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To compare the hemodynamic effect of volume loading with that of dobutamine infusion in severe ischemic right ventricular (RV) dysfunction, 11 patients with inferior and RV infarction complicated by low cardiac output syndrome and important hemodynamic derangement (systolic blood pressure 10 mm Hg) were prospectively studied within 48 hours of symptom onset. After right heart catheterization, volume loading (mean 400 ml saline solution) and dobutamine infusion (5 and 10 [mu]g/kg/min over 10 minutes) were performed according to a randomized, crossover design. Volume loading resulted in increased right atrial (from 15 [+ or -] 2 to 19 [+ or -] 3 mm Hg, p

The handgrip test has been proposed for the evaluation of the hemodynamic reserve in patients with coronary artery disease and to quantitate the impairment of left ventricular (LV) function. The present study was designed to evaluate the effect of thrombolytic therapy in patients with refractory unstable angina in order to test the hypothesis that a reduction in intracoronary thrombosis could ameliorate their hemodynamic response to the handgrip test. During left heart catheterization, 20 patients with refractory unstable angina of recent onset performed a handgrip test before (HG1) and 24-72 hours after (HG2) being randomized to receive recombinant tissue-type plasminogen activator or placebo, according to a double-blind parallel group design. HG1 induced an increase in heart rate (p [less than] 0.001), in systolic pressure (p [less than] 0.001), and a reduction in ejection fraction (p [less than] 0.05). Changes in LV end-diastolic pressure during baseline handgrip were highly different in individual patients, resulting in a trend toward an increase. Similarly, a different individual response was observed in the behavior of the isovolumetric and relaxation indices. In comparison with HG1, no difference was detected during HG2 in the 2 treatment groups with respect to changes in LV volumes, ejection fraction, LV systolic and diastolic pressures, +dP/dt, (dP/dt)/P, -dP/dt, and tau index. In patients with refractory unstable angina of recent onset, the handgrip test performed before and after thrombolysis did not prove to be useful in assessing directional changes of LV performance, mainly because of the different individual response to the baseline handgrip test.

The elastic behavior of the dilated coronary vessel has been reported to affect the immediate results of coronary angioplasty. To determine whether elastic recoil may also influence the long-term restenosis process, 98 consecutive patients with unstable angina and 1-vessel disease were studied. An automated coronary quantitative program was used for the assessment of balloon and coronary luminal diameters. Elastic recoil was defined as the percent reduction between minimal balloon diameter at the highest inflation pressure and minimal lesion diameter immediately after coronary angioplasty. Follow-up coronary arteriography was performed 8 to 12 months after the procedure in all patients. The mean elastic recoil averaged 17.7 [+ or -] 16% and was correlated to the degree of residual stenosis immediately after coronary angioplasty (r = 0.64; p 50% diameter stenosis at follow-up, developed in 53 patients (54%). There was no correlation between the degree of elastic recoil and the changes in minimal lesion diameter observed during follow-up, whereas a positive correlation between the amount of elastic recoil and the incidence of restenosis was documented (r = 0.84); p

It is well known that constriction of the coronary arteries, the vessels that deliver blood to the heart muscle itself, can cause angina, a painful and potentially dangerous heart condition. Measurement of coronary artery constriction in patients suffering from chest pain, however, relies on invasive tests such as angiography that carry a certain risk. The hyperventilation test, in which patients breathe deeply and rapidly for five minutes while the electrical activity of the heart and blood pressure are recorded, is proposed as an alternative to invasive methods for estimating the extent of blood vessel constriction. To test this possibility, 83 patients hospitalized for chest pain or for narrowing of one or more coronary arteries underwent hyperventilation and exercise stress testing. Changes in their electrocardiograms that reflect coronary artery constriction were noted. Patients who showed such changes (Group I) returned the next day and were tested in the same way after receiving a calcium antagonist drug, which reduces blood pressure and oxygen demand by the heart. An equal number of patients whose electrocardiograms had not been affected by hyperventilation served as a control group (Group II). Fifteen out of 16 Group I patients had a more normal electrocardiogram after medication, while there was no change for Group II patients. In addition, exercise duration increased for Group I patients, but not for Group II members. These results suggest that the outcome of the hyperventilation test can serve as a screening measure for patients with stable exertional angina and vasoconstriction to help determine who will benefit from treatment with calcium blockers. (Consumer Summary produced by Reliance Medical Information, Inc.)

Endomyocardial biopsies from 174 patients with dilated cardiomyopathy (DC) were examined. Eight patients with histologically proven myocarditis were excluded from the study. A peculiar pattern of oversized and bizarre nuclei was observed in only some of the remaining patients. Two groups were identified: those with and without this feature (groups A and B, respectively). Myocyte width, nuclear diameter and nuclear/sarcoplasmic ratio were significantly higher in group A. The mean respective values were 36 [+ or -] 5 [mu], 14 [+ or -] 3 [mu] and 0.41 [+ or -] 0.08 for group A versus 20 [+ or -] [mu], 7 [+ or -] 2 [mu] and 0.37 [+ or -] 0.08 for group B. interstitial fibrosis was similarly present in groups A and B. Endocardial thickness was significantly increased in all patients, with group A showing the highest mean value. The morphologic features showed no correlation with the clinical condition of the patients at time of presentation. HLA typing was performed in 50 consecutive patients, 38 from group A and 12 from group B. DR4 and DR5 antigens were significantly more frequent in DC patients than in a normal population control (400 blood donors), while DR3 was less frequent. Group A was more strongly associated with the DR5 antigen than group B (55.3 vs 25.0%, respectively). it was less strongly associated with the DR4 antigen compared with group B (21.5 vs 41.7%, respectively). No difference was observed between the 2 groups concerning negative association with the DR3 antigen. Endemyocardial biopsies from DC patients reveal marked morphologic changes from patient to patient. The histopathologic identification of 2 distinct DC groups with different HLA marker associations suggests that immune-response genetic factors may play a role in the histopathologic expression of the disease. (Am J Cardiol 1989;64:991-995), Dilated cardiomyopathy (DC) is a disease of the heart muscle in which the muscle cells (myocytes) degenerate and fibrous elements invade the tissue causing the wall to thicken. Genetic factors have been suggested as one possible cause. In particular, the association of specific human leukocyte antigens (HLA), molecules present on the surface of blood cells of every individual, with DC has been proposed. Fifty out of 166 patients diagnosed with DC on the basis of cardiac biopsy also provided blood samples for HLA determination. Biopsies were evaluated using the light microscope and measurements were of myocyte width (average width of the heart cell), various cell nuclei dimensions including diameter, extent of fibrosis (or presence of fibrous tissue), thickness of the heart wall, and other related variables. Blood from 400 hundred healthy blood donors was used to determine HLA antigen frequencies in the general population for comparison with the group with DC. The most important finding regarding muscle cells from DC patients was the presence of very large, abnormal cell nuclei. The magnitude of these changes, however, was not correlated with extent of symptoms or duration of the disease. The 60 percent of patients who had this abnormality constituted Group A, while the remainder made up Group B. When DC patients were compared with the population as a whole, they were found to display HLA antigen subtypes DR4 and DR5 more often, with no difference for DR3. Among DC patients as a group, HLA antigen subtype DR4 was more frequent in Group B than Group A; subtype DR5, on the other hand, was more frequent in Group A patients. The lack of correlation between abnormal cells and disease progression argued against interpreting these changes as a pathological response to failure of the heart's contracting mechanism, since they should then be more numerous in advanced disease. The cell nuclei abnormalities resembled changes noted during activation of protein synthetic machinery. Analysis of HLA subtypes showed that a type of cellular damage can be associated with an HLA subtype. This finding is consistent with the hypothesis that DC is one of several diseases caused by the chemical product of an interaction between a virus and the immune system. The hypothesis holds that this product then becomes toxic to the body's cells. While implications of these results for treatment or progression of DC are not clear, clarification of the role of the immune system with respect to this disease could shed light on its etiology. (Consumer Summary produced by Reliance Medical Information, Inc.)

Abstract.: Samples were prepared by addition of a fluorinated poly(aryl ether ketone) (12F-PEK) to a commercial epoxy resin and curing at either 24 °C or 70 °C. The concentrations of fluoropolymer in the samples were 0, 5, 10, 20, 30, 40, and 50%. Phase inversion facilitates the formation of more and more smooth surfaces for scratch testing with increasing fluoropolymer concentration. A progressively increasing load from 0.03 N to 12 N was administered with a diamond tip to the surfaces of the samples; depths were determined within ±7.5 nm. The original scratch depth is a function of the fluoropolymer concentration. Scratch recovery (healing) reaches values up to 95%. Plots of the residual depth versus concentration of the fluoropolymer at 4, 6, 8, and 10 N reveal minima for all forces and both temperatures. Addition of only 5% or 10% 12F-PEK improves the scratch recovery significantly. The results are explained by changes of material morphology with the fluoropolymer concentration.

We have placed a copolymer of poly(ethylene terephthalate + 0.6 mole fraction of p-hydroxybenzoic acid) in magnetic fields up to 1.8 Tesla, heated it to the molten state (at several temperatures in the range 240–315 °C) and cooled to the room temperature under the field to maintain the orientation so acquired. Then the extent of the orientation has been determined with an anisotropy parameter abased on the ultrasound critical–angle reflectometry (UCR); the parameter is calculated from the ratio of the maximum velocity to the minimum velocity of the reflected wave at critical incidence angles at which total internal reflection occurs. A significant orientation effect is found. As expected, anisotropy increases with time, magnetic field strength and to a lesser extent with the temperature. Large changes in the extent of the anisotropy are connected to phase transitions determined before. The Freederickscz transition is observed. The influence of the orientation effect on the mechanical properties of samples has been established by flexural tests. The strengthening observed has been explained using an extension of the statistical–mechanical theory of Flory in terms of channeling of flexible sequences in the polymer liquid crystals (PLC) and changes in phase structures under the magnetic field. The strengthening effect depends strongly on the presence, size and distribution of liquid crystal (LC) islands in the material. The islands act similarly as dispersoids in other types of materials. Maxima of the strengthening effect with respect to the alignment are found and related to the size of LC-rich islands in the structure.

AbstractTryparedoxins (TXNs) catalyse the reduction of peroxiredoxin type peroxidases by the bisglutathionyl derivative of spermidine, trypanothione, and are relevant to hydroperoxide detoxification and virulence of trypanosomes. The 3Dstructures of the following tryparedoxins are presented: authentic tryparedoxin1 of Crithidia fasciculata, CfTXN1; the histagged recombinant protein, CfTXN1H6; reduced and oxidised CfTXN2, and an alternative substrate derivative of the mutein CfTXN2H6-Cys44Ser. Cys41 (Cys40 in TXN1) of the active site motif 40-WCPPCR-45 proved to be the only solventexposed redox active residue in CfTXN2. In reduced TXNs, its nucleophilicity is increased by a network of hydrogen bonds. In oxidised TXNs it can be attacked by the thiol of the [1]Nglutathionyl residue of trypanothione, as evidenced by the structure of [1]Nglutathionylspermidinederivatised CfTXN2H6-Cys44Ser. Modelling suggests Arg45 (44), Glu73 (72), the Ile110 (109) cisPro111 (110)bond and Arg129 (128) to be involved in the binding of trypanothione to CfTXN2 (CfTXN1). The model of TXNsubstrate interaction is consistent with functional characteristics of known and newly designed muteins (CfTXN2H6-Arg129Asp and Glu73Arg) and the [1]Nglutathionylspermidine binding in the CfTXN2H6-Cys44Ser structure.

A Zn-polycarboxylate biocompatible adhesive was synthesized from polyacrylic acid and Zn-acetate solutions. The influence of reactant concentration, from 1 to 3 N, on the properties of this compound, was studied. The reaction product was characterized by both infrared (IR) and Raman spectroscopies and scanning electron microscopy. Adhesion behavior was evaluated by 90° and 180° peel-out testing using wood and cowhide as substrates, to simulate bonding to living tissue. The measured adhesion strength increases with reactant concentration. In-vivo tests were performed in dogs. Preliminary results show a transparent and flexible polymer material with very good adhesion to cornea tissue.

AbstractTryparedoxins (TXN) are thioredoxinrelated proteins which, as trypanothione:peroxiredoxin oxidoreductases, constitute the trypanothionedependent antioxidant defense and may also serve as substrates for ribonucleotide reductase in trypanosomatids. The active site motif of TXN2, [40]WCPPCR[45], of Crithidia fasciculata was mutated by sitedirected mutagenesis and eight corresponding muteins were expressed in E. coli as terminally Histagged proteins, purified to homogeneity by nickel chelate chromatography, and characterized in terms of specific activity, specificity and, if possible, kinetics. Exchange of Cys41 and Cys44 by serine yielded inactive products confirming their presumed involvement in catalysis. Exchange of Arg45 by aspartate resulted in loss of activity, suggesting an activation of active site cysteines by the positive charge of Arg45. Substitution of Trp40 by phenylalanine or tyrosine resulted in moderate decrease of specific activity, as did exchange of Pro42 by glycine. Kinetic analysis of these three muteins revealed that primarily the reaction with trypanothione is affected by the mutations. Simulation of thioredoxin or glutaredoxin like active sites in TXN2 (P42G and W40T/P43Y, respectively) did not result in thioredoxin or glutaredoxin like activities. These data underscore that TXNs, although belonging to the thioredoxin superfamily, represent a group of enzymes distinct from thioredoxins and glutaredoxins in terms of specificity, and appear attractive as molecular targets for the design of trypanocidal compounds.

Fracture and mechanical characterization of bone composite composed of polymethylmethacrylate and hydroxyapatite (HA) at different contents was carried out. Hydroxyapatite is added in order to improve cement biocompatibility, but it is expected that it also affects mechanical properties. Specimens were either stored in air at 37°C for 120 h or in physiological solution (PhS-37), in order to establish the influence of storage conditions upon mechanical behavior. One set of specimens was also postcured at 120°C for 4 h to take into account the influence of free monomer. Fracture experiments revealed some non-linearity in load–displacement records and differences in trends between initiation and propagation values of the fracture surface energies. The trends in the data shows that HA acts as a rigid filler enhancing fracture resistance, flexural modules and yield stress, up to a certain content. Beyond the latter limit, properties suffer a deterioration because the addition of HA also affects the cement porosity. Absorbed water acts as plasticizer leading to a decrease in mechanical properties. The highest propagation strain energies were exhibited by materials aged in PhS-37. ©1999 Kluwer Academic Publishers

Observations on the genus Lulworthia Suth., on its relationship with Limnoria Menzies and records of others species. - Near a coral-limestone before Bogliasco-Genova panels of various woods: Abies alba, Ochroma lagopus, Fagus silvatica, Olea europaea, Larix decidua, Pinus pinaster, Populus alba have been laid as a bait. When they have been fished out again, after lengths of time varying from a minimum of a month and a half to a maximum of eleven months, with intervals of about one month and a half, they have often presented, besides the normal bentonic flora and fauna, numerous long, bright, septate, brown hyphae emerging from the wood. Only after the panels have been perforated by Limnoria tripunctata the perithecia of Lulworthia sp. appear; the quantity of these seems to be inversely proportional to that of the brown hyphae, which is particularly evident in Olea and Populus. In some preparations (slides) it is possible to notice connections between the brown mycelium inside the wood and the perithecia of the ascomicete. It is believed that the brown hyphae represent the vegetative stage of the strain of Lulworthia found at Bogliasco but that only after the perforation and alteration of the wood caused by Limnoria, the fungus is able to form the perithecia. The biometric values of the above mentioned Lulworthia are given. Besides, the finding of the Papulaspora halima Anast. is reported; such species, described in California in 1963, has been found in Japan, too. It is also noticed the presence of Corollospora maritima Wender., already found in other stations of the Mediterranean, and other ubiquitous species.

Objectives. This study in patients with coronary artery disease (CAD) sought to 1) determine the dental pain threshold and reaction to tooth pulp stimulation; 2) correlate the clinical, ergometric and angiographic features of patients with and without pain during percutaneous transluminal coronary angioplasty (PTCA) to pulpal test response; 3) verify whether reactivity to dental pulp stimulation could help to identify patients particularly prone to perceiving angina during myocardial ischemia.

To investigate the significance of hyperventilation-induced ST segment depression, 329 consecutive patients with angina and documented coronary artery disease who underwent hyperventilation and exercise tests during pharmacologic washout were studied. The hyperventilation test induced ST segment depression in 79 patients. In 36 of these 79 patients; the electrocardiographic changes occurred early during overbreathing (Group I), whereas in 26 they occurred late during recovery (Group II). Seventeen patients developed ST segment depression both during overbreathing and during recovery (Group III).

Objective: To evaluate the efficacy and safety of simvastatin administered to a group of heart transplant patients receiving triple-drug immunosuppressive therapy. We also assessed the potential pharmacokinetic interaction between simvastatin and cyclosporine by comparing mean plasma concentrations of simvastatin beta-hydroxy acid, the major metabolite of the drug, in a group of heart transplant patients treated with cyclosporine and in a control group of patients who had not received heart transplants. Both groups received long-term (>6 wk) simvastatin therapy.Design: We monitored hyperlipidemia in 20 hypercholesterolemic heart transplant patients receiving simvastatin 10 mg/d and triple-drug immunosuppressive therapy. Changes in laboratory results before and after 4 months of simvastatin therapy were considered. The same laboratory data were monitored in a control group of 20 nonhypercholesterolemic heart transplant patients who were not treated with simvastatin but were receiving triple-drug immunosuppressive therapy. Plasma concentrations of simvastatin beta-hydroxy acid were measured in 14 hypercholesterolemic patients, 7 of whom had received heart transplants and 7 who had not.Setting: The Division of Cardiology and the First Medical Clinic for the clinical study, as well as the Department of Pharmacology for the pharmacokinetic analysis.Participants: Forty heart transplant patients and 7 hypercholesterolemic nontransplant patients.Main Outcome Measures: Effectiveness of simvastatin was determined by comparing cholesterol and lipoprotein plasma concentrations in 20 patients who underwent heart transplant and were treated with simvastatin for 4 months. The safety of the drug was determined by analyzing changes in laboratory results in the treated group and in the control group, both those who had received heart transplants and those who had received immunosuppressive therapy.Results: After 4 months of simvastatin therapy, total cholesterol decreased by 12.5% and low-density lipoprotein cholesterol decreased by 21.3%. The only statistically significant laboratory change was an increase of 28.7% in the alanine aminotransferase concentrations. Plasma concentrations of simvastatin beta-hydroxy acid were higher in heart transplant patients than in those who had not received heart transplants, the control group.Conclusions: Low-dosage simvastatin treatment seems to be safe and sufficiently effective to decrease cholesterol concentrations. Concomitant treatment with immunosuppressive therapy (primarily cyclosporine) in heart transplant patients appeared to cause a reduced metabolic clearance of simvastatin from the plasma. More extensive studies on the interaction between simvastatin and cyclosporine are needed to understand the marked variability found in the response to simvastatin.

Through this article, the degree of polymerization attainable in a commercial acrylic bone cement based on poly(methyl methacrylate) (PMMA) was investigated by differential scanning calorimetry (DSC) and gas chromatography (GC). The results obtained revealed a marked dependence between the maximum monomer conversion and the cure temperature. Specimens for the mechanical evaluation of the cement were subjected to two different cure conditions: one set of samples was allowed to cure at room temperature and an additional set was also postcured at 140°C for 2 h. The latter thermal treatment permitted one to discard the presence of the unreacted monomer in the hardened material. The effect of the unreacted monomer on the mechanical behavior was evaluated by measuring the flexural modulus (E), the compressive yield stress (σy), and the fracture toughness (KIC). Samples prepared at room temperature for mechanical evaluation contained residual monomer which acts as a plasticizer of the matrix, increasing KIC and decreasing E and σy. The cure temperature and mold di-mensions influence the amount of the residual monomer in the hardened material. Thus, differences in the values of the mechanical properties measured for the same commercial formulation may be attributed to a different mold dimension used in the test. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1367–1383, 1998

Marine mycoflora of Portofino bay.—On a detrital limestone in Portofino bay, wood panels of Fraxinus ornus, Abies alba, Ochroma lagopus, Fagus sylvatica, Larix decidua, Pinus pinaster, Populus alba and Olea europaea have been laid as bait in different periods of the year to show the incidental seasonal influence on the installation of fungine species.A different seasonal frequency has been noticed also concerning fouling organisms. The wooden bait has been fished out after a minimum time of 50 and a maximum of 283 days, and incubated in a moist chamber to foster growth and isolation of fungi.Lulworthia medusa is one of the most frequent species and fructifies plentifully near corpses and holes of the isopod Limnoria tripunctata.This ascomycete fructifies also on wood panels incubated in Petri dishes in contact with filter paper imbued with bacteria, whereas it does not fructify in culture if strips of the same paper are sterilized. It seems therefore that bacteria carry on an important role in the complex relations between isopod crustaceans and fungi; Limnoria carrying bacteria stimulated the forming of perithecia of Lulworthia. This lignicolous fungus has been isolated in two different species, according to the length of the mucillagineous appendages of the ascospora and on some physiological characters.The presence of Trichocladium achrasporum for the Mediterranean, of Halosphaeria maritima for the Italian seas are reported for the first time; the presence of Nia vibrissa and of Humicola alopallonella is reported for the second time for Italy. Papulaspora halima has been isolated again, after protracted immersion and incubation. The partiality for temperate-cold temperatures of Cirrenalia macrocephala and of Corollospora maritima is confirmed. Other ubiquitous species are reported, and the hypothesis of Ceriosporiopsis halima flourishing in polluted water is renewed.

Tyrosine aminotransferase was purified to homogeneity from epimastigotes of Trypanosoma cruzi by a method involving chromatography on DEAE-cellulose, gel filtration on Sephacryl S-200 and chromatography on Mono Q in an f.p.l.c. system. The purified enzyme showed a single band in SDS/PAGE, with an apparent molecular mass of 45 kDa. Since the apparent molecular mass of the native enzyme, determined by gel filtration, is 91 kDa, the native enzyme is a dimer of similar subunits. The amino-acid composition was determined, as well as the sequences of three internal peptides obtained by CNBr cleavage at Met residues. Both criteria suggest considerable similarity with the tyrosine aminotransferases from rat and from human liver. The enzyme contains nine 1/2 Cys residues, three free and the others forming three disulphide bridges. The enzyme is not N-glycosylated. The isoelectric point is 4.6-4.8. The optimal pH for the reaction of the enzyme with tyrosine as a substrate is 7.0. The apparent Km values for tyrosine, phenylalanine and tryptophan, with pyruvate as a co-substrate, were 6.8, 17.9 and 21.4 mM, respectively, whereas those for pyruvate, alpha-oxoglutarate and oxaloacetate, with tyrosine as a substrate, were 0.5, 38 and 16 mM respectively. The purified tyrosine aminotransferase acts as an alanine aminotransferase as well and the activity seems to reside in the same enzyme molecule. The results suggest that the enzyme is a general aromatic-amino-acid transaminase, with high sequence similarity to tyrosine aminotransferases from rat and human liver.

Aim of our study was to assess if the 2D-Echo transverse diameter of the left hepatic vein (LHV) obtained from the subcostal approach is correlated with invasive mean right atrial pressure (RAP). Thirty-two consecutive patients with acute myocardial infarction were studied by simultaneous 2D-Echo and right heart catheterization. LHV could be adequately imaged in 90% of patients. Mean RAP values at catheterization ranged from 0 to 15mmHg (mean 6±3.5 mmHg). A correlation was found between mean RAP and LHV diameter calculated after inspiration (r=0.81, SEE=1.54 mm, slope=0.71,p< 0.001) as well as after expiration (r=0.82, SEE=1.32mm, slope=0.62,p< 0.001) or during post-expiratory apnoea (r=0.85, SEE=1.3 mm, slope=0.71,p< 0.001). Moreover, percent increments of LHV diameter correlated well with percent changes of mean RAP during rapid infusion of 250–500 cc of saline in 4 patients (r=0.98,p< 0.001).

Tryparedoxin peroxidase from Crithidia fasciculata is an essential component of the trypanothione-dependent hydroperoxide metabolism in the trypanosomatids (Nogoceke, E., Gommel, D. U., Kiebeta, M., Kalisz, H. M., and Flohé, L. (1997) Biol. Chem. 378, 827-836). The tryparedoxin peroxidase gene and its flanking regions have been isolated and sequenced from a C. fasciculata genomic DNA library. It consists of an open reading frame of 564 base pairs encoding a protein of 188 amino acid residues. The gene, modified to encode 6 additional histidine residues, was expressed in Escherichia coli and the recombinant protein was purified to homogeneity by metal chelating chromatography. Recombinant tryparedoxin peroxidase has a subunit molecular mass of 21884 +/- 22 and contains two isoforms of pI 6.2 and 6.3. It exhibits a kinetic pattern identical to that of the authentic tryparedoxin peroxidase and has a similar specific activity of 2.51 units mg-1. The enzyme unequivocally belongs to the peroxiredoxin family of proteins, whose members have been found in all phyla. A phylogenetic tree comprising 47 protein and DNA sequences showed tryparedoxin peroxidase and a homologous Trypanosoma brucei sequence to form a distinct molecular clade. The consensus sequence: xnAx5-6Fx9Gx3Vx2Fx1Px2Fx1FVCPTEx21Sx1Dx7Wx16-19Dx15- 16Gx3Rx2Fx2Dx27Ax 1Qx4-11Cx1-3Wxn was demonstrated by alignment of the sequences of tryparedoxin peroxidase and 8 other peroxiredoxins with established peroxidase function.

To compare the efficacy and safety of captopril twice a day with quinapril once a day for the treatment of mild to moderate congestive heart failure in a multicentre, double-blind, randomly allocated, parallel-group, 12-week study.

Objectives. The aims of this study were to correlate betaendorphin plasma levels and anginal pin in patients with ischemia induced by percutaneous transluminal coronary angioplasty and to detect eventual endorphin variations during balloon occlusion.

Exercise-induced silent myocardial ischemia is a frequent feature in patients with coronary artery disease. The purpose of this study was to compare the clinical and angiographic characteristics of 269 patients who complained of chest pain during an exercise test (group I) with those of 204 who developed exercise-induced silent myocardial ischemia (group II). Group I patients more frequently had anginal symptoms of class III and IV of the Canadian Cardiovascular Society than did group II patients, who had milder symptoms (p < 0.001). The only angiographic difference observed between the two groups was a slightly but significantly higher left ventricular end-diastolic pressure in group II patients (p < 0.05), who also showed a longer exercise duration (p < 0.01) with a higher heart rate-systolic pressure product (p < 0.01) and more pronounced ST segment depression at peak exercise (p < 0.001). Moreover, ventricular ectopic beats during exercise were more frequently observed in group II patients (p < 0.05).

The aim of this study was to compare the pharmacokinetics and antiarrhythmic activity of dihydroquinidine and quinidine in 14 patients (11 men, 3 women, aged 28 to 67 years) with heart disease and chronic, stable, highfrequency premature ventricular beats (PVB) (>100/hr). A randomized, double-blind, crossover, placebo-controlled protocol was utilized. During Holter monitoring the patients were given either dihydroquinidine or quinidine as the gluconates in an oral solution (600 mg); blood samples were taken 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours later. The patients were then assigned to three successive treatment periods of 7 days each: dihydroquinidine HCl (900 mg/day), quinidine polygalacturonate (1,650 mg/day), or placebo. At the end of each period 24-hour Holter monitoring was carried out and a blood sample was taken for determination of drug concentration. By comparing the area under the curves dihydroquinidine was 59% as available as quinidine; rates of absorption and elimination were similar. Mean peak blood levels of dihydroquinidine and quinidine were 1.06±0.34 and 2.15±0.96 µg/ml, respectively. After dihydroquinidine, eight patients had a positive response (>50% reduction in PVB frequency), while seven patients responded to quinidine. During maintenance treatment both dihydroquinidine (233±330) and quinidine (234±311) reduced the mean PVB frequency per hour compared to placebo (690±569). Nine patients (64%) on dihydroquinidine and eight (57%) on quinidine had >70% decrease in mean PVB frequency per hour. Steady-state peak plasma concentrations of dihydroquinidine and quinidine were 1.10±0.41 and 2.24±1.13 µg/ml, respectively. Dihydroquinidine thus has stronger antiarrhythmic activity than quinidine and so may be used in lower doses; it is effective with plasma concentrations lower than those of quinidine.

One hundred eight consecutive patients with proved coronary artery disease and reproducible exercise-induced myocardial ischemia were studied. During repeated exercise testing, 52 patients (Group I) had myocardial ischemia in the absence of pain (silent ischemia) whereas 56 patients (Group II) experienced anginal symptoms in the presence of electrocardiographic signs of ischemia. A puipal test was carried out in all patients using an electrical dental stimulator commonly used in dentistry. Electrical current was delivered in increasing intensity from 10 to 500 mA, and the dental pain threshold and the reaction of the patients to maximal stimulation were determined.

To verify whether beta-endorphin plasma levels influence the presence of anginal symptoms. 74 consecutive male patients were studied. All patients had previously documented coronary artery disease and reproducible exerciseinduced myocardial ischemia. Thirty-five patients (Group I) had a history of angina and reported anginal symptoms during exercise stress testing; 39 patients (Group II) were asymptomatic and had documented silent myocardial ischemia during exercise. Baseline beta-endorphin plasma levels were measured in blood ramples taken before exercise stress testing and analyzed by beta-endorphin-I125-RIA Kit-NEN (a radioimmunoassay method).

Objectives. This study was designed to evaluate whether the addition of transdermal nitroglycerin or oral N-acetylcysteine, or both, to conventional medical therapy improves the natural history of unstable angina pectoris.

Studying the mycological flora of paddy and grass-fields we had the opportunity to isolate some species of Eutotiaceae which are of particular interest. Three species were not yet known in Italy and only one was found in a soil of mountain pasture. The last one is also common in paddy fields. One of the isolated species was a Pseudoeurotium van Beyma, ascomycete with asci containing 16 ascospores, not identifiable with the systematically related species described as Pseudoeurotium indicum (Chattopadhyay and Das Gupta) Chattopadhyay from « oryzetis » in India and Pseudoeurotium multisporum (Saito and Minoura) Stolk in Japan. Some distinct morphological differences exist between our isolates and P. multisporum; but they differ only faintly from P. indicum: that is our isolates have pedicellate asci. Therefore we suggest the new variety: Pseudoeurotium indicum (Chattopadhyay and Das Gupta) Chattopadhyay var. orizetorum nobis. Three species of the genus Emericellopsis van Beyma: E. minima Stolk, E. terricola van Beyma and E. humicola (Cain) Cain were also isolated. The first one from the paddy-fields and the last two, not yet described in Italy, from grass fields. The possible relationship between E. minima Stolk arid E. pusilla Mathur, Sukapure and Thirumalachar has been discussed.

Summary A strain ofHaplosporangium parvum has been isolated from Italian soil. It has been comparatively studied with six North American and a Korean strain. Two American and the Italian strains are thermophilic (opt. about 35° C) while the other four grow better at temperatures around 20° C.

Tyrosine aminotransferase from Trypanosoma cruzihas been crystallized from PEG 4000 at pH 6.8. The crystals belong to the monoclinic space group P21and have lattice constants of a= 59.1, b= 103.0, c= 77.8 Å, β = 113.1° for a data set measured at 138 K. The presence of a non‐crystallographic twofold axis together with a Matthews parameter Vmof 2.5 Å3Da−1indicates that the asymmetric unit contains one dimeric molecule. The crystals diffract to at least 2.7 Å and are stable in the X‐ray beam in a shock‐frozen state. Native data sets have been collected at temperatures of 285 and 138 K using a Siemens X1000 detector on a rotating‐anode generator.

The prevalence of right ventricular failure after orthotopic heart transplantation, evaluated in 196 patients, was 11.7%, as assessed by the presence during the first postoperative month of right atrial pressure > 10 mm Hg. Two deaths, related to refractory right ventricular failure, were observed within the first month, both in subjects with preoperative pulmonary arteriolar resistances > 5 Wood Units. The haemodynamic profile after heart transplantation showed a significant decrease (P< 0.01) and an early normalization of pulmonary arterial pressure, pulmonary wedge pressure and pulmonary arteriolar resistances, while right atrial pressure slowly decreased until the third month. In a long‐term analysis of survival (death within 1 year) the probability of death was significantly related to the values of right atrial pressure and cardiac index during the first month after heart transplantation. Otherwise, the presence of elevated values of right atrial pressure did not show a significant correlation with the echocardiographic right ventricular end‐diastolic diameter nor with the presence of right bundle branch block. The careful selection of patients referred for the cardiac transplantation (mean value of pulmonary arteriolar resistances in the evaluated subjects was 2.5 ± 1.5 Wood Units) improves the probability of avoiding the appearance of severe right ventricular failure in the post‐operative period in most cases. The best predictor of right ventricular failure remains to be clearly identified.

Granuloma annulare (GA) is a benign dermatosis of unknown aetiology, characterized by papules with an annular disposition. Observation of the appearance of a GA in patients undergoing cryotherapy for common warts and actinic keratoses of the hands, led us to evaluate a possible relationship between the two conditions. Over 18 months we studied 158 patients treated with Liquid nitrogen and a compound based on formalin and resorcin for warts and actinic keratoses of the hands. After a year we observed GA in three women from group A who had undergone, respectively, six, five and seven applications of liquid nitrogen. There was also one woman from group C who developed GA after eight similar treatments. These observations suggested a possible correlation between the two events.

Epimastigotes of Trypanosoma cruzi in culture produce and excrete into the medium small amounts of phenyllactic acid and p-hydrocyphenyllactic acids, presumbly arising from the catabolism of the aromatic amino acids phenylalanine and tyrosine, respectively. This production might constitute a minor pathway for the reoxidation of cytosolic NADH, through the concerted action of tyrosine aminotransferase and aromatic α-hydroxyacid dehydrogenase.

Tyrosine aminotransferase purified from epimastigotes of Trypanosoma cruzi displays an additional activity of alanine aminotransferase, absent in all other tyrosine aminotransferases characterized so far. Since the parasite's genome contains a high number of copies of the tyrosine aminotransferase gene, we could not rule out the possibility that two very similar proteins, with changed specificity due to a few amino acid substitutions, might be responsible for the two activities. We have now expressed in Escherichia coli a recombinant tyrosine aminotransferase as a fusion protein with glutathione S-trans-ferase. The purified fusion protein, intact or after thrombin cleavage, displays tyrosine aminotransferase and alanine aminotransferase activities with apparent Km values similar to those for the natural enzyme, thus proving that they belong to the same protein.

Cell-free extracts of epimastigotes of Trypanosoma cruzi contain tyrosine aminotransferase (TAT) and p-hydroxyphenyllactate dehydrogenase (pHPLDH). The TAT activity could be separated from aspartate aminotransferase (ASAT) by polyacrylamide gel electrophoresis or DEAE-cellulose chromatography; the latter procedure also allowed complete separation of pHPLDH. The subcellular localization of both T. cruzi enzymes, as determined by digitonin extraction, subcellular fractionation by differential centrifugation, and isopycnic ultracentrifugation in sucrose gradients, was mainly cytosolic, with low mitochondrial activities.