Direct observation of strong coupling in a dense plasma

We present differential x-ray scattering cross sections for a radiatively heated plasma showing overall consistency, in both form and absolute value, with theoretical simulations. In particular, the evolution of the plasma from a strongly coupled high density phase to a lower density weakly coupled phase is quite clearly shown in both experiment and simulation. The success of this experiment shows that x-ray scattering has the potential to become an extremely useful diagnostic technique for dense plasma physics.

Adsorption of phenols by papermill sludges

In this paper we studied the sorption capacity of paper mill sludges for phenols. Phenol, 2-chlorophenol (2-CP), 3-chlorophenol 3-CP). 4-chlorophenol (4-CP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), 2.4-dichlorophenol (2,4-DCP), 3,4-dichlorophenol (3,4-DCP) 3,5-dichlorophenol (3,5-DCP) and 2,4,5-trichlorophenol (2,4,5-TCP) were chosen for the sorption tests. Kinetic experiments showed that substituted-phenol sorption on papermill sludge was rapid (equilibrium was reached after 3 h); conversely, the time taken by the phenol to reach equilibrium conditions was 260 h. Experimental data showed that particle diffusion was involved in the sorption process but was not the only rate-limiting mechanism; several other mechanisms were involved. The adsorption isotherms showed the following order of retention capacity of papermill sludge: 2-NP = 4-NP < < 2-CP < phenol < 4-CP < or = 3-CP < 2,4 DCP<3,4 DCP=2,4,5 TCP<3,5 DCP. In all cases the experimental data showed a good fit with the Hill equation. which is mathemratically equivalent to the Langmuir-Freundlich model obtained by assuming that the surface is homogeneous, and that the adsorption is a cooperative process influenced by adsorbate-adsorbate interactions.

Palmitoyl derivatives of GpMBP epitopes: T-cell response and peptidases susceptibility

We report for the first time the immunoadjuvant effects of lipoconjugation of peptide antigens in an in vitro system by using CD4+ T-cells. The lipopeptides obtained by conjugating a palmitoyl moiety at the N(alpha)-terminal of Gln(74) or at the epsilon-NH(2) of Lys(75) of GpMBP(74-85) induced increased T-cell responsiveness compared to the native nonlipidated peptide. On the other hand, lipoderivatives of GpMBP(82-98) did not increase the T-cell response, demonstrating that the superagonist inducing effect of lipoconjugation is epitope-specific. Digestion of the two native peptides with cathepsin D and L, both implicated in antigen processing, and with a complete lysosomal fraction of a EBV-transformed B cell line shows that GpMBP(74-85) is resistant to cellular proteases, while GpMBP(82-98) is easily digested by these enzymes. These results suggest that the first prerequisite for increasing the T-cell response by lipoconjugation is the stability of the native peptide to peptidases, providing an important insight into the understanding of the immunoadjuvant effect of lipoderivative antigens.

Conformational analysis of a glycosylated human myelin oligodendrocyte glycoprotein peptide epitope able to detect antibody response in multiple sclerosis

Myelin oligodendrocyte glycoprotein (MOG), a minor myelin component, is an important central nervous system specific target autoantigen for primary demyelination in autoimmune diseases such as multiple sclerosis (MS). The native structure of MOG presents a glycosylation site at position 31 (Asn(31)). It has been recently described that glycosylation of a MOG peptide epitope improved the detection of specific autoantibodies in sera of MS patients. The solution conformational behavior of two MOG derived peptides-hMOG(30-50) (1) and the glycosylated analogue [Asn(31)(N-beta-Glc)]hMOG(30-50) (2)-were investigated through NMR analysis in a water/HFA solution. Conformational studies revealed that peptides 1 and 2 adopted similar conformations in this environment. In particular, they showed strong propensity to assume a well-defined amphipatic structure encompassing residues 41-48. The N-terminal region resulted to be almost completely unstructured for both peptides. The presence in 1 of a low populated Asx-turn conformation characteristic of the Asn-Xaa-Thr glycosylation sites was the only conformational difference between peptides 1 and 2. Thus, the specific antibody recognition of peptide 2 is most likely driven by direct interactions of the antibody binding site with the Asn-linked sugar moiety.

Effects of drug therapy on cardiac arrhythmias and ischemia in hypertensives with LVH

Left ventricular hypertrophy (LVH) in hypertensive subjects is associated with an increased prevalence of ventricular arrhythmias. To evaluate the effect of antihypertensive treatment on cardiac arrhythmias (CA) and transient episodes of myocardial ischemia (TEMI), we studied 46 hypertensive patients with LVH, divided into four groups randomly treated with enalapril, hydrochlorothiazide (HCTZ), atenolol, or verapamil (SR-V) for 6 months. Office blood pressure and office heart rate values were recorded, in basal conditions, after 1 and 6 months of treatment, and all patients underwent echocardiography, electrocardiographic Holter monitoring, and stress testing. All drugs significantly lowered blood pressure, whereas left ventricular mass index was reduced by atenolol, enalapril, and SR-V, but not by HCTZ. Treatment induced a significant reduction in the number of patients with supraventricular arrhythmias (35 v 15, P < .034, and 28 v 8, excluding patients treated with HCTZ, P < .008). The number of patients with ventricular arrhythmias was also reduced (32 v 16 considering all groups, P < .08, and 24 v 9, excluding patients treated with HCTZ, P < .04). The number of TEMI during Holter monitoring significantly decreased from 47 to 23 (P = .043) in all patients, and from 39 to 14 (P = .013) excluding patients treated with HCTZ. In all groups, irrespective of treatment, a reduction of blood pressure, heart rate, and systolic blood pressure/heart rate product measured by exercise stress test was observed. The present study shows that in hypertensive patients with LVH, antihypertensive treatment with atenolol, enalapril and SR-V reduces LVH and decreases the prevalence of CA and TEMI. Treatment with HCTZ during the 6-month study did not alter LVH and did not appear to reduce CA and TEMI.

Relationships between 24 h blood pressure load and target organ damage in patients with mild-to-moderate essential hypertension

OBJECTIVE

To analyse the relationships between 24 h blood pressure load (the percentage of systolic/diastolic blood pressures exceeding 140/90 mmHg while awake and 120/80 mmHg during sleep) and some indices of hypertensive target organ involvement, independently of the mean level of 24 h blood pressure.

METHODS

One hundred and thirty patients with mild-to-moderate hypertension underwent 24 h ambulatory blood pressure monitoring, ocular fundus examination, microalbuminuria assay and two-dimensional guided M-mode echocardiography. The study population was divided into subsets according to the systolic and diastolic 24 h blood pressure load values predicted from the regression equation relating 24 h blood pressure load to 24 h mean blood pressure. The subjects with an observed load above this predicted value were included in the higher blood pressure load groups, the remaining ones being included in the lower groups.

RESULTS

Relative myocardial wall thickness and total peripheral resistance were greater, and mid-wall fractional shortening, end-systolic stress-corrected mid-wall fractional shortening and cardiac index lower, in the subjects with a higher systolic blood pressure load. Moreover, the stroke index:pulse pressure ratio was reduced, and a greater prevalence of hypertensive retinopathy was observed in the higher systolic load group. On the contrary, no statistically significant difference was found for any of the cardiac, renal and funduscopic parameters examined when the two groups with a higher and lower 24 h diastolic blood pressure load were compared.

CONCLUSIONS

Our results seem to suggest that, in mild-to-moderate arterial hypertension, a high 24 h systolic blood pressure load may be associated, independently of the average level of 24 h systolic ambulatory blood pressure, with an adverse cardiovascular risk profile.

Structural characterization of lipopeptide agonists for the bradykinin B2 receptor

The conformational features of Pam-Lys(0)-Arg(1)-Pro(2)-Pro(3)-Gly(4)-Phe(5)-Ser(6)-Pro(7)-Phe(8)-Arg(9)-OH (PKD) and Pam-Gly(-1)-Lys(0)-Arg(1)-Pro(2)-Pro(3)-Gly(4)-Phe(5)-Ser(6)-Pro(7)-Phe(8)-Arg(9)-OH (PGKD), the Pam-Lys and Pam-Gly-Lys analogues of bradykinin, have been determined by high-resolution NMR in a zwitterionic lipoid environment. Radical-induced relaxation of the (1)H NMR signals was used to probe the topological orientation of the peptides with respect to the zwitterionic lipid interface. The radical-induced relaxation and molecular dynamics (MD) data indicated that the palmitic acid and N-terminal amino acid residues embed into the micelles, while the rest of the polypeptide chain is closely associated with the water-micelle interface. Throughout the entire nuclear Overhauser effect restrained MD simulation, a nonideal type I beta-turn was observed in the C-terminus of PKD between residues 6 and 9, and a gamma-turn was observed in the C-terminus of PGKD between residues 6 and 7. Therefore, the additional glycine has a dramatic effect on the structural preferences of the biologically important C-terminus, an effect brought about by the interaction with the lipid environment. These structural features are correlated to the biological activity at the bradykinin B2 receptor.

Confining proton beams with longitudinal magnetic fields: Monte Carlo calculations

The problem of the lateral containment of a 160 MeV proton beam interacting with a medium simulating biological material was studied. The confining action of a longitudinal magnetic field was calculated by means of Monte Carlo simulation, where scattering and motion in the magnetic field were treated simultaneously. Appreciable compression of the beam could only be achieved using fields of the order at least 50 T, much beyond the realm of practical feasibility.

X-Ray diffraction from a dense plasma

We report measurements of x-ray scattering cross sections for dense plasmas created by subjecting aluminum foils to strong laser-driven shocks. A narrow cone of quasimonochromatic x-rays at approximately 4.75 keV was used to probe the shocked part of the foil and scattered photons were detected with a CCD camera. The scattering cross section shows a clear peak, indicating diffraction from the plasma. Analysis and simulation of the data suggest that radiative heating and electron-ion energy exchange are important factors in the plasma production.

Electron beam therapy with transverse magnetic fields

Detailed Monte Carlo electron transport simulations were carried out for the purpose of investigating the possibility of improving electron dose distribution for therapeutic applications, by using transverse magnetic fields. The case studied here is that of a 15 MeV electron beam of 6 cm diameter. The electrons pass through 4 cm of field-free tissue and a transverse magnetic field is applied for depth greater than 4 cm. A field of 3 T was found to improve the skin sparing factor by a factor of 2, when compared to field-free irradiation. A field of 2 T could also have a significant effect although less pronounced than 3 T while, for the case at hand, a magnetic field of only 1 T is not effective. The results here include detailed energy deposition contours in three dimensions.

A synthetic glycopeptide of human myelin oligodendrocyte glycoprotein to detect antibody responses in multiple sclerosis and other neurological diseases

Glycopeptides of hMOG(30-50) containing a glucosyl moiety on the side-chains of Asn, Ser or Hyp at position 31 were synthesised. Antibody titres to hMOG(30-50) and to its glucoderivatives were measured by ELISA in sera of patients affected by different neurological diseases. Anti-hMOG(30-50) antibodies were detected only using the glycopeptide [Asn31(N-Glc)]hMOG(30-50).

Changes of plasma endothelin and growth factor levels, and of left ventricular mass, after chronic AT1-receptor blockade in human hypertension

The stimulation of autocrine and paracrine factors such as basic fibroblast- (bFGF) and platelet-derived (PDGF) growth factors mediates many of the growth-promoting actions of angiotensin II. The aim of this study was to evaluate the effect of chronic AT1-receptor blockade on plasma endothelin-1 (ET-1) and growth factors levels, and on left ventricular mass, in essential hypertension (EH). The study population consisted of 16 patients with mild-moderate EH, and 25 normotensive controls. In the EH patients under basal conditions, and after 3 and 6 months of chronic therapy with Losartan 50 mg/day, we measured serum levels of ET-1, bFGF and PDGF, and tumor necrosis factor (TNF). At the same time, all patients underwent 24-h ambulatory blood pressure monitoring and an echocardiographic evaluation to measure the thickness of the posterior wall (PWT) of the left ventricle and of the interventricular septum (IVS). The healthy controls underwent the same analyses, under basal conditions, at baseline and after 3 and 6 months of observation. In the EH patients, after 3 months of AT1-receptor blockade bFGF was reduced from 13.6 +/- 0.7 to 10.9 +/- 0.7 pg/mL (P < .004), and both TNF and PDGF were significantly decreased (P < .006 and P < .007, respectively). After 6 months of therapy, ET-1 was significantly diminished in comparison with baseline (6.9 +/- 0.8 v 5.5 +/- 0.1 fmol/mL; P < .05), and the reduction in the levels of growth factors were even more significant than at 3 months of treatment. Both PWT and IVS were significantly changed after 6 months of therapy with losartan after basal evaluation (P < .05, respectively). Systolic and diastolic 24-h blood pressures declined significantly after 3 and 6 months of therapy with losartan (P < .01, respectively). It seems likely that the inhibition of the action of angiotensin II by the specific AT1-receptor blockade, by reducing circulating levels of ET-1 and those of some growth factors, may offer an advantage regarding the effect on hypertensive cardiovascular changes in human hypertension.

Increased prevalence of cardiac arrhythmias and transient episodes of myocardial ischemia in hypertensives with left ventricular hypertrophy but without clinical history of coronary heart disease

To evaluate the behavior of cardiac arrhythmias (CA) and transient episodes of myocardial ischemia (TEMI), in relation to the circadian pattern of blood pressure in patients suffering from arterial hypertension, with or without echocardiographically ascertained left ventricular hypertrophy (LVH), we studied 128 patients, 87 men (M) and 41 women (F), aging from 21 to 76 years, subdivided into two groups: Group I, including 66 patients with LVH (45 M and 21 F; mean age of 53.7 +/- 9.1 years; Group II, including 62 patients without LVH (42 M and 20 F; mean age of 49.7 +/- 9.5 years). Office blood pressure (OBP) as well as nighttime ambulatory blood pressure (ABP) were higher in patients with LVH (P < .05 and P < .01). CA were present in a higher number of patients of Group I (P < .001): premature supraventricular beats (PSVB) 22.7 v 4.8%, supraventricular couplets (SVC) 36.4 v 16.1%, supraventricular tachycardia runs (SVT runs) 27.3 v 12.9%, ventricular ectopic beats (VEB) 25.6 v 8.0%, ventricular couplets (VC) 30.3 v 12.9%, ventricular tachycardia runs (VT runs) 12.1 v 3.2%. The absolute number of ectopic beats was also significantly higher in patients of Group I. Ventricular arrhythmias were significantly related to ASBP (r = 0.83, P < .01), to ADBP (r = 0.74, P < .01) and to heart rate (r = 0.87, P < .01) in patients of Group I. TEMI were more frequent in patients of Group I (73 v 41 episodes, 39.39% v 25.8% of patients, P < .01) and were related to ABP peaks. In fact, in both groups of patients all TEMI without heart rate increase and most TEMI with heart rate increase were registered between 6:00 and midnight, hours in which ABP values were higher. We conclude that hypertensives with LVH, but without clinical history of coronary heart disease, have a higher prevalence of ventricular arrhythmias and of transient episodes of myocardial ischemia in relation to the circadian pattern of ABP.

[Globulomaxillary cysts]

Globulomaxillary cyst is a non odontogenic cyst arising in the upper lateral incisor and canine region. Evaluation of clinical picture and careful histologic examination are essential for distinguishing it from other odontogenic and non odontogenic cystic growths. Presenting five new cases of globulomaxillary cysts, authors discuss and accept the "fissural" histogenetic hypothesis.

Microalbuminuria, renal dysfunction and cardiovascular complication in essential hypertension

OBJECTIVE

To evaluate the prevalence of microalbuminuria (albumin excretion rate, AER) in a wide hypertensive population, and to evaluate any relationship with cardiovascular damage and renal dysfunction.

DESIGN

A transversal study.

SUBJECTS AND METHODS

In 383 hospitalized Caucasian essential hypertensives (198 men, 185 women) of mean age 44 +/- 0.5 years and mean clinic blood pressure 170.3 +/- 0.95/ 103.4 +/- 0.47 mmHg, metabolic parameters, serum creatinine level (Cs), creatinine clearance rate (Ccs), 24 AER and plasma renin activity (PRA) were measured. Furthermore, each patient underwent 24 h ambulatory blood pressure monitoring (ABPM) and echocardiography to measure left ventricular mass, which was indexed both by body surface area to obtain left ventricular mass index (LVMI) and by height to obtain the left ventricular mass indexed for height (LVMH). By Doppler echocardiography, the diastolic compliance by early:late peak filling velocity ratio was analysed. The fundus oculi was also observed. Three subsets of hypertensives were obtained by dividing the 383 essential hypertensives on the basis of their AER: < or = 11 (group A), 11 < or = 20 (group B) and > 20 micrograms/min (group C).

MAIN OUTCOME MEASURES

Microalbuminuria, creatinine clearance, PRA, ABPM, LVMI, LVMH, early:late peak filling velocity ratio, hypertensive retinopathy.

RESULTS

Among the 383 essential hypertensives, AER was < 11 micrograms/min in 55% of the patients (group A), 18% had AER in the range 11-20 micrograms/min (group B) and 27% had AER > 20 micrograms/min (group C). In the entire essential hypertensive population the prevalence of left ventricular hypertrophy was 44.39% and hypertensive retinopathy was observed in 54.83%. Moreover, AER significantly correlated with clinic systolic blood pressure (SBP) and diastolic blood pressure (DBP), with 24 SBP and DBP and with 24 h daytime and night-time mean blood pressure (MBP). AER was correlated also with LVMH and creatinine clearance. The analysis of the three subsets revealed no differences in age, body mass index, serum creatinine level and PRA. Group C in comparison with group A showed higher values of clinic SBP, 24 h SBP, DBP and MBP, and of daytime and night-time MBP. Furthermore, in group C, LVMI and LVMH were significantly greater than in group A, with a prevalence of left ventricular hypertrophy of 55% in the former group. Group C showed a prevalence of hypertensive retinopathy of 69% whereas in group A the prevalence was 48%. In group C, AER was significantly correlated with serum creatinine level.

CONCLUSIONS

The transversal phase of our research, performed in a homogeneous population of Caucasian essential hypertensives with no metabolic disturbances, confirms the relationship between blood pressure pattern and early glomerular changes in essential hypertensives without overt proteinuria. Furthermore, these results emphasize the role of microalbuminuria as a marker of early cardiac, renal and retinal structural and functional changes in essential hypertension. The longitudinal study, which is in progress, will confirm the prognostic value of microalbuminuria in essential hypertension.

White-coat hypertension and cardiovascular risk

OBJECTIVE

To compare cardiovascular risk in white-coat hypertensives, normotensives and established hypertensives.

METHODS

We studied 61 hypertensive individuals, 27 of whom were white-coat hypertensives, and 35 normotensives. All subjects underwent 24 h noninvasive blood pressure monitoring and Doppler echocardiographic examination of the heart; urine was tested for microalbuminuria and the fundi of the eyes examined for retinopathy.

RESULTS

The 24 h as well as the day- and night-time mean systolic blood pressure (SBP) was slightly but significantly higher in white-coat hypertensives than in normotensives; no significant difference was observed in diastolic blood pressure (DBP) between these groups. In white-coat hypertensives, 24 h SBP and DBP were lower than in established hypertensives (P < 0.001). The echocardiographic study showed higher values of posterior wall thickness, left ventricular mass index (LVMI), and ventricular septum thickness (P < 0.05) in white-coat hypertensives than in normotensives; fractional shortening and ejection fraction were similar. The E:A ratio, obtained from the Doppler study, was lower in white-coat hypertensives than in normotensives (1.14 +/- 0.3 versus 1.24 +/- 0.25; P < 0.05). LVMI values were smaller in white-coat hypertensives than in established hypertensives (P < 0.05), and both ejection fraction and fractional shortening were similar in the two groups. Among white-coat hypertensives, eight out of 27 showed hypertensive retinal damage; microalbuminuria values were similar to those obtained in normotensives.

CONCLUSIONS

The results of this cross-sectional and therefore limited study lead us to hypothesize that white-coat hypertensives are at higher risk than normotensives and lower risk than established hypertensives for developing cardiovascular damage.