Amino acids L-phenylalanine and L-lysine involvement in trans and cis piperamides biosynthesis in two Piper species

Several Piper species accumulate piperamides as secondary metabolites, and although they have relevant biological importance, many details of their biosynthetic pathways have not yet been described experimentally. Experiments involving enzymatic reactions and labeled precursor feeding were performed using the species Piper tuberculatum and Piper arboreum. The activities of the phenylalanine ammonia lyase (PAL) enzymes, which are involved in the general phenylpropanoid pathway, were monitored by the conversion of the amino acid L-phenylalanine to cinnamic acid. The activity of the 4-hydroxylase (C4H) enzyme was also observed in P. tuberculatum by converting cinnamic acid to p-coumaric acid. L-[UL-14C]-phenylalanine was fed into the leaves of P. tuberculatum and incorporated into piperine (1), 4,5-dihydropiperine (2), fagaramide (4), trans-piplartine (7), and dihydropiplartine (9). In P. arboreum, it was only incorporated into the piperamide 4,5-dihydropiperiline (3). L-[UL-14C]-lysine was successfully incorporated into the 4,5-dihydropiperine piperidine group (2), dihydropyridinone, and trans- (7) and cis-piplartine (8). These data corroborate the proposal of mixed biosynthetic origin of piperamides with the aromatic moiety originating from cinnamic acid (shikimic acid pathway) and key amide construction with amino acids as precursors.

Thrombolysis in elderly stroke patients in Italy (TESPI) trial and updated meta-analysis of randomized controlled trials

BACKGROUND

Since its approval, the use of alteplase had been limited to patients aged ≤80 years.

AIMS

TESPI trial had been designed to evaluate whether alteplase treatment within 3 h in patients with acute ischemic stroke aged >80 years resulted in favorable benefit/risk ratio compared with standard care. The meta-analysis of randomized controlled trials was updated to put findings in the context of all available evidence.

METHODS

TESPI was a multicenter, open-label with blinded outcome evaluation, randomized, controlled trial. Main clinical endpoints were 90-day favorable functional outcome (mRS score 0-2) and mortality and symptomatic intracerebral hemorrhage. The trial was prematurely terminated for ethical reasons after publication of IST-3 trial which provided evidence of treatment benefit in elderly.

RESULTS

Of the planned 600 patients, 191 (88 assigned to alteplase) were enrolled. Overall, 24/83 (28.9%) alteplase patients had a favorable outcome compared to 22/95 (23.2%) controls (non-significant absolute difference of 5.7% for alteplase; OR 1.35, 95% CI 0.69-2.64, P = 0.381). Rates of death were non-significantly lower in the alteplase patients (18.1% vs. 26.5%); rates of symptomatic intracerebral hemorrhage were similar between the two groups (5.9% vs. 5.1%). The updated meta-analysis showed consistent results with prior estimates and add weights.

CONCLUSIONS

The effects of alteplase observed in this interrupted trial did not reach statistical significance, probably for the small numbers, but are consistent with and add weight to the sum total of the randomized evidence demonstrating that alteplase is beneficial in patients with acute ischemic stroke aged over 80 years, particularly if given within 3 h.

Robot-assisted Partial Nephrectomy and Bilateral Pyelolithotomy in Ectopic Pelvic Kidneys

OBJECTIVE

To show how to perform a robot-assisted partial nephrectomy and bilateral pyelolithotomy in ectopic pelvic kidneys. This is a congenital abnormality of position and rotation¹ frequently associated with urolithiasis.² Renal cell carcinoma is a very rare event in pelvic kidneys.^3,4 These 2 findings in the same patient could be a surgical challenge and whenever possible a "one stage" treatment is preferred.

MATERIALS AND METHODS

A 44-year-old male with bilateral pelvic kidneys admitted because of left back pain. Abdominal CT scan showed a 17 mm stone in the left renal pelvis, a 12 mm stones in the right pelvis and a 34 × 27 mm right lower pole renal mass. A robotic surgery was indicated. Patient was placed in Trendelenburg position with ports configuration as for transperitoneal radical prostatectomy. The right kidney was firstly approached: after isolation of the ureter and suspension of the renal artery, a clampless partial nephrectomy was performed; then through a longitudinal pyelotomy the stone was extracted. To minimize the opening of the posterior peritoneum covering the left kidney, the site of the stone was identified by intraoperative ultrasound; then, through a longitudinal pyelotomy the stone was extracted. Given the watertight sutures and the lack of ureteral obstructions no pigtails ureteral catheters were inserted. A Jackson-Pratt drainage was placed through the inferior port.

RESULTS

Consolle time was 190 minutes. Estimated Blood Loss (EBL) was 50 ml. No complications were reported. The drain was removed on the second postoperative day, assessed that creatinine dosage was equal to serum. The length of stay was 4 days. Histopathology showed a pT1a G2 clear cell renal cell carcinoma with negative surgical margins, while stones analysis was calcium oxalate.

CONCLUSION

With the availability of robotic technology, the indications for minimally invasive surgery may be safely expanded to include concomitant morbidities in uncommon presentations.

INFN muon tomography demonstrator: past and recent results with an eye to near-future activities

A short description of the muon tomography demonstrator at the INFN Laboratori Nazionali di Legnaro near Padua, Italy, is given and the principal achievements owing to the data collected at that experimental facility are presented. In particular, the feasibility studies for several applications based on the muon-tomographic technology, within national and European projects, are discussed. The experimental problems and the procedures used to improve the performance are underlined. In addition, new activities and the related detector optimization are illustrated.This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.

An Accelerated Red-Cell Hemagglutination Inhibition Immunoassay for Measuring Fibrinogen Degradation Products in Human Serum

A further modification of Merskey’s hemagglutination inhibition assay for measurement of fibrinogen degradation products (FDP) in human serum was developed. Blood is clotted in the presence of protamine chloride (25 u/ml), in addition to thrombin and s-aminocaproic acid, and at room temperature. Defibrination is complete within 5 min even in blood obtained from patients on heparin treatment. The hemagglutination immunoassay was also considerably accelerated by immediate addition of sensitized red cells to the mixtures of antiserum and antigen dilutions at 37° C. Accurate readings of FDP titers may thus be obtained within 20 min following venipuncture.

Interactions of Purified Rat Factor VIII/von Willebrand Factor with Rat and Human Platelets – Effect of Albumin and Ristocetin

Rat platelets do not respond to ristocetin in their own plasma nor do they aggregate in the presence of bovine or porcine factor VIII von Willebrand factor (F VIII R:WF) or human F VIII R:WF in presence of ristocetin. However, rat plasma supports ristocetin induced aggregation of washed human platelets. In this study we report on purification of rat F VIII R:WF from cryoprecipitate. Similarly to porcine or bovine material, purified rat F VIII R:WF induced aggregation of human washed fixed platelets. This effect was enhanced by addition of ristocetin and was not modified by addition of albumin. Rat washed platelets were aggregated by ristocetin in the presence of rat or human F VIII R:WF provided that high concentrations of ristocetin are added in a system essentially free of extraneous proteins. Increasing concentrations of albumin dramatically reduced the ability of ristocetin to aggregate rat platelets while human platelet aggregation by human or rat F VIII R:WF was only moderately affected.

These studies show that rat F VIII R:WF can interact with rat and human platelets. The lack of response of rat platelets to ristocetin in their own plasma is most likely due to a low sensitivity of rat platelets to this drug and to an inhibitory activity of plasma proteins on this reaction.

Reactivity of Small Molecular Forms of Human Factor VIII/von Willebrand Factor with Botrocetin and Anti-Factor VIII-Coated Latex Particles

Two recently developed tests for measurement of factor VIII/von Willebrand factor (FVIII/vWF), i.e. platetelet agglutination by botrocetin and a kinetic latex antigen assay, were compared with ristocetin cofactor and electroimmunoassay, in respect with FVIII/vWF size-distribution. FVIII/vWF was measured in six cases of atypical von Willebrand’s disease (type II), in gel-filtered fractions of normal cryoprecipitate and in the course of depolymerization of purified normal FVIII/vWF by disulfide reduction. Small molecular forms of FVIII/vWF from normal and variant type II plasma, and those derived by disulfide reduction of high-molecular weight FVIII/vWF, showed remarkably decreased reactivity in ristocetin-, botrocetin- and latex-assay. We conclude that for botrocetin-induced platelet agglutination, as well as for agglutination of antibody-coated latex particles, multiple interactions with repeating subunits of FVIII/vWF are required. As a practical consequence, the combined measurement of FVIII/vWF by the latex test and electroimmunoassay provides a simple tool for discriminating between the classical von Willebrand’s disease and its variants.

Three Abnormal Fibrinogen Variants with the Same Amino Acid Substitution (γ 275 Arg → His): Fibrinogens Bergamo II, Essen and Perugia

We report on three unrelated individuals with the same uncommon type of dysfibrinogenemia, originating from Bergamo, Essen and Perugia. None of them showed bleeding symptoms while the Bergamo patient and members of her family presented with a thrombotic tendency. The presence of a defective fibrinogen was suggested by prolonged thrombin and rep-tilase times. Furthermore, fibrinogen concentrations of less than 0.28 g/L were determined by the functional assay whereas values of 1.5-2.4 g/L were measured by heat precipitation or electroimmunoassay. Fibrinogen was isolated by affinity chromatography on insoluble fibrin monomer. The rate of fibrinopeptide release by thrombin was normal while the fibrin polymerization reaction was strongly delayed. An abnormal peptide (γ265-310) was isolated by high-performance liquid chromatography after cyanogen bromide cleavage of the purified γ-chain of fibrinogen Bergamo II and Essen. The same peptide was also isolated following cyanogen bromide treatment of the intact fibrinogen Perugia. Sequence analyses of these peptides demonstrated the same amino acid exchange in all three fibrinogens: γ275 arginine → histidine. The described fibrinogen variants appear to possess a molecular defect which has thus far only been observed in fibrinogen Haifa.

Fibrinogen Bergamo I (Aα16Arg → Cys): Susceptibility Towards Thrombin Following Aminoethylation, Methylation or Carboxamidomethylation of Cysteine Residues

An abnormal fibrinogen, denoted as “fibrinogen Bergamo I”, has been characterized. Its defect consists in an exchange of arginine by cysteine in position 16 of the Aα-chain, thus corresponding to that found in a number of other fibrinogen variants. The abnormal fibrinopeptide A cannot be split off by thrombin from intact fibrinogen Bergamo I. We describe three different chemical modifications of the cysteine Aαl6, i.e. aminoethylation, methylation and carboxamidomethylation, and their effects on the susceptibility of fibrinogen Bergamo I towards thrombin attack. S-aminoethylation of the Aαl6Cys renders the peptide bond Aαl6–17 cleavable by thrombin. Following methylation or carboxamidomethylation, the Aαl9-arginyl bond becomes accessible for thrombin. The chemically modified extended fibrinopeptide A can be readily separated from the normal fibrinopeptide A by HPLC. The latter two modifications are suitable alternative procedures for detecting the molecular defect Aαl6Arg → Cys of fibrinogen.

Effect of Calcium and Synthetic Peptides on Fibrin Polymerization

Human fibrinogen was subjected to limited proteolytic attack by thrombin, batroxobin or Agkistrodon contortrix thrombin-like enzyme, yielding desAB-, desA- or desB-fibrin monomers, respectively. Turbidity curves demonstrated that, with all three enzymes, the polymerization process was strongly accelerated by increasing the calcium concentration from 10−5 M to 10−4 M. Synthetic peptide Gly-His-Arg (5 mM), an analogue of the aminoterminal sequence of fibrin β-chain, inhibited aggregation of desB-fibrin monomers at physiological calcium concentration whereas it enhanced aggregation of desA- and desAB-fibrin monomers at calcium concentrations below 10−4 M. On the other hand, Gly-Pro-Arg (1 mM) corresponding to the amino-terminus of fibrin α-chain, dramatically inhibited aggregation of both desA- and desB-fibrins, but it only moderately affected the polymerization of thrombin-induced monomers. We conclude that the observed effects of Gly-Pro-Arg and Gly-His-Arg are not due solely to their competition with fibrin amino-termini for the respective binding sites in the D-domain, but rather reflect conformational changes in fibrin monomers which affect the polymerization process.

Functional Characterization of a Variant Prekallikrein (PK Zürich)

The plasma of a 68-year-old man with cross reacting material (CRM)-positive prekallikrein (PK) deficiency was studied. PK clotting activity was <0.01 U/ml, and PK antigen was 0.1 U/ml. No circulating anticoagulant against PK was detectable. The abnormal PK molecule, denoted as prekallikrein Zürich, was partially characterized by immunological and functional studies on the propositus’ plasma. Immunobiotting analysis showed the abnormal PK being a single chain molecule of the same M r (80 kDa) as normal PK. Dextran sulfate activation of the propositus’ plasma did not lead to proteolytic cleavage of the variant PK molecule, in contrast to dextran sulfate activation of a mixture of 1 volume normal plasma and 9 volumes CRM-negative PK deficient plasma. Agarose gel electrophoresis followed by immunoblotting demonstrated that PK Zürich was complexed with high molecular weight kininogen similarly to PK in normal plasma. Incubation of the propositus’ plasma with purified β-FXIIa resulted in impaired cleavage of PK Zürich when compared with PK hydrolysis in a mixture of 10% normal plasma and 90% CRM-negative PK deficient plasma. Moreover, proteolytically cleaved PK Zürich showed no enzymatic activity against factor XII and high molecular weight kininogen.

These studies show that the functional defect of prekallikrein Zürich is due to an impaired cleavage by activated factor XII and probably the lack of enzymatic activity of the cleaved variant molecule.

Clottability and Cross-Linking Reactivity of Fibrin(ogen) Following Differential Release of Fibrinopeptides A and B

Human fibrinogen was treated at pH 6.0, 7.3 and 9.0 with thrombin, batroxobin (thrombinlike fraction of Bothrops atrox venom) or an extract of the venom from Ancistrodon contortrix contortrix. These three enzymes released the NH2-terminal fibrinopeptides A and B at different rates. Thrombin-free, preactivated factor XIII (factor XIIIa) was added to incubation mixtures to stabilize resulting fibrin(ogen) aggregates. Cross-linking of γ-chains and the size of covalently linked fibrin-fibrinogen oligomers were studied in an early stage of fibrinopeptide cleavage using polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate.

Batroxobin (pH 7.3) and thrombin (pH. 6.0) preferentially released fibrinopeptide A, and resulting fibrin aggregates became rapidly insoluble. However, when fibrinopeptide B was removed with the contortrix enzyme, soluble cross-linked oligomers appeared initially. The opaque fibrin clots, produced by thrombin (pH 6.0) or contortrix procoagulant fraction (pH 7.3), were found to be devoid of α-polymers even after prolonged incubation with factor XIIIa. Our data suggest that the solubility and opacity of fibrin networks are not primarily related to the type of the cross-link (γ-γ versus α-α interactions).

Reevaluation of the Incidence of Thromboembolic Complications in Congenital Factor XII Deficiency

To further elucidate the debated role of hereditary FXII deficiency as a thrombophilic risk factor this follow-up study on 65 subjects out of 12 Swiss families was undertaken (follow-up: 6 yrs). Fifteen severely FXII deficient subjects (FXII:C < 1%), 35 partially FXII deficient subjects (FXII:C ≥ 1-59%), 10 with normal FXII values (FXII:C ≥ 70%), and 5 non-classifiable subjects (FXII:C ≥ 60-69%) were reevaluated. Eight subjects (4 severely and 3 partially FXII deficient, 1 non-classifiable) were newly enrolled. Four instances of deep vein thrombosis, one superficial vein thrombosis and one myocardial infarction were noted in 2 out of 19 severely FXII deficient subjects during a total life-time period of 866.6 patient-years. In 38 partially FXII deficient subjects (1862.8 patient-years) one ischemic cerebrovascular stroke and one superficial vein thrombosis were recorded in 2 individuals. The 10 subjects with normal FXII values (498.2 patient-years) remained thrombosis-free. One superficial vein thrombosis occurred in an unclassifiable woman. None of the 3 different FXII gene defects revealed in our patients was specifically associated with thromboembolic complications. Kaplan-Meier analysis of thrombosis-free survival suggests that hereditary partial (and probably severe) FXII deficiency does not constitute a thrombophilic condition.

Is Plasminogen Deficiency a Thrombotic Risk Factor ? – A Study on 23 Thrombophilic Patients and their Family Members

The role of plasminogen (plg) deficiency in the pathogenesis of venous thromboembolism is debated in the literature. In the present study we evaluated the prevalence of plg deficiency in our thrombophilia patients and aimed to elucidate the thrombosis risk of plg deficiency as a single defect or in combination with other defects, with special focus on APC resistance.

The study cohort included 1192 consecutive patients with a history of clinically or objectively diagnosed venous and/or arterial thromboembolism and/or positive family history who were referred to our department for thrombophilia investigation from 02/1988 to 03/1997. All available family members of patients with plg deficiency were tested for plg, APC resistance and other thrombophilic defects that were established in the propositus.

23/1192 propositi were plg-deficient corresponding to an overall prevalence of 1.9%, i.e. 2.2% in patients with venous thrombosis and 1.4% in those with arterial events. Out of the 23 plg-deficient propositi, 8 showed one or multiple additional thrombophilic defects, and in 4 patients relevant circumstantial risk factors were present. Of the 53 available family members, 28 were plg-deficient including 5 with additional APC resistance, and 4 subjects had isolated APC resistance. Ten of the 53 family members had already suffered thromboembolic events, i.e. 5 (18%) in the plg-deficient group and 5 (20%) in the non-deficient group, both groups showing an almost identical median age at the time of investigation (28.9 years and 27.1 years, respectively).

Based on our data, plg deficiency is a rare defect in thrombophilic patients and as a single defect it does not seem to be a strong thrombotic risk factor, as 11 of 23 propositi had additional thrombophilic defects or circumstantial risk factors, and in the family members thrombotic events were equally frequent in the plg-deficient and non-deficient subjects.

Proteomic profile of Piper tuberculatum (Piperaceae)

Abstract Piper tuberculatum (Piperaceae) is a species that accumulates especially amides as secondary metabolites and several biological activities was previously reported. In this article, we report a proteomic study of P. tuberculatum. Bidimensional electrophoresis (2D SDS-PAGE) and mass spectrometry (ESI-Q-TOF) were used in this study. Over a hundred spots and various peptides were identified in this species and the putative functions of these peptides related to defense mechanism as biotic and abiotic stress were assigned. The information presented extend the range of molecular information of P. tuberculatum.

Reproductive features of the swimming crab Callinectes danae(Crustacea, Portunoidea) on the subtropical coast of Brazil: a sampling outside the estuary

The life cycle of the crab Callinectes danae is estuarine-dependent, and studies on aspects of their biology should also cover marine areas. The present study investigated the sexual maturity, as well as habitat preference by adults in different gonadal stages, and the crabs' reproductive periodicity outside the estuary. Three bays on the subtropical southeastern coast of Brazil were sampled monthly for two years. For each bay, six transects were established, four of them parallel to the beach line (5, 10, 15 and 20 m depth), as well as one transect in an exposed area, and another sheltered from the action of waves. The results showed that the pattern of spatio-temporal distribution of adults C. danae was similar in three bays, although the highest abundance was found in Ubatumirim. Females with developed gonads/ovigerous females were found in greater abundance than females with rudimentary/developing gonads, mainly in deeper transects. Although the areas sampled have different environmental characteristics, the reproductive pattern of the species did not change, showing continuous reproduction throughout, with more abundance of reproductive females on spring and summer. Males reached maturity at larger sizes than females in all three bays.

The THRombolysis and STatins (THRaST) study

OBJECTIVE

To assess the impact on stroke outcome of statin use in the acute phase after IV thrombolysis.

METHODS

Multicenter study on prospectively collected data of 2,072 stroke patients treated with IV thrombolysis. Outcome measures of efficacy were neurologic improvement (NIH Stroke Scale [NIHSS] ≤ 4 points from baseline or NIHSS = 0) and major neurologic improvement (NIHSS ≤ 8 points from baseline or NIHSS = 0) at 7 days and favorable (modified Rankin Scale [mRS] ≤ 2) and excellent functional outcome (mRS ≤ 1) at 3 months. Outcome measures of safety were 7-day neurologic deterioration (NIHSS ≥ 4 points from baseline or death), symptomatic intracerebral hemorrhage type 2 with NIHSS ≥ 4 points from baseline or death within 36 hours, and 3-month death.

RESULTS

Adjusted multivariate analysis showed that statin use in the acute phase was associated with neurologic improvement (odds ratio [OR] 1.68, 95% confidence interval [CI] 1.26-2.25; p < 0.001), major neurologic improvement (OR 1.43, 95% CI 1.11-1.85; p = 0.006), favorable functional outcome (OR 1.63, 95% CI 1.18-2.26; p = 0.003), and a reduced risk of neurologic deterioration (OR: 0.31, 95% CI 0.19-0.53; p < 0.001) and death (OR 0.48, 95% CI 0.28-0.82; p = 0.007).

CONCLUSION

Statin use in the acute phase of stroke after IV thrombolysis may positively influence short- and long-term outcome.

[Managing the hospitalizations for older patients in University Hospital of Pisa]

We have analyzed hospitalizations of older people (> 64) from 2002 to 2005. Patients, discharges and stay in hospital have increased, the variation has been statistically significant. We have noticed the same trend about the rehospitalizations. Patients and discharges coming from ASL 5 and zone 4 have decreased in relation with all the elderly people. The reduction of stay in hospital and the decrease of rehospitalizations have been statistically significant.

Antioxidant activity of Agaricus blazei

The ethanolic extract of Agaricus blazei and ethyl acetate and hydroalcoholic fractions were evaluated for their antioxidant activity.

Antioxidant activity of Maytenus ilicifolia root bark

Maytenus ilicifolia is an important plant with potential on cancer treatment and has been largely used in Brazil and other countries. We have evaluated the crude ethanolic extract of M. ilicifolia as a potential antioxidant source using an assay based on the bleaching of the radical monocation 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(*+)) and by HOCl scavenger capacity. Trolox and uric acid were used as positive controls. The results indicated M. ilicifolia root bark as a great source of antioxidants based on its potential as scavenger of radicals.

Remission of thrombotic thrombocytopenic purpura in a patient with compound heterozygous deficiency of von Willebrand factor-cleaving protease by infusion of solvent/detergent plasma

Plasma exchange or plasma infusion is considered to be the therapy of choice in patients with thrombotic thrombocytopenic purpura (TTP) who are deficient in von Willebrand factor-cleaving protease (VWF-CP). Recently, mutations in the ADAMTS 13 gene were identified as being responsible for VWF-CP deficiency in patients with familial TTP (VWF-CP deficiency in the absence of an inhibitor). Here we report on a girl who presented with recurrent thrombocytopenia and anaemia since birth, developing the full pentad of characteristic TTP at the age of 16 y. Congenital TTP was confirmed on the basis of severe VWF-CP deficiency in the absence of an acquired inhibitor. The patient was found to be compound heterozygous for two hitherto undescribed mutations in the ADAMTS 13 gene: a truncating frame shift mutation, 4143insA in exon 29, and the nonsense mutation 3100A >T in exon 24 (R1034X). After infusion of solvent/detergent plasma, the patient went into remission and remained asymptomatic under regular plasma therapy at 2-wk intervals for over two years.

CONCLUSION

TTP in childhood may be mild and oligosymptomatic. Determination of VWF-CP activity is helpful in the differential diagnosis of thrombocytopenia.

A Phase II trial of docetaxel and cisplatin in patients with recurrent or metastatic nasopharyngeal carcinoma

A Phase II study was conducted to determine the efficacy and toxicity of the combination of docetaxel and cisplatin, in patients with recurrent or metastatic nasopharyngeal carcinoma (NPC). Nine patients (median age 39 years) with NPC were enrolled, none had prior chemotherapy for their recurrent or metastatic disease. Docetaxel was administered as a 1-h intravenous infusion at a dose of 75 mg/m(2) on day 1; cisplatin was administered at a dose of 75 mg/m(2) on day 1, immediately after docetaxel. Treatment was repeated every 3 weeks. The primary endpoint was objective response rate and the secondary endpoints were duration of response, time to progression, and overall survival. A total of 45 chemotherapy cycles were administered. In an intention-to-treat analysis two patients (22%, 95% confidence interval (CI): 3-60%) achieved a partial response. The median duration of response was 4.1 months, the median time to progression 8.4 months and the overall survival at 1 year from start of treatment was 76%. Grade 3-4 neutropenia was observed in all (100%) patients over 93% of the treatment cycles, and in three cases this was complicated by fever. Other toxicities were mild.

CONCLUSIONS

The combination of docetaxel and cisplatin has manageable toxicity but little efficacy as first-line treatment in patients with recurrent or metastatic NPC. In view of the low response rate, accrual was terminated and the trial was aborted.

Partial amino acid sequence of purified von Willebrand factor-cleaving protease

von Willebrand factor-cleaving protease (vWF-cp) is responsible for the continuous degradation of plasma vWF multimers released from endothelial cells. It is deficient in patients with thrombotic thrombocytopenic purpura, who show unusually large vWF multimers in plasma. Purified vWF-cp may be useful for replacement in these patients, who are now treated by plasma therapy. In this study, vWF-cp was purified from normal human plasma by affinity chromatography on the IgG fraction from a patient with autoantibodies to vWF-cp and by a series of further chromatographic procedures, including affinity chromatography on Protein G, Ig-TheraSorb, lentil lectin, and heparin. Four single-chain protein bands, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions, showed M(r) of 150, 140, 130, and 110 kd and were found to share the same N-terminal amino acid sequence, suggesting that they were derived from the same polypeptide chain that had been partially degraded at the carboxy-terminal end. A hydrophobic sequence (Ala-Ala-Gly-Gly-Ile-Leu-His-Leu-Glu-Leu-Leu-Val-Ala-Val-Gly) of the first 15 residues was established. The protease migrates in gel filtration as a high-molecular-weight complex with clusterin, a 70-kd protein with chaperonelike activity. vWF-cp bound to clusterin is dissociated by the use of concentrated chaotropic salts. vWF-cp in normal human plasma or serum is not associated with clusterin, suggesting that the observed complex is due to vWF-cp denaturation during the purification procedure. Activity of vWF-cp is unusually stable during incubation at 37 degrees C; its in vitro half-life in citrated human plasma, heparin plasma, or serum is longer than 1 week. There was even a temporary increase in protease activity during the first 3 days of incubation.

Congenital microangiopathic hemolytic anemia and thrombocytopenia with unusually large von Willebrand factor multimers and von Willebrand factor-cleaving protease

Infantile or congenital cases of thrombotic microangiopathy have been reported that were familial and characterized by ongoing microangiopathic hemolysis and thrombocytopenia in the absence of regular fresh-frozen plasma transfusions. The authors describe a child with congenital microangiopathic hemolytic anemia and thrombocytopenia (CMHAT) who has received regular fresh-frozen plasma transfusions since infancy and has never had thrombotic complications. von Willebrand factor (vWF)-cleaving protease activity was studied in the patient's pretransfusion and posttransfusion plasma samples as well as in her parents' plasma. The effects of the patient's and a control subject's plasma on human microvascular endothelial cells were also investigated. Unusually large vWF multimers were present in the patient's plasma both before transfusion (thrombocytopenic) and after transfusion. Unlike cases of chronic relapsing thrombotic thrombocytopenic purpura, vWF-cleaving protease activity was present and treatment of cultured human endothelial cells with the patient's plasma did not induce apoptosis. These findings suggest that the patient with CMHAT may represent a different group in the broad spectrum of thrombotic microangiopathies.

Fibrinogen Milano XII: a dysfunctional variant containing 2 amino acid substitutions, Aalpha R16C and gamma G165R

Fibrinogen Milano XII was detected in an asymptomatic Italian woman, whose routine coagulation test results revealed a prolonged thrombin time. Fibrinogen levels in functional assays were considerably lower than levels in immunologic assays. Polymerization of purified fibrinogen was strongly impaired in the presence of calcium or ethylenediaminetetraacetic acid (EDTA). Two heterozygous structural defects were detected by DNA analysis: Aalpha R16C and gamma G165R. As seen previously with other heterozygous Aalpha R16C variants, thrombin-catalyzed release of fibrinopeptide A was 50% of normal. Additionally, the release of fibrinopeptide B was delayed. Immunoblotting analysis with antibodies to human serum albumin indicated that albumin is bound to Aalpha 16 C. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of plasmin digests of fibrinogen Milano XII in the presence of calcium or EDTA showed both normal and novel D1 and D3 fragments. Further digestion of abnormal D3 fragments by chymotrypsin resulted in degradation products of the same size as the fragments derived from normal fibrinogen. SDS-PAGE analysis under reducing conditions showed no difference between normal fibrinogen and fibrinogen Milano XII or between their plasmic fragments. Circular dichroism analysis revealed a shift in the mean residual ellipticity and a significant reduction of the alpha-helix content in the variant D3 fragment. It is concluded that the Aalpha-chain substitution is mainly responsible for the coagulation abnormalities, whereas the substitution in the gamma-chain induced a conformational change in the D3 fragment.

Ten years of prophylactic treatment with fresh-frozen plasma in a child with chronic relapsing thrombotic thrombocytopenic purpura as a result of a congenital deficiency of von Willebrand factor-cleaving protease

We report the results of 10 years of prophylactic fresh-frozen plasma (FFP) infusion therapy in a 14-year-old girl with chronic relapsing thrombotic thrombocytopenic purpura (TTP), in whom a severe congenital von Willebrand factor (VWF)-cleaving protease deficiency has been documented. Severe haemolytic crises triggered by infections were prevented and her present renal and neurological functions have been preserved. Sequential measurements of protease activity and platelet count after FFP infusion led us to conclude tentatively that 5% may be sufficient to degrade very large and adhesive VWF multimers.

Aetiology and pathogenesis of thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome: the role of von Willebrand factor-cleaving protease

Thrombotic thrombocytopenic purpura (TTP) and haemolytic uraemic syndrome (HUS) are today often regarded as variants of one syndrome denoted as TTP/HUS, characterized by thrombocytopenia caused by intravascular platelet clumping, microangiopathic haemolytic anaemia, fever, renal abnormalities and neurological disturbances. Unusually large von Willebrand factor multimers have been observed in plasma from patients with chronic relapsing forms of TTP. Their appearance in patients with classic TTP is caused by deficiency of a specific von Willebrand factor-cleaving protease. A constitutional deficiency of this protease has consistently been found in familial cases of TTP, whereas in acquired TTP the protease deficiency is caused by the presence of an inhibiting autoantibody. A normal activity of von Willebrand factor-cleaving protease has been established in patients with HUS. In this chapter, we report 23 cases with severe constitutional protease deficiency: about one half of these patients had their first acute episode as children, whereas the other half had their first TTP event at an adult age, several of them during their first pregnancy. Two of these 23 individuals with congenital protease deficiency, both older than 35 years, have never had an acute TTP event. These results indicate that a deficiency of von Willebrand factor-cleaving protease alone is not sufficient to cause acute TTP. Patients with long-lasting dormant protease deficiency have been found to experience multiple relapses of TTP after having had their first acute episode. In one protease-deficient, plasma-dependent patient with chronic relapsing TTP, we estimated that 5% of normal protease activity is sufficient to remove the most adhesive von Willebrand factor multimers and prevent the formation of platelet microthrombi. The deficiency of von Willebrand factor-cleaving protease is a very strong risk factor for TTP, but the development of an acute bout requires a trigger, possibly causing the activation or apoptosis of endothelial cells in the microcirculation. It is unclear whether anti-endothelial cell antibodies, cytokines or other agents are involved in triggering thrombotic microangiopathy. The release of platelet calpain (and/or other proteases), leading to a degradation of von Willebrand factor and to platelet aggregation, has been reported in patients during their acute TTP episode. It is unknown whether calpain directly triggers an acute event or whether it merely reflects its release during the aggregation of platelets by the unusually large von Willebrand factor multimers. With regard to the heterogeneous aetiology of thrombotic microangiopathies, requiring distinct therapeutic measures, a new classification of thrombotic microangiopathy should replace the current, frequently inappropriate clinical discrimination between TTP and haemolytic uraemic syndrome.

von Willebrand factor-cleaving protease in childhood diarrhoea-associated haemolytic uraemic syndrome

A deficiency of von Willebrand factor (vWF)-cleaving protease, either due to a congenital deficiency or to the presence of a protease inhibitor of vWF-cleaving protease has been associated with thrombotic thrombocytopenic purpura (TTP). We have studied vWF-cleaving protease in diarrhoea-associated haemolytic uraemic syndrome (D+ HUS), which shares clinical features with TTP. 29 children with acute D+ HUS and 13 control children were studied. vWF-cleaving protease activity was normal (range 50-150%) in 39 of 42 plasma samples. Levels of protease activity between 25 and 50% were noted in plasma from two D+ HUS patients. One D+HUS patient, who had clinical features of TTP, had a vWF-cleaving protease inhibitor producing a severe deficiency of vWF-cleaving protease. Thus a deficiency of vWF-cleaving protease appears to be atypical in D+HUS. The detection of a vWF-cleaving protease inhibitor in one patient suggests it may be associated with infection such as E. coli O157.

Microangiopathic haemolytic anaemia in metastasizing malignant tumours is not associated with a severe deficiency of the von Willebrand factor-cleaving protease

Complete deficiency of von Willebrand factor-cleaving protease (VWF-cp) has recently been identified as a pathogenetically important factor for thrombotic thrombocytopenic purpura (TTP). Microangiopathic haemolytic anaemia (MAHA) with thrombocytopenia in patients with metastasizing neoplasms is clinically similar to TTP, however, the pathogenesis of the condition is unclear. Partial deficiency of VWF-cp in metastasizing malignancy has recently been reported in patients without MAHA. Our study shows normal or subnormal VWF-cp activity in four patients with metastasizing neoplasia-associated MAHA but, in contrast to classical TTP, no complete deficiency of VWF-cp despite the full clinical picture of MAHA.

Biosynthesis of friedelane and quinonemethide triterpenoids is compartmentalized in Maytenus aquifolium and Salacia campestris

Maytenus aquifolium (Celastraceae) and Salacia campestris (Hippocrateaceae) species accumulate friedelane and quinonemethide triterpenoids in their leaves and root bark, respectively. Enzymatic extracts obtained from leaves displayed cyclase activity with conversion of the substrate oxidosqualene to the triterpenes, 3beta-friedelanol and friedelin. In addition, administration of (+/-)5-(3)H mevalonolactone in leaves of M. aquifolium seedlings produced radio labelled friedelin in the leaves, twigs and stems, while the root bark accumulated labelled maytenin and pristimerin. These experiments indicated that the triterpenes once biosynthesized in the leaves are translocated to the root bark and further transformed to the antitumoral quinonemethide triterpenoids.

Antifungal amides from Piper hispidum and Piper tuberculatum

Piper hispidum and Piper tuberculatum accumulate amides bearing isobutyl, pyrrolidine, dihydropyridone and piperidine moieties. The isolation and characterization of several representatives including two hitherto unreported amides were performed by chromatographic techniques and by analysis of spectroscopic data. The antifungal activity of each amide was determined by direct bioautography against Cladosporium sphaerospermum.