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1.
Eur Rev Med Pharmacol Sci ; 26(4): 1235-1240, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35253179

ABSTRACT

OBJECTIVE: An increasing number of robotic hysterectomies are being performed and the most common indication is fibroids. Fibroid uterus is common indication for hysterectomy for enlarged uteri. The role of robotic approach for complex pathologies as enlarged uterus is still debatable. The study aimed to analyze the feasibility of robotic hysterectomy in patients with enlarged uteri and the impact of uterine weight on surgical outcomes and on operative time length. PATIENTS AND METHODS: One hundred and thirty-eight patients who underwent robotic hysterectomy for benign indications at the 2nd Division of Obstetrics and Gynecology, Azienda Ospedaliero-Universitaria Pisana, University of Pisa were consecutively enrolled. RESULTS: Data of patients undergoing robotic surgery for benign indications were collected. Patients were stratified in two groups based on their uterine weight, to analyze the effective impact of uterine weight and dimension on surgical performance, operative time and postoperative outcomes. Conversion rate was 0%. Median uterine weight was 615 g (range 400-1900 g). Median total operating time was 131 minutes (range 70-255 minutes). Increase in uterine weight significantly increased operative times (p=0.003) and morcellation time (p=0.001). On the other hand, operative time was just partially influenced by route for removal of the uterus (p=0.085) but significantly affected by uterine weight (p=0.008), previous surgeries (p=0.003) and BMI of the patient (p=0.005). CONCLUSIONS: Robotic hysterectomy is feasible and safe for challenging cases as large uteri. This technique could enable patients with outsized uteri, not suitable for vaginal hysterectomy, to undergo minimally invasive surgery with excellent results. Larger studies to investigate and compare robotic with other surgical approaches for difficult hysterectomies are needed to confirm these data.


Subject(s)
Laparoscopy , Leiomyoma , Robotic Surgical Procedures , Female , Humans , Hysterectomy/adverse effects , Hysterectomy, Vaginal/adverse effects , Hysterectomy, Vaginal/methods , Laparoscopy/adverse effects , Leiomyoma/pathology , Leiomyoma/surgery , Organ Size , Postoperative Complications/etiology , Retrospective Studies , Robotic Surgical Procedures/adverse effects , Robotic Surgical Procedures/methods , Urogenital Abnormalities , Uterus/abnormalities , Uterus/pathology , Uterus/surgery
2.
Ann Cardiol Angeiol (Paris) ; 69(5): 311-316, 2020 Nov.
Article in French | MEDLINE | ID: mdl-33039117

ABSTRACT

We report the case of a 89 year-old woman admitted to the emergency department for epigastric pain, nausea, vomiting. Because of a circulatory failure with electrocardiographic ST changes and a slight elevation of ultra-sensible troponin, a coronary angiography was performed and found normal coronary arteries. Thoraco-abdominal CT scan revealed a large hiatal hernia causing a cardiac compression, and a left intraventricular obstruction showed by Doppler echocardiography. All signs resolved after fasting and gastric drainage.


Subject(s)
Hernia, Hiatal/complications , Non-ST Elevated Myocardial Infarction/classification , Non-ST Elevated Myocardial Infarction/etiology , Aged, 80 and over , Female , Hernia, Hiatal/pathology , Humans , Pressure , Ventricular Outflow Obstruction/complications
4.
Sci Total Environ ; 691: 516-527, 2019 Nov 15.
Article in English | MEDLINE | ID: mdl-31325852

ABSTRACT

European standards for the protection of forests from ozone (O3) are based on atmospheric exposure (AOT40) that is not always representative of O3 effects since it is not a proxy of gas uptake through stomata (stomatal flux). MOTTLES "MOnitoring ozone injury for seTTing new critical LEvelS" is a LIFE project aimed at establishing a permanent network of forest sites based on active O3 monitoring at remote areas at high and medium risk of O3 injury, in order to define new standards based on stomatal flux, i.e. PODY (Phytotoxic Ozone Dose above a threshold Y of uptake). Based on the first year of data collected at MOTTLES sites, we describe the MOTTLES monitoring station, together with protocols and metric calculation methods. AOT40 and PODY, computed with different methods, are then compared and correlated with forest-health indicators (radial growth, crown defoliation, visible foliar O3 injury). For the year 2017, the average AOT40 calculated according to the European Directive was even 5 times (on average 1.7 times) the European legislative standard for the protection of forests. When the metrics were calculated according to the European protocols (EU Directive 2008/50/EC or Modelling and Mapping Manual LTRAP Convention), the values were well correlated to those obtained on the basis of the real duration of the growing season (i.e. MOTTLES method) and were thus representative of the actual exposure/flux. AOT40 showed opposite direction relative to PODY. Visible foliar O3 injury appeared as the best forest-health indicator for O3 under field conditions and was more frequently detected at forest edge than inside the forest. The present work may help the set-up of further long-term forest monitoring sites dedicated to O3 assessment in forests, especially because flux-based assessments are recommended as part of monitoring air pollution impacts on ecosystems in the revised EU National Emissions Ceilings Directive.


Subject(s)
Air Pollutants/analysis , Air Pollution/statistics & numerical data , Environmental Monitoring/methods , Ozone/analysis , Conservation of Natural Resources , Ecosystem , Forestry , Forests , Plant Stomata
5.
Br J Dermatol ; 180(3): 565-573, 2019 03.
Article in English | MEDLINE | ID: mdl-30328107

ABSTRACT

BACKGROUND: Recent studies have shown an increasing incidence of cutaneous adnexal carcinomas (CACs). OBJECTIVES: The aim of our study was to evaluate incidence and survival for cases of CACs and investigate their association with other skin neoplasms. METHODS: We conducted a population-based study. Data on incident cases of CACs were obtained from the Tuscany Cancer Registry between 1985 and 2010. In order to determine whether the occurrence of squamous cell carcinoma (SCC) among patients with CAC is higher or lower than expected in the general population, the standardized incidence ratio (SIR) was calculated. RESULTS: A total of 242 patients with CAC were observed; the age-standardized incidence rate was 3·8 cases per million person-years. From 1997 to 2010 crude incidence rates increased by 159%. Age-specific incidence was higher in men over 80 years old than in women of the same age and younger individuals. Carcinomas of sweat gland origin prevailed; the most common histotype was porocarcinoma and the most frequently affected site was the head/neck. Overall, 88% of CACs were diagnosed at a localized stage. The 5-year overall survival and disease-specific survival rates were 59% [95% confidence interval (CI) 53-65] and 94% (95% CI 91-98), respectively. In the observation cohort, the number of SCCs was significantly higher than expected as the SIR was calculated to be 33·7 (P < 0·001). CONCLUSIONS: Increasing incidence warrants awareness and early diagnosis of CACs. Increased SCC incidence among patients with these tumours highlights the relevance of careful skin examination and follow-up.


Subject(s)
Carcinoma, Skin Appendage/epidemiology , Carcinoma, Squamous Cell/epidemiology , Cost of Illness , Skin Neoplasms/epidemiology , Adult , Age Distribution , Age Factors , Aged , Aged, 80 and over , Female , Humans , Incidence , Italy/epidemiology , Male , Middle Aged , Registries/statistics & numerical data , Risk Factors , Sex Distribution , Sex Factors , Survival Rate
6.
Sci Total Environ ; 636: 1373-1381, 2018 Sep 15.
Article in English | MEDLINE | ID: mdl-29913598

ABSTRACT

The role that land-use and socioeconomic factors exert on consolidating land degradation (LD) processes is a major research issue. However, intensity and type of the impact played by LD on such land use factors is still underexplored. The present study investigates the role of LD on land-use change (LUC) trajectories of land abandonment (LA) and urban expansion (URB) in the three geographical repartitions (North, Centre, South) of Italy between 1990 and 2012, by means of the Environmental Niche Factor Analysis (ENFA). ENFA is a multivariate approach originally introduced in the analysis of animal ecology allowing to compute habitat suitability (HS) models without requiring presence/absence data. Four environmental quality indices about climate (CQI), soil (SQI), vegetation (VQI) and land management (MQI) have been analyzed for the years 1990 and 2000 and related to the trajectories of LA and URB, respectively, for the time periods 1990-2000 and 2000-2012. Empirical results have indicated that different driving forces are linked to LA and URB, and that for each trajectory, the role of some forces may change over time. Evidence shows that soil quality and low human pressure represent the main drivers of LA. By contrast, as for URB, high human pressure represented the main driving factor throughout the country, both during 1990-2000 and 2000-2012. The HS maps show the probability arrangement of LA and URB in the three geographical repartitions. Starting from this work, further research is increasingly required to implement prediction models of future LA and URB trajectories according to the current land quality status.

7.
J Environ Manage ; 183(Pt 3): 754-762, 2016 Dec 01.
Article in English | MEDLINE | ID: mdl-27649608

ABSTRACT

This study investigates the relationship between fine resolution, local-scale biophysical and socioeconomic contexts within which land degradation occurs, and the human responses to it. The research draws on experimental data collected under different territorial and socioeconomic conditions at 586 field sites in five Mediterranean countries (Spain, Greece, Turkey, Tunisia and Morocco). We assess the level of desertification risk under various land management practices (terracing, grazing control, prevention of wildland fires, soil erosion control measures, soil water conservation measures, sustainable farming practices, land protection measures and financial subsidies) taken as possible responses to land degradation. A data mining approach, incorporating principal component analysis, non-parametric correlations, multiple regression and canonical analysis, was developed to identify the spatial relationship between land management conditions, the socioeconomic and environmental context (described using 40 biophysical and socioeconomic indicators) and desertification risk. Our analysis identified a number of distinct relationships between the level of desertification experienced and the underlying socioeconomic context, suggesting that the effectiveness of responses to land degradation is strictly dependent on the local biophysical and socioeconomic context. Assessing the latent relationship between land management practices and the biophysical/socioeconomic attributes characterizing areas exposed to different levels of desertification risk proved to be an indirect measure of the effectiveness of field actions contrasting land degradation.


Subject(s)
Conservation of Natural Resources , Data Mining/methods , Environmental Policy , Agriculture , Environmental Policy/economics , Fires , Greece , Humans , Morocco , Principal Component Analysis , Socioeconomic Factors , Soil , Spain , Tunisia , Turkey , Water Supply
8.
Environ Res ; 147: 590-600, 2016 May.
Article in English | MEDLINE | ID: mdl-26654561

ABSTRACT

Land Degradation (LD) is a complex phenomenon resulting in a progressive reduction in the capacity of providing ecosystem services (ES). Landscape transformations promoting an unsustainable use of land often reveal latent processes of LD. An evaluation carried out in respect to the different ecosystem services is nowadays regarded as the most appropriate approach for assessing the effects of LD. The aim of this study is to develop an evaluation framework for identifying the linkages between land changes, LD processes and ES and suggesting Sustainable Land Management (SLM) options suited to reverse (or mitigate) LD impact. A SWOT analysis was carried out with the aim to identify internal and external factors that are favorable (or unfavorable) to achieve the proposed SLM actions. The study areas are the Fortore valley and the Valpadana, in Italy. The main trajectory identified for the Fortore valley is related to land abandonment due to population aging and the progressive emigration started in the 1950s. The most relevant LD processes are soil erosion and geomorphological instability, affecting regulating services such as natural hazard and erosion control. SLM options should consider interventions to contrast geomorphological instability, the promotion of climate smart agriculture and of typical products, and an efficient water resources management. The main trajectories identified for Valpadana are related to urban expansion and farmland abandonment and, as a consequence, land take due to anthropogenic pressure and woodland expansion as the main LD process. The reduction of food production was identified as the most relevant provisioning service affected. SLM should envisage best practices finalized to water saving and soil consumption reduction: efficient irrigation solutions, climate smart agriculture and zero sealing practices. This study highlights the diagnostic value of the suggested approach where LD processes are elicited from land change trajectories determining specific impacts on ES and providing operational support for the implementation of SLM options.


Subject(s)
Conservation of Natural Resources/trends , Ecological and Environmental Phenomena , Ecosystem , Humans , Italy , Population Dynamics
9.
Environ Manage ; 56(4): 916-32, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25975440

ABSTRACT

This study implements an exploratory data analysis of landscape metrics and a change detection analysis of land use and population density to assess landscape dynamics (1954-2008) in two physiographic zones (plain and hilly-mountain area) of Emilia Romagna, northern Italy. The two areas are characterized by different landscape types: a mixed urban-rural landscape dominated by arable land and peri-urban settlements in the plain and a traditional agro-forest landscape in the hilly-mountain area with deciduous and conifer forests, scrublands, meadows, and crop mosaic. Urbanization and, to a lesser extent, agricultural intensification were identified as the processes underlying landscape change in the plain. Land abandonment determining natural forestation and re-forestation driven by man was identified as the process of change most representative of the hilly-mountain area. Trends in landscape metrics indicate a shift toward more fragmented and convoluted patterns in both areas. Number of patches, the interspersion and juxtaposition index, and the large patch index are the metrics discriminating the two areas in terms of landscape patterns in 1954. In 2008, mean patch size, edge density, interspersion and juxtaposition index, and mean Euclidean nearest neighbor distance were the metrics with the most different spatial patterns in the two areas. The exploratory data analysis of landscape metrics contributed to link changes over time in both landscape composition and configuration providing a comprehensive picture of landscape transformations in a wealthy European region. Evidence from this study are hoped to inform sustainable land management designed for homogeneous landscape units in similar socioeconomic contexts.


Subject(s)
Agriculture/trends , Environmental Monitoring/methods , Forests , Urbanization/trends , Italy , Multivariate Analysis
10.
Environ Manage ; 54(5): 951-70, 2014 Nov.
Article in English | MEDLINE | ID: mdl-23797485

ABSTRACT

An approach to derive relationships for defining land degradation and desertification risk and developing appropriate tools for assessing the effectiveness of the various land management practices using indicators is presented in the present paper. In order to investigate which indicators are most effective in assessing the level of desertification risk, a total of 70 candidate indicators was selected providing information for the biophysical environment, socio-economic conditions, and land management characteristics. The indicators were defined in 1,672 field sites located in 17 study areas in the Mediterranean region, Eastern Europe, Latin America, Africa, and Asia. Based on an existing geo-referenced database, classes were designated for each indicator and a sensitivity score to desertification was assigned to each class based on existing research. The obtained data were analyzed for the various processes of land degradation at farm level. The derived methodology was assessed using independent indicators, such as the measured soil erosion rate, and the organic matter content of the soil. Based on regression analyses, the collected indicator set can be reduced to a number of effective indicators ranging from 8 to 17 in the various processes of land degradation. Among the most important indicators identified as affecting land degradation and desertification risk were rain seasonality, slope gradient, plant cover, rate of land abandonment, land-use intensity, and the level of policy implementation.


Subject(s)
Environmental Monitoring/methods , Environmental Restoration and Remediation/methods , Africa , Asia , Desert Climate , Environmental Restoration and Remediation/trends , Europe, Eastern , Latin America , Mediterranean Region , Plant Development/physiology , Rain , Regression Analysis , Seasons , Socioeconomic Factors , Soil/chemistry
11.
Environ Manage ; 54(5): 971-82, 2014 Nov.
Article in English | MEDLINE | ID: mdl-23811772

ABSTRACT

Indicator-based approaches are often used to monitor land degradation and desertification from the global to the very local scale. However, there is still little agreement on which indicators may best reflect both status and trends of these phenomena. In this study, various processes of land degradation and desertification have been analyzed in 17 study sites around the world using a wide set of biophysical and socioeconomic indicators. The database described earlier in this issue by Kosmas and others (Environ Manage, 2013) for defining desertification risk was further analyzed to define the most important indicators related to the following degradation processes: water erosion in various land uses, tillage erosion, soil salinization, water stress, forest fires, and overgrazing. A correlation analysis was applied to the selected indicators in order to identify the most important variables contributing to each land degradation process. The analysis indicates that the most important indicators are: (i) rain seasonality affecting water erosion, water stress, and forest fires, (ii) slope gradient affecting water erosion, tillage erosion and water stress, and (iii) water scarcity soil salinization, water stress, and forest fires. Implementation of existing regulations or policies concerned with resources development and environmental sustainability was identified as the most important indicator of land protection.


Subject(s)
Conservation of Natural Resources/methods , Environmental Monitoring/methods , Environmental Restoration and Remediation/methods , Soil/chemistry , Agriculture/methods , Agriculture/statistics & numerical data , Conservation of Natural Resources/trends , Desert Climate , Environmental Monitoring/statistics & numerical data , Environmental Restoration and Remediation/trends , Fires , Rain , Risk Assessment/methods , Salinity , Socioeconomic Factors , Water Movements
12.
Environ Manage ; 49(5): 980-9, 2012 May.
Article in English | MEDLINE | ID: mdl-22419398

ABSTRACT

In the last decades, due to climate changes, soil deterioration, and Land Use/Land Cover Changes (LULCCs), land degradation risk has become one of the most important ecological issues at the global level. Land degradation involves two interlocking systems: the natural ecosystem and the socio-economic system. The complexity of land degradation processes should be addressed using a multidisciplinary approach. Therefore, the aim of this work is to assess diachronically land degradation dynamics under changing land covers. This paper analyzes LULCCs and the parallel increase in the level of land sensitivity to degradation along the coastal belt of Sardinia (Italy), a typical Mediterranean region where human pressure affects the landscape characteristics through fires, intensive agricultural practices, land abandonment, urban sprawl, and tourism concentration. Results reveal that two factors mainly affect the level of land sensitivity to degradation in the study area: (i) land abandonment and (ii) unsustainable use of rural and peri-urban areas. Taken together, these factors represent the primary cause of the LULCCs observed in coastal Sardinia. By linking the structural features of the Mediterranean landscape with its functional land degradation dynamics over time, these results contribute to orienting policies for sustainable land management in Mediterranean coastal areas.


Subject(s)
Agriculture/trends , Climate Change , Conservation of Natural Resources/trends , Ecosystem , Environmental Pollution , Agriculture/economics , Conservation of Natural Resources/economics , Conservation of Natural Resources/methods , Geographic Information Systems , Italy , Mediterranean Sea , Models, Theoretical , Socioeconomic Factors
13.
Int J Biometeorol ; 51(4): 253-63, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17139500

ABSTRACT

A new approach to characterise geographical areas with a drought risk index (DRI) is suggested, by applying an artificial neural network (ANN) classifier to bioclimatic time series for which operational temporal units (OtUs) are defined. A climatic database, corresponding to a grid of 8 km x 8 km cells covering the Italian peninsula, was considered. Each cell is described by the time series of seven variables recorded from 1989 to 2000. Sixteen cells were selected according to land cover homogeneity and completeness of the time series data. The periodic components of the time series were calculated by means of the fast Fourier transform (FFT) method. Temporal units corresponding to the period of the sinusoidal functions most related to the data were used as OtUs. The ANN for each OtU calculates a DRI value ranging between -1 and 1. The value is interpretable as the proximity of the OtUs to one of two situations corresponding to minimum and maximum drought risk, respectively. The former set (DRI = -1) is represented by an ideal OtU with minimum values of temperatures and evapo-transpiration, and maximum values of rainfall, normalised difference vegetation index (NDVI) and soil water content. The second set (DRI = 1) is represented by the reciprocal OtU to the former one. The classification of the cells based on DRI time profiles showed that, at the scale used in this work, DRI has no dependence on land cover class, but is related to the location of the cells. The methodology was integrated with GIS (geographic information system) software, and used to show the geographic pattern of DRI in a given area at different periods.


Subject(s)
Disasters , Climate , Databases, Factual , Disasters/statistics & numerical data , Fourier Analysis , Geographic Information Systems , Italy , Neural Networks, Computer , Risk , Software , Time Factors
14.
Andrologia ; 35(1): 64-70, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12558530

ABSTRACT

The Fas system is involved in the control of immune system homeostasis and nonfunctional Fas system leads to autoimmune disease in mice and humans. The Fas system is a mechanism through which cells expressing Fas ligand (FasL) induce apoptosis of Fas expressing cells. In mouse and rat, the testis represents the main source of constitutive FasL in the body. The roles so far proposed for this molecule in the testis, such as maintenance of immunoprivilege and regulation of physiological germ cell apoptosis, need to be reconsidered as both hypotheses are based on an erroneous cellular location of FasL in the seminiferous epithelium. Recently, we demonstrated that in rodents FasL mRNA is present in germ cells and not in Sertoli cells, and that FasL protein is displayed on the surface of spermatozoa. Here we propose that, for the mouse spermatozoa, the FasL may represent a self-defence mechanism against lymphocytes present in the female genital tract. To verify this hypothesis, we performed crossings between males gld, with nonfunctional FasL, and syngenic or nonsyngenic females. We observed a significant decrease of litter size in outbred crossings with gld males compared with wild-type males, suggesting a possible role of FasL in immunoprotection of the sperm in the female genital tract. The possibility that in humans, by analogy with mouse, FasL plays a self-protective role for the spermatozoon cannot be excluded, and awaits experimental information on the expression of FasL on human sperm cells.


Subject(s)
Membrane Glycoproteins/physiology , Seminiferous Epithelium/chemistry , fas Receptor/physiology , Animals , Apoptosis , Fas Ligand Protein , Gene Expression , Humans , Immunity , Male , Membrane Glycoproteins/genetics , Mice , Models, Biological , RNA, Messenger/analysis , Spermatozoa/chemistry , Testis
15.
J Enzyme Inhib ; 16(3): 287-92, 2001.
Article in English | MEDLINE | ID: mdl-11697049

ABSTRACT

Phosphomannose isomerase (PMI; EC. 5.3.1.8) is an essential metalloenzyme in the early steps of the protein glycosylation pathway in both prokaryotes and eukaryotes. The Cys150 residue (according to Candida albicans PMI numbering) is conserved in the active centre of mammalian and yeast PMI, but not in bacterial species where it is replaced by Asn. Here, the dose- and time-dependent inhibitory effect of the NO-donor S-nitroso-acetyl-penicillamine on the Saccharomyces cerevisiae PMI catalytic activity is reported. The analysis of the X-ray crystal structure of C. albicans PMI and of the molecular model of S. cerevisiae PMI provides a rationale for the low reactivity of Cys150 towards alkylating and nitrosylating agents.


Subject(s)
Enzyme Inhibitors/pharmacology , Mannose-6-Phosphate Isomerase/antagonists & inhibitors , S-Nitroso-N-Acetylpenicillamine/pharmacology , Saccharomyces cerevisiae/enzymology , Binding Sites , Enzyme Inhibitors/metabolism , Mannose-6-Phosphate Isomerase/chemistry , Mannose-6-Phosphate Isomerase/metabolism , Molecular Structure , Protein Structure, Tertiary , S-Nitroso-N-Acetylpenicillamine/metabolism , Time Factors , Zinc/metabolism
16.
FEBS Lett ; 501(2-3): 103-5, 2001 Jul 20.
Article in English | MEDLINE | ID: mdl-11470265

ABSTRACT

The hemoflagellate protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease, a progressive fatal cardiomyopathy widespread in South and Central America. Here, we postulate that the preferential colonization of cardiomyocytes by T. cruzi may reflect the role of myoglobin (Mb) as a nitric oxide (NO) scavenger, protecting the parasite from the trypanocidal effects of NO. The proposal of this novel function of Mb is based on knowledge that ferrous oxygenated Mb reacts rapidly and irreversibly with NO yielding nitrate and ferric oxidized Mb, which is reduced back to the physiologically active form by an intracellular reductase. The postulated protective role of Mb on the viability of T. cruzi is reminiscent of that postulated for hemoglobin in protecting intraerythrocytic Plasmodia from the parasiticidal effect of NO.


Subject(s)
Myoglobin/metabolism , Nitric Oxide/pharmacology , Protective Agents/metabolism , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Animals , Host-Parasite Interactions , Humans , Trypanosoma cruzi/physiology
17.
Eur J Biochem ; 268(11): 3253-8, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11389727

ABSTRACT

Cysteine proteinases are relevant to several aspects of the parasite life cycle and of parasite-host relationships. Here, a quantitative investigation of the effect of temperature and pH on the total substrate inhibition of cruzipain, the major papain-like cysteine proteinase from Trypanosoma cruzi, is reported. Values of the apparent catalytic and inhibition parameters Km, Vmax, Vmax/Km, and K(i) for the cruzipain-catalysed hydrolysis of N-alpha-benzyloxycarbonyl-L-phenylalanyl-L-arginine-(7-amino-4-methylcoumarin) (Z-Phe-Arg-AMC) and azocasein were determined between 10.0 degrees C and 40.0 degrees C and between pH 4.5 and 8.5. Values of Km were independent of temperature and pH, whereas values of Vmax, Vmax/Km, and K(i) were temperature-dependent and pH-dependent. Over the whole pH range explored, values of logVmax, log(Vmax/Km), and logK(i) increased linearly with respect to T(-1). Values of Vmax and Vmax/Km were affected by the acid-base equilibrium of one temperature-independent ionizing group (i.e. pK(unl)' = pK(lig)' = 5.7 +/- 0.1, at 25.0 degrees C). Moreover, values of K(i) were affected by the alkaline pK shift of one ionizing group of active cruzipain (from pK(unl)" = 5.7 +/- 0.1 to pK(lig)" = 6.1 +/- 0.1, at 25.0 degrees C) upon Z-Phe-Arg-AMC binding. Values of logK(unl)', logK(lig)', and logK(lig)" were temperature-independent. Conversely, values of logK(unl)" were linearly dependent on T(-1). As a whole, total substrate inhibition of cruzipain decreased with increasing temperature and pH. These data suggest that both synthetic and protein substrates can bind to the unique active centre of cruzipain either productively or following a binding mode which results in enzyme inhibition. However, allosteric effect(s) cannot be excluded.


Subject(s)
Cysteine Endopeptidases/chemistry , Trypanosoma cruzi/enzymology , Animals , Caseins/chemistry , Catalysis , Coumarins/chemistry , Cysteine Endopeptidases/isolation & purification , Dipeptides/chemistry , Hydrogen-Ion Concentration , Hydrolysis , Kinetics , Protozoan Proteins , Substrate Specificity , Temperature , Thermodynamics
18.
Biochim Biophys Acta ; 1545(1-2): 357-66, 2001 Feb 09.
Article in English | MEDLINE | ID: mdl-11342060

ABSTRACT

Nitric oxide (NO) releasing drugs (e.g., glyceryl trinitrate) were successfully used in the treatment of cutaneous leishmaniasis in man. In the present study, the effect of NO donors on the catalytic activity of the cysteine proteinase from promastigotes of Leishmania infantum, an agent of Old World visceral and cutaneous leishmaniases, is reported. In particular, one equivalent of NO, released by the NO donors S-nitrosoglutathione, glyceryl trinitrate, (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide, 3-morpholinosydnonimine, S-nitrosoacetylpenicillamine and sodium nitroprusside, inhibited one equivalent of the parasite cysteine proteinase. As expected, NO-deprived compounds did not affect the catalytic activity of the parasite cysteine proteinase. Furthermore, the absorption spectrum of the (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide-treated inactive L. infantum enzyme displayed a maximum in the 330-350 nm wavelength range. The reducing agents dithiothreitol and L-ascorbic acid completely prevented parasite cysteine proteinase inhibition by NO, fully restored the catalytic activity, and reversed the NO-induced absorption spectrum of the inactive enzyme. Moreover, S-nitrosoacetylpenicillamine displayed a leishmanicidal effect, inhibiting the cysteine proteinase activity in vivo. As expected, the NO-deprived compound N-acetylpenicillamine did not affect significantly the parasite viability and the enzyme activity in vivo. These data suggest that the L. infantum cysteine proteinase undergoes NO-mediated S-nitrosylation, thereby representing a possible mechanism of antiparasitic host defence.


Subject(s)
Cysteine Endopeptidases/metabolism , Cysteine Proteinase Inhibitors/pharmacology , Glutathione/analogs & derivatives , Leishmania infantum/drug effects , Nitric Oxide Donors/pharmacology , Nitric Oxide/physiology , Penicillamine/analogs & derivatives , Protozoan Proteins/antagonists & inhibitors , Animals , Ascorbic Acid/pharmacology , Dithiothreitol/pharmacology , Glutathione/pharmacology , Kinetics , Leupeptins/pharmacology , Molsidomine/analogs & derivatives , Molsidomine/pharmacology , Nitro Compounds/pharmacology , Nitroglycerin/pharmacology , Nitroprusside/pharmacology , Nitroso Compounds/pharmacology , Penicillamine/pharmacology , S-Nitrosoglutathione
19.
Curr Protein Pept Sci ; 2(2): 137-53, 2001 Jun.
Article in English | MEDLINE | ID: mdl-12370021

ABSTRACT

Cysteine proteases represent a broad class of proteolytic enzymes widely distributed among living organisms. Although well known as typical lysosomal enzymes, cysteine proteases are actually recognized as multi-function enzymes, being involved in antigen processing and presentation, in membrane-bound protein cleavage, as well as in degradation of the cellular matrix and in processes of tissue remodeling. Very recently, it has been shown that the NO(-donor)-mediated chemical modification of the Cys catalytic residue of cysteine proteases, including Coxsackievirus and Rhinovirus cysteine proteases, cruzain, Leishmania infantum cysteine protease, falcipain, papain, as well as mammalian caspases, cathepsins and calpain, blocks the enzyme activity in vitro and in vivo. Here, inhibition of representative cysteine proteases by NO(-donors) is reviewed.


Subject(s)
Cysteine Proteinase Inhibitors/pharmacology , Nitric Oxide Donors/pharmacology , Animals , Calpain/chemistry , Calpain/drug effects , Caspases/chemistry , Caspases/drug effects , Catalytic Domain , Cathepsins/chemistry , Cathepsins/drug effects , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/drug effects , Humans , In Vitro Techniques , Mammals , Models, Chemical , Models, Molecular , Papain/chemistry , Papain/drug effects , Parasites/enzymology , Plants/enzymology , Protozoan Proteins/chemistry , Protozoan Proteins/drug effects , Viruses/enzymology
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