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Biomedical subjects

S Milani

Publications and source records attributed to S Milani.

At least 19 recordsLinked to original sources
PubMed1995

Role of epidermal growth factor in peptic ulcer healing.

In recent years, increasing interest has been focused on peptide growth factors, and impressive progress has been made in the understanding of their role in tumor development and progression. However, evidence is mounting that peptides such as epidermal growth factor and transforming growth factor-alpha may be of much more physiological than pathological importance. This brief article is intended to give a rapid overview of the available data supporting a role for epidermal growth factor and its human homologue urogastrone in peptic ulcer healing.

Animals↗
PubMed1995

Duodenal ferritin synthesis in genetic hemochromatosis.

BACKGROUND/AIMS: The molecular defect of genetic hemochromatosis (GH) is unknown. It is believed that low expression of duodenal ferritin in GH is caused by tissue or cell specific defect of ferritin synthesis. Our study was designed to ascertain whether the control of duodenal ferritin synthesis in GH was defective. METHODS: Expression at the single cell level of H and L ferritin messenger RNAs and protein and activity of the iron regulatory factor, which controls the translation of ferritin messenger RNA, were assessed in 43 duodenal biopsy specimens from individuals with GH, secondary hemochromatosis (SH), anemia, or normal iron balance. RESULTS: Signal for ferritin H and L subunit messenger RNAs was detected in both absorptive and nonabsorptive cells by in situ hybridization, but in 10 of 14 patients with untreated GH, the signal was lower than in patients with SH or normal subjects. However, immunostaining for ferritin protein documented a diffuse/cytoplasmic pattern, whereas a supranuclear/granular staining was found in normal subjects or patients with SH. The spontaneous activity of duodenal iron regulatory factor was consistently higher in patients with GH than in normal subjects or subjects with anemia or SH. CONCLUSIONS: In patients with GH, ferritin gene transcription is preserved in both absorptive and nonabsorptive intestinal cells. Low accumulation of ferritin is not caused by a defective control of ferritin synthesis but by low expression of ferritin messenger RNA and sustained activity of iron regulatory factor.

Adolescent↗
PubMed1995

Modeling hemodynamic profiles by telemetry in the rat. A study with A1 and A2a adenosine agonists.

The newly developed radiotelemetry system offers a number of advantages for the measurement of blood pressure and heart rate in laboratory animals. However, no available statistical methods permit valid use of the many data gathered with this continuous recording of hemodynamic parameters. This study describes elaboration and testing of mathematical functions as applied to the measurement of the effects of drugs on blood pressure and heart rate in spontaneously hypertensive rats. We used parametric functions analogous to those for pharmacokinetic studies. Curve fitting is in fact the only approach that provides reasonable estimates of hemodynamic kinetic constants. Nonlinear functions were assessed by analyzing telemetric hemodynamic effects induced by three adenosine receptor agonists with different selectivity for the A1 or A2a receptor. After acute administration in conscious rats, the A1 agonist 2-chloro-N6-cyclopentyladenosine induced dose-related hypotension (eg, 0.03 mg/kg; peak, -70 mm Hg; time to peak, 0.34 hour) and bradycardia (eg, 0.03 mg/kg; peak, -186 beats per minute [bpm]; time to peak, 0.38 hour). The A2a agonist 2-hexynyl-5'-N-ethylcarboxamidoadenosine induced dose-related hypotension (eg, 0.003 mg/kg; peak, -36 mm Hg; time to peak, 0.32 hour) with reflex tachycardia (eg, 0.003 mg/kg; peak, 152 bpm; time to peak, 0.35 hour). The nonselective adenosine agonist 5'-N-ethylcarboxamidoadenosine (0.1 mg/kg) induced hypotension (peak, -75 mm Hg; time to peak, 2.2 hours) and bradycardia followed by tachycardia (first peak, -131 bpm; time to peak, 1.26 hours; second peak, 123 bpm; time to peak, 13.9 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1995

Deflazacort versus methylprednisolone in polymyalgia rheumatica: clinical equivalence and relative antiinflammatory potency of different treatment regimens.

OBJECTIVE: To assess the clinical efficacy and equivalence of a daily vs alternate day regimen, and the potency ratio between 2 glucocorticoids, deflazacort and 6-methylprednisolone. METHODS: Thirty-one patients with recent onset polymyalgia rheumatica (PMR) were randomly assigned to deflazacort (n = 16) or 6-methylprednisolone (n = 15), according to a 2 period (duration of each period = 6 weeks), crossover, open design for comparing 2 dose regimens (daily vs alternate day), and according to a between-patients, double blind design for comparing the therapeutic effects of the 2 glucocorticoids (deflazacort vs 6-methylprednisolone). The patients, either during alternate day or daily regimen, were treated with fixed oral doses for the first 2 weeks (assuming a potency ratio deflazacort/6-methylprednisolone of 1.5 mg/1.0 mg: deflazacort 24 mg or 6-methylprednisolone 16 mg, daily; deflazacort 48 mg or 6-methylprednisolone 32 mg, alternate day), and with titrated doses for the next 10 weeks. RESULTS: Two patients dropped out during the first 6 week period. The time course and extent of the improvement of disease activity indices (limb-girdle pain, morning stiffness, erythrocyte sedimentation rate, C-reactive protein, and plasma fibrinogen) were not statistically different under the 2 regimens. The satisfactory equivalent glucocorticoid response observed in 12 pairs of patients treated with deflazacort and 6-methylprednisolone progressed significantly from baseline to the end of the study, under daily or alternate day regimen, with no significant difference between the 2 glucocorticoids. Deflazacort proved less potent than 6-methylprednisolone (1.78 mg: 1.0 mg minimum effective daily dose; 1.68: 1.0, alternate day), but equally effective. CONCLUSION: The 2 dose regimens, 6-methylprednisolone and deflazacort showed no significant differences in terms of efficacy during the short term treatment of PMR. Deflazacort proved less potent than initially estimated.

Aged↗
PubMed1995

In situ hybridization in the study of the kidney and renal diseases.

In situ hybridization (ISH), combined with immunohistochemistry, has become a powerful tool in the investigation of temporal and spatial relationships between specific cellular sources of mRNA and ultimate localization of translated protein. This review provides a discussion on basic ISH methods and a comprehensive examination of the literature on applications of ISH to the study of nephrogenesis, normal kidney, and renal disease. The review covers literature examining expression of mRNA encoding growth factors, proteins involved in signal transduction and transcription, proteolysis, extracellular matrix and a variety of other products involved in regulating cell remodeling during nephrogenesis. Expression of mRNA encoding many of these products diminishes in normal adult renal tissue, only to be reactivated during renal disease. Such a recapitulation of the expression of mRNAs involved in nephrogenesis might indicate that similar cellular events are required for remodeling during renal disease. In addition, ISH has allowed for the investigation of interactions between cells intrinsic to the kidney and inflammatory cells (and their biologically active products) recruited from exogenous sources. Although diagnostic use of ISH is currently limited, the implications for the use of this methodology in future clinical applications is promising.

Adult↗
PubMed1995

Transforming growth factor-beta 1 regulates platelet-derived growth factor receptor beta subunit in human liver fat-storing cells.

Activated liver fat-storing cells (FSC) are known to play a key role in the development of liver fibrosis. An important element in FSC activation process is the increased expression of receptors for platelet-derived growth factor (PDGF), a potent mitogen for FSC. The aim of the present study was to evaluate the expression PDGF-receptor alpha and beta subunits in cultured human FSC and their regulation induced by transforming growth factor-beta 1 (TGF-beta), a cytokine potentially involved in an autocrine loop. TGF-beta induced a significant increase of the mitogenic effect of PDGF-BB and did not affect the mitogenicity of PDGF-AA and PDGF-AB, suggesting a selective action of the PDGF-receptor-beta subunit. This hypothesis was confirmed by regulation experiments showing selective and time-dependent upregulation of the messenger (m)RNA encoding for the PDGF-receptor-beta subunit and the relative protein induced by TGF-beta. In addition, binding studies showed a parallel increase of PDGF-BB binding sites after incubation of human FSC with TGF-beta. These studies provide evidence for an additional mechanism leading to the perpetuation of FSC activation and proliferation and contribute to a better understanding of the role of TGF-beta and PDGF in the development of liver fibrosis.

Becaplermin↗
PubMed1994

Undulin RNA and protein expression in normal and fibrotic human liver.

We have analyzed the distribution, gene expression and cellular origin of undulin, a large extracellular matrix glycoprotein associated with mature collagen fibrils, in human liver by immunohistochemistry, Northern-blot analysis and in situ hybridization. In normal liver, undulin was distributed as densely packed fibers in portal tract stroma, and as fine fibers along sinusoids, and around central veins. Undulin ribonucleic acid expression was low in normal liver, and confined to mesenchymal cells of portal tract stroma, vessel walls and perisinusoidal space. In fibrotic liver, undulin deposition and gene expression were enhanced in fibrotic stroma and areas of fibrogenesis identified by the presence of active septa and inflammatory infiltrate. Undulin gene expression in fibrotic liver was exclusively localized in mesenchymal cells that could be identified by staining for vimentin, and partially for alpha-smooth muscle actin as (myo)fibroblasts, and possibly fat-storing cells. These data suggest that undulin is a constituent of the hepatic extracellular matrix of normal human liver, and that it participates in the rearrangement of connective tissue occurring in hepatic fibrosis.

Adolescent↗
PubMed1992

Cellular localization of procollagen gene transcripts in inflammatory bowel diseases.

The cellular localization of procollagen types I, III, IV, and V gene transcripts was determined in tissues from 12 patients with either Crohn's disease (CD) or ulcerative colitis (UC) and nine controls by in situ hybridization with 35S-labeled RNA probes. In CD, the signal intensity and number of labeled cells were significantly increased, particularly in deeper intestinal layers. In contrast, the labeled cells in UC were concentrated in the subepithelial intestinal layers, with an overexpression of procollagen III RNA transcripts. Immunohistological stainings for procollagen types I, III, and IV showed a weaker staining in UC than in CD, indicating that increased transcript levels in UC are unrelated to the enhanced collagen protein deposition, although the increase of procollagen messenger RNA levels correlated with the density of the inflammatory infiltrate. It was concluded that both CD and UC show highly increased procollagen RNA transcript levels but differ in collagen deposition. Thus, different posttranscriptional or posttranslational regulatory mechanisms, such as collagen degradation, may account for the observed differences.

Adult↗
PubMed1992

Effects of sulglycotide on endogenous prostaglandin synthesis in human antral mucosa.

The effect of sulglycotide, a polysulphated glycopeptide isolated from pig duodenum, on PGE2, 6-ketoPGF1 alpha and TxB2 production from isolated biopsy specimens of human antral mucosa was investigated in vitro, in comparison with carbenoxolone. In addition to a tendency toward increased PGE2 production just short of statistical significance, both sulglycotide and carbenoxolone significantly increased 6-ketoPGF1 alpha accumulation in the incubation medium. TxB2 levels were not significantly modified by the two drugs. Therefore, changes in the prostanoid production by human antral mucosa could, at least partially account for the cytoprotective effects of sulglycotide in man.

6-Ketoprostaglandin F1 alpha↗
PubMed1992

Fat-storing cells as liver-specific pericytes. Spatial dynamics of agonist-stimulated intracellular calcium transients.

Liver perisinusoidal fat-storing cells (FSC) show morphological and ultrastructural characteristics similar to pericytes regulating local blood flow in other organs. In the present study we have analyzed whether FSC respond to local vasoconstrictors such as thrombin, angiotensin-II, and endothelin-1 with an increase in intracellular free calcium concentration ([Ca2+]i) coupled with effective cell contraction. All agonists tested induced a rapid and dose-dependent increase in [Ca2+]i followed by a sustained phase lasting several minutes in confluent monolayers of Fura-2-loaded human FSC. Pharmacological studies performed using different Ca2+ channel blockers indicated that, at least for thrombin and angiotensin-II, the sustained phase is due to the opening of voltage-sensitive membrane Ca2+ channels. To analyze the temporal and spatial dynamics of Ca2+ release in response to these agonists, we performed experiments on individual Fura-2-loaded human FSC using a dual wavelength, radiometric video imaging system. The rise in [Ca2+]i was exclusively localized to the cytoplasm, particularly in the branching processes. Increases in [Ca2+]i more than four-fold were associated with a simultaneous and transient reduction of cell area indicating reversible cell contraction. Our results indicate that the Ca(2+)-dependent contraction of human FSC in vitro may reflect a potential role in regulating sinusoidal blood flow in vivo.

Angiotensin II↗
PubMed1992

[Pathomorphology of acute and chronic stages of CCl4-induced liver fibrosis: immunohistochemical and in situ hybridization studies].

The cellular localization of expression of various genes activated during the course of liver fibrosis and regeneration was studied by immunohistology and in situ hybridization in rat and human liver tissues. Mesenchymal cells proved to be the principal sources of extracellular matrix proteins and of fibrogenic growth factors, whereas the collagenase-activating protease transin/stromelysin gene was transcribed in parenchymal cells as well. Fibrogenesis by the mesenchymal compartment appears to be balanced by fibrolysis controlled by parenchymal cell functions. Continuous parenchymal damage may thus disrupt this balance between fibrogenesis and fibrolysis, resulting in fibrosis.

Animals↗
PubMed1991

Comparison of growth retarding effects induced by two different glucocorticoids in prepubertal sick children: an interim long-term analysis.

The low interference with growth expected in child for a cortisol analogue, deflazacort (DFZ), prompted us to verify if DFZ could affect growth less than prednisone (PDN). An interim analysis relative to 27 girls and 38 boys (out of 100 expected) aged 3-12 yrs, after a median period of 14 mo.s is reported. Children with connective tissues (CTD) and glomerular disorders (KD) were randomly allocated to DFZ or PDN. Anthropometric measurements and maturity ratings were performed. Mean daily doses of PDN (or DFZ equivalent), from 0.57 to 0.64 mg/kg (DFZ 0.92 to 0.94 mg/kg) to induce control and from 0.19 to 0.39 mg/kg (DFZ 0.34 to 0.36 mg/kg) to maintain disease under control were given in CTD and KD, respectively. The increase in bone age delay over time was significantly greater than for PDN (-4.0 mo/yr) than DFZ (-1.8 mo/yr) in the overall group. The increases in statural age delay and loss over time were significantly greater than for PDN (-5.9 and -5.9 mo/yr) than DFZ (-2.4 and -2.4 mo/yr), only in children with "taller" midparents. Although doses of DFZ 1.1-1.8 times those of PDN were given, growth retardation in PDN-treated children was nevertheless 2.3-2.5 times that in DFZ-ones.

Age Determination by Skeleton↗
PubMed1991

Temporal and spatial patterns of transin/stromelysin RNA expression following toxic injury in rat liver.

We have examined the expression of the extracellular matrix-degrading metalloprotease transin/stromelysin during the early phases of rat liver regeneration following toxic injury by a single dose of carbon tetrachloride (CCl4). In situ hybridization displayed cell type-specific spatial and temporal RNA expression patterns with high transcript levels in small proportions of hepatocytes and non-parenchymal cells, peaking at 24 and 48 h after intoxication, respectively. In agreement with the presence of c-fos and c-jun recognition sites on the transin gene, expression of these oncogenes preceded transin expression. Transin-expressing hepatocytes were largely localized in areas subsequently eliminated by necrosis due to CCl4 intoxication. As a consequence of these expression patterns and the key function of transin as an activator of interstitial collagenase, it seems that the hepatic fibrosis observed after CCl4 administration may be related to fibrogenesis unbalanced by fibrolysis due to altered transin expression.

Animals↗
PubMed1991

Effects of selected beta-adrenergic blocking agents on sleep stages in spontaneously hypertensive rats.

The effects on sleep of six beta-adrenergic blockers (propranolol, dilevalol, pindolol, metoprolol, celiprolol and atenolol) which differ in their pharmacological characteristics were studied in spontaneously hypertensive rats. Electroencephalographic activity was recorded for 6 hr after p.o. administration of drugs or vehicle, and the stages of wakefulness, rapid eye movements (REM) sleep and non-REM sleep (non-REM) were classified thereafter. In separate experiments antihypertensive activity of each drug was assessed by the tail-cuff technique. The most common effect of the beta-blockers examined was a decrease of the duration of REM. The effect was marked for propranolol (10-100 mg/kg), celiprolol (10-100 mg/kg) and pindolol (1-10 mg/kg), whereas it occurred at low doses, but not at high doses for metoprolol (10 mg/kg) and atenolol (3 and 10 mg/kg). Dilevalol induced a moderate REM decrease at 30 mg/kg only. For the beta-1 antagonists, the dose reducing REM substantially (ED30) was slightly above (1.4- to 3.7-fold) that effective on blood pressure (ED10), whereas the separation was high for pindolol (17.4-fold) and dilevalol (22.4-fold). Conversely, propranolol displayed a weak antihypertensive activity in this model and was more potent on REM than in reducing blood pressure. Propranolol, celiprolol and atenolol also increased duration of wakefulness. Considering the pharmacological characteristics of the beta-blockers examined, it is suggested that selective beta-1 antagonism and interaction with other neurotransmitters, such as serotonin, are relevant to the potential effects of this class of antihypertensive drugs on sleep function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1991

Transforming growth factors beta 1 and beta 2 are differentially expressed in fibrotic liver disease.

Transforming growth factor (TGF) beta 1 has been implicated in the control of hepatocyte growth and stimulation of extracellular matrix synthesis in acute and chronic liver disease. The cellular localization of transforming growth factor (TGF) beta 1 and beta 2 RNA transcripts was determined in normal and fibrotic liver by in situ hybridization with [35S]-labeled RNA probes in combination with immunostaining for cell type characteristic markers. Fibrotic specimens were from patients with hepatitis B virus infection or alcohol abuse and rats with fibrosis secondary to bile duct ligation and scission. In normal liver, low levels of TGF beta 1 transcripts were found in some portal tract stromal cells, and TGF beta 2 RNA was not detectable. In fibrotic liver, high TGF beta 1 RNA levels were present in most mesenchymal liver cells, in most inflammatory cells, and in few bile duct epithelial cells. Hepatocytes did not express this cytokine with the exception of few limiting plate hepatocytes in cases of human cirrhosis with high activity. TGF beta 2 transcripts were detected at high levels in proliferating bile ducts of fibrotic livers, but were absent in all other cell types. TGF beta 1 expression in the liver is thus a function predominantly of mononuclear and mesenchymal cells as well as of some hepatocytes, whereas TGF beta 2 expression is a specific property of bile duct epithelial cells that may be related to the formation of specialized periductular connective tissue during bile duct proliferation.

Animals↗