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Biomedical subjects

F Marino

Publications and source records attributed to F Marino.

At least 55 records · Page 3Linked to original sources
PubMed2000

Glutamate receptors of the AMPA type modulate neurotransmitter release and peristalsis in the guinea-pig isolated colon.

To assess the role of AMPA and kainate receptors in modulating neurotransmitter release from the myenteric plexus, the effect of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainic acid on endogenous acetylcholine (ACh) and noradrenaline (NA) overflow from the guinea-pig isolated colon was studied. AMPA inhibited spontaneous ACh overflow and increased electrically-evoked NA overflow. Kainic acid did not influence both ACh and NA overflow. AMPA-mediated effects on ACh and NA overflow were significantly reduced by the AMPA/kainate antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, CNQX. The inhibitory effect of AMPA on ACh overflow could be due, at least in part, to the AMPA-induced NA overflow as it was greatly reduced after adrenoceptor blockade and virtually abolished in sympathetically-denervated animals. The possible functional significance of these findings was studied by measuring the efficiency of the peristaltic reflex in the presence of the different agonists. The efficiency of peristalsis was enhanced by AMPA, whereas it was not modified by kainic acid. In conclusion, AMPA receptors, but not kainate receptors, may play a role in the modulation of ACh and NA release and of peristalsis in the guinea-pig colon.

Acetylcholine↗
PubMed2000

Diazepam-binding inhibitor-derived peptides induce intracellular calcium changes and modulate human neutrophil function.

We studied the effects of two diazepam-binding inhibitor (DBI)-derived peptides, triakontatetraneuropeptide (DBI 17-50, TTN) and eiksoneuropeptide (DBI 51-70, ENP), on cytosolic free Ca2+ concentrations ([Ca2+]i), chemotaxis, superoxide anion (O2-) generation, and phagocytosis in human neutrophils. Both TTN and ENP induced a rapid and transient rise of [Ca2+]i. The effect of TTN depended on the presence of extracellular Ca2+, whereas the effect of ENP also persisted after extracellular Ca2+ chelation. TTN induced neutrophil chemotaxis, stimulated O2- generation, and enhanced phagocytosis. ENP did not affect cell migration and oxidative metabolism but enhanced phagocytosis. Both peptides modulated N-formyl-methionyl-leucyl-phenylalanine- and phorbol myristate acetate-induced O2- generation. Because neutrophils express benzodiazepine receptors of the peripheral type (pBRs) and DBI-derived peptides may interact with such receptors, we investigated the possible role of pBRs in TTN- or ENP-induced effects. The synthetic pBR ligand RO 5-4864 increased [Ca2+]i through extracellular Ca2+ influx and this effect was prevented by the pBR antagonist PK-11195. RO 5-4864, however, was ineffective on neutrophil migration and O2- generation and only slightly affected phagocytosis. Moreover, PK-11195 delayed the [Ca2+]i rise induced by TTN but did not significantly affect its extent, and had no effect on the [Ca2+]i rise induced by ENP. We conclude that DBI-derived peptides induce [Ca2+]i changes and modulate neutrophil function mainly through pBR-independent pathways. In view of the wide cell and tissue distribution of DBI in the brain and in peripheral organs, modulation of neutrophil function by DBI-derived peptides may be relevant for both the neuroimmune network and the development and regulation of the inflammatory processes.

Antineoplastic Agents↗
PubMed2000

Trk neurotrophin receptor-like proteins in the teleost Dicentrarchus labrax.

In recent years, data have accumulated suggesting that the role of neurotrophins and Trk receptors may not be limited to the nervous system, and the presence of these substances has been detected in a variety of vertebrate and invertebrate non-nervous tissues. This study was designed to map the expression of immunoreactivity (IR) for Trk-like proteins in alevins of the teleost Dicentrarchus labrax, with particular emphasis on non-nervous structures. We used antibodies against specific epitopes of the intracellular domain of these proteins, a region that is highly conserved in phylogeny. Trk-like IR was seen in segregate cell populations of the nervous system, and non-nervous tissues. In the central nervous system TrkA-like and TrkC-like IR was abundant, whereas TrkB-like IR was restricted to a low number of brain areas. Expression of Trk-like protein IR was observed in the peripheral nervous system and sensory organs, with the exception of the lateral line organ. Outside the nervous system, TrkA-like IR was mainly found in different epithelia, TrkB-like IR in the endocrine and digestive system, and TrkC-like IR in the cardiovascular and immune systems. The gills showed IR for all three Trk-like proteins, whereas they were absent from the gonads. Furthermore, scattered cells positive for Trk-like proteins were found in most of the investigated tissues. The distribution of Trk-like IR in this teleost is compared with that of mammals and birds, which it often paralleled, and the possible role of neurotrophins and Trk-like receptor proteins in different non-neuronal tissues is discussed.

Animals↗
PubMed2000

Nitro-PAH in ambient particulate matter in the atmosphere of Athens.

Nitrated polynuclear aromatic hydrocarbons (NPAH) with a molecular mass of 247 Daltons were found in soot collected in downtown Athens during a campaign performed in 1996. In particular, 2-nitrofluoranthene (2-NFa) and 2-nitropyrene (2-NPy), which are mainly related to photo-induced chemical processes occurring in the atmosphere, were more abundant than 1-nitropyrene (1-NPy) usually associated to motor vehicle exhaust.

Air Pollutants↗
PubMed2000

The pattern of response to interferon alpha (alpha-IFN) predicts sustained response to a 6-month alpha-IFN and ribavirin retreatment for chronic hepatitis C. TVVH Study Group.

BACKGROUND/AIMS: In chronic hepatitis C, interferon-alpha (alpha-IFN) and ribavirin combination therapy improves sustained response compared to alpha-IFN monotherapy, both in naive patients and in previous alpha-IFN relapsers, but the efficacy of such therapy remains limited in non-responder cases. The aim of this study was to assess whether the pattern of response to alpha-IFN alone may predict sustained response to combination therapy during retreatment. METHODS: Fifty previous alpha-IFN relapsers and 50 previous alpha-IFN non-responders were retreated with a high alpha-IFN dose (6 MU/thrice weekly for 2 months; induction phase) and then randomised to continue with alpha-IFN alone (3 MU/thrice weekly) or to receive combination therapy (3 MU/thrice weekly of alpha-IFN and 1000-1200 mg/daily of ribavirin) for an additional 6 months according to the biochemical response to alpha-IFN shown after the induction phase. All patients were also evaluated for virological and histological response. RESULTS: Eleven of 25 (44%) relapsers treated with combination therapy and 4/25 (16%) treated with alpha-IFN alone achieved a sustained response. The corresponding figures among non-responders were 1/25 (4%) and 0/25, respectively. Among 26 patients with a complete ALT and HCV-RNA response after 2 months of alpha-IFN, sustained response was seen in 11/14 (79%) treated with combination therapy and in 4/12 (33%) treated with alpha-IFN alone (p=0.05). On the other hand, of 74 cases still HCV-RNA positive after 2 months of alpha-IFN alone, biochemical and virological end of therapy response was better with combination therapy (11/36; 30.5%) compared to alpha-IFN alone (4/38; 10.5%), but only one patient developed a sustained response (1/36; 3%). CONCLUSIONS: The retreatment with a 6-month combination therapy was associated with a high rate of sustained response only in patients showing a complete biochemical and virological response to alpha-IFN alone. Longer retreatment with combination therapy may be needed to achieve a sustained response in patients without a prompt virological response to alpha-IFN.

Adult↗
PubMed2000

The ultrastructure of pearl organs in Rutilus rubilio as revealed by scanning electron microscopy.

Pearl organs are epidermal structures that in the mating season appear on different body regions of fishes belonging to Catastomidae and Ciprynidae families. In veterinary medicine, pearl organs were studied for their possible role as index of fish good quality for human feeding. Recently some authors put in evidence the possible relationship with other secondary sexual characters to establish the stage of sexual maturation in fishes. Little is known about their morphology and morphogenesis. For these reasons, pearl organs of 10 specimens of Rutilus rubilio, collected in Caserta (Italy), were studied by light and scanning electron microscopy (SEM). By means of SEM, the presence of pearl organs was demonstrated on dorsal and lateral fins too and their fine structure was studied. This study permitted to show pearl organs at different evolutive stages clarifying their morphogenesis and suggesting some inspective and functional considerations.

Animals↗
PubMed1999

Distribution of n-alkanes, polynuclear aromatic hydrocarbons and nitrated polynuclear aromatic hydrocarbons between the fine and coarse fractions of inhalable atmospheric particulates.

The distribution ratios of n-alkanes, polynuclear aromatic hydrocarbons (PAHs) and nitrated PAH components between fine and coarse fractions of soot has been investigated in downtown Rome through three field campaigns carried out at different times of the year. The preferential accumulation of almost all species investigated onto fine particles has been observed in all field experiments performed. Moreover, nitrated PAHs had varied distributions, according to the origin of their occurrence in the atmosphere; in fact, congeners of photochemical origin accumulated more in fine particles than those released by primary sources.

Air Pollutants↗
PubMed1999

Endogenous catecholamine synthesis, metabolism, storage and uptake in human neutrophils.

Evidence is presented that human neutrophils contain catecholamines and several of their metabolites. In vitro, incubation with alpha-methyl-p-tyrosine or pargyline affects intracellular dopamine, norepinephrine and their metabolites, suggesting catecholamine synthesis and degradation by these cells. Reserpine reduces intracellular dopamine and norepinephrine and desipramine reduces intracellular norepinephrine, suggesting the presence of storage and uptake mechanism. In view of the ability of catecholamines to affect neutrophil function, the present results support the hypothesis that autoregulatory adrenergic mechanisms may exist in these cells.

Adult↗
PubMed1999

Modulation of enteric cholinergic neurons by hetero- and autoreceptors: cooperation among inhibitory inputs.

In the guinea-pig colon, acetylcholine (ACh) release from intrinsic cholinergic motor neurons is inhibited by adrenoceptors, opioid and muscarinic receptors. Chronic sympathetic denervation resulted in supersensitivity to the inhibitory effect of DAMGO (mu-opioid agonist) on ACh release and on the peristaltic reflex. After chronic treatment with naltrexone (NTX) supersensitivity to DAMGO and subsensitivity to UK14,304 (alpha2-adrenoceptor agonist) developed for both functional parameters. The facilitatory effect of scopolamine on ACh release remained unchanged after chronic NTX treatment, whereas it was potentiated after chronic sympathetic denervation. These data suggest the existence of a functional interaction between different inhibitory pathways modulating cholinergic motor neurons in the guinea-pig colon. Namely, chronic manipulation of an inhibitory pathway may entail adaptive sensitivity changes in another inhibitory pathway so that homeostasis can be maintained.

Acetylcholine↗
PubMed1999

Endogenous catecholamine synthesis, metabolism storage, and uptake in human peripheral blood mononuclear cells.

Evidence has been obtained that peripheral blood mononuclear cells contain dopamine, norepinephrine, epinephrine, and their metabolites. Pharmacologic inhibition of tyrosine hydroxylase or monoamine oxidase profoundly affected intracellular catecholamines (CTs) and their metabolites, indicating that these cells are able to synthesize and breakdown CTs. The sensitivity of intracellular CTs to reserpine and the presence of CTs in the extracellular medium suggest that CTs are stored and released. Moreover, the increase of extracellular CTs in the presence of monoamine uptake blockers point to the presence of functional uptake mechanisms. Altogether, these results indicate the existence of a CT lifecycle in human mononuclear cells and warrant further studies to investigate the role of adrenergic autoregulatory mechanisms in modulation of the immune response and in the pathogenesis of diseases involving the immune system.

Adult↗
PubMed1999

Plexiform schwannoma of the cheek.

We present a case of subcutaneous plexiform schwannoma, a rare benign peripheral nerve sheath tumour characterized by a multinodular and plexiform growth pattern. A review of the literature was performed to identify the relationship between plexiform schwannoma and neurofibromatosis types 1 and 2, and schwannomatosis. It is also important to distinguish plexiform schwannoma from plexiform neurofibroma, a particular type 1 neurofibromatosis lesion, because of the propensity of the latter for malignant degeneration.

Adult↗
PubMed1999

Biotypology. I: Scope and history.

From ancient times, the principal medical cultures tried to classify individuals according to their morpho-functional characteristics in order to study and understand their tendencies in terms of health and sickness. In the last two centuries, in Europe and America, a number of academic schools emerged whose theoretical concepts and ideas were important theoretically but had relatively little practical application. By contrast, in France and Italy, there was the joining of biotypological schools and homoeopathy, which permitted the correlation between biotypes and their relevant homoeopathic remedies. This article outlines the evolution of biotypological thinking and the results of the above said merger.

Complementary Therapies↗
PubMed1999

Biotypology II: modern concepts.

Modern concepts of biotypology are based on embryological concepts. Based on the work of Nebel and Vannier, described in part I of this article, Bernard related endoblast mesoblast and ectoblast to Carbonic, Sulphuric and Phosphoric constitutions respectively. These in turn are linked to particular morphologies and disease susceptibilities, and the question of an inherited tuberculous predisposition has been much debated. The reaction of particular biotypes to stress has been analysed in terms of Selye's Adaptation Syndrome. Bernard has also analysed the pathological progression of biotypes in terms of a sequence of salts: Calcium, Magnesium, Potassium, Sodium, Barium and Ammonium.

Body Constitution↗
PubMed1999

Energy cost of sport rock climbing in elite performers.

OBJECTIVES: To assess oxygen uptake (VO2), blood lactate concentration ([La(b)]), and heart rate (HR) response during indoor and outdoor sport climbing. METHODS: Seven climbers aged 25 (SE 1) years, with a personal best ascent without preview or fall (on sight) ranging from 6b to 7a were assessed using an indoor vertical treadmill with artificial rock hand/foot holds and a discontinuous protocol with climbing velocity incremented until voluntary fatigue. On a separate occasion the subjects performed a 23.4 m outdoor rock climb graded 5c and taking 7 min 36 s (SE 33 s) to complete. Cardiorespiratory parameters were measured using a telemetry system and [La(b)] collected at rest and after climbing. RESULTS: Indoor climbing elicited a peak oxygen uptake (VO2climb-peak) and peak HR (HRpeak) of 43.8 (SE 2.2) ml/kg/min and 190 (SE 4) bpm, respectively and increased blood lactate concentration [La(b)] from 1.4 (0.1) to 10.2 (0.6) mmol/l (p < 0.05). During outdoor climbing VO2 and HR increased to about 75% and 83% of VO2climb-peak and HRpeak, respectively. [La(b)] increased from 1.3 (0.1) at rest to 4.5 mmol/l (p < 0.05) at 2 min 32 s (8 s) after completion of the climb. CONCLUSIONS: The results suggest that for elite climbers outdoor sport rock climbs of five to 10 minutes' duration and moderate difficulty require a significant portion of the VO2climb-peak. The higher HR and VO2 for outdoor climbing and the increased [La(b)] could be the result of repeated isometric contractions, particularly from the arm and forearm muscles.

Adult↗
PubMed1999

Granulocyte-macrophage colony stimulating factor modulates the production of TNF alpha by differentiated U937 cells infected with Leishmania major.

In this work, the production of tumor necrosis factor alpha (TNF alpha) during interaction of human phagocytes with the intracellular parasite Leishmania major was further investigated. The human monocytic cell line U937, differentiated with a combination of 1 alpha, 25 dihydroxyvitamin D3 (VD) and retinoic acid (RA), or with granulocyte macrophage colony stimulating factor (GM-CSF) was used. Differentiated U937 cells were infected with Leishmania major promastigotes, and TNF alpha was assayed in cell culture supernatants. It was found that the cytokine was produced only by U937 cells differentiated with VD/RA and further incubated with GM-CSF and LPS or interferon gamma (IFN gamma). L. major induced TNF alpha production only in the presence of GM-CSF. No direct relationship was found, however, between production of TNF alpha and resistance of differentiated U937 cells to infection with L. major.

Adjuvants, Immunologic↗
PubMed1998

Whole body cooling by immersion in water at moderate temperatures.

This study investigated the potential use of whole body cooling by water immersion for lowering body temperatures prior to endurance exercise. Rectal temperature (Tre), mean skin temperature (Tsk), oxygen consumption (VO2), and ventilation (VE) were measured in 7 male and 3 female subjects who were immersed in a water bath for up to 60 min. Initial water temperature was 28.8+/-1.5 degrees C and decreased to 23.8+/-1.1 degrees C by the end of immersion. Pre-immersion Tre of 37.34+/-0.36 degrees C was not altered by 60 min water immersion but decreased to 36.64+/-0.34 degrees C at 3 min post immersion (p < 0.01). Tsk decreased from 33.23+/-1.4 degrees C to 26.95+/-1.8 degrees C (p < 0.01) at the end of immersion. Reductions in Tre and Tsk resulted in reduced body heat content (Hc) of approximately 545 kJ (p < 0.01) at the end of immersion. VO2 and VE increased from pre-immersion values of 0.34+/-0.08 L x min(-1) and 6.2+/-1.4 L x min(-1) to 0.54+/-0.09 L x min(-) and 11.5+/-5.4 L x min(-1) at the end of immersion, respectively. Heart rate remained unchanged throughout immersion. These results indicate that whole body immersion in moderately cold water temperatures is an effective cooling maneuver for lowering body temperatures and body Hc in the absence of severe physiological responses generally associated with sudden cold stress.

Analysis of Variance↗