Efficacy and tolerance of interferon-alpha(2b) in the treatment of chronic hepatitis C virus infection in haemodialysis patients. Pre- and post-renal transplantation assessment

BACKGROUND

Hepatitis C virus (HCV) infection represents an important problem for the dialysis population due to its high prevalence and the long-term development of chronic liver disease, particularly following renal transplantation.

METHODS

In order to assess the efficacy and tolerance of interferon (IFN) in the treatment of chronic hepatitis C in haemodialysis (HD) patients and their clinical course following renal transplantation, a multicentre, randomized, open-label study was conducted to compare IFN therapy vs a control group.

RESULTS

Nineteen HCV RNA-positive patients received 3 x 10(6) U of IFN s.c., three times a week (post-HD), and 17 HCV RNA-positive patients were assigned to the control group. Tolerance to IFN therapy was good in nine patients, while treatment was discontinued in the other 10 due to the occurrence of side effects. HCV RNA was negative at the end of treatment in 14 out of 19 patients (74%) receiving IFN and in one patient (5%) in the control group. Six out of the 14 patients who initially responded to IFN therapy had a virological relapse (43%). Eight patients (42%) remained HCV RNA-negative, three of them until the day that renal transplantation (RT) was performed (7, 12 and 27 months, respectively), as did five patients on HD during the follow-up (27+/-5 months). Eight out of the nine patients (89%) who completed therapy were HCV RNA-negative at the end of treatment, and seven of them (78%) remained HCV RNA-negative during the follow-up on dialysis (21+/-8 months). Mean transaminase (ALT) values were significantly decreased following IFN therapy, while no changes were observed during the follow-up period in the control group. Fifteen patients (10 in the treatment group and five in the control group) underwent RT. Three patients in the treatment group were HCV RNA-negative at RT, and one of them had a virological relapse 20 months after RT, while the other two remained HCV RNA-negative at 3 months and 24 months after RT, respectively. In contrast to the control group, transaminase (ALT) remained within normal limits in all patients in the treatment group. Finally, during the post-RT follow-up, the transaminase mean values were significantly lower in treated patients vs patients in the control group (P<0.05).

CONCLUSIONS

It is concluded that the biochemical and virological response to IFN therapy is good in HD patients. In addition, IFN therapy appears to exert a beneficial effect on the course of liver disease following RT, regardless of the virological response. Despite the fact that IFN therapy was discontinued in 10 out of the 19 patients due to the occurrence of side effects, these disappeared following discontinuation of therapy. Therefore, IFN therapy is advisable for HCV-infected dialysis patients who are candidates for RT.

Monitoring toasting intensity of barrels by chromatographic analysis of volatile compounds from toasted oak wood

Toasting changes both the quantity and the quality of the extractable substances in the oak wood of barrels used for the aging of fine wines and spirits. Mastery and repeatability of toasting are vital in the production of quality barrels to be used for the aging of wines and spirits. In this study, we show that it is possible for a given cooperage to differentiate barrel toasting levels by analyzing a certain number of volatile and semivolatile compounds resulting from the thermal degradation of oak. Toasted wood components, which can be extracted by the wines or spirits during the aging process, are normally analyzed after the wood has soaked in standard alcoholic solutions and can be used to control the intensity of the wood toasting. The results of the comparative analysis presented in this work show that headspace analysis with a microextractive method using a stationary polydimethylsiloxane type phase is a promising technique for analyzing toasted oak wood from barrels. It is easier to use than the traditional maceration and extraction method and provides similar information.

Chronic constrictive pericarditis induced by long-term bromocriptine therapy: report of two cases

OBJECTIVE

To report two cases of chronic constrictive pericarditis that appear to be related to the intake of bromocriptine for Parkinson's disease.

CASE SUMMARY

Two white men (aged 63 and 69 y) were treated with bromocriptine for four (40 mg/d) and two years (30 mg/d), respectively, with a cumulative dose intake of 58.4 and 21.9 g, respectively. The patients experienced dyspnea with bilateral lower-limb edema and pleural effusion, suggesting right cardiac dysfunction. Echocardiography, computed tomography, and cardiac catheterization results were compatible with a diagnosis of constrictive pericarditis, so pericardectomy was performed on both patients. The anatomic pathology examination showed a fibrous pericardium; cultures were sterile. In the first case, pleural effusion recurred seven months after the pericarditis; bromocriptine was suspected and treatment was discontinued. In the second case, just prior to the pericardectomy, an episode of mental confusion occurred and prompted the cessation of bromocriptine therapy.

DISCUSSION

To the best of our knowledge, only one case of constrictive pericarditis induced by bromocriptine therapy has previously been described in the literature.

CONCLUSIONS

Our cases call attention to a possible association between bromocriptine use in patients who have Parkinson's disease and constrictive pericarditis.

Reporter cell lines to study the estrogenic effects of xenoestrogens

In order to characterize the estrogenic activity of chemicals, we established complementary in vitro recombinant receptor-reporter gene assays in stably transfected MCF-7 and HeLa cells. MCF-7 cells which express the endogenous estrogen receptor alpha (ER alpha) were stably transfected with only an estrogen-regulated luciferase gene. These cells enable the detection of compounds which bind to ER alpha or interfere with the induction of ER alpha mediated gene expression. Furthermore, HeLa cells, which do not express endogenous ERs, were transfected with an ER alpha or an ER beta construct together with an estrogen-regulated luciferase gene, or a chimeric GAL4-ER alpha receptor and the corresponding luciferase reporter gene. Finally, we tested these four cellular models as tools to check the estrogenic activities of several potential xenoestrogens and to detect estrogenic activity in wastewater sewage treatment effluents. In all of the models, nonylphenol mixture (NPm), 4n-nonylphenol (4nNP), 2,4'-DDE, 4,4'-DDE and wastewater sewage treatment effluent were active, while PCB mixture (Aroclor 1254), PCB 77, atrazine and lindane (gamma hexachlorocyclohexane) were inactive. Dioxin partially activates the estrogen receptor in MCF-7 cells while in HeLa-derived cell lines, it decreased the estrogenic-induced expression of luciferase.

Measurement of relaxation rates of N(H) and H(alpha) backbone protons in proteins with tailored initial conditions

Several methods are presented for the selective determination of spin-lattice and spin-spin relaxation rates of backbone protons in labeled proteins. The relaxation rates of amide protons in (15)N labeled proteins can be measured by using two-way selective cross-polarization (SCP). The measurement of H(alpha) relaxation rates can be achieved by combining this method with homonuclear Hartmann-Hahn transfer using doubly selective irradiation. Various schemes for selective or nonselective inversion of the longitudinal proton magnetization lead to different initial recovery rates. The methods have been applied to lysine K6 in (15)N-labeled human ubiquitin and to leucine L5 in (15)N- and (13)C-labeled octapeptide YG*G*F*LRRI (GFL) in which the marked residues are (15)N- and (13)C-labeled.

A "dysautonomic" head-up tilt test pattern in elderly patients with neurocardiogenic syncope

The characteristics of neurocardiogenic syncope (NCS) in elderly patients remain unclear. We compared the hemodynamic profiles of young and older patients with consecutive and positive head-up tilt tests (HUT). Continuous, noninvasive, and reliable monitoring of arterial pressure (AP) and heart rate (HR) was done throughout 46 consecutive positive HUTs of symptomatic patients. The population (12-82 years old) was divided into two groups: younger patients, Y (n = 25, < or = 65 years), and older patients, O (n = 21). Changes in AP and HR after the first minute of tilting, during the stable orthostatic phase and during syncope were compared. Except for systolic pressure, baseline hemodynamic parameters were similar in Y and O. No difference appeared in the mean time elapsed before syncope (19+/-9 vs 22+/-2 min). Asymptomatic hypotension was observed, only in O, 1 minute after tilting, followed by a progressive fall in the mean AP before syncope (0+/-0.9 vs -1+/-0.7 mmHg/min) without HR increase (0.7+/-1 vs 0+/-0.6 beats/min). This pressure slope was strongly related to age (r = 0.54, P < 0.001). Hemodynamic recording during HUT identifies a dysautonomic pattern in elderly patients with NCS and the abnormal AP/HR responses to orthostasis may be a feature specific to this population. Although the central mechanism of NCS is common to all ages, the age-related characteristics of the trigger event may indicate the need for specific management at different ages.

[Electrocardiographic aspects of the pathology of the bundle of His]

The ECG appearances of His bundle pathology are very variable and endocavitory recordings are often required to confirm the diagnosis which may be suspected by close analysis of the surface ECG. Truncular AVB is a serious condition as the block is infranodal but with a supraventricular and therefore a narrow QRS complex: it may be median with a double His potential or proximal and distal, which are more difficult to diagnose. Hisian extrasystoles are particularly polymorphic, either overtly, suggesting successively atrial and ventricular extrasystoles, or masked with deceptive pseudo-1st or 2nd degree atrioventricular block. More rarely, hisian tachycardias complicating congenital heart disease in children are observed, particularly in the postoperative period.

Infected total hip arthroplasty--the value of intraoperative histology

Intraoperative histology showed a sensitivity of 100% and a specificity of 98%. These results were better than those observed for the other tests evaluated. Our data provide evidence that intraoperative histology is useful tool in the diagnosis of infected total hip arthroplasty.

Molecular dynamics study of kaliotoxin in water

Kaliotoxin (KTX), a potassium channel blocker found in the venom of the scorpion Androctonous Mauretanicus is a 38 residue polypeptide with a well defined structure consisting of a alpha-helix and a three strand antiparallel beta-sheet interconnected by three disulfide bonds. Although the 3D structure has been determined by NMR, there is a number of features, mainly concerning the conformation and flexibility of the side chains, but also the long range order in the peptide and its fluctuations, that may have escaped the experimental study. These questions are now being addressed using molecular dynamics (MD) simulations. Accordingly, the present work reports the analysis of a 430 ps molecular dynamics trajectory of the polypeptide soaked with 4700 TIP3 water molecules inside a 56 A box. MD calculations were performed with periodic boundary conditions. Analysis of the conformational space sampled by each of the residues along the trajectory, suggests a special behavior of Pro17 and Lys19 both located on the helix. Furthermore, analysis of the relative movements of the secondary structure elements indicates that the alpha-helix and beta-sheets fluctuate in a correlated motion, preserving the tertiary structure of the polypeptide along the trajectory. Finally, analysis of the charge distribution was also examined. The direction of the dipole moment, computed from the center of masses appears to be an interesting feature of the structure probably related to the biological function of the molecule.

Correspondence analysis of protein kinase C (PKC) inhibition by bis-basic substituted benzamides

We describe the synthesis of a novel series of bis-basic substituted benzamides and their relative potency in inhibiting rat brain protein kinase alpha (PKC alpha) activity. None of the compounds inhibited enzyme activity via the catalytic domain but several did via the regulatory domain at 1-5 microM concentrations. Inhibition was comparable to that of several di- and triphenylacrylonitriles and triphenylethylenes. According to a multivariate factor (correspondence) analysis of QSAR descriptors, hydrophobicity (log p) and hydration energy were the most discriminant descriptors, much more so than molecular mass, molar refractivity, polarizability, molecular volume and solvent-accessible surface. Inhibitory activity was correlated with high hydrophobicity and low hydration energy. The higher potency of GL9 (N,N'-oxalyl-bis[(o-amino)[2-(diethylamino)ethyl]-benzamide]) that differed from its congener (GL25) by the presence of an oxamide rather than succinamide moiety was tentatively explained by the greater negative charges associated with the carbonyl groups of its oxamide residue. The higher potency of GL22 (N,N'-tere-phthalyl-bis[(o-amino)[2-(diethylamino)ethyl]-benzamide ] in which an aromatic ring is inserted between two benzamide moieties in para, para' rather than ortho, ortho' positions as in GL23 might be due to a planar conformation facilitating membrane insertion. In conclusion, correspondence analysis is a neat way of highlighting similarities and differences in molecular properties (QSAR descriptors and potency). Therapeutic doses of many classes of drug might interfere with the regulatory domain of PKC alpha if, like our test-compounds, they have basic side-chain(s), high hydrophobicity, low hydration energy, a planar conformation and/or a highly charged reactive (oxamide) moiety.

Determination of indomethacin residues in poultry by high-performance liquid chromatography

A HPLC method using a C18 column and UV detection (254 nm) is described for the determination of indomethacin residues in chicken tissues (liver, muscle and fat). Drug extraction from tissue homogenate in phosphate buffer (pH 3.5) was performed with dichloromethane. Mobile phase was acetonitrile-acetic acid (0.5% in water) (50:50). Indomethacin detection limit was 20 ng/g for the studied tissues. After administration of an oral dose of indomethacin (2 mg/kg), only three of the eight poultry studied showed drug tissue levels, in those cases the levels were below 50 ng/g.

Non-invasive assessment of inspiratory muscle performance during exercise in patients with chronic heart failure

AIMS

The aim of this study was to assess inspiratory performance at rest and during exercise in patients with chronic heart failure in comparison with healthy controls using a non-invasive index: the tension-time index of inspiratory muscles (TTMUS).

METHODS

We studied 13 patients with chronic heart failure (57 +/- 7 years) and 10 control subjects (58 +/- 6 years) at rest and during an incremental maximal exercise test. Measurements included breathing pattern (inspiratory time, total time of respiratory cycle, minute ventilation, tidal volume and respiratory frequency), mouth occlusion pressure and mean inspiratory pressure (calculated as follows: 5 x mouth occlusion pressure x inspiratory time). The maximal inspiratory pressure was measured at rest. TTMUS was calculated from the equation: TTMUS = PI/PIMAX x TI/TTOT, where PI/PIMAX is the ratio of mean inspiratory pressure to maximal inspiratory pressure and TI/TTOT is the ratio of mean inspiratory time to total time of the respiratory cycle.

RESULTS

At rest, the results in patients showed non-significantly higher mouth occlusion pressure, lower maximal inspiratory pressure (P < 0.001), and a higher ratio of mean inspiratory pressure to maximal inspiratory pressure (P < 0.01). There was no difference in the breathing pattern. TTMUS was thus significantly higher in the patients with chronic heart failure (P < 0.001). At maximal exercise (77 +/- 16 W for patients with chronic heart failure vs 142 +/- 27 W for controls, P < 0.001), the ratio of mean inspiratory time to total time of respiratory cycle, the mouth occlusion pressure and the ratio of mean inspiratory pressure to maximal inspiratory pressure were not different. TTMUS was thus comparable in the two groups. During exercise, at comparable workloads (20, 40 and 60 W), the patients showed higher mouth occlusion pressure (P < 0.01) and a higher ratio of mean inspiratory pressure to maximal inspiratory pressure (P < 0.001), whereas the ratio of mean inspiratory time to total time of the respiratory cycle was similar. TTMUS was thus higher in the patients at each workload (P < 0.05).

CONCLUSION

This study shows that the determination of TTMUS at rest and during exercise allows the observation of alterations in inspiratory muscle performance as a result of both reduced inspiratory strength, as measured by the maximal inspiratory pressure, and increased ventilatory drive, as reflected by the mouth occlusion pressure in patients with chronic heart failure. The non-invasiveness of this new index is an additional argument for its use in a clinical setting.

Solution conformation of an immunogenic peptide from HRV2: comparison with the conformation found in a complex with a Fab fragment of an anti-HRV2 neutralizing antibody

The conformation of a [15]-peptide (H-VKAETRLNPDLQPTE-NH2) from VP2 of rhinovirus HRV2 complexed with a Fab fragment was previously shown by X-ray crystallographic studies to be similar to the one found in the corresponding region of HRV1A. Antibodies raised against this peptide bind to and neutralize HRV2. In order to identify structural features preserved in solution that may explain the ability of this short peptide to mimic the structure of the protein surface, the peptide has been studied by NMR in aqueous solution as well as under denaturing conditions. The peptide is shown to be a random coil in solution. However, the sequence forming a 3(10)helix in the complex is biased into a helical conformation according to NOE intensity data as well as from urea and pH titrations. This sequence adopts the same conformation in an unrelated protein. NOE data suggest that a beta-turn found in the complex may be sampled in solution. Also, Glu4, interacting with Arg6 in the crystal, has a reduced pKa value in solution. It is concluded that the local structure present in the random coil state of VP2(156-170) contains enough information to direct the production of antibodies that bind to and neutralize HRV2.

A new method for measuring diffusion coefficients by 2D NMR using accordion spectroscopy

Translational diffusion measurements are a useful tool for studying supramolecular complexes and for characterizing the association state of molecules that aggregate at NMR concentrations. Pulsed field gradients can be used to measure diffusion coefficients. Spectral overlap problems in complex mixtures can be alleviated by using 2D spectroscopy but the need to record a complete series of 2D spectra with increasing gradient strength makes these experiments extremely time consuming. Concerted incrementation of the gradient strength and the evolution time provides a new version of accordion spectroscopy that allows the measurement of individual diffusion coefficients in complex mixtures in a single experiment. Copyright 1998 Academic Press.

[Vasovagal syndromes]

Most cases of dizziness or syncope referred to the emergency department or to services of internal medicine are caused by vasovagal syndromes. They comprise relative bradycardia with vasoplegia, the cardiovascular response to a neurological stimulus. It is possible to distinguish vagal or vasovagal syncope which is very common, the very stereotype reflex syncopes, carotid sinus hypersensitivity sometimes associated with sinus node dysfunction and borderline forms such as orthostatic sinus tachycardia and cerebrovascular syncope. The differential diagnosis is vast, from simple hysteria to severe cardiac disease. Tilt testing should be indicated for diagnosis of most cases of syncope with apparently normal hearts. Therapeutic abstention is the rule, providing certain preventive measures are taken, but, should treatment be necessary, cardiac pacing remains an exceptional modality in vasovagal syncope. Strict clinical and physiopathological studies are still required to determine the long-term prognosis and the underlying mechanisms of these syndromes.

Rapid tamoxifen-induced inactivation of an estrogenic response is accompanied by a localized epigenetic modification but not by mutations

In a previous study (Cancer Res 54: 5860-5866, 1994), we observed irreversible inactivation of a chimeric estrogenic response induced by the antiestrogen 4-hydroxytamoxifen. This rapidly occurring effect (t1/2= 7 days) was not a consequence of a cell selection process, nor of a loss of estrogen receptor functionality, but was a direct antiestrogen effect occurring on every cell at the transcriptional level. In the present study, we analyzed the detailed methylation status of the chimeric gene, and investigated the gene for the presence of mutations. The inactivation process was found to be strictly correlated with a modification at a methylation-sensitive restriction site Not I borne by the integrated gene. As the gene promoter contains part of the Herpes simplex virus promoter for thymidine kinase. which is a CpG-rich promoter, we investigated the CpGs located in this part of the promoter by genomic sequencing procedures. None of these CpGs were methylated, suggesting that the inactivation process was not driven by particular modifications of this foreign part of the promoter. Furthermore, no mutations were found in the entire gene promoter of inactivated cells. In conclusion, the present study highlighted a connection between the rapid silencing of an estrogenic response induced by 4-hydroxytamoxifen, and a localized epigenetic modification of the corresponding gene. No genotoxicity of 4-hydroxytamoxifen was observed. Similar epigenetic modifications might also occur for natural genes, and lead to the acquisition of a new cell phenotype.

Sepsis due to group G Streptococcus after a total hip arthroplasty. A case report

A patient with a total hip arthroplasty developed an aggressive infection with group G Streptococcus. Very few similar cases have been reported, but they all resolved with antibiotics or drainage. A Girdlestone resection was necessary in our case because of loosening and extensive bony destruction. The true incidence may be greater than that reported and the prognosis may be worse.

Physicochemical properties of enrofloxacin

The physicochemical properties of enrofloxacin, a fluoroquinolone that inhibits the activity of bacterial DNA gyrase, are described. Its spectral, solubility and related physicochemical characteristics are discussed. The dissociation behaviour of enrofloxacin was examined by UV spectrophotometry at 25 degrees C in a series of buffers ranging from pH 1 to 10. The corresponding macro- and microscopic dissociation constants were calculated. The apparent n-octanol-water partition coefficients were measured from pH 2 to 10.

Steroidal affinity labels of the estrogen receptor. 3. Estradiol 11 beta-n-alkyl derivatives bearing a terminal electrophilic group: antiestrogenic and cytotoxic properties

With the aim of developing a new series of steroidal affinity labels of the estrogen receptor, six electrophilic 11 beta-ethyl (C2), 11 beta-butyl (C4), or 11 beta-decyl (C10) derivatives of estradiol bearing an 11 beta-terminal electrophilic functionality, i.e. bromine (C4), (methylsulfonyl)oxy (C2 and C4), bromoacetamido (C2 and C4), and (p-tolylsulfonyl)oxy (C10), were synthesized. The range of their affinity constants for binding the estrogen receptor was 0.4-37% that of estradiol; the order of increasing affinity (i) relative to the 11 beta-alkyl arm was ethyl < butyl and (ii) relative to the electrophilic functionality was bromoacetamido < bromine < (methylsulfonyl)oxy. Regardless of the conditions used, including prolonged exposure of the receptor to various pH levels (7-9) and temperatures (0-25 degrees C), the extent of receptor affinity labeling by the 11 beta-ethyl and 11 beta-butyl compounds, if any, was under 10%. This was in sharp contrast to results obtained using 11 beta-((tosyloxy)decyl)estradiol which labeled from 60% to 90% of the receptor hormone-binding sites with an EC50 of approximately 10 nM. Estrogenic and antiestrogenic activities of the compounds were determined using the MVLN cell line, which was established from the estrogen-responsive mammary tumor MCF-7 cells by stable transfection of a recombinant estrogen-responsive luciferase gene. The two 11 beta-ethyl compounds were mainly estrogenic, whereas the three 11 beta-butyl and the 11 beta-decyl compounds essentially showed antiestrogenic activity. The fact that the chemical reactivities of 11 beta-ethyl and 11 beta-butyl compounds were not compromised by interaction with the estrogen receptor made the synthesized high-affinity compounds potential cytotoxic agents which might be able to exert either (i) a specific action on estrogen-regulated genes or (ii) a more general action in estrogen-target cells. Therefore the ability of the compounds (1) to irreversibly abolish estrogen-dependent expression of the luciferase gene and (2) to affect the proliferation of MVLN cells were determined. All electrophiles were able to irreversibly suppress expression of the luciferase gene; the antiestrogenic electrophiles were more potent than the estrogenic ones but less efficient than 4-hydroxytamoxifen, a classical and chemically inert triphenylethylene antiestrogen. Only the antiestrogenic electrophiles decreased cell proliferation; however, they were less potent than 4-hydroxytamoxifen. In conclusion, the synthesized electrophilic estradiol 11 beta-ethyl and 11 beta-butyl derivatives (i) were not efficient affinity labels of the estrogen receptor and (ii) did not display significant cytotoxicity in estrogen-sensitive mammary tumor cells. However, since these derivatives displayed high affinity for the estrogen receptor, they could be used to prepare potential cytotoxic agents which might be selective for tumors affecting estrogen-target tissues, by coupling them with a toxic moiety.

Chronic left main coronary artery occlusion: a complication of radiofrequency ablation of idiopathic left ventricular tachycardia

We describe in this report the development of chronic left main coronary artery (LMCA) occlusion in a young patient 2 years after an uncomplicated, successful ablation of idiopathic left ventricular tachycardia. This complication appears to be a late consequence of trauma to the LMCA during the procedure rather than an acute or subacute embolic event.