only 11 (7)% and 10 (8)% respectively, 60 s after stimulation. BIS did not change significantly. In all children, alfentanil injection induced a rapid decrease of PD and restored pre-incision values in 2 min. CONCLUSION: PD is a more sensitive measure of noxious stimulation than the commonly used variables of heart rate, arterial blood pressure and BIS in children anaesthetized with sevoflurane.

Fatty acid incorporation depicts brain activity in a rat model of Parkinson's disease.

Following pulse labeling with [3H]arachidonic acid ([3H]AA), its incorporation pattern in brain reflects regional changes in neurotransmitter signal transduction using phospholipase A2, that is, functional activity. In a rat model of Parkinson's disease, unilateral 6-hydroxydopamine lesion in the substantia nigra, [3H]AA acid incorporation from blood was increased in cerebral cortex, caudate putamen, globus pallidus, entopeduncular nucleus, subthalamic nucleus and substantia nigra pars reticulata ipsilateral to the lesion. This increased [3H]AA incorporation likely reflects disinhibition of basal ganglia and cortical circuits secondary to absent inhibitory nigrostriatal dopaminergic input.

Chemically induced CD4 mutants of a human T cell line. Evidence for dissociation between binding of HIV I envelope and susceptibility to HIV I infection and syncytia formation.

This study describes the derivation of a series of mutants from the human leukemic cell line CEM using the frame shift mutagen Ethyl-methanesulfonate followed by negative selection with multiple treatments of OKT4A + C, and sorting into CD4-, CD4-dull, and CD4-intermediate mutants. These mutants express reduced CD4 levels ranging from 0 to 60% of the parental line. The mutants were analyzed by staining with a battery of CD4-specific mAb, by assessing their ability to bind soluble gp120, and by their ability to form syncytia after infection with cell-free HIV I virus and a gp160-vaccinia vector. Two groups of particularly interesting mutants were identified: (1) CD4-dull mutants expressing only 5 to 10% of the wild type surface CD4 density, which nevertheless were infectable by HIV I and produced as many syncytia and reverse transcriptase activity as the parental line after infection with gp160-vaccinia or cell free HIV I. (2) CD4-intermediate mutants (30 to 60% of parental CD4 level), which express CD4-epitopes required for interaction with the HIV I envelope protein, yet are markedly deficient in their ability to form syncytia after gp160-vaccinia or HIV I infection. Two of these mutants did form syncytia after transient reconstitution with a wild type CD4 containing vaccinia vector. Inasmuch as they were found to bind soluble gp120 with the same avidity as other, functionally normal, CD4-intermediate mutants, these human T cell mutants may have a reduced susceptibility to HIV I infection due to the absence of a "fusogenic component" or to a structural alteration in a region of the CD4 molecule not required for binding of the HIV I envelope, but for the subsequent fusion and entry process.

Invasive activity and chemotactic response to growth factors by Kaposi's sarcoma cells.

Kaposi's sarcoma (KS) is a relatively low grade neoplasm, classically occurring in the skin of elderly men. A more virulent and invasive form of Kaposi's sarcoma has been described in patients with acquired immune deficiency syndrome (AIDS). The origin and identification of the tumor cells in these lesions is controversial. Here we have studied the behavior of cells derived from KS lesions in an in vitro assay which measures the ability of cells to invade through a reconstituted basement membrane. In agreement with previous work, KS cells obtained under selective culture conditions were invasive showing activity comparable to that of malignant tumor cells. Normal fibroblasts, smooth muscle cells, and endothelial cells did not demonstrate invasive behavior under the same experimental conditions. To characterize further the nature of the KS cells we tested the chemotactic response of cells from the most invasive line to a variety of growth factors and compared their response to those of fibroblasts, smooth muscle, and endothelial cells. These studies suggest that normal cells respond to a unique repertoire of chemotactic factors. The chemotactic response of the KS cells most closely resembled that of smooth muscle cells and was quite distinct from endothelial cells. These results indicate that the KS-derived cultures contain invasive cells with a smooth muscle cell-like phenotype.

Standards for patient monitoring during anesthesia at Harvard Medical School.

As part of a major patient safety/risk management effort, the Department of Anaesthesia of Harvard Medical School, Boston, has devised specific, detailed, mandatory standards for minimal patient monitoring during anesthesia at its nine component teaching hospitals. Such standards have not previously existed, and resistance to the concept was anticipated but not seen. The standards are technically achievable in all settings and affordable in terms of effort and cost. Early detection of untoward trends or events during anesthesia will result in prevention or mitigation of patient injury; this, in turn, may also help counter the explosive increases in anesthesia-related malpractice actions, settlements, judgments, and insurance premiums. The committee process used is applicable to the promulgation of standards of practice for all medical specialties and any organized group of medical practitioners.

Pulmonary cryptococcosis: a report of two cases and review of the literature.

Two cases of primary pulmonary cryptococcosis are described. In both cases diagnosis was established using specimens obtained at bronchoscopy and in one case confirmed by detecting cryptococcal antigen. Knowledge of the natural history of the condition allowed rational decisions to be made regarding treatment. Difficulties surrounding the diagnosis and treatment of this unusual condition are discussed.

Anti-inflammatory properties of copper implants in the rat paw edema: a preliminary study.

Metallic copper has been shown to possess anti-inflammatory activity in the carrageenan foot paw edema of the rat, when applied in the form of an implant. The implant was installed two months before the edema was induced. It is postulated that the anti-inflammatory activity is due to dissolved copper from the implant.

Propylene-a competitor of ethylene action.

Propylene competed with the ethylene-induced reduction in length growth of the epicotyl of the etiolated garden pea (Pisum sativum L. cv. Alaska). These results constitute further evidence that ethylene acts by attaching itself loosely to a site.