Sexually dimorphic differences in angiogenesis markers predict brain aging trajectories

Aberrant angiogenesis could contribute to cognitive impairment, representing a therapeutic target for preventing dementia. However, most angiogenesis studies focus on model organisms. To test the relevance of angiogenesis to human cognitive aging, we evaluated associations of circulating blood markers of angiogenesis with brain aging trajectories in two deeply phenotyped human cohorts (n=435, age 74 + 9) with longitudinal cognitive assessments, biospecimens, structural brain imaging, and clinical data. Machine learning and traditional statistics revealed sex dimorphic associations of plasma angiogenic growth factors with brain aging outcomes. Specifically, angiogenesis is associated with higher executive function and less brain atrophy in younger women (not men), a directionality of association that reverses around age 75. Higher levels of basic fibroblast growth factor, known for pleiotropic effects on multiple cell types, predicted favorable cognitive trajectories. This work demonstrates the relevance of angiogenesis to brain aging with important therapeutic implications for vascular cognitive impairment and dementia.

Identification of MRC2 and CD209 receptors as targets for photodynamic therapy of retinoblastoma using mesoporous silica nanoparticles

An overexpression of MRC2 and CD209 mannose receptors was revealed in retinoblastoma and antibodies against these receptors were grafted to multifunctional nanoparticles for targeting of imaging and photodynamic therapy.

The contributions of MRI-based measures of gray matter, white matter hyperintensity, and white matter integrity to late-life cognition

BACKGROUND AND PURPOSE

GM volume, WMH volume, and FA are each associated with cognition; however, few studies have detected whether these 3 different types of MR imaging measurements exert independent or additive effects on cognitive performance. To detect their extent of contribution to cognitive performance, we explored the independent and additive contributions of GM atrophy, white matter injury, and white matter integrity to cognition in elderly patients.

MATERIALS AND METHODS

Two hundred and 9 elderly patients participated in the study: 97 were CN adults, 65 had MCI, and 47 had dementia. We measured GM on T1-weighted MR imaging, WMH on FLAIR, and FA on DTI, along with psychometrically matched measures of 4 domains of cognitive performance, including semantic memory, episodic memory, executive function, and spatial abilities.

RESULTS

As expected, patients with dementia performed significantly more poorly in all 4 cognitive domains, whereas patients with MCI performed generally less poorly than dementia patients, though considerable overlap in performance was present across groups. GM, FA, and WMH each differed significantly between diagnostic groups and were associated with cognitive measures. In multivariate models that included all 3 MR imaging measures (GM, WMH, and FA), GM volume was the strongest determinant of cognitive performance.

CONCLUSIONS

These results strongly suggest that MR imaging measures of GM are more closely associated with cognitive function than WM measures across a broad range of cognitive and functional impairment.

[Interfacial behaviour of glycoconjugated tetraphenylporphyrins and their interaction with biomimetic models of the cell membrane]

INTRODUCTION

Porphyrins are photosensitizers usable in photodynamic therapy. Although these molecules are clinically effective, their low water solubility and their lack of specificity are major drawbacks to their development. Our study was aimed at analysing the interfacial behaviour of glycoconjugated tetraphenylporphyrins newly synthesized at the Curie Institute, and their interaction with model membranes bearing a specific lectin mimicking a mannose membrane receptor in retinoblastoma.

MATERIAL AND METHODS

The interfacial behaviour of the porphyrins was analysed by surface pressure measurements, and their specific interaction with the lectin, by dynamic light scattering (liposomes) and the quartz crystal microbalance technique (supported bilayers).

RESULTS

All porphyrin derivatives were able to organize at the air/liquid interface. The dendrimeric compounds formed more stable monolayers than the others, and generally showed good mixing properties with the phospholipid used for liposome preparation. In the presence of concanavalin A, the porphyrin bearing-liposomes behaved differently depending on the nature (mannosylated or not) of the porphyrins.

DISCUSSION

The interfacial behaviour of the tetraphenylporphyrins is directly related to the orientation of the tetrapyrrolic macrocycle controlled by the grafted groups. Incorporated into a liposome bilayer, glycodendrimeric porphyrins expose their sugar moieties at the vesicle surface. The spacer length plays a crucial role by increasing sugars freedom and enhancing glycosylated liposomes interaction with the lectin.

CONCLUSION

Compared to the other studied compounds, the glycodendrimeric porphyrins seem very promising compounds and are now evaluated on cell cultures.

FLAIR and diffusion MRI signals are independent predictors of white matter hyperintensities

BACKGROUND AND PURPOSE

WMH, associated with cognitive decline and cardiovascular risk factors, may represent only the extreme end of a more widespread continuous WM injury process that progresses during aging and is poorly understood. We investigated the ability of FLAIR and DTI to characterize the longitudinal course of WMH development.

MATERIALS AND METHODS

One hundred nineteen participants (mean age, 74.5 ± 7.4), including cognitively healthy elders and subjects diagnosed with Alzheimer disease and mild cognitive impairment, received a comprehensive clinical evaluation and brain MR imaging, including FLAIR and DTI on 2 dates. The risk for each baseline normal-appearing WM voxel to convert into WMH was modeled as a function of baseline FA (model M1) and both baseline FA and standardized FLAIR (M2). Sensitivity, specificity, accuracy, and AUC for predicting conversion to WMH were compared between models.

RESULTS

Independent of clinical diagnosis, lower baseline FA (P < .001, both models) and higher baseline FLAIR intensity (P < .001, M2) were independently associated with increased risk for conversion from normal WM to WMH. M1 exhibited higher sensitivity but lower specificity, accuracy, and AUC compared with M2.

CONCLUSIONS

These findings provide further evidence that WMH result from a continuous process of WM degeneration with time. Stepwise decreases in WM integrity as measured by both DTI and FLAIR were independently associated with stepwise increases in WMH risk, emphasizing that these modalities may provide complementary information for understanding the time course of aging-associated WM degeneration.

Nitrogen sources for current-year shoot growth in 50-year-old sessile oak trees: an in situ (15)N labeling approach

We used long-term in situ (15)N labeling of the soil to investigate the contribution of the two main nitrogen (N) sources (N uptake versus N reserves) to sun shoot growth from bud burst to full leaf expansion in 50-year-old sessile oaks. Recovery of (15)N by growing compartments (leaves, twigs and buds) and presence of (15)N in phloem sap were checked weekly. During the first 2 weeks following bud burst, remobilized N contributed ~90% of total N in growing leaves and twigs. Nitrogen uptake from the soil started concomitantly with N remobilization but contributed only slightly to bud burst. However, the fraction of total N due to N uptake increased markedly once bud burst had occurred, reaching 27% in fully expanded leaves and 18% in developed twigs. In phloem sap, the (15)N label appeared a few days after the beginning of labeling and increased until the end of bud burst, and then decreased at full leaf expansion in June. Of all the shoot compartments, leaves attracted most of the absorbed N, which accounted for 68% of new N in shoots, whereas twigs and new buds accounted for only 28 and 3%, respectively. New N allocated to leaves increased from unfolding to full expansion as total N concentration in the leaves decreased. Our results underline the crucial role played by stored N in rapid leaf growth and in the sustained growth of oak trees. Any factors that reduce N storage in autumn may therefore impair spring shoot growth.

Seasonal changes of C and N non-structural compounds in the stem sapwood of adult sessile oak and beech trees

We assessed the pools of non-structural nitrogen compounds (NSNC) through a year, thereby addressing the question of whether mature sessile oak [Quercus petraea (Matt.) Liebl.] and beech (Fagus sylvatica L.), which differ in wood anatomy and growth patterns, exhibit contrasting seasonal dynamics of NSNC pools as previously shown for non-structural carbohydrate (NSC) pools. Seasonal fluctuations of NSNC (amino acids and soluble proteins) and NSC (starch and soluble sugars) pools were analyzed in the inner and the outer stem sapwood. In oak, NSC showed marked seasonal variation within the stem sapwood (accumulation during winter and decrease during bud burst and early wood growth), whereas in beech seasonal fluctuations in NSC were of minor amplitude. Even if the distribution and intensity of the NSNC pools differed between the two species, NSNC of the stem sapwood did not show seasonal variation. The most significant change in NSNC pools was the seasonal fluctuation of protein composition. In both species, two polypeptides of 13 kDa (PP13) and 26 kDa (PP26) accumulated during the coldest period in parallel with starch to sugar conversion and disappeared with the onset of spring growth. The absence of seasonal changes in total soluble protein concentration suggests that the polypeptides are involved in the internal nitrogen (N) cycling of the stem rather than in N storage and remobilization to the other growing organs of the tree.

[Towards a new treatment of retinoblastoma?]

Photodynamic therapy (PDT) is a recent approach for the treatment of small cancerous tumours, on-surface or accessible by endoscopy in which a dye (usually a tetrapyrrolic macrocycle) absorbs light and generates cytotoxic reactive oxygen species leading to cellular damage. Retinoblastoma (Rb) is a rare intraocular tumour of childhood. All the multifocal forms are hereditary and constitute a syndrome of genetic predisposition in the cancer. The current treatments with etoposide or carboplatine expose the patient to the late risk of second cancer. The use of PDT as cancer therapy is particularly attractive due to the use of few mutagenic and non-toxic photosensitizers (PS) prior light excitation and to the localized tumour illumination. The photoefficiency towards Rb of a glycoconjugated porphyrin is discussed and compared with the results obtained with a second-generation photosensitizer, the Foscan. Some in vivo results on an animal model of Rb are presented by a point of view of photoefficiency, biodistribution, pharmacokinetic and longitudinal follow-up of the PDT effect using a new non-invasive method of magnetic resonance imaging of real-time. Photodynamic treatments in association with non-invasive sodium imaging open ways for new treatment tailoring or treatment individualization of retinoblastoma in clinic.

Neuroimaging correlates of subjective memory deficits in a community population

BACKGROUND

Subjective memory deficit (SMD) is one of few potential presenting symptoms for people with early cognitive impairment. However, associations with underlying brain changes are unclear.

METHODS

In a community sample of 1,779 people without dementia, and with neuroimaging (MRI) data, associations were investigated for SMD with white matter lesion volume and with the following volumetric measures: gray and white matter, CSF, hippocampal, parahippocampal, and amygdalar. Covariates included depressive symptoms (Center for Epidemiologic Studies Depression Scale), a battery of cognitive tests, physical health, and social activity.

RESULTS

SMD was present in 26.4% of the sample. Of the neuroimaging measures analyzed, SMD was most strongly associated with temporal WML (OR for highest quintile compared to the remainder 1.44, 95% CI 1.12-1.85), and lower hippocampal volume (OR per decreasing quintile 1.22, 1.11-1.35). These associations were independent of all other covariates, including cognitive function.

CONCLUSIONS

Subjective memory deficit (SMD) was associated with neuroimaging characteristics in the temporal and hippocampal regions, suggesting that SMD may, at least in some cases, represent a realistic appraisal of underlying brain function independent of measured cognition. However, further research is required for volumetric measures and SMD to establish whether the association reflects lifelong structure or neurodegenerative changes.

[Malignant tumors arising in extra-ovarian endometriosis: a case report]

We report a case of degenerative extra-ovarian endometriosis. This is a rare complication of endometriosis, the frequency of which is estimated at 0.9%. In more than 50% of the cases, the diagnosis is made following investigation for abdominal pain. If the degeneration is of the same histological type as the endometriosis, it can be said to have arisen from the endometriosis. First-line treatment is surgery, removing as much endometriosis as possible, staging at this point is also necessary. Second-line treatment, with chemotherapy, radiotherapy and even hormonotherapy may be needed. Prognosis for this tumor is variable, from 10 to 100% five-year survival, depending on histological type and localization of the disease.

[Different methods for assessing quality in health sector]

AN OBLIGATION: The "management" of quality is an integral part of "medical" management today. The health centers and professionals have to prove their value and know-how through distinct signs of recognition. A METHOD FOR ASSESSING QUALITY: This paper defines the method of assessment of quality and specifies the typology of the persons, organisms, supervisors and clients of the French health system who have a personal or collective interest in judging the quality of health services. DIFFERENT POSSIBILITIES: Numerous existing methods for assessing quality are presented together with their use, implementation and the use made by the actors and consumers of the health system. Some of these assessment methods are formal, others informal, some are mandatory, others optional; some concern the general population, others the professionals. Although know-how is essential in health, making it known is strategic today.

Nonenveloped nucleocapsids of hepatitis C virus in the serum of infected patients

One of the characteristics of hepatitis C virus (HCV) is the high incidence of persistent infection. HCV core protein, in addition to forming the viral nucleocapsid, has multiple regulatory functions in host-cell transcription, apoptosis, cell transformation, and lipid metabolism and may play a role in suppressing host immune response. This protein is thought to be present in the bloodstream of the infected host as the nucleocapsid of infectious, enveloped virions. This study provides evidence that viral particles with the physicochemical, morphological, and antigenic properties of nonenveloped HCV nucleocapsids are present in the plasma of HCV-infected individuals. These particles have a buoyant density of 1.32 to 1.34 g/ml in CsCl, are heterogeneous in size (with predominance of particles 38 to 43 or 54 to 62 nm in diameter on electron microscopy), and express on their surface epitopes located in amino acids 24 to 68 of the core protein. Similar nucleocapsid-like particles are also produced in insect cells infected with recombinant baculovirus bearing cDNA for structural HCV proteins. HCV core particles isolated from plasma were used to generate anti-core monoclonal antibodies (MAbs). These MAbs stained HCV core in the cytoplasm of hepatocytes from experimentally infected chimpanzees in the acute phase of the infection. These chimpanzees had concomitantly HCV core antigen in serum. These findings suggest that overproduction of nonenveloped nucleocapsids and their release into the bloodstream are properties of HCV morphogenesis. The presence of circulating cores in serum and accumulation of the core protein in liver cells during the early phase of infection may contribute to the persistence of HCV and its many immunopathological effects in the infected host.

Photobiological activity of exogenous and endogenous porphyrin derivatives in Escherichia coli and Enterococcus hirae cells

Photodynamic treatment, the combined application of a photosensitiser and visible light, represents a new and promising approach for the inactivation of microorganisms. The photosensitising potentials of exogenous zinc-phthalocyanine-tetrasulphonate (ZnPsTS), tetraphenylporphyrins (TPPs) and endogenous porphyrin derivatives were tested and compared on Gram-negative and Gram-positive bacteria, Escherichia coli B. and Enterococcus hirae, respectively. The synthesis of endogenous porphyrins was induced by 5-aminolevulinic acid (delta-ALA). The porphyrin- or delta-ALA-treated cells were irradiated with white light. The photosensitising efficiency of endogenous derivatives on both types of bacteria is ZnPcTS < TP(4-OGluOH)3P < TP(4-OGluOH)4P. However, neither exogenous derivatives exhibit appreciable photosensitising activity for disinfection application. ALA-induced photodynamic treatment showed good potential for the inactivation of Escherichia coli cells, but not towards Enterococcus hirae cells. The failure of photosensitisation of the Enterococcus hirae strain selected indicates that apart from the Gram-positive character, other structural elements of the membrane can influence the result of photodynamic treatments.

Photoinduced inactivation of T7 phage sensitized by symmetrically and asymmetrically substituted tetraphenyl porphyrin: comparison of efficiency and mechanism of action

We investigated the efficiency and the mechanism of action of two--one symmetrically and one asymmetrically substituted--glycoconjugated tetraphenyl porphyrins in their photoreaction with T7 phage as a model of nucleoprotein (NP) complexes. A correlation was found between the dark inactivation of T7 and the binding of porphyrins determined by fluorescence spectroscopy. Both types of porphyrin sensitized the photoinactivation of T7, but the slopes of inactivation kinetics were markedly different. There was no correlation between the dark binding and the photosensitizing efficacy of the two derivatives. Inactivation was moderated by 1,3-diphenylisobenzofuran and 1,3-dimethyl-2-thiourea; however, neither of them inhibited T7 inactivation completely. This result suggests that both Type-I and Type-II reactions play a role in the virus inactivation. Optical melting studies revealed structural changes in the protein part but not in the DNA of the photochemically treated NP complex. Polymerase chain reaction analysis of a 555 bp segment of gene 1 and a 3826 bp segment of genes 3 and 4 failed to demonstrate any DNA damage.

Interactive effects of elevated CO2 concentration and nitrogen supply on partitioning of newly fixed 13C and 15N between shoot and roots of pedunculate oak seedlings (Quercus robur)

Pedunculate oak (Quercus robur L.) seedlings were grown for 3 or 4 months (second- and third-flush stages) in greenhouses at two atmospheric CO2 concentrations ([CO2]) (350 or 700 micromol mol(-1)) and two nitrogen fertilization regimes (6.1 or 0.61 mmol N l(-1) nutrient solution). Combined effects of [CO2] and nitrogen fertilization on partitioning of newly acquired carbon (C) and nitrogen (N) were assessed by dual 13C and 15N short-term labeling of seedlings at the second- or third-flush stage of development. In the low-N treatment, root growth, but not shoot growth, was stimulated by elevated [CO2], with the result that shoot/root biomass ratio declined. At the second-flush stage, overall seedling biomass growth was increased (13%) by elevated [CO2] regardless of N fertilization. At the third-flush stage, elevated [CO2] increased growth sharply (139%) in the high-N but not the low-N treatment. Root/shoot biomass ratios were threefold higher in the low-N treatment relative to the high-N treatment. At the second-flush stage, leaf area was 45-51% greater in the high-N treatment than in the low-N treatment. At the-third flush stage, there was a positive interaction between the effects of N fertilization and [CO2] on leaf area, which was 93% greater in the high-N/elevated [CO2] treatment than in the low-N/ambient [CO2] treatment. Specific leaf area was reduced (17-25%) by elevated [CO2], whereas C and N concentrations of seedlings increased significantly in response to either elevated [CO2] or high-N fertilization. At the third-flush stage, acquisition of C and N per unit dry mass of leaf and fine root was 51 and 77% greater, respectively, in the elevated [CO2]/high-N fertilization treatment than in the ambient [CO2]/low-N fertilization treatment. However, there was dilution of leaf N in response to elevated [CO2]. Partitioning of newly acquired C and N between shoot and roots was altered by N fertilization but not [CO2]. More newly acquired C and N were partitioned to roots in the low-N treatment than in the high-N treatment.

Docetaxel in combination with 5-fluorouracil in patients with metastatic breast cancer previously treated with anthracycline-based chemotherapy: a phase I, dose-finding study

This phase I study evaluated the maximum tolerated dose, dose-limiting toxicity and recommended dose of docetaxel in combination with 5-fluorouracil (5-FU) in patients with metastatic breast cancer previously treated with anthracycline-based chemotherapy. 32 patients received docetaxel at 60, 75, 85 or 100 mg/m(2) by 1-h intravenous (i.v.) infusion, followed, after a 1-h interval, by 5-FU at 250, 350, 500 or 750 mg/m(2)/day by continuous infusion over 5 days every 3 weeks. Dose-limiting stomatitis defined the maximum tolerated dose at a docetaxel dose of 100 mg/m(2) with 5-FU 750 mg/m(2)/day. None of 5 patients treated at the previous dose level (docetaxel 85 mg/m(2) with 5-FU 750 mg/m(2)/day) had a dose-limiting toxicity in the first cycle, and this was, therefore, considered the recommended dose. The combination was generally well tolerated. Grade 4 neutropenia was common (29 patients; 91%), but no patient experienced febrile neutropenia of duration >3 days requiring i.v. antibiotics. An objective response was achieved by 18 patients overall (56%), and in 4 out of 5 patients treated with the determined recommended dose. No pharmacokinetic interaction between docetaxel and 5-fluorouracil was apparent. The activity of docetaxel 85 mg/m(2) with 5-fluorouracil 750 mg/m(2)/day will be explored more extensively in phase II studies of patients with metastatic breast cancer previously treated with anthracycline-based chemotherapy.

Tetrapyrrolic Glycosylated Macrocycles for an Application in PDT

The synthesis and characterization of amphiphilic glycoconjugated porphyrins, benzochlorin, and azaporphyrins were reported. Among these molecules, several were found to be efficient photosensitizers in an in vitro assay using the human tumoral cell line HT29. Moreover, glycosylated benzochlorin and azaporphyrins, whose absorption bands in the red region of the visible spectrum are substantially increased as compared to porphyrins, display a good photocytotoxicity on tumor cells after irradiation with wavelength above 590 nm. © 1999 Society of Photo-Optical Instrumentation Engineers.

Modelling of allocation and balance of carbon in walnut (Juglans regia L.) seedlings during heterotrophy-autotrophy transition

A deterministic and dynamic model of carbon allocation in walnut seedlings is described. Two experimental data sets were used to calibrate and validate the model. These data included: time course of the carbon content, chemical and isotope composition (12C and 13C) of the kernel and growing organs (roots, stem, leaves), and gas exchange rates during the first 55 days of the life of the plant with continuous 13CO2 feeding. The plant is modelled as a network with nodal organs acting as sources or sinks for carbohydrates. In a sink organ the demand for carbon is the sum of four elementary demands: maintenance respiration, structural growth, growth-associated respiration and carbon storage. The organs of the plant are assumed to be in exponential growth phase. The supply of carbon readily accessible for the organs is the store of soluble sugars present in a local reservoir. Carbon flow in the network is determined by the source/sink activities of the organs and local levels of demand and supply. Two carbon sources are considered: soluble sugars from the kernel, and gross photosynthesis. The rate of synthesis of soluble sugars in the kernel, and measured photosynthesis in the leaves are inputs for the plant model. The outputs are the predicted fluxes of carbon within the seedling; 13C composition,carbohydrate allocation to the growing organs, starch and soluble sugars accumulation, and respiration. The mathematical equations were translated into PSPICE software instructions. After optimisation of the parameter values, the model provided an accurate description of experimental observations in the seed-plant system during the critical transition from heterotrophy to autotrophy, especially C allocation to organs and C partitioning between storage, structural growth and respiration in each organ. The growth of the young plant is supply-limited, except at the earliest stages. A sensitivity analysis suggests that intense competition for carbohydrates dominates the relations among and within organs. Copyright 1998 Academic Press Limited

At least three epitopes are recognized by the human repertoire in the hepatitis B virus group a antigen inducing protection; possible consequences for seroprevention and serodiagnosis

Many recent investigations have shown that both HBV and anti-HBs antibodies coexist in the same patient, and HBV can be found in individuals with anti-HBc antibodies in the absence of immunologically detectable HBsAg. In most cases, mutant forms of HBV affecting the region of the envelope gene coding for the group a determinant recognized by human antibodies have been found. The nature of the group a determinant was revisited with an ELISA involving dissociated, but not alkylated, envelope subunits. No antibody recognizing a continuous epitope of the major S envelope protein could be found in humans; the full activity of human anti-HBs antibodies appeared to be focused on the discontinuous group a determinant. The immunological human repertoire against the HBsAg group a determinant was analysed by competitive inhibition of three mouse monoclonal antibodies (mAbs) selected as recognizing three distinct specificities on the group a determinant. Antibodies to specificities #1 and 3 were found in 52/70 anti-HBs human sera and generally predominated over specificity #2, which was lacking in some sera. The heterogeneity of the group a determinant suggested by these data argue for the use of more than one type of anti-HBs mAb for seroprevention of recurrence after liver transplantation and HBs serodiagnosis. Provided all three types of mAbs characterized here recognize HBV variants with mutations in the a determinant and are virus-neutralizing, it may be helpful, after association of such mAbs, to use them for diagnosis and to devise new immunotherapeutic strategies to prevent emergence of HBsAg escape mutants.

Activation of the envelope proteins by a metalloproteinase enables attachment and entry of the hepatitis B virus into T-lymphocyte

Previously, we identified an HBV binding factor (HBV-BF), a 50-kDa serum glycoprotein which interacts with HBV envelope proteins and which is also located in the membrane of normal human hepatocyte (A. Budkowska et al. (1993) J. Virol. 67, 4316). Here we show that HBV-BF is a neutral metalloproteinase which shares substrate specificity and properties with a newly described family of membrane type matrix metalloproteinases. HBV-BF treatment of the HBV resulted in the cleavage of the N-terminal part of the middle HBV envelope protein at the pre-S2(136-141) amino acid sequence VRGLYF/L (containing a single arginine cleavage site). HBV-BF affected the reactivity of the large HBV protein with pre-S1-specific MAbs, probably inducing the conformational change of the pre-S1 domain. The HBV-BF-digested virus remained morphologically intact with unchanged S antigenic determinants. The structural modifications of the viral envelope proteins induced by HBV-BF enabled cell membrane attachment and viral entry into the T-lymphocyte. Both processes were blocked by the metalloproteinase inhibitor 1,10 phenanthroline. Thus, the host-dependent proteolytic activation of the envelope proteins seems to be essential for the HBV entry into the cell. HBV-BF under a membrane bound or a secreted form could be (one of) the molecule(s) responsible for the HBV proteolytic activation.

Polymerase chain reaction to monitor repair of the HBV genome, the first step in viral replication

A method based on the polymerase chain reaction (PCR) for evidencing repair of the hepatitis B virus (HBV) genome is described. Hepadnaviruses have a partially double-stranded relaxed circular genome (RC-DNA) which is converted into a covalently closed circular DNA (CCC-DNA) after entry of the virus into a target cell. Our aim was to set up a technique enabling us to determine whether possible in vitro replication of the virus in non-hepatic cells is initiated by formation of CCC-DNA. The relevant part of the strategy used for this PCR consisted of priming the HBV-DNA template with the same forward primer and with a reverse primer located either downstream or upstream from the minus strand gap. The CCC-DNA form was found, as expected, in cells in which the virus was known to be actively replicating; although most sera contained only the RC-DNA form, it was also possible to evidence the CCC form. Such PCR amplification led to detection of 50-500 copies of the viral DNA. The method described should be useful in studying the biological fate of HBV in non-hepatic cells (considered as non-permissive for virus replication), and in exploring the clinical significance of the presence of CCC-DNA in sera.

Anti-pre-S responses and viral clearance in chronic hepatitis B virus infection

Serial sera were collected prospectively during the clinical course of 13 HBsAg carriers with chronic liver disease and analyzed for ALT levels, pre-S1 and pre-S2 antigens and corresponding antibodies and other serological hepatitis B virus markers. In five patients, anti-pre-S1 and anti-pre-S2 antibodies became detectable in multiple serum samples, whereas in eight patients anti-pre-S was never detected or only appeared transiently during the follow-up. The first pattern was associated with normalization of ALT levels and undetectable pre-S antigens and viral DNA by the polymerase chain reaction assay at final follow-up. HBsAg clearance occurred in two of the five patients. The second pattern was one of persistence of HBsAg and pre-S antigens, associated with the presence of serum HBV DNA detectable by spot hybridization or polymerase chain reaction regardless of clinical outcome. These findings demonstrate the occurrence of anti-pre-S antibodies in chronic hepatitis B virus-induced liver disease and associate anti-pre-S appearance with the clearance of hepatitis B virus from serum.

A biphasic pattern of anti-pre-S responses in acute hepatitis B virus infection

The clinical relevance of the immune response to the translation products of the pre-S1 and pre-S2 regions of hepatitis B virus was examined by testing sequential serum samples from 17 patients with acute self-limited hepatitis B and from two patients in whom chronic liver disease developed. Anti-pre-S antibodies were determined by enzyme immunoassays based on the inhibition of binding of monoclonal antibodies to epitopes in the pre-S1 and pre-S2 sequence. In acute, self-limited infection, anti-pre-S antibodies appeared in a biphasic pattern. The early antibodies were detected at the time of clinical signs of acute disease when HBsAg and often HBeAg were present, but hepatitis B virus DNA was no longer detectable in serum. Anti-pre-S levels then fell, but subsequently reappeared as the late antibody during the recovery phase, after development of anti-HBe, but before anti-HBs. Anti-pre-S responses were detected in 15 of 17 patients who recovered (88.2%) and in both patients with acute hepatitis B virus infection evolving to chronic liver disease. Although the early antibodies to pre-S1 and pre-S2 proteins appeared at the time of decreasing levels of infectious virus in serum in cases of self-limited infection, these antibodies also were transiently or continuously present with high levels of serum hepatitis B virus DNA in patients in whom chronic hepatitis B infection developed. Thus the anti-pre-S response in acute hepatitis is not a prognostic marker for clinical resolution.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein F. A novel F(ab)-binding factor, present in normal liver, and largely released in the digestive tract during hepatitis

Significant percentages of patients suffering from non-A non-B hepatitis (43%) and B hepatitis (35%) were found to release an Ig-binding factor in their stools. This factor, which we called "protein F" was less frequently observed (20%) in patients suffering from other liver disorders, and was found in only 6.7% of healthy subjects (p less than 10(-7), less than 10(-4), and less than 0.03, respectively). The specificity of the detection test (a nonimmune ELISA-like assay) was confirmed by inhibition experiments. Binding was located on the F(ab) fragment of Ig, irrespectively of their isotype. Protein F was inactivated by pepsin, neuraminidase, and high concentrations of subtilisin, whereas it was resistant to trypsin and chymotrypsin. Molecular sieving by HPLC indicated an apparent molecular mass of 175 kDa. In preparative SDS-PAGE, the molecular mass was 85 kDa in favor of a dimer disrupted under dissociating conditions. Preparative IEF showed the isoelectric charge to lie between 3.9 and 4.1. Analysis of liver extracts from two patients suffering fron non-A non-B hepatitis, and from a transplant donor, revealed the presence of the factor in the three cases.

Protein F. A novel F(ab)-binding factor, present in normal liver, and largely released in the digestive tract during hepatitis

Significant percentages of patients suffering from non-A non-B hepatitis (43%) and B hepatitis (35%) were found to release an Ig-binding factor in their stools. This factor, which we called "protein F" was less frequently observed (20%) in patients suffering from other liver disorders, and was found in only 6.7% of healthy subjects (p less than 10(-7), less than 10(-4), and less than 0.03, respectively). The specificity of the detection test (a nonimmune ELISA-like assay) was confirmed by inhibition experiments. Binding was located on the F(ab) fragment of Ig, irrespectively of their isotype. Protein F was inactivated by pepsin, neuraminidase, and high concentrations of subtilisin, whereas it was resistant to trypsin and chymotrypsin. Molecular sieving by HPLC indicated an apparent molecular mass of 175 kDa. In preparative SDS-PAGE, the molecular mass was 85 kDa in favor of a dimer disrupted under dissociating conditions. Preparative IEF showed the isoelectric charge to lie between 3.9 and 4.1. Analysis of liver extracts from two patients suffering fron non-A non-B hepatitis, and from a transplant donor, revealed the presence of the factor in the three cases.

Serial passage of west-European sporadic non-A non-B hepatitis in rhesus monkeys by inoculation with fecal extracts

An experimental model of sporadic non-A non-B hepatitis involving a Fab nonimmune binding activity in stools was established in the rhesus monkey. The first animal was inoculated intravenously with a stool extract from a French patient who had never left the country and in whom post-transfusion hepatitis was excluded. Four passages were performed, and the infection was transmitted by parenteral as well as the oral routes by inoculation of stools or liver extracts. Infection led in three monkeys to reversible hepatocyte injury manifested by a transitory increase in serum aminotransferases. The other three animals, in which persistently high levels of aminotransferases was observed, were sacrificed on day 60 after inoculation. The incubation period, as evidenced by elevation of aminotransferases was about 3 to 4 weeks. The infectious agent was transitorily present in the stools before aminotransferase elevation. The presence of the infectious agent in the stools was correlated with the nonimmune Fab binding activity.

Type IV Ehlers-Danlos syndrome with isolated arterial involvement

Ehlers-Danlos syndrome is a connective tissue disorder characterized by skin hyperelasticity and friability, hyperextensible small articulations, vascular fragility, and ocular and visceral symptoms. Ten types of Ehlers-Danlos syndrome have been described to date. Type IV is characterized by isolated arterial involvement with the risk of rupture, making diagnosis difficult. A 25-year-old man was operated on for a ruptured left and then right iliac artery and once again for a hepatic artery aneurysm within a nine month period. The diagnosis of Ehlers-Danlos syndrome was based on clinical and histopathologic findings. An asymptomatic iliac artery aneurysm was found in the patient's 23-year-old brother.

[Plasmapheresis and acute attacks of uveitis]

Our study concerns the effects of plasma exchange in acute attacks of posterior or total chronic uveitis. The treatment undertaken in 10 patients consisted of 8 plasma exchanges in a 2 weeks period, associated with a corticosteroid and immunosuppressive therapy. Immediately after the plasma exchanges, there was a significant improvement in visual acuity and a decrease in inflammatory activity in most patients (70%). Plasma exchange seems to be an interesting adjuvant in the difficult treatment of some uveitis.