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Biomedical subjects

A Benzer

Publications and source records attributed to A Benzer.

At least 55 records · Page 3Linked to original sources
PubMed1996

CSF of neuroleptic-naive first-episode schizophrenic patients: levels of biogenic amines, substance P, and peptides derived from chromogranin A (GE-25) and secretogranin II (secretoneurin).

Lumbar cerebrospinal fluid (CSF) was collected from controls and neuroleptic-naive patients with their first acute schizophrenic episode. The CSF was analyzed for several biogenic amines and their metabolites [dopamine,dihydroxyphenylacetic acid (DOPAC), noradrenaline, 5-hydroxytryptamine (5-HT), 5-hydroxyindolacetic acid (5-HIAA)]. For these transmitters, which are stored and secreted from synaptic vesicles, there was no significant difference between controls and schizophrenic patients. As constituents of large dense-core vesicles substance P (SP) and GE-25 (derived from chromogranin A)-and secretoneurin (derived from secretogranin 11)-immunoreactivities were determined. SP-like immunoreactivity levels did not differ between controls and patients; however, GE-25 was elevated and especially the GE-25/secretoneurin ratio was significantly (p < .001) higher in patients. Characterization of the immunoreactivities by high-performance liquid chromatography did not reveal any difference between patients (n = 3) and controls in the processing of the two proproteins chromogranin A and secretogranin II. These data indicate that proteolytic processing of the two widespread constituents of large dense-core vesicles, i.e., chromogranin A and secretogranin II, is not altered in schizophrenic patients. The increase in the chromogranin A /secretoneurin ratio in schizophrenic patients deserves further investigation in order to elucidate its possible pathogenetic significance.

Adult↗
PubMed1996

The onset of pipecuronium following application of the priming principle.

Pipecuronium bromide, a long acting non-depolarizing neuromuscular blocking agent was administered to four groups of 10 patients using the priming technique. The effects of the combination of two different priming doses (0.01 or 0.015 mg kg-1) given at two different time intervals (3 or 4 min) before the 'main' intubating dose (0.07 or 0.065 mg kg-1) were investigated. Onset times were recorded and the intubation conditions were scored and compared with a group of patients receiving the same total amount of pipecuronium (0.08 mg kg-1) in a single bolus injection. Intubating conditions at 90 s after administration of the intubating dose were found to be significantly improved in all primed groups but the onset times, evaluated using the response of the adductor pollicis muscle to a single twitch stimulation, were similar to that observed after the single bolus injection. The optimal priming combination is considered to be 0.01 mg kg-1 of pipecuronium followed 3 to 4 min later by 0.07 mg kg-1.

Adult↗
PubMed1996

Bupivacaine plasma concentrations during continuous epidural anesthesia in infants and children.

Venous bupivacaine plasma concentrations were measured in six neonates and infants aged 4 days to 3.9 mo (mean, 2.1 mo) and 10 infants and children aged 9 mo to 6 yr (mean, 3.1 yr) after administration of an initial bolus of 0.5 mL/kg bupivacaine 0.25%, followed by a continuous infusion of local anesthetic (0.25 mL.kg-1.h-1) over a period of 4 h (first hour: bupivacaine 0.25%, then reduced to 0.125%). Plasma concentrations of local anesthetic measured at 180 min and 300 min after beginning of bupivacaine administration were significantly higher in younger infants when compared to older infants and children (180 min: 0.67 +/- 0.24 micrograms/mL [0.25-0.97] vs 0.27 +/- 0.11 micrograms/mL [0.19-0.55], P < 0.01; 300 min: 0.86 +/- 0.36 micrograms/mL [0.35-1.25] vs 0.34 +/- 0.12 micrograms/mL [0.18-0.57], P < 0.01). The results of our study show that despite applying the same dosage of epidural bupivacaine significantly higher plasma concentrations were seen after short periods of continuous infusion in infants up to 4 mo than in children older than 9 mo.

Age Factors↗
PubMed1995

Influence of urapidil on cerebrospinal fluid pressure in humans with uncompromised intracranial compliance.

OBJECTIVE: Determine the influence of urapidil on mean lumbar cerebrospinal fluid pressure (CSFP), mean arterial pressure (MAP), mean central venous pressure (CVP) and heart rate (HR) in awake humans without any evidence of cerebral or cardiovascular disease. DESIGN: Open, single-dose volunteer study. INTERVENTIONS: CSFP was measured via a spinal needle after i.v. injection of a single dose of 0.2 mg kg-1 urapidil in six volunteers (2 female, 4 male). MEASUREMENTS AND RESULTS: After administration of urapidil, CSFP increased from 7 +/- 1 mmHg to 10 +/- 1 mmHg (p < 0.05), MAP decreased from 88 +/- 7 mmHg to 74 +/- 5 mmHg (p < 0.05), CPP decreased from 81 +/- 7 mmHg to 64 +/- 5 mmHg (p < 0.05) and CVP decreased from 0 +/- 1 mmHg to -3 +/- 1 mmHg (p < 0.05). CONCLUSION: Our data suggest that in humans with presumed normal intracranial compliance the administration of urapidil causes a small but statistically significant increase in CSFP due to a parallel decrease in MAP.

Adult↗
PubMed1995

Statistical modelling in analysis of outcome after trauma Glasgow-Coma-Scale and Innsbruck-Coma-Scale.

AIM OF THE STUDY: The current study investigated the Glasgow-Coma-Scale (GCS) and the Innsbruck-Coma-Scale (ICS) for accuracy and reliability of prehospital prediction of non-survival. METHODS: 254 patients were scored immediately after trauma. RESULTS: Both scales equally predicted non-survival with low scores (p < 0.001). The ICS was slightly better in overall prediction of patient outcome (ICS: 84.98%; GCS: 82.68%), but more importantly, statistical analysis (logistic regression model) showed a greater distance between the median scores of survivors and non-survivors, when scored with the ICS (survival: 12; non-survival: 3) than when scored with the GCS (survival: 7; non-survival: 4). CONCLUSION: The results of the present study not only suggest that it is possible to predict mortality prior to therapy for any individual GCS and ICS coma score, but also indicated the ICS to be safer to use than the GCS because of the greater distance of the median scores for survivors and non survivors.

Adolescent↗
PubMed1995

Hyperventilation reverses the nitrous oxide-induced increase in cerebral blood flow velocity in human volunteers.

Because hypocapnia is routine during general anaesthesia for intracranial procedures, we have compared, in 13 healthy volunteers, the effect of normocapnia (PE'CO2 5.3 kPa) and hypocapnia (PE'CO2 3.3 kPa) on mean blood flow velocity in the middle cerebral artery (Vmca) during normoventilation and hyperventilation with air and with 50% nitrous oxide in oxygen. After replacement of air with 50% nitrous oxide in oxygen, there was an increase in mean Vmca during normoventilation (air: mean 68.23 (SD 16.98) cm s-1 vs nitrous oxide in oxygen: 90.69 (20.41) cm s-1; P < 0.01), whereas during hyperventilation mean Vmca values were similar regardless of the inhaled gas mixture (air: 43.46 (9.97) cm s-1 vs nitrous oxide in oxygen: 41.69 (8.08) cm s-1. Our data suggest that the nitrous oxide-induced increase in mean Vmca can be blocked by hyperventilation.

Adult↗
PubMed1995

Low-dose sufentanil increases cerebrospinal fluid pressure in human volunteers.

Although sufentanil is frequently used in neuroanesthesia, the effect of the drug on intracranial pressure is still controversial. In our study, we used an invasive measurement technique to study the effects of 0.1 micrograms/kg-1 sufentanil on mean lumbar cerebrospinal fluid pressure (CSFP), mean arterial pressure (MAP), cerebral perfusion pressure (CPP), central venous pressure (CVP), heart rate (HR), and end-tidal dioxide (ETCO2) in five human volunteers. After i.v. injection of sufentanil, mean lumbar CSFP increased from 6 mm Hg to 12 mm Hg (p < 0.05), and mean CPP decreased from 92 mm Hg to 78 mm Hg (p < 0.05), whereas MAP, CVP, HR, and ETCO2 remained stable. The results of this study clearly show that even a low dose of sufentanil transiently increases lumbar CSFP in volunteers with uncompromised intracranial compliance.

Adult↗
PubMed1994

Early diagnosis of fat embolism syndrome by automated image analysis of alveolar macrophages.

To evaluate the value of automated semiquantitative analysis of fat within alveolar macrophages as an early diagnostic tool for fat embolism syndrome (FES), we investigated 3 patients with respiratory failure following long-bone fractures. The mean area of fat droplets per alveolar macrophage was determined in pixels and, additionally, the percentage of the evaluated areas was calculated. In 2 patients, the diagnosis of FES could be established as early as 24 hr after trauma. Both patients showed an increase in the area of fat per alveolar macrophage (pixels: 851, 1069) as well as in the percentage of fat area per alveolar macrophage area (40.04%, 52.73%), whereas the analysis of the bronchoalveolar lavage (BAL) specimens of a third patient, who later recovered without appearance of clinical signs of FES, revealed only minimal fat content (pixels: 82; 3.82%). Automated semiquantitative analysis of fat within alveolar macrophages may be helpful in the early diagnosis of FES.

Embolism, Fat↗
PubMed1994

Molecular characterization of immunoreactivities of peptides derived from chromogranin A (GE-25) and from secretogranin II (secretoneurin) in human and bovine cerebrospinal fluid.

Chromogranin A and secretogranin II are members of the so-called chromogranins, the acidic proteins stored in neuroendocrine large dense-core vesicles. We characterized chromogranin A and secretogranin II immunoreactivities in cerebrospinal fluid by radioimmunoassays using synthetic peptides derived from these components (GE-25 for chromogranin A and secretoneurin for secretogranin II). In lumbar cerebrospinal fluid, high levels (more than 1000 fmol/ml) of these two components were found, whereas in ventricular cerebrospinal fluid the secretoneurin levels were relatively low. The cerebrospinal fluid/serum ratio for secretoneurin was close to 170. High-performance liquid chromatography revealed that in both cerebrospinal fluid and extracts from human brain secretoneurin was the predominant immunoreactive component. In cerebrospinal fluid chromogranin A immunoreactivity was present as intermediate-sized peptides with little intact chromogranin A and free GE-25 peptide. In human brain samples smaller peptides including GE-25 were more predominant. Analogous findings for secretoneurin and chromogranin A were obtained for bovine brain samples. We can conclude that chromogranins are present in cerebrospinal fluid in concentrations much higher than those of classical neuropeptides also stored in large dense-core vesicles. Therefore, their degree of proteolytic processing can be analysed with small samples of cerebrospinal fluid. A possible disturbance of proteolytic processing in large dense-core vesicles in various pathological conditions can now be discovered.

Adult↗
PubMed1994

Who publishes in the large anaesthesia journals?

We have analysed, with the aid of an online database, the number of all types of contributions from scientists of various countries to four leading international anaesthesia journals (British Journal of Anaesthesia, Anaesthesia, Anesthesia and Analgesia and Anesthesiology) during the period 1987-1991. Although American and British publications played the leading roles in the total number of anaesthetic publications (40.4% and 32.5%, respectively), more detailed analysis revealed an unexpectedly high "publication output" of smaller countries, which sometimes exceeded those of larger nations (publications per million inhabitants: United Kingdom 41.9, Denmark 24.2, Sweden 15.4, Finland 15.3, Israel 14.6, Ireland 13.1, U.S.A. 11.9, Switzerland 11.0).

Anesthesia↗
PubMed1994

Continuous positive airway pressure breathing increases cerebral blood flow velocity in humans.

The effect of a continuous positive airway pressure (CPAP) of 12 cm H2O on mean middle cerebral artery flow velocity (CBFV) was studied in nine human volunteers by means of transcranial Doppler sonography (TCD). During CPAP breathing, CBFV increased (45 +/- 9 vs 59 +/- 11 cm/s; P < 0.001; mean +/- SD), and pulsatility index (PI) decreased (0.87 +/- 0.1 vs 0.74 +/- 0.2; P < 0.05), indicating an increase in cerebral blood flow due to cerebral vasodilation. This phenomenon should be taken into account when CPAP is applied to patients with intracranial disease or when assessing CBFV patterns of patients during CPAP respiration.

Adult↗