Assessing Heavy Metals in the Sele River Estuary: An Overview of Pollution Indices in Southern Italy

Rapid industrialization, coupled with a historical lack of understanding in toxicology, has led in an increase in estuary pollution, frequently resulting in unexpected environmental situations. Therefore, the occurrence of heavy metals (HMs) constitutes a major environmental issue, posing a serious risk both to aquatic ecosystems and public health. This study aimed to evaluate the levels of eight HMs (As, Hg, Cd, Cr, Cu, Ni, Pb, and Zn) in water, suspended particles, and sediment near the Sele River estuary (Italy) in order to assess their environmental impacts on the sea and health risks for humans. The results revealed an increasing order of HM concentration according to the scheme suspended particulate matter (SPM) > sediment (SED) > dissolved phase (DP) and a moderate contamination status in sediment. The health risk assessment indicated that the non-carcinogenic risk was negligible. Carcinogenic risk, expressed as the incremental lifetime cancer risk (ILCR), was negligible for Cd and Ni and within tolerable limits for As, Pb, and Cr. The findings suggested that, even if there are currently no specific limits for chemical parameters in the transitional waters of Italy, monitoring systems should be implemented to determine pollution levels and implement effective steps to improve river water quality and reduce human health risks.

KS01.5.A Impact of reduced treatment volumes on pattern of tumor recurrence and radiation dose to normal brain parenchyma in glioblastoma

Background

to analyze GBM recurrence pattern after standard chemoradiotherapy according to different target volume delineations. We hypothesized that reduced target volume margins may result in similar pattern of failure.

Material and Methods

207 patients with GBM who recurred after standard chemoradiation were evaluated. According to the Advisory Committee for Radiation Oncology Practice (ACROP) committee of the European Organisation for Research and Treatment of Cancer (EORTC) target volume delineation guideline, the clinical target volume (CTV) used for treatment planning consisted of residual tumor and resection cavity plus 2-cm margin. MRI scans showing tumor recurrences were fused with the planning computed tomography (CT), and the patterns of failure were analyzed dosimetrically using dose-volume histograms. The recurrent lesions were defined as in-field, marginal, or distant if >80%, 20-80%, or <20% of the intersecting volume was included in the 95% isodose line. For each patient a theoretical plan consisting of a reduced CTV using 1-cm margin was created and patterns of failure evaluated.

Results

The median overall survival and progression-free survival were 15.3 months and 7.8 months, respectively, from the date of surgery. Recurrences were in-field in 180 patients, marginal in 5 patients, and distant in 22 patients. Analysis of O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation status showed different recurrence patterns of GBMs in patients with MGMT methylated compared with patients with MGMT unmethylated status. Recurrences occurred in-field and distant in 75.6% and 18.6% of methylated patients and in 91.8% and 6% of unmethylated patients, respectively (p=0.0046). Patterns of failure were similar between the different treatment plans. Reduced target volumes were associated with significantly lower doses of 20-50 Gy to normal brain and hippocampi (p=0.0001).

Conclusion

Most of patients treated with standard chemioradiotherapy have in-field recurrences; however, an increased risk of distant recurrences occurs in methylated tumors. The use of target delineation using 1-cm CTV margin is associated with smaller volumes of normal brain and hippocampi irradiated to high doses, without significant changes in the pattern of failure. The impact of different target delineation in terms of efficacy and risk of late radiation-induced toxicity should be assessed prospectively.

Occurrence, Distribution, and Risk Assessment of Organophosphorus Pesticides in the Aquatic Environment of the Sele River Estuary, Southern Italy

The intensive use of organophosphorus pesticides (OPPs) causes concern among authorities in different countries, as many of them, remaining unchanged for a long time, pose a threat to environmental sustainability. This study assessed the spatio-temporal trends of nine OPPs in the water dissolved phase (WDP), suspended particulate matter (SPM), and sediment samples from the Sele River estuary, Southern Italy. Samples were collected in 10 sampling sites during four seasons. The highest levels were found at the mouth (mean value 28.25 ng L⁻¹ as WDP + SPM) and then decreased moving southwards to the Mediterranean Sea. Moreover, highest concentrations were detected in the warm season (July) with a mean value of 27.52 ng L⁻¹. The load contribution to the Mediterranean Sea was evaluated in about 61.5 kg year⁻¹, showing that the river was an important source of OPPs through discharge into the sea. The risk assessment revealed that no high-risk indices for the general-case scenario were observed, but for the worst-case scenario, potential risks were associated with chlorpyrifos, pyrimifos-methyl, and parathion, suggesting that OPP contamination should not be neglected. This study makes up the first record of OPPs in the surface waters of the Sele River and provides helpful data as a starting point for future studies.

Smoke Evacuation During Laparoscopic Surgery: A Problem Beyond the COVID-19 Period. A Quantitative Analysis of CO2 Environmental Dispersion Using Different Devices

Background. The COVID-19 pandemic leads to several debates regarding the possible risk for healthcare professionals during surgery. SAGES and EAES raised the issue of the transmission of infection through the surgical smoke during laparoscopy. They recommended the use of smoke evacuation devices (SEDs) with CO₂ filtering systems. The aim of the present study is to compare the efficacy of different SEDs evaluating the CO₂ environmental dispersion in the operating theater. Methods. We prospectively evaluated the data of 4 group of patients on which we used different SEDs or standard trocars: AIRSEAL system (S1 group), a homemade device (S2 group), an AIRSEAL system + homemade device (S3 group), and with standard trocars and without SED (S4 group). Quantitative analysis of CO2 environmental dispersion was carried out associated to the following data in order to evaluate the pneumoperitoneum variations: a preset insufflation pressure, real intraoperative pneumoperitoneum pressure, operative time, total volume of insufflated CO₂, and flow rate index. Results. 16 patients were prospectively enrolled. The [CO₂] mean value was 711 ppm, 641 ppm, 593 ppm, and 761 ppm in S1, S2, S3, and S4 groups, respectively. The comparison between data of all groups showed statistically significant differences in the measured ambient CO₂ concentration. Conclusion. All tested SEDs seem to be useful to reduce the CO₂ environmental dispersion respect to the use of standard trocars. The association of AIRSEAL system and a homemade device seems to be the best solution combining an adequate smoke evacuation and a stable pneumoperitoneum during laparoscopic surgery.

Relapse of pemphigus vulgaris after topical application of ingenol mebutate

Ingenol mebutate is a recently approved topical agent for the treatment of actinic keratosis. Its most common adverse effects are transient local skin reactions. We report a 63-year-old white man who presented with a red-brownish crusted plaque involving the dorsum of his nose and an eroded area on his lower lip, which appeared soon after topical application of ingenol mebutate gel. Clinical, histological and immunopathological features were consistent with a diagnosis of pemphigus vulgaris (PV). To our knowledge, this is the first report of relapse of PV after topical application of ingenol mebutate gel. The temporal relationship between the application of the drug and the outbreak of PV supports the involvement of this agent in triggering the disease. It is plausible that ingenol mebutate may have induced the disease by its action on the production of proinflammatory cytokines.

Environmental quality of the operating theaters in Campania Region: long lasting monitoring results

BACKGROUND

The health risk level in the operating theaters is directly correlated to the safety level offered by the healthcare facilities. This is the reason why the national Authorities released several regulations in order to monitor better environmental conditions of the operating theaters, to prevent occupational injuries and disease and to optimize working conditions. For the monitoring of environmental quality of the operating theaters following parameters are considered: quantity of supplied gases, anesthetics concentration, operating theatres volume measurement, air change rate, air conditioning system and air filtration. The objective is to minimize the risks in the operating theaters and to provide the optimal environmental working conditions. This paper reports the environmental conditions of operating rooms performed for several years in the public hospitals of the Campania Region.

METHODS

Investigation of environmental conditions of 162 operating theaters in Campania Region from January 2012 till July 2014 was conducted. Monitoring and analysis of physical and chemical parameters was done. The analysis of the results has been made considering specific standards suggested by national and international regulations.

RESULTS

The study showed that 75% of the operating theaters presented normal values for microclimatic monitoring, while the 25% of the operating theaters had at least one parameter outside the limits. The monitoring of the anesthetics gases showed that in 9% of measurements of nitrous oxides and 4% of measurements of halogenated was not within the normal values.

Cutaneous melanoma in solid organ transplant patients

Solid organ transplant patients are at greatly increased risk of developing a wide variety of skin cancers, particularly epithelial skin cancers. On the other hand, it is well known that an intact immune system limits the development of benign melanocytic lesions. The eruptive nevi phenomenon, which we can observe in solid organ transplant recipients, is indicative of the relationship between melanocyte proliferation and immune system. Regression of melanocytic nevi after restoration of complete immune responsiveness is a further clinical example the role of immunosurveillance on melanocyte proliferation. However, melanoma incidence in organ transplant recipients appears only 2-3 folds higher than in general population. To this regard, organ transplant recipients who develop de novo melanomas thicker than 2mm seem to have a significantly worse outcome with a greatly increased risk of dying of metastatic melanoma, whereas those who develop a ≤2 mm thickness melanoma seem to have a prognosis similar to that of the general population. Furthermore, there is no evidence supporting an increased risk of melanoma recurrences after transplant in patients with a history of low-risk melanoma. Melanoma is also one of the most frequent and lethal donor-derived malignancies suggesting that a history of invasive melanoma should be considered an absolute contraindication to donation. The aim of this review is to investigate the relationship between immunosuppression and melanoma and to discuss its clinical implications for the management of transplant-associated melanoma.

The kiwi fruit peptide kissper displays anti-inflammatory and anti-oxidant effects in in-vitro and ex-vivo human intestinal models

Literature reports describe kiwi fruit as a food with significant effects on human health, including anti-oxidant and anti-inflammatory activity. Fresh fruit or raw kiwi fruit extracts have been used so far to investigate these effects, but the molecule(s) responsible for these health-promoting activities have not yet been identified. Kissper is a kiwi fruit peptide displaying pore-forming activity in synthetic lipid bilayers, the composition of which is similar to that found in intestinal cells. The objective of this study was to investigate the kissper influence on intestinal inflammation using cultured cells and ex-vivo tissues from healthy subjects and Crohn's disease (CD) patients. The anti-oxidant and anti-inflammatory properties of kissper were tested on Caco-2 cells and on the colonic mucosa from 23 patients with CD, by challenging with the lipopolysaccharide from Escherichia coli (EC-LPS) and monitoring the appropriate markers by Western blot and immunofluorescence. EC-LPS challenge determined an increase in the intracellular concentration of calcium and reactive oxygen species (ROS). The peptide kissper was highly effective in preventing the increase of LPS-induced ROS levels in both the Caco-2 cells and CD colonic mucosa. Moreover, it controls the calcium increase, p65-nuclear factor (NF)-kB induction and transglutaminase 2 (TG2) activation inflammatory response in Caco-2 cells and CD colonic mucosa. Kissper efficiently counteracts the oxidative stress and inflammatory response in valuable model systems consisting of intestinal cells and CD colonic mucosa. This study reports the first evidence supporting a possible correlation between some beneficial effects of kiwi fruit and a specific protein molecule rather than generic nutrients.

The kiwi fruit peptide kissper displays anti-inflammatory and anti-oxidant effects in in-vitro and ex-vivo human intestinal models

Literature reports describe kiwi fruit as a food with significant effects on human health, including anti-oxidant and anti-inflammatory activity. Fresh fruit or raw kiwi fruit extracts have been used so far to investigate these effects, but the molecule(s) responsible for these health-promoting activities have not yet been identified. Kissper is a kiwi fruit peptide displaying pore-forming activity in synthetic lipid bilayers, the composition of which is similar to that found in intestinal cells. The objective of this study was to investigate the kissper influence on intestinal inflammation using cultured cells and ex-vivo tissues from healthy subjects and Crohn's disease (CD) patients. The anti-oxidant and anti-inflammatory properties of kissper were tested on Caco-2 cells and on the colonic mucosa from 23 patients with CD, by challenging with the lipopolysaccharide from Escherichia coli (EC-LPS) and monitoring the appropriate markers by Western blot and immunofluorescence. EC-LPS challenge determined an increase in the intracellular concentration of calcium and reactive oxygen species (ROS). The peptide kissper was highly effective in preventing the increase of LPS-induced ROS levels in both the Caco-2 cells and CD colonic mucosa. Moreover, it controls the calcium increase, p65-nuclear factor (NF)-kB induction and transglutaminase 2 (TG2) activation inflammatory response in Caco-2 cells and CD colonic mucosa. Kissper efficiently counteracts the oxidative stress and inflammatory response in valuable model systems consisting of intestinal cells and CD colonic mucosa. This study reports the first evidence supporting a possible correlation between some beneficial effects of kiwi fruit and a specific protein molecule rather than generic nutrients.

Current practice and recent advances in pediatric pain management

BACKGROUND

Differently from the adult patients, in pediatric age it is more difficult to assess and treat efficaciously the pain and often this symptom is undertreated or not treated. In children, selection of appropriate pain assessment tools should consider age, cognitive level and the presence of eventual disability, type of pain and the situation in which it is occurring. Improved understanding of developmental neurobiology and paediatric analgesic drugs pharmacokinetics should facilitate a better management of childhood pain.

AIM

The objective of this review is to discuss current practice and recent advances in pediatric pain management.

METHODS

Using PubMed we conducted an extensive literature review on pediatric pain assessment and commonly used analgesic agents from January 2000 to January 2012.

CONCLUSIONS

A multimodal analgesic regimen provides better pain control and functional outcome in children. Cooperation and communication between the anaesthesiologist, surgeon, and paediatrician are essential for successful anaesthesia and pain management.

To be or not to be translational

Translational Research means different things to different people, but it seems crucial to almost everyone. This discipline, although defined differently in academia, regulatory institutions, and industry, shares the fundamental vision of Translational Medicine, which efficiently and effectively translates basic scientific findings relevant to human disease into knowledge that benefits patients. In the present perspective, we collected commentaries and descriptions about Translational Medicine to stimulate discussion and better understand what Translational Medicine is.

CD30+ lymphoproliferative disorders of the skin: still an open question

CD30+ lymphoproliferative disorders of the skin represent a well-defined spectrum of primary cutaneous T-cell lymphomas. They include lymphomatoid papulosis and cutaneous anaplastic large-cell lymphoma which are characterized by the common expression of the CD30 antigen, but different clinical, histological and molecular features. Recent progress in the pathobiology and identification of therapeutic targets has contributed to our current understanding of this peculiar group of cutaneous lymphoproliferative disorders. The characteristic features of this group of cutaneous lymphoproliferative disorders are reviewed with particular emphasis to their diagnosis and treatment strategies.

Mammary-derived growth inhibitor (MDGI) cloned from human breast epithelial cells is expressed in fully differentiated lobular structures

Mammary-derived growth inhibitor (MDGI), an inducer of rodent mammary differentiation and suppressor of human breast cancer cell growth, has been cloned from bovine and rodent mammary glands. The present study reports the cloning of MDGI from cultured human breast epithelial cells (HBEC-MDGI) as a cDNA fragment encoding a protein of 133 amino acids identical to heart fatty acid binding protein. Expression of HBEC-MDGI, as detected by in situ hybridization in paraffin-embedded normal breast tissues, was maximal in the most differentiated lobules type 4, low in the moderately differentiated lobules type 3, and absent in the least differentiated lobules types 1 and 2. HBEC-MDGI was not expressed in breast tissues that contained ductal hyperplasia, carcinoma in situ or invasive carcinomas. Our results indicate that HBEC-MDGI is a biomarker of lobular differentiation in the human breast, and its expression is silenced in poorly differentiated lobules as well as in the early and late stages of breast cancer progression.

Human parvovirus B 19 and Epstein-Barr virus co-infection in a child with hereditary spherocytosis

BACKGROUND

In patients with chronic congenital haemolytic disorders, human Parvovirus B19 (HPV B19) is frequently involved in pure red-cell aplastic crises. Furthermore, it may inhibit three-lineage haematopoiesis in the bone marrow, causing severe pancytopenia. In such patients, Epstein Barr virus (EBV) infection also seems to share the same mechanism as HPV B19 in inducing bone marrow aplasia, but at present the clinical effect of an infection sustained by both viruses is unknown.

CLINICAL REPORT

We present a 7-year-old boy affected by hereditary spherocytosis (HS) who suffered from transient aplastic crisis, in whom laboratory findings revealed a double HPV B19 and EBV infection.

CONCLUSIONS

To our knowledge, this is the first report of a case of HPV B19 and EBV co-infection diagnosis in a paediatric patient. Despite underlying HS, no signs of haemolytic anaemia were detected, but the infection only produced transient pancytopenia. Nevertheless, the reason why there was no additive effect of the two viruses on the aplastic crisis is still unclear.

Stage-Specific Expressions of GLUT-1, GLUT-3 and GLUT-12 in Estrogen-Induced Breast Cancer

Increased glucose uptake and glycolysis are main metabolic characteristics of malignant cells. The glucose transporter-1 (GLUT-1), GLUT-3 and recently GLUT-12 have been shown in breast cancer cells in which estrogen play a critical role on its regulation and also associated with poor prognosis. However. the stage-specific GLUT regulation during the process of mammary carcinogenesis is unclear. In the present study we are aiming to study the GLUT expression pattern in an in vitro-in vivo model of estrogen induced carcinogenesis in which the human breast epithelial cell line MCF-10F is considered the normal counterpart E2 the transformed, C5 the invasive and T4 the tumorigenic stage. The gene expression of GLUTs was correlated with the ductulogenic pattern in a collagen matrix and the invasive properties using the Boyden chamber The RT-PCR data showed that the GLUT1 expression was downregulated in MCF10F after the treatment with 17β-estradiol (E2) and in the invasive cell type (C5), but not in the tumor cells (T4), which had no changes compared to MCF10F. C5 and T4 cells showed the highest rate of GLUT-3 expression. These cells were also found to be associated with loss of ductulogenesis, solid mass formation and higher invasion capacity. Whereas, GLUT-12 is downregulated in invasive and tumorigenic cells. We conclude that the estrogen-induced malignant transformation is associated with remarkably GLUT-3 expression, GLUT-1 re-expression at further stages, as well as GLUT-12 downregulation for transformed MCF-10F cells. (This work was supported by grant R21 ES015894from the NIEHS)

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5152.

Efficacy of budesonide therapy in the early phase of treatment of adult coeliac disease patients with malabsorption: an in vivo/in vitro pilot study

1. Budesonide is a glucocorticosteroid with a local anti-inflammatory effect. Coeliac disease is an immune-mediated disease caused by gluten ingestion in intolerant patients. The aim of the present study was to investigate the efficacy of budesonide in malabsorptive coeliac patients and its effect in an in vitro gliadin challenge. 2. Twenty coeliac patients with malabsorption were enrolled in the present study and were randomly assigned to one of two 4 week treatments: (i) a gluten-free diet alone; or (ii) a gluten-free diet plus 6 mg budesonide daily. At the end of 4 weeks treatment, all patients underwent clinical evaluation, laboratory tests and self-evaluation of well-being using a visual analogue scale. Intestinal biopsies from five coeliac patients (selected randomly) and four non-coeliac disease controls who underwent upper endoscopy for intestinal bleeding were challenged with gliadin (0.5 mg/mL) and budesonide (10-30 microg/mL) for 3 and 24 h. Biopsies were tested by immunohistochemistry and immunofluorescence for known markers of inflammation. 3. Treatment of patients with 6 mg budesonide daily for 4 weeks resulted in increased bodyweight, a decreased number of evacuations and decreased stool weight compared with patients on a gluten-free diet alone for 4 weeks. Well-being scores were higher in patients treated with both a gluten-free diet and budesonide compared with those receiving a gluten-free diet alone. 4. In vitro studies showed that budesonide reduced epithelial tyrosine phosphorylation and expression of histocompatibility leucocyte antigen complex DR (HLA-DR) elicited by gliadin-derived peptides. In addition, the expression of cyclo-oxygenase (COX)-2 and intercellular adhesion molecule (ICAM)-1 in the lamina propria was reduced in patients treated with both gliadin and budesonide compared with patients treated with gliadin alone. Budesonide alone decreased HLA-DR in crypt enterocytes, as well as ICAM-1 and COX-2 expression in the lamina propria of biopsy specimen of coeliac patients. Budesonide had no effect in control samples. 5. In conclusion, the results of the present study indicate that budesonide shows efficacy in the treatment of symptoms in adult coeliac patients with overt malabsorption. The mechanism underlying the effects of budesonide in reducing symptoms was elucidated by in vitro studies involving a gliadin challenge.

In ataxia-teleangiectasia betamethasone response is inversely correlated to cerebellar atrophy and directly to antioxidative capacity

BACKGROUND AND PURPOSE

Ataxia-telangiectasia (A-T) is a rare autosomal recessive disorder caused by alterations of the A-T mutated (ATM) gene. Although A-T is a non-curable disease, we, previously, documented a clear improvement of cerebellar functions during a short-term betamethasone trial. The aim of this study was to define the underlying biochemical mechanism.

METHODS

In six A-T patients receiving a short-term steroid therapy, intracellular glutathione (GSH) levels were evaluated with a colorimetric assay. The lipid peroxidation level and reactive oxygen species (ROS) production were evaluated using commercial assays. All the parameters were compared with the improvement of cerebellar functions expressed as delta (Delta) of the Scale for the Assessment and Rating of Ataxia (SARA).

RESULTS

We observed an inverse correlation between Delta SARA and the severity of cerebellar atrophy and between the latter and basal GSH values. Four of the five patients with the highest Delta SARA also had the highest GSH values. Moreover, even though basal ROS values were comparable in patients and controls, in the only patient studied at different time-points of therapy, a remarkable reduction in ROS levels was documented.

CONCLUSION

We suggest that antioxidative mechanisms play a role in favouring the improvement of cerebellar functions observed in A-T patients receiving a short-term betamethasone trial.

Platelet dysfunction in central obesity

Central obesity is a relevant risk factor for major cardiovascular events due to the atherosclerotic involvement of coronary, cerebral and lower limb arterial vessels. A major role in the increased cardiovascular risk is played by platelets, which show an increased activation and a reduced sensitivity to the physiological and pharmacological antiaggregating agents. This review focuses on platelet dysfunction in central obesity. The mechanisms involved are related to: i) the reduced sensitivity to insulin and other substances acting via intracellular cyclic nucleotides, such as nitrates and prostacyclin; ii) the altered intracellular ionic milieu with elevated cytosolic Ca(2+); and iii) the increased oxidative stress, which elicits isoprostane production from arachidonic acid. Therapeutic guidelines recommend a multifactorial prevention of cardiovascular disease including antiplatelet drugs in high risk patients, even though, at present, the protective effect of antiplatelet therapy in obese, insulin resistant subjects has not been evaluated by specific trials. Some reports, however, suggest a decreased sensitivity to the antiaggregating effects of both acetylsalicylic acid (aspirin) and thienopyridines in human obesity. Platelet defects may play a pivotal role in the reduced efficacy of antiplatelet therapy in obese subjects in the setting of cardiovascular prevention and acute coronary syndrome treatment. Thus, a specifically tailored antiaggregating therapy is likely necessary in obese, insulin resistant subjects, especially in the presence of type 2 diabetes mellitus.

Steroid-induced improvement of neurological signs in ataxia-telangiectasia patients

A recent clinical observation reported on a dramatic improvement of neurological symptoms following short-term betamethasone administration in a child affected with ataxia-teleangiectasia (A-T). The aim of this study was to extend this observation to additional A-T patients followed at a single Immunodeficiency Center. Six consecutive patients (three males; mean age 16.3 years, range 5-30 years) were enrolled into this monocentric before-after trial. A cycle of oral betamethasone at the dosage of 0.1 mg/kg/day was administered for 10 days. The neurological evaluation was performed through the Scale for the Assessment and Rating of Ataxia. Overall, five of the six patients exhibited a clear amelioration of the neurological performances. Only in two patients, a slight amelioration persisted 7 days after the therapy withdrawal, whilst in the other patients the score reached approximately the pre-treatment value at the end of the therapy. Twenty-eight of the 46 evaluated neurological items (60%) improved during therapy. The speech disturbance, finger chase and nose-finger test showed the more significant improvement. The clinical amelioration was inversely correlated with the level of cerebellum atrophy, as revealed by the magnetic resonance. Our data indicate that neurological signs in A-T are susceptible of beneficial pharmacological intervention even years after the disease onset.

Resistance to the nitric oxide/cyclic guanosine 5'-monophosphate/protein kinase G pathway in vascular smooth muscle cells from the obese Zucker rat, a classical animal model of insulin resistance: role of oxidative stress

Some in vivo and ex vivo studies demonstrated a resistance to the vasodilating effects of nitric oxide (NO) in insulin-resistant states and, in particular, obese Zucker rats (OZR). To evaluate the biochemical basis of this phenomenon, we aimed to identify defects of the NO/cGMP/cGMP-dependent protein kinase (PKG) pathway in cultured vascular smooth muscle cells (VSMCs) from OZR and lean Zucker rats (LZR) by measuring: 1) NO donor ability to increase cGMP in the absence and presence of inhibitors of soluble guanylate cyclase (sGC) and phosphodiesterases (PDEs); 2) NO and cGMP ability to induce, via PKG, vasodilator-stimulated phosphoprotein (VASP) phosphorylation at serine 239 and PDE5 activity; 3) protein expression of sGC, PKG, total VASP, and PDE5; 4) superoxide anion concentrations and ability of antioxidants (superoxide dismutase+catalase and amifostine) to influence the NO/cGMP/PKG pathway activation; and 5) hydrogen peroxide influence on PDE5 activity and VASP phosphorylation. VSMCs from OZR vs. LZR showed: 1) baseline cGMP concentrations higher, at least in part owing to reduced catabolism by PDEs; 2) impairment of NO donor ability to increase cGMP, even in the presence of PDE inhibitors, suggesting a defect in the NO-induced sGC activation; 3) reduction of NO and cGMP ability to activate PKG, indicated by the impaired ability to phosphorylate VASP at serine 239 and to increase PDE5 activity via PKG; 4) similar baseline protein expression of sGC, PKG, total VASP, and PDE5; and 5) higher levels of superoxide anion. Antioxidants partially prevented the defects of the NO/cGMP/PKG pathway observed in VSMCs from OZR, which were reproduced by hydrogen peroxide in VSMCs from LZR, suggesting the pivotal role of oxidative stress.

[Environmental quality of the operating theatres in Campania: long lasting monitoring results]

In this study the microbiological, physical and chemical results of an investigation concerning the environmental conditions of operating theatres in 38 public hospitals of the Campania Government are presented. The analysis of the results has been made by considering specific standards suggested by national and international regulations. The results showed that 84% of the operating theatres presented normal microbiological values, in relation to the total bacterial load, while 16% did not. By considering the microclimatic monitoring 55% of the operating theatres showed normal values while 45% at least a microclimatic index did not. In relation to the concentrations of anaesthetics gases the survey pointed out that the nitrous oxides was within non prescribed environmental limits (50 ppm for N2O); while 15% of the halogenated was not in normal values.

A case of clear renal cell cancer associated to meningioma and verrucous carcinoma of frontal region in an old patient

Here we report the concomitant development in an 82 year-old patient of three different neoplasms with different histology, degree of differentiation and clinical aggressiveness. In fact, the patient presented a verrucous carcinoma with unusual location at her head frontal region and a concomitant calcified meningioma of the frontal region of the brain. At the moment of the examination also a clear renal cell carcinoma, that was the cause of patient decease, was discovered. At our knowledge, this is the first case of concomitant presentation of these three tumours. Even if the present case was not correlated with any hereditary feature the presence of a genetic predisposition common to all the three tumours can not be excluded, but the casual co-existence of different both genetic and environmental factors can be also suggested.

Insulin activates hypoxia-inducible factor-1alpha in human and rat vascular smooth muscle cells via phosphatidylinositol-3 kinase and mitogen-activated protein kinase pathways: impairment in insulin resistance owing to defects in insulin signalling

AIMS/HYPOTHESIS

We previously demonstrated that insulin stimulates vascular endothelial growth factor (VEGF) synthesis and secretion via phosphatidylinositol-3 kinase (PI3-K) and mitogen-activated protein kinase (MAPK) pathways in vascular smooth muscle cells (VSMC) from humans and from insulin-sensitive lean Zucker fa/+ rats. We also showed that this effect is attenuated in VSMC from insulin-resistant obese Zucker fa/fa rats. As it is not known whether the effects of insulin on VEGF involve activation of hypoxia-inducible factor-1 (HIF-1), we aimed to evaluate: (1) whether insulin modulates HIF-1alpha protein synthesis and activity; (2) the insulin signalling pathways involved; and (3) the role of insulin resistance.

METHODS

Using aortic VSMC taken from humans and Zucker rats and cultured in normoxia, the following were evaluated: (1) dose-dependent (0.5, 1, 2 nmol/l) and time-dependent (2, 4, 6 h) effects exerted by insulin on HIF-1alpha content in both nucleus and cytosol, measured by Western blots; (2) insulin effects on HIF-1 DNA-binding activity on the VEGF gene, measured by electrophoretic mobility shift assay; and (3) involvement of the insulin signalling molecules in these insulin actions, by using the following inhibitors: LY294002 (PI3-K), PD98059 (extracellular signal regulated kinase [ERK]), SP600125 (Jun N terminal kinase [JNK]), SB203580 (p38 mitogen-activated protein kinase) and rapamycin (mammalian target of rapamycin), and by detecting the insulin signalling molecules by Western blots.

RESULTS

In aortic VSMC from humans and Zucker fa/+ rats cultured in normoxia insulin increases the HIF-1alpha content in cytosol and nucleus via dose- and time-dependent mechanisms, and HIF-1 DNA-binding activity on the VEGF gene. The insulin-induced increase of HIF-1alpha is blunted by the translation inhibitor cycloheximide, LY294002, PD98059, SP600125 and rapamycin, but not by SB203580. It is also reduced in Zucker fa/fa rats, which present an impaired ability of insulin to induce Akt, ERK-1/2 and JNK-1/2 phosphorylation.

CONCLUSIONS/INTERPRETATION

These results provide a biological mechanism for the impaired collateral vessel formation in obesity.

Insulin activates vascular endothelial growth factor in vascular smooth muscle cells: influence of nitric oxide and of insulin resistance

BACKGROUND

We aimed to evaluate whether insulin influences vascular endothelial growth factor (VEGF) synthesis and secretion in cultured vascular smooth muscle cells (VSMCs) via nitric oxide (NO) and whether these putative effects are lost in insulin-resistant states.

MATERIALS AND METHODS

In VSMC derived from human arterioles and from aortas of insulin-sensitive Zucker fa/+rats and insulin-resistant Zucker fa/fa rats incubated with different concentrations of human regular insulin with or without inhibitors of phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3-K), mitogen-activated protein kinase (MAPK), nitric oxide synthase (NOS) and guanosine 3',5'cyclic monophosphate(cGMP)-dependent protein kinase (PKG), we measured protein expression (Western blot) and secretion (ELISA) of VEGF.

RESULTS

We found that in VSMCs from humans and from insulin-sensitive Zucker fa/+rats, insulin increases VEGF protein expression and secretion, with mechanisms blunted by wortmannin and LY294002 (PI3-K inhibitors), PD98059 (MAPK inhibitor), L-NMMA (NOS inhibitor) and Rp-8pCT-cGMPs (PKG inhibitor). Also the NO donor sodium nitroprusside (SNP) and the cGMP analogue 8-Bromo-cGMP increase VEGF protein expression and secretion, with mechanisms inhibited by wortmannin and PD98059. The insulin effects on VEGF are impaired in VSMCs from Zucker fa/fa rats, which also present a reduced insulin ability to increase NO.

CONCLUSIONS

In VSMCs from humans and insulin-sensitive Zucker fa/+rats: (i) insulin increases VEGF protein expression and secretion via both PI3-K and MAPK; (ii) the insulin effects on VEGF are mediated by nitric oxide. The insulin action on both nitric oxide and VEGF is impaired in VSMCs from Zucker fa/fa rats, an animal model of metabolic and vascular insulin-resistance.

Impaired synthesis and action of antiaggregating cyclic nucleotides in platelets from obese subjects: possible role in platelet hyperactivation in obesity

BACKGROUND

Subjects with central obesity exhibit platelet hyperactivity, which is involved in the atherosclerotic process and therefore can account for the increased risk of cardiovascular morbidity and mortality. The aim of the study was to evaluate whether alterations of platelet function in obesity involve synthesis and/or action of the two antiaggregating cyclic nucleotides adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP).

MATERIALS AND METHODS

In platelets from 16 obese and 15 control subjects we investigated the influence on platelet responses to the Adenosine-5-diphosphate sodium salt (ADP) exerted by (i) prostacyclin analogue Iloprost (0.31-5 nmol L(-1)) and the cAMP analogue 8-bromo-cAMP (10-500 micro mol L(-1)); and by (ii) nitric oxide (NO) donor sodium nitroprusside (SNP) (5-100 micro mol L(-1)) and the cGMP analogue 8-bromo-cGMP (10-500 micro mol L(-1)). IC(50) (minimal concentration of each inhibitor necessary to reduce platelet response to ADP by half) was determined. Iloprost and SNP ability to increase cyclic nucleotides was also measured.

RESULTS

Significantly greater IC(50) were observed in obese subjects than in healthy controls (1.59 +/- 0.16 vs. 0.80 +/- 0.08 nmol L(-1), P = 0.0001 for Iloprost, and 27.6 +/- 6.5 vs. 7.0 +/- 1.7 micro mol L(-1), P = 0.006, for SNP); when data from control and obese subjects were pooled together, IC(50) of Iloprost and SNP correlated with the homeostasis model assessment (HOMA IR), which is a parameter used to measure the insulin resistance (r = 0.588, P = 0.029 and r = 0.640, P = 0.006, respectively). Also the antiaggregating effect of 8-Br-cAMP and 8-Br-cGMP was smaller in the obese subjects. Finally, the ability of Iloprost to increase platelet cAMP and the ability of SNP to increase both cGMP and cAMP were reduced in obese subjects.

CONCLUSIONS

Platelet resistance to the antiaggregating effects of prostacyclin and NO in obesity is attributable to impairment of cyclic nucleotide synthesis and action. As cyclic nucleotides are the main effectors of platelet antiaggregation, the resistance to them can account for platelet hyperactivity in obesity.

Insulin stimulates glucose transport via nitric oxide/cyclic GMP pathway in human vascular smooth muscle cells

OBJECTIVE

In cultured human vascular smooth muscle cells, insulin increases cyclic GMP production by inducing nitric oxide (NO) synthesis. The aim of the present study was to determine whether in these cells the insulin-stimulated NO/cyclic GMP pathway plays a role in the regulation of glucose uptake.

METHODS AND RESULTS

Glucose transport in human vascular smooth muscle cells was measured as uptake of 2-deoxy-d-[3H]glucose, cyclic GMP synthesis was checked by radioimmunoassay, and GLUT4 recruitment into the plasma membrane was determined by immunofluorescence. Insulin-stimulated glucose transport and GLUT4 recruitment were blocked by an inhibitor of NO synthesis and mimicked by NO-releasing drugs. Insulin- and NO-elicited glucose uptake were blocked by inhibitors of soluble guanylate cyclase and cyclic GMP-dependent protein kinase; furthermore, glucose transport was stimulated by an analog of cyclic GMP.

CONCLUSIONS

Our results suggest that insulin-elicited glucose transport (and the corresponding GLUT4 recruitment into the plasma membrane) in human vascular smooth muscle cells is mediated by an increased synthesis of NO, which stimulates the production of cyclic GMP and the subsequent activation of a cyclic GMP-dependent protein kinase.

In vitroeffects of ultraviolet A on histamine release from human basophils

BACKGROUND

As long-wave ultraviolet (UV) radiation penetrates the dermis, connective tissue cellular components and circulating blood cells can be possible targets for solar UVA. Basophils, involved in the effector phase of the inflammatory response, play a part in skin diseases such as chronic urticaria, psoriasis, atopic dermatitis, fixed drug eruption, allergic contact dermatitis, urticaria pigmentosa, systemic sclerosis and bullous pemphigoid.

OBJECTIVE

The evaluation of the in vitro effect of UVA on histamine release from human basophils.

METHODS

Basophils from healthy human volunteers were irradiated, respectively, with UVA at doses of 2.5, 5, 7.5, 10, 20 and 50 J/cm2 and then incubated with an anti-IgE serum. A fluorimetric technique was employed to determine histamine release from samples: (i) incubated with 2% HClO4 (complete lysis of basophils); (ii) irradiated with increasing doses of UVA; and (iii) unirradiated (controls).

RESULTS

Histamine release was: 100% for HClO4 incubated basophils, 30% for unirradiated and anti-IgE incubated cells (controls) and 27%, 24%, 34%, 41%, 60% and 70% for basophils irradiated with UVA doses, respectively, of 2.5, 5, 7.5, 10, 20 and 50 J/cm2 and incubated with anti-IgE. Histamine releasability from irradiated samples was statistically significant (P < 0.05), in comparison with controls, at UVA doses equal to 5, 10, 20 and 50 J/cm2.

CONCLUSIONS

UVA exerts, at least in vitro, a biphasic dose-dependent action on histamine release from human basophils incubated with an anti-IgE serum: at the lowest irradiation doses (< 5 J/cm2) it exerts an inhibitory effect and at the highest doses (> or = 10 J/cm2) histamine release increases significantly.

Natural history and clinical features of progressive supranuclear palsy: a clinical study

Progressive supranuclear palsy (PSP or Steele-Richardson-Olszewski syndrome) is one of the most-common types of atypical parkinsonism. To characterize the natural history and the clinical features of PSP, we reviewed the records of 25 patients followed in our clinic since 1991, with a clinical diagnosis of PSP according to NINDS and Golbe criteria. Progressive onset of early bilateral bradykinesia and postural instability with falls during the 5th decade strongly support the diagnosis of PSP in our patients. Pseudobulbar symptoms are very common at onset and during the course of the illness.

ALS-plus: 5 cases of concomitant amyotrophic lateral sclerosis and parkinsonism

According to El Escorial criteria, amyotrophic lateral sclerosis (ALS), combined with other neurologic disorders, such as dementia and parkinsonism, is defined as ALS-plus. These overlaping syndromes are extremely rare. Here we report 5 cases (3 men, 2 women) of ALS-plus; mean age at the onset of symptoms was 67 years (range, 65-72). In 3 patients, motoneuronal signs preceded the onset of parkinsonian syndrome. In 4 cases, the clinical picture was characterized by the prevalence of motoneuronal signs. Parkinsonism was poorly responsive to L-dopa treatment in all patients. The clinical course did not differ from that expected in patients with only ALS. Our clinical observations and neuropathological reports of nigral neuronal loss in ALS patients suggest a common pathogenic mechanism underlying these disorders.

[Detection of anomalous origin of left coronary artery by spiral CT as a cause of angina pectoris]

The anomalous origin of the left coronary artery can lead to angina pectoris, acute myocardial infarction or even sudden death, especially during exercise. We present a patient in whom the anomalous origin of the left coronary artery is from the right sinus of Valsalva, crossing between the aorta and the pulmonary trunk and causing ischemic chest pain. The anomaly was verified by a Spiral CT, as the coronary angiographic findings were not conclusive, particularly regarding the left course in relation to the major arteries. We suggest that Spiral CT is useful for detecting this kind of anomaly, particularly in clarifying the relationship between the left main coronary artery and the major arteries.

Studies on inhibition of human platelet function by sodium nitroprusside. Kinetic evaluation of the effect on aggregation and cyclic nucleotide content

In this study, we explored the ability of sodium nitroprusside to inhibit the aggregation of human platelets in platelet-rich plasma (PRP) and whole blood and its effects on intracellular levels of guanosine 3',5'-cyclic monophosphate (cGMP) and adenosine 3',5'-cyclic monophosphate (cAMP). The experiments investigated dose-dependent effects of nitroprusside starting from concentrations in the range of circulating levels achievable in vivo during drug administration in humans. Furthermore, we investigated the time-course of both antiaggregating action and the influence on cyclic nucleotide synthesis. Results showed that sodium nitroprusside inhibited the aggregation induced by adenosine 5-diphosphate (ADP) and collagen starting from concentration as low as 2 micromol/l. The IC(50) value for ADP-induced aggregation in PRP was 18.7+/-2.4 micromol/l. The inhibition of platelet aggregation showed a time-dependent behaviour and was not reversible within 90 min. The accumulation of intraplatelet cGMP in the presence of sodium nitroprusside exhibited a comparable time-course characterized by an early increase, a steady state and a late further increase. The time-course of cAMP synthesis was very similar to that of cGMP. Our data evidenced a long-lasting inhibition of platelet responses by sodium nitroprusside and excluded a desensitization of platelet guanylyl cyclase after 3-h exposure to nitric oxide (NO). Furthermore, they indicated a role of cAMP accumulation in the antiaggregating effects of nitroso donor: the simultaneous increase of intracellular content of cAMP and cGMP can synergize in the reduction of the platelet responses.

N-acetyl-L-cysteine exerts direct anti-aggregating effect on human platelets

BACKGROUND

N-acetyl-L-cysteine, a thiol compound, has been shown to potentiate the inhibition of platelet aggregation exerted by organic nitrates and to increase the anti-aggregating effect of L-arginine, which promotes endogenous synthesis of nitric oxide (NO) acting as substrate of platelet constitutive nitric oxide synthase (NOS). It is not known whether this thiol can exert direct effects on platelet aggregability.

MATERIALS AND METHODS

14 healthy male volunteers provided platelet samples to investigate whether N-acetyl-L-cysteine directly influences platelet function and intraplatelet levels of 3',5' cyclic guanosine monophosphate (cGMP), which represents the second messenger involved in NO-induced antiaggregation. Some experiments were repeated in the presence of NOS inhibitor NG-monomethyl-L-arginine (L-NMMA), of nitric oxide-sensitive guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), of the selective cGMP phosphodiesterase inhibitor zaprinast and of calcium ionophores (A23187, ionomycin).

RESULTS

N-acetyl-L-cysteine at 3000-6000 micromol L-1 decreases the responses of human platelets both in platelet-rich plasma (aggregation induced by adenosine 5-diphosphate) and in whole blood (aggregation induced by collagen). The anti-aggregating effect was prevented by preincubation with L-NMMA and guanylyl cyclase inhibitor ODQ. In resting platelets, N-acetyl-L-cysteine increased the levels of cGMP starting from a concentration of 3000 micromol L-1. Permeabilized platelets exhibited an increased sensitivity to the anti-aggregating effect of N-acetyl-L-cysteine. Also, cGMP phosphodiesterase inhibition or the increase in calcium availability, enhanced N-acetyl-L-cysteine effects on platelets.

CONCLUSION

N-acetyl-L-cysteine exerts direct anti-aggregating effects through an increased bioavailability of platelet nitric oxide.

17q21-qter trisomy is an indicator of poor prognosis in acute myelogenous leukemia

A reciprocal translocation (9;11) is often found in acute myeloid leukemia (AML), mostly of the M5a type. We report a case of a child with AML, in whom t(9;11) was observed at diagnosis as the sole structural abnormality, together with trisomies 19 and 21. The diagnosis was AML evolving from a myelodysplastic syndrome (MDS), and the blast morphology was undifferentiated. Chemotherapy failed to induce morphological remission and the patient's condition soon worsened. A subclone appeared and expanded during the course of the disease, with an additional unbalanced translocation (1;17) leading to trisomy of the long arm of chromosome 17 (17q). The data available from the literature on acquired anomalies involving 17q and our observation led us to postulate a specific link between the gain of 17q and complete chemoresistance.

Whipple's disease. Description of a case and survey of the literature

A case of Whipple's disease (WD) personally observed is described. A 28-year-old male was admitted to hospital for evaluation of weakness, intermittent fever and weight loss arisen since a month. On clinical investigation, he complained of vomit and diarrhea since three months. He had neither familial and personal past history of gastrointestinal diseases, nor any other important diseases. He denied use of drugs. Physical examination was negative. Laboratory findings showed anemia, low blood lymphocytes, low serum iron and total iron binding capacity, low total serum protein and low serum albumin and high level of ESR. Stool were negative for parasites and occult blood. Cultures of blood and urine were negative. Stool fat assay was > 7 g/24 h and D-xylose test showed a two-hour serum concentration < 25 mg/dl. Abdominal TC showed lumbo-aortic and mesenteric enlarged lymph nodes. An upper video endoscopy showed a duodenal lymphangectasia. Histological examination showed villar atrophy with massive infiltration of large PAS-positive diastase-resistant foamy cells. Ziehl-Nielsen staining was negative. WD was diagnosed and patient underwent therapy based on cotrimoxazole. This report emphasizes the difficulty to diagnose WD correctly, because of its rareness and clinical polymorphism. Recently, studies have identified a bacillus, Tropheryma whippelii, associated with WD, so that, in the next future, the diagnosis of WD will be faster and more accurate. Finally, it is important to administer antibiotics which can cross the blood brain barrier for at least one year, in order to prevent neurological relapse, often lethal.

Full cytogenetic characterization of a new neuroblastoma cell line with a complex 17q translocation

Recent studies have shown that structural abnormalities of chromosome 17 resulting in gain of material are the most frequent genetic changes in neuroblastoma. We have established a new neuroblastoma cell line from a patient whose disease had evolved from stage 4s to 4, without evidence of deletion of the short arm of chromosome 1 and MYCN amplification, which are considered the most typical genetic indicators of aggressive disease. The cytogenetic study allowed a full characterization of the chromosome changes, and revealed a complex translocation of chromosome 17 leading to a derivative marker which may be described as follows: der(11)t(11;17)(p15;q12)t(11;17) (q22;q12). This resulted in a gain of part of the long arms of chromosome 17, which was recently associated with poor prognosis.

Frequent estrogen and progesterone receptor immunoreactivity in renal angiomyolipomas from women with pulmonary lymphangioleiomyomatosis

OBJECTIVE

To determine whether renal angiomyolipomas from women with pulmonary lymphangioleiomyomatosis (LAM) express estrogen receptor (ER) and progesterone receptor (PR).

DESIGN

Retrospective study of archival tissue.

PATIENTS

Twelve women with LAM and angiomyolipomas.

SETTING

Fox Chase Cancer Center.

INTERVENTIONS

ER and PR expression was studied using immunohistochemistry. The hormonal status of the patients at the time of resection of the angiomyolipoma was determined.

RESULTS

Ten of the angiomyolipomas had ER immunoreactivity (83%), and all 12 had PR immunoreactivity (100%). The ER and PR positivity was in the smooth muscle component of the angiomyolipomas only. For five women, pulmonary LAM specimens were also available; two were ER positive (40%), and all five were PR positive (100%). All four angiomyolipomas from women receiving progesterone therapy were ER and PR positive. One tumor from a woman receiving tamoxifen was ER negative and strongly PR positive. One woman was pregnant; her tumor was ER and PR positive.

CONCLUSIONS

ER and PR expression is frequent in renal angiomyolipoma cells from women with LAM. PR was more consistently present than ER in angiomyolipomas and in LAM. Our data suggest that angiomyolipoma growth could be affected by hormonal factors. If the growth of LAM-associated angiomyolipomas slows during hormonal therapy, there are two potential implications for LAM patients: first, angiomyolipoma size could serve as a measurable indication of response to hormonal therapy; and second, surgical removal of angiomyolipomas might be avoided in some cases.

Incorporation of noncoded amino acids into the N-terminal domain 1-47 of hirudin yields a highly potent and selective thrombin inhibitor

Hirudin is an anticoagulant polypeptide isolated from a medicinal leech that inhibits thrombin with extraordinary potency (Kd = 0.2-1.0 pM) and selectivity. Hirudin is composed of a compact N-terminal region (residues 1-47, cross-linked by three disulfide bridges) that binds to the active site of thrombin, and a flexible C-terminal tail (residues 48-64) that interacts with the exosite I of the enzyme. To minimize the sequence of hirudin able to bind thrombin and also to improve its therapeutic profile, several N-terminal fragments have been prepared as potential anticoagulants. However, the practical use of these fragments has been impaired by their relatively poor affinity for the enzyme, as given by the increased value of the dissociation constant (Kd) of the corresponding thrombin complexes (Kd = 30-400 nM). The aim of the present study is to obtain a derivative of the N-terminal domain 1-47 of hirudin displaying enhanced inhibitory potency for thrombin compared to the natural product. In this view, we have synthesized an analogue of fragment 1-47 of hirudin HM2 in which Val1 has been replaced by tert-butylglycine, Ser2 by Arg, and Tyr3 by beta-naphthylalanine, to give the BugArgNal analogue. The results of chemical and conformational characterization indicate that the synthetic peptide is able to fold efficiently with the correct disulfide topology (Cys6-Cys14, Cys16-Cys28, Cys22-Cys37), while retaining the conformational properties of the natural fragment. Thrombin inhibition data indicate that the effects of amino acid replacements are perfectly additive if compared to the singly substituted analogues (De Filippis V, Quarzago D, Vindigni A, Di Cera E, Fontana A, 1998, Biochemistry 37:13507-13515), yielding a molecule that inhibits the fast or slow form of thrombin by 2,670- and 6,818-fold more effectively than the natural fragment, and that binds exclusively at the active site of the enzyme with an affinity (Kd,fast = 15.4 pM, Kd,slow = 220 pM) comparable to that of full-length hirudin (Kd,fast = 0.2 pM, Kd,slow = 5.5 pM). Moreover, BugArgNal displays absolute selectivity for thrombin over the other physiologically important serine proteases trypsin, plasmin, factor Xa, and tissue plasminogen activator, up to the highest concentration of inhibitor tested (10 microM).