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Biomedical subjects

C Benedetti

Publications and source records attributed to C Benedetti.

53 records · Page 3Linked to original sources

Effect of nitrous oxide concentration on event-related potentials during painful tooth stimulation.

Effects of inhaling three levels of nitrous oxide in oxygen on event-related brain potentials (ERPs) and pain report were examined in 10 volunteers undergoing painful electrical stimulation of tooth pulp. Previous work by the authors demonstrated that inhalation of nitrous oxide 33 per cent in oxygen, iv injection of 0.1 mg fentanyl, oral administration of 975 mg aspirin, and electrical acupunctural stimulation all reduced ERP amplitudes obtained a vertex during painful tooth pulp stimulation. The authors report here the demonstration of a dose-response relationship between increasing concentrations of nitrous oxide in oxygen and measures of ERP amplitude and pain report. Subjects inhaled room air, nitrous oxide 25 per cent, 37 per cent, and 50 per cent in oxygen while ERPs were recorded and pain reports were given. The procedure was repeated on three separate days with each subject experiencing all levels of treatment on each day. Analyses of variance revealed that both ERP amplitude and pain report significantly decreased as dosage increased, and a significant linear trend was observed for the positive-going ERP wave-form deflection between 160 and 240 ms. Pain report scores decreased significantly (P less than 0.001) and proportionally as dosage increased, but there was not a significant linear trend. Inhalation of nitrous oxide in oxygen increased peak latency for the negative component at 50 ms and the positive component at 90 ms but not for later components. These outcomes demonstrate that amplitude measures of the vertex ERP obtained with dental dolorimetry correlate consistently with pain and analgesia. Simultaneous assessment of brain electrical activity and subjective report appears to be a useful approach for the assessment of analgesia in humans.

Adult↗

Circadian variation of plasma catecholamines in young and old men: relation to rapid eye movement and slow wave sleep.

Young and old healthy subjects with indwelling venous cannulae were found to undergo significant diurnal variations in plasma catecholamine levels. Both norepinephrine and epinephrine levels peaked in late morning and reached lowest values at night during sleep. Catecholamine levels were similar during slow wave and rapid eye movement sleep. While epinephrine levels were unaffected by age, norepinephrine levels were greater in older subjects by 28% during the day (at 1100 h; P less than 0.01) and by 75% at night (between 2200--0900 h; P less than 0.01). Older subjects slept less well; they had 90% less stage 4 sleep, 27% less rapid eye movement sleep, and twice as much wakefulness at night (P less than 0.05). These findings raise the possibility that this well known age effect on sleep may be related to increased sympathetic nervous system activity.

Adult↗

Base composition changes in hepatocyte nuclei DNA of rats at different ages.

DNA extracted from isolated hepatic nuclei of rats at different aged (1 h, 6 and 30 days of life) has been characterized by (i) melting temperature, (ii) buoyant density, (iii) thermal denaturation on hydroxyapatite and (iv) nucleoside composition. The melting midpoint (Tm) determined spectrophotometrically in 0.1 X SSC (0.15 M NaCl/0.0015 M sodium citrate) is 71.9 +/- 0.4 for 1-h-old rats and decreases to 70.7 +/- 0.3 in 6-day-old animals. The buoyant densities of DNAs determined by CsCl on both native and alkaline-denaturated and reneutralized DNA were also found to decrease with age. Hydroxyapatite thermal denaturation of sonicated DNA confirmed the significant difference between the Tm values of 1-h-old and 6-day-old rats (86.5 +/- 0.5 and 85.2 +/- 0.1, respectively). The possibility that these differences in Tm values could be due to an increase in methyl bases, has been ruled out by the finding that the amount of [3H]methyl incorporated in relation to the DNA synthesis is constant at these two ages. The alternative possibility of a change in base composition has been tested by the chromatographic analysis of nucleosides. The dG + dC content is 0.433 +/- 0.003 in 1-h-old rats and decreases to 0.411 +/- 0.002 and to 0.403 +/- 0.005 in 6-day- and 30-day-old rats, respectively. The physiological significance of the different base composition is discussed in relation to the possibility that specific DNA sequences are synthesized during the non-premitotic synthesis which has been found to take place during the first 6 days of life.

Aging↗

Iron deficiency in children with celiac disease.

To evaluate the incidence of either evident anemia or a subclinical status of iron deficiency in celiac disease (CD), we studied 80 celiac children aged 6 months to 18 years. They were subdivided into various groups according to morphology of gut mucosa and diet. Only eight of 47 celiac children had an evident anemia at the time of the first peroral bowel biopsy. In addition, 51% of the patients with atrophic mucosa and 56% of the children on a gluten-containing diet had serum iron levels less than 50 micrograms/dl; 35% of patients of both groups had serum ferritin levels less than 12 micrograms/L. On the contrary, only a small number of children with normal mucosa on a gluten-free diet showed a laboratory, subclinical picture of iron deficiency. The results of our study can therefore be summarized in three major items: (a) Low levels of both serum iron and ferritin can frequently be found during active CD. (b) Regular determination of serum iron levels appears to be useful in controlling the state of iron stores in such patients, as well as in deciding whether and when to recommend temporary iron supplementation. (c) Serum ferritin tests did not offer more information than the easier and cheaper serum iron determinations.

Adolescent↗

In vitro effects of meropenem and imipenem/cilastatin on some functions of human natural effector cells.

Meropenem, a new carbapenem antibiotic, was assessed to evaluate its effects on some functional parameters of human polymorphonuclear (PMN) and natural killer (NK) cells in comparison with imipenem/cilastatin. Both drugs significantly inhibited PMN phagocytosis and chemotaxis at concentrations of 2,000 and 4,000 microg/ml. They affected PMN microbicidal activity, evaluated against Candida albicans, only at 4,000 microg/ml. A study of the effects of both drugs on peripheral NK populations and the human NK line (NK-92) showed that even at 4,000 microg/ml there was no effect on antitumor activity. These data indicate that meropenem can reduce some PMN antimicrobial functions only at very high concentrations like imipenem/cilastatin, whereas no concentration influenced NK activity.

Candida↗

Mirtazepine: heir apparent to amitriptyline?

"What's new in therapeutics?" will examine and evaluate drugs that may have a place in hospice, palliative, and long-term care. Mirtazepine will be examined and evaluated. Mirtazepine is a potential alternative anti-depressant with multiple additional benefits. It is an atypical anti-depressant, which has both noradrenergic and specific serotonergic receptor antagonism (NaSSa), and a unique pharmacological profile. Mirtazepine appears to be a "designer drug" for palliative medicine with a number of benefits, but cost may be a drawback.

Amitriptyline↗

[Drug-induced taste disorders: analysis of the French Pharmacovigilance Database and literature review].

Taste disorders, generally poorly studied, have various causes. From 1985 to 1997, 305 observations of taste disorders imputed to drugs were notified to Regional Pharmacovigilance Centres. Patients were on average 54.4 years old and 58 per cent were women. Quantitative as well as qualitative disorders have been observed. Drugs mainly found were: angiotensin converting enzyme inhibitors, terbinafine, zopiclone, D-penicillamine, imidazole derivatives, quinolones, macrolides, carbimazole and calcium channel blockers. The outcome was favourable for 60.3 per cent of patients. The possible efficacy of zinc is discussed. It is generally considered that taste disorders are not a serious side-effect, but they can reduce the quality of life and lead to poor compliance with treatment.

Databases as Topic↗

Sprotte needle for obstetric anesthesia: decreased incidence of post dural puncture headache.

BACKGROUND AND OBJECTIVES: Reports have emphasized the importance of spinal needle tip configuration in the development of post dural puncture headache (PDPH). METHODS: Charts from 366 consecutive obstetric patients receiving spinal anesthesia for labor, cesarean delivery, postpartum surgical procedures, or postpartum tubal ligations were reviewed retrospectively for evidence of PDPH in the five days after dural puncture. Spinal anesthesia was administered to these patients using 25-gauge Quincke (n = 74), 26-gauge Quincke (n = 160), or 24-gauge Sprotte (n = 132) spinal needles. RESULTS: The groups were well matched demographically. The incidence of PDPH in the three groups was 9%, 8%, and 1.5%, respectively. Half of the patients developing PDPH in each group were treated with an epidural blood patch. CONCLUSIONS: Our data indicate that the Sprotte spinal needle, with its non-cutting tip, results in a significantly lower (p less than 0.05) incidence of PDPH than Quincke cutting-tip needles of smaller gauge.

Anesthesia, Obstetrical↗

Applied nanotechnology for the management of breakthrough cancer pain.

Pain, often considered the 5th vital sign, plays a significant role in the pathophysiology of cancer. Often addressed as an afterthought, untreated or under-treated cancer-related pain can have deleterious effects on a patient's physical and psychological well-being. Additionally, patients with breakthrough cancer pain tend to have more intense and more frequent background pain than patients without breakthrough pain. Currently, only oral transmucosal fentanyl citrate (OTFC) has reached the market for the treatment of cancer-related breakthrough pain. OTFC is an excellent first step in addressing the unmet need for symptomatic relief of breakthrough cancer pain; however, there is much room for improvement. Nanoscale science and engineering advancements have the long-term potential to bring revolutionary changes in society and across virtually all physical, biological and engineering disciplines, particularly medicine. Nanotechnology offers the potential to address multiple, major unmet problems in the diagnosis, treatment and symptom management of a large variety of diseases and conditions, including cancer. Nanotechnology can engender transformational progress in crucial aspects of the fight against cancer, spanning the continuum that ranges from prevention, to early detection, screening and monitoring, to innovative diagnostics and therapeutic modalities in the era of patient-centered, molecular medicine. Specifically, the authors will discuss their current research in the field of biomedical nanotechnology and its application to the management of breakthrough cancer pain.

Animals↗

Eosinophilic fasciitis: a case with IgA deficiency.

A case of eosinophilic fasciitis with IgA deficiency is presented. The increased recognition of this association suggests that IgA deficiency may be pathogenetically involved in the etiology of eosinophilic fasciitis.

Eosinophilia↗

Analgesic action of intravenous diazepam.

Intravenous diazepam is commonly used in clinical dentistry to produce sedation for dental procedures. Its chief benefit seems to derive from its sedative and amnesic properties. The literature contains conflicting reports about the direct analgesic effects of the drug. In the present study, we observed significant increases for conventional pain threshold measures in response to electric tooth pulp stimulation and decreased sensitivity to a fixed painful stimulus when diazepam was administered intravenously using clinical criteria for conscious sedative dosages. The data support the possibility that intravenously administered diazepam in conscious sedative doses may have some analgesic action in addition to its better documented sedative and amnesic properties.

Adult↗

In vitro production of leukemia inhibitory factor (LIF) by Hep G2 hepatoblastoma cells.

This study shows that the human hepatoblastoma cell line Hep G2 constitutively expressed a high level of Leukemia Inhibitory Factor (LIF) mRNA in the characteristic major 3.8 and minor 1.8 Kb forms. DNA analysis of the LIF gene from Hep G2 revealed no rearrangements. Production and secretion of significant concentrations of LIF were demonstrated by enzyme-linked immunoabsorbent assay (ELISA) in culture supernatants of Hep G2 cells. The highest LIF concentration in culture was found at 48-h (250 pg/ml). LIF produced by Hep G2 cells was biologically active since cell-free culture supernatants were able to induce in vitro differentiation of the M1 murine myeloid leukemia cell line. On the contrary, no LIF mRNA expression was detected in normal liver cells by PCR analysis. Our results suggest that LIF acts on normal parenchymal hepatocytes through a paracrine mechanism and on Hep G2 cells by an autocrine action. Furthermore they indicate that the Hep G2 cell line could be an useful model for studying the LIF autocrine mechanism in hepatomas.

Base Sequence↗