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Biomedical subjects

A Villani

Publications and source records attributed to A Villani.

At least 55 records · Page 3Linked to original sources
PubMed1991

Respiratory syncytial virus infection of human mononuclear phagocytes stimulates synthesis of platelet-activating factor.

Production of platelet-activating factor 1-O-alkyl-2-acetyl-sn-glycero-3- phosphocholine (PAF), a potent mediator of inflammation, by mononuclear phagocytes varies with their stage of cellular differentiation and the nature of the eliciting stimulus. The human monocytic cell line U937 can be induced to differentiate to a macrophage-like cell following phorbol myristate acetate exposure, and after differentiation, these cells efficiently support replication of respiratory syncytial virus (RSV). U937 cells induced to differentiate with phorbol myristate acetate demonstrated a time-dependent decrease in PAF synthesis. RSV infection of these differentiated U937 cells caused a sustained stimulation of PAF synthesis that paralleled viral replication and was dependent on infectious virus. Virus increased the activity of lyso-PAF:acetyl-CoA acetyl-transferase (PAF acetyltransferase) in cell lysates, thus enhancing the anabolic pathway of PAF synthesis without altering the activity of PAF acetylhydrolase, which regulates PAF catabolism. RSV infection of human monocytes also caused a marked increase in [3H] monocytes also caused to uninfected monocytes. Thus, virus infection serves as a novel stimulus to induce PAF synthesis in human mononuclear phagocytes and suggests that increased PAF production may have a critical role in the inflammatory response to RSV.

Acetyltransferases↗
PubMed1991

[Intraoperative radiotherapy: anesthesiologic problems during transport of patients].

In this study the condition of anesthesia in 8 patients, undergoing intraoperative radiation therapy (IORT) for pancreatic or rectal tumors, is evaluated. Patients with reapproximated surgical incision were transferred from the operating room to the radiotherapy department while still under anesthesia. The risks of such transport as well as guidelines for the patient's care during this phase are examined. The results of this study indicate that in order to move anesthetized patients safely it is necessary to ensure stable cardiovascular, respiratory and metabolic conditions prior to their transfer. It is also important to guarantee adequate analgesia and to establish appropriate monitoring during transport.

Anesthesia↗
PubMed1990

Virus-induced alterations in macrophage production of tumor necrosis factor and prostaglandin E2.

The cellular immune response to respiratory syncytial virus (RSV) is felt to contribute to viral clearance and/or the inflammation accompanying pulmonary infections with this virus. Both tumor necrosis factor (TNF) and prostaglandin E2 (PGE2) are important regulatory mediators of the cellular immune response. We examined the production of these mediators from purified human alveolar and blood mononuclear phagocytes (MP) after RSV infection in vitro and compared production induced by virus with that induced by lipopolysaccharide (LPS). RSV infection of alveolar MP did not alter PGE2 production but increased expression of TNF alpha mRNA paralleled by increased secretion of immunoreactive and biologically active TNF. TNF production by alveolar MP was dependent on the infectious dose of virus and occurred early in the viral replication cycle. In contrast, RSV had minimal effects on blood MP production of TNF and PGE2. However, blood MP (and not alveolar MP) infected with RSV and costimulated with LPS demonstrated a 1.7-fold increase in PGE2 levels compared with LPS alone (P less than 0.001). Therefore, RSV has differential effects on human alveolar and blood MP production of these immunoregulatory molecules.

Adult↗
PubMed1990

Early 24-hour blood pressure elevation in normotensive subjects with parental hypertension.

Subjects with a family history of parental hypertension are reported to have a slightly higher office blood pressure in the prehypertensive stage. Whether this reflects a hyperreactivity to blood pressure measurement or a more permanent blood pressure elevation, however, is not known. In the present study, blood pressure was measured in 15 normotensive subjects whose parents are both hypertensive (FH++), 15 normotensive subjects with one hypertensive parent (FH(+)-), and 15 normotensive subjects whose parents are not hypertensive (FH--); among the three groups, subjects were matched for age, sex, and body mass index. The measurements were made in the office during a variety of laboratory stressors and during a prolonged resting period, and for a 24-hour period (ambulatory blood pressure monitoring). Office blood pressure was higher in the FH++ group than in the FH-- group (p less than 0.05). The pressor responses to laboratory stressors were similar in the two groups, but the FH++ group had higher prolonged resting and 24-hour blood pressure than the FH-- group; the difference was always significant (p less than 0.05) for systolic blood pressure. The FH++ group also had a greater left ventricular mass index (on echocardiographic examination) than the FH-- group (p less than 0.01). The blood pressure values and echocardiographic values of the FH(+)- group tended to be between those of the other two groups. Thus, the higher blood pressure shown by individuals in the prehypertensive stage with a family history of parental hypertension does not reflect a hyperreactivity to stress but an early permanent blood pressure elevation.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1990

Advantages and disadvantages of non-invasive ambulatory blood pressure monitoring.

Our studies have shown that (1) automatic blood pressure readings obtained from portable monitors do not induce any alerting reaction or pressor response in the patient; (2) although the measurements are intermittent, non-invasive ambulatory blood pressure monitoring is able to provide a true estimate of 24-h blood pressure and heart rate mean values (the assessment of 24-h blood pressure and heart rate variabilities is less accurate); (3) the nocturnal fall in blood pressure is not altered by the possible disturbance to the patient's sleep induced by repeated cuff inflations; and (4) even when the automatic blood pressure readings obtained are similar to simultaneous readings obtained by a sphygmomanometer, the accuracy of the values provided by portable monitors used in truly ambulatory conditions cannot be taken for granted. These findings have particular implications for the cost: benefit ratio if ambulatory blood pressure monitoring is to be used in the routine evaluation of hypertensive patients.

Blood Pressure↗
PubMed1990

[The effects of nitrous oxide on evoked potentials recorded during enflurane and isoflurane anesthesia].

The effects on median nerve somatosensory evoked potentials produced by nitrous-oxide (67%) were studied in 20 patients undergoing elective surgery under enflurane or isoflurane anaesthesia. This study demonstrates that nitrous-oxide does not significantly modify spinal (N13) and cortical (N20) component latencies nor central conduction time. The addition of nitrous-oxide to enflurane or isoflurane (up to 1 MAC) causes a significant reduction of N20 amplitude.

Adult↗
PubMed1989

Early twenty-four-hour blood pressure elevation in subjects with parental hypertension.

We studied 15 normotensive offspring of hypertensive parents, comparing them with 15 normotensive controls matched for sex, body mass index and age. In the offspring, both parents were hypertensive, while in the controls, neither parent was hypertensive. Blood pressure was measured at rest, during a variety of laboratory stressors (mental arithmetic, mirror drawing test, hand grip and cold pressor test), and was also monitored for 24 h in ambulatory conditions (Spacelabs 5300 M, Richmond, Washington, USA). Resting mean and diastolic blood pressures were higher (P less than 0.05) in the subjects with parental hypertension than in those without. The mean blood pressure rise induced by the laboratory stressors was not significantly greater at any time in the subjects with hypertensive parents compared with controls. Twenty-four-hour systolic and mean blood pressures, however, were significantly higher (P less than 0.05) in the subjects with hypertensive parents than in the controls. Thus the higher office blood pressure shown in the prehypertensive stage by subjects with parental hypertension is not due to hypersensitivity to stress, but represents an early and permanent blood pressure elevation.

Adult↗
PubMed1989

Cardiomyopathy in phaeochromocytoma: a case report.

This case report describes the anaesthetic management of a patient with bilateral phaeochromocytoma and cardiomyopathy. The hypertension and supraventricular tachycardia commonly seen during manipulation of this tumour was controlled by administration of sodium nitroprusside and verapamil. Verapamil allowed effective management of supraventricular rhythm disturbances and arterial blood pressure, and cardiac index remained unchanged during and after phaeochromocytoma removal. As the haemodynamic side-effects of the calcium blocking agent are readily reversed by intravenous calcium chloride, it may have a useful part to play in such cases.

Adrenal Gland Neoplasms↗
PubMed1989

[Somatosensory evoked potentials during isoflurane anesthesia].

Changes in Sensory Evoked Potentials (SEPs) produced by different concentrations of isoflurane with or without N2O have been studied. In all subjects the early components have always remained well defined. A significant increase of N 13 and N 20 latency and of the central conduction time has been noted. The amplitude of N 20 was not much modified by isoflurane, but was affected by the addition of N2O. Isoflurane may be used during SEP monitoring if its concentration remains below 1 MAC.

Anesthesia, Inhalation↗
PubMed1989

Evaluating bronchial hyperreactivity tests in epidemiology.

The aim of this study is to assess the value of the most common tests which can be used in epidemiological surveys to identify asthmatic children. We reviewed anamnestic information from a self-administered questionnaire, bronchial reactivity by means of exercise-test, bronchodilation-test with trimethochinol, carbachol-test (PD20 FEV1 was reported), cutaneous reactivity monitored by prick-test. (Data from a polycentric epidemiological study). We conclude that, while these tests are very useful in the initial study and in the further follow-up of the asthmatic child, providing also information about the possibilities of management of bronchoconstriction and its pharmacologic prevention, they show a limited value in the absolute diagnosis of asthma.

Air Pollutants↗
PubMed1988

Twenty-four hour ambulatory intra-arterial blood pressure in normotensive and borderline hypertensive subjects.

A number of studies have shown that blood pressure values obtained by ambulatory monitoring are lower than those obtained in the doctor's office by cuff readings. However, there is still no suitable information on 'normal' 24-h ambulatory blood pressure values. In 19 normotensive and 13 borderline hypertensive subjects, defined by repeated office blood pressure measurements, we recorded intra-arterial blood pressure under ambulatory conditions for 24 h (Oxford method) in order (1) to assess the 24-h blood pressure values of normal subjects, and (2) to compare their 24-h blood pressure values with those of borderline hypertensive patients. In the normotensive subjects systolic, diastolic and mean ambulatory blood pressure values over 24 h were significantly lower than the corresponding office values, the differences being -15.0, -22.1 and -17.9 mmHg, respectively. In the borderline hypertensives 24-h ambulatory blood pressure was significantly lower than office readings. On average, the 24-h mean blood pressure of normotensive subjects was significantly lower than that of borderline patients (P less than 0.01). However, individual 24-h blood pressure values showed a considerable overlap. Thus, (1) ambulatory blood pressure values just below 140/90 mmHg do not necessarily mean that the blood pressure is in the normal range, the mean 24-h blood pressure of true normotensive subjects being much lower; (2) ambulatory blood pressure monitoring in patients with high office blood pressure readings may help to identify subjects whose 24-h mean values are indistinguishable from those of normotensives. However, the clinical relevance of these findings in the diagnosis of hypertension has to be validated by prospective clinical trials.

Adult↗
PubMed1988

Circadian blood pressure variations and their impact on disease.

Errors can be made when blood pressure is measured only by a single clinic measurement. Such assessments bear only a limited relationship to mean 24-h blood pressure and do not provide complete information on potentially important features of the circadian pattern of blood pressure. Measurement of clinic or "casual" cuff blood pressure by the doctor can produce a large, variable, and unpredictable overestimation caused by the pressor response associated with anxiety in the patient. Single cuff measurements rarely reflect the 24-h mean and classifications of severity based on cuff measurements are therefore subject to a large degree of overlap. Estimation of the response to antihypertensive treatment by casual cuff measurements is therefore subject to the same criticisms. Although superiority of measurement of 24-h mean blood pressure has not been demonstrated in any prospective controlled study, several cross-sectional investigations have shown that complications of hypertension relate more closely to the 24-h mean than to casual measurements. The degree of variability of blood pressure during a 24-h period (which can only be measured by 24-h monitoring) bears a relation to target-organ damage that is independent of mean blood pressure value. Nighttime blood pressure mean has been shown to correlate with target organ damage approximately as closely as daytime blood pressure mean, implying that antihypertensive drugs must act during the night as well as the day if they are to influence the complications of hypertension.

Blood Pressure↗