PubMed Health⌕ Search

Biomedical subjects

E P Guazzo

Publications and source records attributed to E P Guazzo.

9 recordsLinked to original sources
PubMed1996

Cortisol, dehydroepiandrosterone (DHEA), and DHEA sulfate in the cerebrospinal fluid of man: relation to blood levels and the effects of age.

The relation between blood and cerebrospinal fluid (CSF) concentrations of cortisol, dehydroepiandrosterone (DHEA), and its sulfate (DHEAS) was measured in 62 subjects aged 3-85 yr old, fitted with ventriculo-peritoneal or lumbar-peritoneal shunts for a variety of diagnoses. There were 36 males and 36 females. Forty-eight subjects were not taking exogenous corticosteroids; the other 14 were receiving either systemic or local steroids. A single sample of blood and CSF was taken from each subject within 10 min for measurement of cortisol, DHEA, and DHEAS. The proportional levels of cortisol (5.8%) and DHEA (5.4%) in the CSF compared with those in the blood were similar in subjects not taking steroids. However, CSF DHEAS levels were only 0.15% of those in the blood. Because DHEAS blood levels were so much greater than DHEA, DHEAS in the CSF was still higher than DHEA despite the reduced penetration of the sulfated steroid. The blood/CSF ratios were similar in subjects taking steroids. There were significant correlations in steroid-free subjects between blood and CSF levels for DHEA (r = 0.65) and DHEAS (r = 0.88) but not for cortisol (r = 0.26). Steroid treatment significantly lowered blood cortisol, DHEA and DHEAS, and CSF DHEA, but not CSF cortisol or DHEAS compared with an age- and sex-matched sample of steroid-free subjects. In steroid-free adults (18 yr and over; n = 37), blood cortisol showed no age-related change. However, CSF cortisol was markedly raised in a proportion of steroid-free subjects over the age of 60 yr. Levels of corticoid-binding globulin in plasma did not alter with age. As expected, there were significant age-related decrements in both blood DHEA and DHEAS. CSF DHEA (r = 0.42) and CSF DHEAS (r = 0.39) were significantly negatively correlated with age. In steroid-free juveniles (n = 11) there were no age-related changes in either blood or CSF cortisol, but significant increases with age in DHEA and DHEAS in both blood and CSF. Calculation of the cortisol/DHEA and cortisol/ DHEAS molar ratios in the CSF showed both to be raised in the very young (3-8 yr) and the elderly (60 yr and over) by a factor of 4-5 compared with young adults aged 18-39. There were no sex differences in any of the parameters measured. These findings show that the relation between levels in the blood and CSF differ for each of these three neuroactive steroids. The brain is exposed to relatively high levels of DHEA and DHEAS during later childhood and early adulthood but to relatively or absolutely high levels of cortisol during infancy and older age. In view of the known antiglucocorticoid action of DHEA and DHEAS, and the direct action of these steroids on membrane-bound transmitter events (such as gamma-aminobutyric acidA receptors), these changes may have important implications for age-related alterations in brain function.

Adolescent↗
PubMed1995

Safe removal of retained ventricular catheters using intraluminal choroid plexus coagulation. Technical note.

The authors describe a simple technique that reduces the incidence of retained ventricular catheters and minimizes the risk of life-threatening intraventricular hemorrhage during the removal of an obstructed, adherent ventricular catheter in patients with hydrocephalus. The technique requires no special equipment and has been successfully used, without complications, in a prospective series of 12 patients with 13 blocked, adherent ventricular catheters.

Catheters, Indwelling↗
PubMed1994

Computer supported multimodal bed-side monitoring for neuro intensive care.

Multimodal monitoring in neuro-intensive care requires computer supported data analysis and archiving. This paper describes a computer system that is able to integrate the results of analysis of intracranial pressure, cerebral perfusion pressure, transcranial Doppler blood flow velocity, jugular bulb oxygen saturation, laser Doppler blood flow, near infrared spectroscopy. A research-oriented software installed in a standard IBM PC equipped with a low-cost analog-to-digital converter allows a broad spectrum of waveform analyses, from calculation of simple mean values to a selective waveform detection and cross-correlation analysis. The architecture for the signal processing algorithm, the principles of system interfacing and data presentation are discussed briefly. Results from two years of multimodal monitoring in neuro-intensive care show that, apart from simple recording of time trends of monitored variables, certain calculated parameters are particularly useful in the continuous assessment of cerebral haemodynamic and compensatory reserves. Such parameters include: transcranial Doppler pulsatility indices, the dependence between blood flow velocity or laser Doppler flux and cerebral perfusion pressure and the correlation coefficient between pulse amplitude and mean intracranial pressure.

Adolescent↗
PubMed1994

Spontaneous thrombosis of an arteriovenous malformation.

A patient with a spontaneously thrombosed arteriovenous malformation (AVM) presented with epilepsy. The CT and MRI appearances were of an intrinsic cerebral neoplasm with extensive surrounding vasogenic cerebral oedema and a mass effect. Histopathology confirmed a large thrombosed AVM. The natural history of AVMs and spontaneous thrombosis are reviewed.

Adult↗
PubMed1989

Management of solitary melanoma metastasis of the brain.

A retrospective analysis of 31 patients operated upon for cerebral secondary melanoma was conducted. There was no operative mortality and no operative complications in 76% of cases. Significant and life-threatening complications occurred in five patients (17%). The major benefit from surgical excision is relief of symptoms: 64% had complete remission of symptoms while a further 20% were substantially improved. A few patients' lives were prolonged by surgery and there are a number of long-term survivors. Surgical excision should be performed when a patient has an accessible solitary cerebral secondary without evidence of melanoma elsewhere.

Adult↗