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Biomedical subjects

G Carelli

Publications and source records attributed to G Carelli.

At least 19 recordsLinked to original sources
PubMed1998

Methanol Laser Line Assignments: Evidence of Four-Level Laser Systems

The "Ritz" computer program, developed for facilitating the assignment of molecular Fourier transform absorption spectra and described in a previous work, determines the energy level values involved in the assigned transitions by the Rydberg-Ritz combination principle. Combining the data obtained from the analyses of high-resolution infrared (IR) and far-infrared (FIR) spectra, it is possible to predict possible FIR laser emissions of molecules. In the present work we have applied this method to the common isotopomer methanol, 12CH3 16OH, and obtained 14 proposed assignments for previously unassigned FIR laser lines. We also predict 15 possible new FIR laser emissions. For the first time, an assignment involving a four-level laser system with collisional population transfer to a slightly higher energy level is reported. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Blood lead concentration and biological effects in workers exposed to very low lead levels.

A longitudinal study was carried out on two groups of workers engaged in tin/lead alloy welding in the telecommunication sector. The risk of exposure was evaluated by measuring levels of airborne lead (PbA) and the amount of lead absorbed (PbB). The-correlated effects were assessed by determining zinc protoporphyrin (ZPP) and hemoglobin levels (Hb) and red blood cell (RBC) count. We also recorded subjective symptoms reported by workers. One group of welders composed of 365 subjects underwent two monitoring sessions performed in 1991 and 1995, respectively (Group A). A second group of welders (whose number fluctuated between 148 and 247 subjects) underwent yearly testing for 7 consecutive years (1988-1994; Group B). Results indicated a very low risk of lead exposure during microwelding operations (PbA range, 1.5-24 micrograms/m3). In fact, blood concentrations of Pb (range, 5-55, micrograms/dL) among both groups of welders were significantly higher than those in the general population in Rome (PbB range, 5-16 micrograms/dL); nevertheless, they were significantly lower than the Occupational Safety and Health Administration's permissible exposure limits ZPP determined only in Group B of welders ranged from 5 to 16 micrograms/dL (median, 22 micrograms/dL). No variation was found in the other biological parameters investigated, and no health effects were observed. During the study period, the introduction of some technological innovations led to a further reduction in Pb exposure and, subsequently, to its total elimination. PbB concentrations gradually declined to lower values (6-36 micrograms/dL), and it was interesting to note that ZPP concentrations also decreased to normal levels (range, 2-47 micrograms/dL; median, 11 micrograms/dL), demonstrating that the effect of lead on heme synthesis may occur even at very low levels of Pb exposure.

Adult↗
PubMed1998

Occupational exposure to chromium--an assessment of environmental pollution levels and biological monitoring of exposed workers.

In an aircraft construction factory where adhesives containing Cr(VI) compounds were used, the risk of chromium exposure was studied by assessing airborne chromium levels and urinary levels of chromium excretion. Chromium exposure was evaluated by personal sampling over a period of 4 hr in a group of 16 occupational workers selected from a group of 55. Chromium absorption was determined by collecting urine samples from all subjects (n = 55) at 3 different times: prior to the work-shift at the beginning of the working week and prior to and after the workshift at the end of the working week. Each urine sample was tested for chromium and creatinine concentration. Results showed very low exposure to airborne chromium, since values obtained (0.02-1.5 micrograms/m3, GM: 0.17, GSD: 5.34 micrograms/m3) were significantly lower than the ACGIH Hygiene Standard (50 micrograms/m3). Likewise, urinary chromium excretion (0.16-7.74 micrograms/g creat.) was higher than excretion in the general population (0.07-0.17 microgram/g creat.) but lower than BEI-ACGIH (30 micrograms/g creat.). The greatest difference between excretion levels measured before and after the workshift was 2.44 micrograms/g creat, i.e. 4 times lower than the difference proposed by ACGIH (10 micrograms/g creat.).

Adult↗
PubMed1997

Changes in EEG power density during sleep laboratory adaptation.

First- and second-night effects on the electroencephalogram (EEG) were investigated by means of polygraphic sleep recordings and all-night spectral analysis. Eighteen normal subjects were studied for three consecutive nights in a hospital sleep laboratory. Visual sleep scoring showed that there was a first-night effect in normal subjects similar to that reported previously [increased wakefulness; decreased total sleep time, sleep efficiency, and rapid eye movement (REM) sleep]. Spectral analysis of the sleep EEG revealed important changes, most of which occurred in REM sleep. Increased delta, theta, and beta1 power densities accompanied by decreased mean frequency were seen in REM sleep in the second night. On the basis of REM sleep deprivation results previously published, our data suggest that the second night could be affected by partial REM sleep deprivation that occurred in the first night. Delta and theta power density values decreased in the first non-rapid eye movement episode of nights 1 and 2; this could result from increased REM sleep pressure. The overall consistency of spectral data in the first and second night with REM sleep findings derived from visual scoring in the first night lends further support to this hypothesis. The sleep disturbance experienced during the first night in a sleep laboratory may be a useful and valid model of transient insomnia. Therefore, we conclude that data from all nights recorded should be included in assessing a subject's sleep.

Adult↗
PubMed1996

Pharmacokinetics and dosing regimen of aminosidine in the dog.

The kinetic behaviour of the aminoglycoside aminosidine, given at 15 mg/kg intravenously, intramuscularly and subcutaneously, was studied in 5 dogs to determine the appropriate dosage schedule. The pharmacokinetic behaviour of aminosidine in dogs was similar to that in other species, except that it was eliminated more slowly (beta = 0.007 +/- 0.0003 min-1). Intramuscular and subcutaneous administration produced peak serum concentrations (Cmax[im] = 32 +/- 6.4 micrograms/ml; Cmax[ac] = 36 +/- 3.4 micrograms/ml) and times to peak concentration (Tmax = 60 min for both) that did not differ significantly; and neither compartmental nor non-compartmental analysis revealed any significant differences between any of the kinetic parameters obtained for these two extravenous routes of administration. Comparison of these results with previously published data suggests that aminosidine given once daily at 15 mg/kg would be as effective all, and safer than, the two or three daily administrations commonly employed in dogs.

Absorption↗
PubMed1996

Sleep stage scoring using the neural network model: comparison between visual and automatic analysis in normal subjects and patients.

In this paper, we compare and analyze the results from automatic analysis and visual scoring of nocturnal sleep recordings. The validation is based on a sleep recording set of 60 subjects (33 males and 27 females), consisting of three groups: 20 normal controls subjects, 20 depressed patients and 20 insomniac patients treated with a benzodiazepine. The inter-expert variability estimated from these 60 recordings (61,949 epochs) indicated an average agreement rate of 87.5% between two experts on the basis of 30-second epochs. The automatic scoring system, compared in the same way with one expert, achieved an average agreement rate of 82.3%, without expert supervision. By adding expert supervision for ambiguous and unknown epochs, detected by computation of an uncertainty index and unknown rejection, the automatic/expert agreement grew from 82.3% to 90%, with supervision over only 20% of the night. Bearing in mind the composition and the size of the test sample, the automated sleep staging system achieved a satisfactory performance level and may be considered a useful alternative to visual sleep stage scoring for large-scale investigations of human sleep.

Adult↗
PubMed1995

First-night effect in normal subjects and psychiatric inpatients.

The goal of the present study was to evaluate the first-night effect in psychiatric inpatients using large subject samples (n > 30) in order to obtain a good statistical evaluation. Thirty-two normal subjects and 94 psychiatric inpatients (38 depressives and 56 insomniacs) were studied for three consecutive nights in the hospital sleep laboratory. Our results showed clearly that there was a first-night effect in normal subjects, similar to that reported in previously published data, characterized by a longer rapid eye movement (REM) sleep latency (p < 0.05), increased wakefulness (p < 0.01) and total sleep time (p < 0.02) and a decreased sleep efficiency (p < 0.01). REM sleep latency and stage REM in the first third of the night were still altered in the second night. Both clinical groups had a less marked first-night effect than normal subjects, showing alterations only observed in REM sleep (p < 0.01) (decreased REM sleep, longer REM sleep latency, increased REM sleep gravity center). However, the first-night effect was more pronounced in insomniacs than in depressed patients. No statistical differences between the second and third nights' recordings were found in sleep parameters. It is suggested that first-night data should not be simply discarded but could be used in subsequent analyses.

Adaptation, Psychological↗
PubMed1994

Clinical pharmacokinetics of carboplatin in children.

The present study was undertaken to evaluate in children the plasma pharmacokinetics of free carboplatin given at different doses and schedules and to evaluate the inter- and intrapatient variability and the possible influence of schedule on drug exposure. A total of 35 children (age range, 1-17 years) with malignant tumors were studied. All patients had normal renal function (creatinine clearance corrected for surface body area, above 70 ml min-1 m-2; range, 71-151 ml min-1 m-2) and none had renal involvement by malignancy. Carboplatin was given at the following doses and schedules: 175, 400, 500, and 600 mg/m2 given as as a 1-h infusion; 1,200 mg/m2 divided into equal doses and infused over 1 h on 2 consecutive days; and 875 and 1,200 mg/m2 given as a 5-day continuous infusion. A total of 57 courses were studied. Carboplatin levels in plasma ultrafiltrate (UF) samples were measured both by high-performance liquid chromatography and by atomic absorption spectrophotometry. Following a 1-h infusion, carboplatin free plasma levels decayed biphasically; the disappearance half-lives, total body clearance, and apparent volume of distribution were similar for different doses. In children with normal renal function as defined by creatinemia and blood urea nitrogen (BUN) and creatinine clearance, we found at each dose studied a limited interpatient variability of the peak plasma concentration (Cmax) and the area under the concentration-time curve (AUC) and a linear correlation between the dose and both Cmax (r = 0.95) and AUC (r = 0.97). The mean value +/- SD for the dose-normalized AUC was 13 +/- 2 min m2 l-1 (n = 57).2+ The administration schedule does not seem to influence drug exposure, since prolonged i.v. infusion or bolus administration of 1,200 mg/m2 achieved a similar AUC (13.78 +/- 2.90 and 15.05 +/- 1.44 mg ml-1 min, respectively). In the nine children studied during subsequent courses a limited interpatient variability was observed and no correlation (r = 0.035) was found between AUC and subsequent courses by a multivariate analysis of dose, AUC, and course number. The pharmacokinetic parameters were similar to those previously reported in adults; however, a weak correlation (r = 0.52, P = 0.03) between carboplatin total body clearance and creatinine clearance varying within the normal range was observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1992

Canine leishmaniasis in the Gargano promontory (Apulia, South Italy).

We examined 444 dogs by visiting farms and peripheral districts on the Gargano promontory (Province of Foggia, Apulia, South Italy). Clinical examination and immunofluorescence antibody test for leishmaniasis were performed. Bone marrow and lymph node samples obtained from 25 dogs with positive serological test were cultured on Tobie-Evans medium. The results obtained show both a higher seropositivity rate for canine leishmaniasis (14.4%) and a higher percentage of asymptomatic dogs with positive serological test (53.1%) compared to previous research in the same area. Seven strains isolated from infected dogs belonged to Leishmania infantum species zymodeme Montpellier 1. None of 82 sera of humans living in close contact with infected dogs were positive for leishmaniasis.

Animals↗
PubMed1992

Cerebrospinal fluid pharmacokinetics of carboplatin in children with brain tumors.

The pharmacokinetics of carboplatin in cerebrospinal fluid (CSF) and plasma was studied in five children with brain tumors (four medulloblastomas and one ependimoblastoma) who underwent preirradiation treatment with carboplatin. Carboplatin pharmacokinetics was studied following the administration of 600 mg/m2 as a 1-h infusion. Four children were treated a few weeks after surgery, whereas one child with an unresectable tumor was treated prior to surgery. All patients had a ventricular-peritoneal CSF shunt connected to a subcutaneous reservoir. Total platinum and free carboplatin were measured. The mean AUC values for free carboplatin in CSF and plasma were 2.29 +/- 1.20 and 8.18 +/- 1.27 mg ml-1 min, respectively. The mean ratio of CSF AUC to plasma AUC was 0.28 (range, 0.17-0.46). Both plasma peak levels and AUC values showed limited interpatient variability. On the other hand, carboplatin levels in CSF showed substantial interpatient variability, with a greater than 5-fold difference in peak levels and a 3-fold difference in AUC values being recorded. The interpatient difference in CSF pharmacokinetics may have been related at least in part to the different anatomical alterations induced by the surgical procedures or by the presence of a large tumor mass. In the four evaluable patients exhibiting macroscopic residual tumor, we observed one complete remission (CR) and two partial remissions (PR) following two cycles that consisted of two doses of 600 mg/m2 carboplatin given on 2 consecutive days (total dose, 1200 mg/m2) and were separated by a 1-month interval. These results may give some indication as to the optimal dose and schedule for carboplatin administration in the treatment of primitive neuroectodermic tumors (PNET).

Brain Neoplasms↗
PubMed1992

Zinc and copper in tissues of rats with blood hypertension induced by long-term lead exposure.

Male Sprague-Dawley rats received for 14 months 0, 15, 30 and 60 micrograms/ml of lead in drinking water. Both blood pressure and tissue lead were augmented with a dose-response effect, while cardiac inotropism was increased only in the rats treated with 60 ppm of lead. In the exposed animals, zinc and copper were unchanged in kidneys and testicles and augmented in the brain, while copper, but not zinc, was reduced in the heart. These data suggest a possible relation between the modifications of copper and zinc metabolism and the effects of lead on cardiovascular homeostasis.

Administration, Oral↗
PubMed1990

Effect of oral gold salt therapy on bile acid absorption in rheumatoid arthritis patients.

Several studies pointed out an altered stool pattern as the most common side effect of auranofin therapy. The major mechanism in the aetiology of auranofin-induced impairment in bowel habit seems to be the inhibition of Na+/K+ ATPase in the gut. In vitro experiments proved that auranofin can affect active bile acid (BA) reabsorption in rat terminal ileum; this action, due to the ability of the drug to reduce Na+ pump activity by inhibiting Na+/K+ ATPase, may make a significant contribution to the auranofin-induced diarrhoea. The ability of auranofin to reduce the Na+ gradient necessary for active BA reabsorption, however, could cause a decrease of serum BA levels in patients taking auranofin before or without the development of an overt diarrhoea. We measured fasting and postprandial serum conjugated BA levels in 10 female rheumatoid arthritis patients before and after one month and two months' auranofin treatment. No patient developed diarrhoea during the chrysotherapy. When oral gold salt therapy was started, we observed a slight decrease in serum BA levels, but difference was not statistically significant. We can conclude that auranofin therapy does not cause BA malabsorption in patients who do not develop diarrhoea during the treatment.

Absorption↗
PubMed1990

Circulating immune complexes and autoantibodies in canine leishmaniasis.

In sera of 35 dogs with generalised leishmaniasis elevated levels of circulating immune complexes were detected by the 125I-C1q binding test. Furthermore, anti-heart muscle and anti-smooth muscle antibodies were detected by an indirect immunofluorescence technique in sera of infected dogs.

Animals↗
PubMed1989

Present possibilities for the determination of inorganic arsenic and organoarsenical compounds in biological fluids.

A survey is presented of the applicability of atomic spectrometry and other techniques for the quantitation of both inorganic and organic arsenic in biological fluids. Pretreatment of samples and speciation of the different As forms are particularly emphasized. The potential of inductively-coupled plasma spectrometry combined with high performance liquid chromatography separations is also highlighted.

Arsenic↗
PubMed1986

Zinc and copper metabolism during open-heart surgery.

Zinc and copper changes were studied in plasma, whole blood, urine and myocardium in 15 patients undergoing valve replacement in hypothermic cardiopulmonary bypass with hemodilution. During the cardiopulmonary bypass, a fall in plasma copper and zinc concentration was related to hemodilution. The zinc concentration also decreased in whole blood, but remained unchanged intracellularly. The urinary concentration of both cations, but not the output, decreased at the end of the operation in relation to the baseline values. The myocardial copper and zinc concentrations increased during the aortic cross-clamping period. The possible causes and significance of these changes are considered.

Adult↗