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Biomedical subjects

C Baraldi

Publications and source records attributed to C Baraldi.

At least 19 recordsLinked to original sources
PubMed2003

Opposite effect of acute and subchronic treatments with Ferula hermonis on copulatory behavior of male rats.

Sexually potent and sluggish/impotent male rats were orally treated with an extract of Ferula hermonis (30 and 60 mg/kg). The acute administration stimulated sexual motivation in potent rats and improved copulatory performance in sluggish/impotent rats. This last effect was elicited only by the higher dose, which, in parallel, increased serum testosterone levels in rats. On the contrary, when the extract was subchronically administered (10 days) a marked reduction in the percentage of rats achieving ejaculation was detected, together with a general impairment of the copulatory pattern. Furthermore, the repeated administration of the extract (6 mg/kg/day for 10 days) resulted in a significant reduction of testosterone levels in comparison with controls. The present results discourage a repeated assumption of F. hermonis, while suggesting its acute administration to improve the performance in sexual dysfunctions.

Animals↗
PubMed2002

Updating of form factor tabulations for coherent scattering of photons in tissues.

An updating of photon transport modelling in tissues is carried out by including the effect of molecular interference in the coherent (Rayleigh) scattering. To this end, the present tabulations--which permit us to obtain the linear differential scattering coefficient of compounds from a simple weighted sum of the elemental components--are integrated by adding files for a limited set of molecular interference functions. This set originates from a four-component model which is found to be capable of reproducing human tissues in situations involving bony and soft tissues. The proposed procedure overcomes, in the computation, the hindrance that the dependence on molecular interference effects leads every tissue to have its own diffraction pattern, which is not easily obtained by means of measurements or calculations.

Algorithms↗
PubMed2002

Extraction and purification from Ceratonia siliqua of compounds acting on central and peripheral benzodiazepine receptors.

The presence of molecules with high affinity for central and peripheral benzodiazepine receptors was determined in the pod and leaves of Ceratonia siliqua (carob). The amount of the substances able to selectively bind the central benzodiazepine receptor recovered from carob pods and leaves was respectively 12.17 and 18.7 ng diazepam equivalent/g. The amount of compounds active on peripheral benzodiazepine receptor in both pods and leaves was higher in comparison with the central one, being 49.83 and 40.00 PK 11195 equivalent/g, respectively. In particular the compounds acting on peripheral benzodiazepine receptors were found to be extremely concentrated in the young leaves (2572.57 ng PK 11195 equivalent/g). The presence of substances with central benzodiazepine activity in carob extracts seems of great importance in view of the possibility to use carob extract as potential natural products with anxiolytic-sedative effects. Moreover, the prevalence in leaves of substances acting on peripheral benzodiazepine receptor suggests the possible utilisation of leave extracts as chemopreventive agents.

Adrenal Glands↗
PubMed2002

Antiproliferative effects of Ceratonia siliqua L. on mouse hepatocellular carcinoma cell line.

Extracts from pods and leaves of carob (Ceratonia siliqua L.) were tested for their ability to inhibit cell proliferation of mouse hepatocellular carcinoma cell line (T1). The two extracts showed a marked alteration of T1 cell proliferation in a dose-related fashion reaching the maximal effect at 1 mg/ml. Moreover, we demonstrated that leaf and pod extracts were able to induce apoptosis in T1 cell lines after 24-h treatment mediating a direct activation of the caspase 3 pathway. HPLC analysis revealed the presence of gallic acid, (-) epigallocatechin-3-gallate and (-) epicatechin-3-gallate in pod and leaf extracts, compounds well known to exert antiproliferative effects. Their concentration reached 6.28 mg/g in carob leaves and 1.36 mg/g in carob pods extract. The discovery that carob pod and leaf extracts contained antiproliferative agents could be of practical importance in the development of functional foods and/or chemopreventive drugs.

Animals↗
PubMed2002

Pharmacological activity of hyperforin acetate in rats.

Hyperforin, the main antidepressant component of Hypericum extract, is not stable with regard to heat and light. Therefore, we investigated a newly synthetized derivative, hyperforin acetate. Herein we demonstrate its efficacy in animal models sensitive to antidepressant and anxiolytic drugs. In the forced swimming test, triple administration of hyperforin (5-20 mg/kg) significantly reduced the immobility time of rats, while in the learned helplessness test a daily treatment of 10 mg/kg for seven consecutive days was necessary to elicit an antidepressant effect. In the elevated plus-maze and in the light-dark test, the acute administration of hyperforin acetate (3-5 mg/kg) exerted an anxiolytic activity, which, however, was smaller than that of diazepam. The effect was inhibited by the pretreatment of rats with metergoline, a serotoninergic antagonist, but not with CGS-8216, a benzodiazepine receptor antagonist. Hyperforin acetate (3-10 mg/kg) was also able to reduce locomotion in rats without eliciting myorelaxant activity. As Hypericum extract was claimed to exert a potential influence on the liver drug metabolizing system, we showed that neither acute nor repeated oral doses of hyperforin acetate altered pentobarbital sleeping time in rats. Taken together, the present results show that hyperforin acetate is a pharmacologically active derivative of hyperforin and may be a starting point from which to develop new compounds for therapeutic purposes.

Animals↗
PubMed2001

Ammonia and endogenous benzodiazepine-like compounds in the pathogenesis of hepatic encephalopathy.

BACKGROUND: Ammonia and endogenous benzodiazepines (BDZs) are two of the most important agents among those taken into consideration in the pathogenesis of hepatic encephalopathy (HE). METHODS: Venous ammonia and endogenous BDZs sera levels were assayed in 58 liver cirrhosis patients (34 male, 24 female) free of commercial BDZs. Endogenous BDZs were measured by binding assay after high-performance liquid chromatography purification. Ammonia was assessed by colorimetric test. RESULTS: Endogenous BDZs and ammonia were significantly higher in Child-Pugh class C than in class B and class A (P < 0.05), correlating to the severity of the liver dysfunction but not with the degree of HE. A significant difference, in fact, was noted between degree 0 (no HE) versus III-IV of HE (P < 0.05), but not between degrees I-II versus III-IV. Regression analysis performed to find a correlation between the ammonia and BDZ levels in HE resulted negative. CONCLUSION: Clinical evidence is provided in cirrhotic patients that ammonia and endogenous BDZ levels do not correlate with each other in the outcome of HE.

Ammonia↗
PubMed1998

Diazepam binding inhibitor and total cholesterol plasma levels in cirrhosis and hepatocellular carcinoma.

Cholesterol is used by cells for biosynthetic processes and for steroid synthesis. Although the role of cholesterol in tumorigenesis is not clear it is known that steroids are important factors in human carcinogenesis. A polypeptide, diazepam binding inhibitor (DBI), which is an endogenous ligand for peripheral benzodiazepine receptors enhances steroidigenesis by promoting cholesterol delivery to the inner mitochondrial membrane which represents the rate-limiting step of steroid biosynthesis. We have assayed the total cholesterol (TC) and the DBI plasma concentrations in patients with liver cirrhosis complicated by hepatocellular carcinoma (HCC) in comparison with those of uncomplicated liver cirrhosis. TC and DBI levels have been studied in 73 cirrhotic patients and in 23 patients with HCC. Both TC and DBI levels were higher in HCC patients when compared with age, sex and Child-Pugh class matched cirrhotic controls. The values (mean+/-S.D.) in patients in Child-Pugh class B and C with and without HCC were respectively 128+/-30 mg/dl vs. 106+/-27 mg/dl (P < 0.01) and 2.05+/-0.78 pmol/ml vs. 0.78+/-0.84 pmol/ml (P < 0.0001). The data may be the result of the metabolic influence of tumors that enhances steroid biosynthesis during tumor proliferation.

Adult↗
PubMed1998

Up-regulation of peripheral benzodiazepine receptor system in hepatocellular carcinoma.

Increased number of peripheral benzodiazepine receptors (PBRs) have been found in some tumors outside the liver. The present study was to verify whether the PBR system is altered in hepatocellular carcinoma (HCC). The levels of endogenous benzodiazepine-like compounds (BZDs), measured by radioreceptor binding technique after HPLC purification and the endogenous ligand for PBRs, termed diazepam binding inhibitor (DBI), measured by radioimmunoassay utilizing a specific antibody for human DBI, were studied in the blood of 15 normal subjects, 12 liver cirrhosis and 10 patients with HCC. The levels of BZDs in serum were increased hundred fold in liver cirrhosis patients and slightly elevated in HCC patients. DBI was found to be increased in HCC patients. The binding recognition sites for PBRs (Bmax) were increased 4 to 7 fold in HCC tissue in comparison with that found in non-tumoral liver tissue (NTLT). On the contrary the concentrations of DBI were found to be significantly decreased in HCC tissue in comparison with the respective NTLT. These results seem to suggest an implication of PBRs and of their putative endogenous ligands in the metabolism of these neoplastic cells and possibly in their proliferation. The up-regulation of PBRs found in HCC tissue seems to indicate an increased functional activity of these receptors and opens up the possibility of new pharmacological and diagnostic approaches while the changes in the circulating endogenous ligands for the above receptors might be envisaged as early markers of tumorigenesis in liver cirrhosis.

Adult↗
PubMed1998

The effect of delta rays on the ionometric dosimetry of proton beams.

The interface effects arising in the measurement of absorbed dose by ionization chambers, owing to the inhomogeneity between the walls and the gas, have been evaluated by an analytical model. The geometrical situation considered here is appropriate for representing the behaviour of a plane-parallel ionization chamber exposed to a radiotherapeutic beam of protons. Two gases, dry air and tissue equivalent gas (methane based), as well as six materials commonly used in ionization chamber walls, i.e. graphite, A-150 tissue equivalent plastic, C-522 air equivalent plastic, nylon type 6, polymethyl methacrylate and polystyrene, have been examined. The analysis of the results shows that, within the limits of the detector dimensions and proton energies commonly used in the dosimetry of radiotherapeutic beams, these effects, if not taken into account in the measurement interpretation, can entail deviations of up to about 2% with respect to the correct absorbed dose in gas.

Biophysical Phenomena↗
PubMed1998

Endogenous benzodiazepine-like compounds and diazepam binding inhibitor in serum of patients with liver cirrhosis with and without overt encephalopathy.

BACKGROUND/AIM: Despite some controversy, it has been suggested that endogenous benzodiazepine plays a role in the pathogenesis of hepatic encephalopathy. The aim of the present study was to evaluate the concentrations of endogenous benzodiazepines and the peptide, diazepam binding inhibitor, in the blood of patients with liver cirrhosis with and without overt encephalopathy, and to compare these levels with those of consumers of commercial benzodiazepines. SUBJECTS: Normal subjects (90), benzodiazepine consumers (14), and cirrhotic patients (113) were studied. METHODS: Endogenous benzodiazepines were measured by the radioligand binding technique after high performance liquid chromatography (HPLC) purification. The presence of diazepam and N-desmethyldiazepam was assayed by HPLC-electrospray tandem mass spectrometry. Diazepam binding inhibitor was studied in serum by radioimmunoassay. RESULTS: Endogenous benzodiazepines were below the limit of detection in 7% of patients with encephalopathy. When detectable, their levels were at least comparable with those of benzodiazepine consumers and correlated with the liver dysfunction but not the stage of encephalopathy. Serum levels of diazepam binding inhibitor tended to decrease when endogenous benzodiazepines levels increased. CONCLUSIONS: Endogenous benzodiazepines may accumulate in patients with liver cirrhosis during the course of the disease, and the phenomenon appears to be independent of the presence or absence of encephalopathy.

Aged↗
PubMed1997

In vivo monitoring of bone-Pb and retrospective exposure: an assessment in occupationally exposed subjects.

In this work we present the preliminary results of an investigation in to the bone burden of lead in occupationally exposed subjects. The assessment of bone lead levels normalised to the mineral content (mg/kg bone mineral) were carried out by means of an in vivo X ray fluorescence techniques (Pb-XRF). The measurements were performed on the second phalanx of the right index finger and the minimum detectable limits of the XRF techniques was estimated around 25-30 mg/kg. Although the blood lead level monitoring over long time seems to indicate working activities in environments with low sources of lead contamination, high Pb-XRF levels, and not well correlated with the exposure time, were found. These anomalous values could be explained in term of the dependence of zinc protoporphyrin assessment against the measurement time.

Bone and Bones↗
PubMed1997

Molecular differential cross sections for x-ray coherent scattering in fat and polymethyl methacrylate.

Molecular differential cross sections for the coherent scattering of x-rays in polymethyl methacrylate (PMMA) and fat were determined from measured diffraction patterns in the interval chi = 0 to 6.4 nm-1 (chi = [sin theta/2)]/lambda; lambda being the incident wavelength having the units of nm and theta the scattering angle). All measurements were performed at a controlled temperature of 23 degrees C. The final results for PMMA show overall agreement when compared with the data existing in the literature. However, some discrepancies with the results reported by Kosanetzky et al in 1987 are found at the first three maxima. The data for filtered fat material are reported here for the first time. Finally, data sets of molecular form factors for fat and PMMA were compiled from the smoothed corrected experimental results by assuming these materials to be mono-molecular.

Adipose Tissue↗
PubMed1996

Hepatic encephalopathy in liver transplant recipients precipitated by benzodiazepines present in transfused blood.

The observation that there are episodes of encephalopathy in liver cirrhosis patients after orthotopic liver transplantation, despite a well functioning graft and despite the lack of cerebral complications, prompted us to investigate the potential role of circulating benzodiazepine-like compounds in these episodes. The plasma levels of benzodiazepines were examined in 14 liver cirrhotic patients before and after transplantation. The benzodiazepines in the fluids infused during surgery and in individual bags of blood administered after surgery to 4 of these patients were also assayed. Herein we report that benzodiazepines accumulating in the blood of some transplanted patients appear to derive from blood transfusions utilized during surgery. The analysis of the types of benzodiazepines present in the blood utilized for transfusions suggests the use of commercial benzodiazepines by the donors. These compounds seem to be able to precipitate hepatic encephalopathy in patients with preexisting encephalopathy. Hence we suggest not using benzodiazepine consumers as blood donors, at least for patients with encephalopathy undergoing to liver transplantation.

Adult↗
PubMed1994

Photon backscattering tissue characterization by energy dispersive spectroscopy evaluations.

Techniques for in vivo tissue characterization based on scattered photons have usually been confined to evaluating coherent and Compton peaks. However, information can also be obtained from the energy analysis of the Compton scattered distribution. This paper looks at the extension of a technique validated by the authors for characterizing tissues composed of low-atomic-number elements. To this end, an EDXRS (energy dispersive x-ray spectrometry) computer simulation procedure was performed and applied to test the validity of a figure of merit able to characterize binary compounds. This figure of merit is based on the photon fluence values in a restricted energy interval of the measured distribution of incoherently scattered photons. After careful experimental tests with 59.54 keV incident photons at scattering angles down to 60degrees, the simulation procedure was applied to quasi-monochromatic and polychromatic high-radiance sources. The results show that the characterization by the figure of merit, which operates satisfactorily with monochromatic sources, is unsatisfactory in the latter cases, which seem to favour a different parameter for compound characterization.

Computer Simulation↗
PubMed1991

Modulation of the cancer susceptibility measure, adenosine diphosphate ribosyl transferase (ADPRT), by differences in low-dose n-3 and n-6 fatty acids.

Adenosine diphosphate ribosyl transferase (ADPRT) is related to oxidants, and lower values for ADPRT in white cells suggest increased cancer susceptibility. Ordinarily, oxidants are generated intracellularly via metabolism of n-6 fatty acids common in western diets. However, n-3 fatty acids in fish oils might limit oxidants via competitive inhibition of key enzymes, elevate ADPRT, and lower cancer risk. In this controlled trial, 47 women were assigned either lecithin (an n-6 fatty acid, 7.2 g daily) or eicosapentaenoic acid-docosahexaenoic acid (n-3 fatty acids, 1.5 g daily) for six weeks, and 45 women completed all four visits. After six weeks, ADPRT increased by 9.3 +/- 10.8% (SD) for the n-3 fatty acid group relative to the n-6 fatty acid group. For the subset of 39 women with good compliance, ADPRT increased by 20.9 +/- 11.1% (nonparametric p = 0.039). This increase persisted after adjustment for regression to the mean. The trial suggests a "normalizing" effect of low-dose n-3 fatty acids on the ADPRT measure.

Disease Susceptibility↗