Photocatalyzed radiosynthesis of 11C-phenylacetic acids

Fast and straightforward incorporation of radionuclides into pharmaceutically relevant molecules is one of the main barriers to preclinical and clinical tracer research. Late-stage direct incorporation of cyclotron-produced [11C]CO2 to afford carbon-11-labeled radiopharmaceuticals has the potential to provide ready-to-inject positron emission tomography agents in less than an hour. The present work describes photocatalyzed carboxylation of alkylbenzene derivatives to afford 11C-phenylacetic acids. Reaction conditions and scope are investigated followed by application of this methodology to the preparative radiosynthesis of [11C]fenoprofen, a nonsteroidal anti-inflammatory drug.

Aldehyde-catalysed carboxylate exchange in α-amino acids with isotopically labelled CO2

The isotopic labelling of small molecules is integral to drug development and for understanding biochemical processes. The preparation of carbon-labelled α-amino acids remains difficult and time consuming, with established methods involving label incorporation at an early stage of synthesis. This explains the high cost and scarcity of C-labelled products and presents a major challenge in 11C applications (11C t1/2 = 20 min). Here we report that aldehydes catalyse the isotopic carboxylate exchange of native α-amino acids with *CO2 (* = 14, 13, 11). Proteinogenic α-amino acids and many non-natural variants containing diverse functional groups undergo labelling. The reaction probably proceeds via the trapping of *CO2 by imine-carboxylate intermediates to generate iminomalonates that are prone to monodecarboxylation. Tempering catalyst electrophilicity was key to preventing irreversible aldehyde consumption. The pre-generation of the imine carboxylate intermediate allows for the rapid and late-stage 11C-radiolabelling of α-amino acids in the presence of [11C]CO2.

Synthesis and Optical Properties of Excited-State Intramolecular Proton Transfer (ESIPT) Emitters with Sulfobetaine Fragments

This article describes the synthetic efforts towards the solubilization of organic fluorescent emitters based on a 2-(2'-hydroxybenzofuranyl)benzazole (HBBX) scaffold in aqueous media under physiological conditions (PBS, pH 7.4). These dyes are well-known to display the excited-state intramolecular proton transfer (ESIPT) process which leads to a Stokes-shifted fluorescence with enhanced photostability and strong environment dependent features. Organic dyes are hydrophobic by nature and their vectorization into aqueous media usually necessitates amphiphilic polymers. In this study, we show that the incorporation of one or two sulfobetaine fragments, a highly biocompatible zwitterionic unit leads to the vectorization in buffer solution at pH 7.4 while keeping a reasonable ESIPT fluorescence emission. The photophysical properties of all dyes were studied in multiple solvents and showed that, depending on structure and environment, different excited-state species are observed: normal or tautomeric species, as well as a competitive anionic fluorescent derivative. This study shows that it is not only possible to solubilize fluorescent ESIPT dyes in water using sulfobetaine(s) but also that the optical properties can be finely tuned depending on small structural inputs.

Blue-Emitting 2-(2'-Hydroxyphenyl)benzazole Fluorophores by Modulation of Excited-State Intramolecular Proton Transfer: Spectroscopic Studies and Theoretical Calculations

This article describes the synthesis, spectroscopic studies, and theoretical calculations of nine original fluorophores based on the 2-(2'-hydroxyphenyl)benzazole (HBX) scaffold, functionalized at the 4-position of the phenol ring by ethynyl-extended aniline moieties. HBX dyes are well-known to display an excited-state intramolecular proton transfer (ESIPT) process, owing to a strong six-membered hydrogen bond in their structure that allows for an enol/keto tautomerism after photoexcitation. Appropriate electronic substitution can perturb the ESIPT process, leading to dual fluorescence, both excited tautomers emitting at specific wavelengths. In the examples described herein, it is demonstrated that the proton transfer can be finely frustrated by a modification of the constitutive heteroring, leading to a single emission band from the excited enol or keto tautomer or a dual emission with relative intensities highly dependent on the environment. Moreover, the nature of the functionalization of the N-alkylated aniline moiety also has a significant importance on the relative excited-state stabilities of the two tautomers in solution. To shed more light on these features, quantum chemical calculations by the density functional theory are used to determine the excited-state energies and rationalize the experimental spectroscopic data.

Selective Imaging of Matrix Metalloproteinase-13 to Detect Extracellular Matrix Remodeling in Atherosclerotic Lesions

PURPOSE

Overexpression and activation of matrix metalloproteinase-13 (MMP-13) within atheroma increases susceptibility to plaque rupture, a major cause of severe cardiovascular complications. In comparison to pan-MMP targeting [¹⁸F]BR-351, we evaluated the potential for [¹⁸F]FMBP, a selective PET radiotracer for MMP-13, to detect extracellular matrix (ECM) remodeling in vascular plaques possessing markers of inflammation.

PROCEDURES

[¹⁸F]FMBP and [¹⁸F]BR-351 were initially assessed in vitro by incubation with en face aortae from 8 month-old atherogenic ApoE^-/- mice. Ex vivo biodistributions, plasma metabolite analyses, and ex vivo autoradiography were analogously performed 30 min after intravenous radiotracer administration in age-matched C57Bl/6 and ApoE^-/- mice under baseline or homologous blocking conditions. En face aortae were subsequently stained with Oil Red O (ORO), sectioned, and subject to immunofluorescence staining for Mac-2 and MMP-13.

RESULTS

High-resolution autoradiographic image analysis demonstrated target specificity and regional concordance to lipid-rich lesions. Biodistribution studies revealed hepatobiliary excretion, low accumulation of radioactivity in non-excretory organs, and few differences between strains and conditions in non-target organs. Plasma metabolite analyses uncovered that [¹⁸F]FMBP exhibited excellent in vivo stability (≥74% intact) while [¹⁸F]BR-351 was extensively metabolized (≤37% intact). Ex vivo autoradiography and histology of en face aortae revealed that [¹⁸F]FMBP, relative to [¹⁸F]BR-351, exhibited 2.9-fold greater lesion uptake, substantial specific binding (68%), and improved sensitivity to atherosclerotic tissue (2.9-fold vs 2.1-fold). Immunofluorescent staining of aortic en face cross sections demonstrated elevated Mac-2 and MMP-13-positive areas within atherosclerotic lesions identified by [¹⁸F]FMBP ex vivo autoradiography.

CONCLUSIONS

While both radiotracers successfully identified atherosclerotic plaques, [¹⁸F]FMBP showed superior specificity and sensitivity for lesions possessing features of destructive plaque remodeling. The detection of ECM remodeling by selective targeting of MMP-13 may enable characterization of high-risk atherosclerosis featuring elevated collagenase activity.

Interrupted aza-Wittig reactions using iminophosphoranes to synthesize 11C-carbonyls

A direct CO2-fixation methodology couples structurally diverse iminophosphoranes with various nucleophiles to synthesize ureas, carbamates, thiocarbamates, and amides, and is amenable for 11C radiolabeling. This methodology is practical, as demonstrated by the synthesis of >35 products and isolation of the molecular imaging radiopharmaceuticals [11C]URB694 and [11C]glibenclamide.

Impact of Heteroatom Substitution on Dual-State Emissive Rigidified 2-(2'-hydroxyphenyl)benzazole Dyes: Towards Ultra-Bright ESIPT Fluorophores*

2-(2'-Hydroxyphenyl)benzazole (HBX) fluorophores are well-known excited-state intramolecular proton transfer (ESIPT) emitters largely studied for their synthetic versatility, photostability, strong solid-state fluorescence and ability to engineer dual emission, thus paving the way to applications as white emitters, ratiometric sensors, and cryptographic dyes. However, they are heavily quenched in solution, due to efficient non-radiative pathways taking place as a consequence of the proton transfer in the excited-state. In this contribution, the nature of the heteroring constitutive of these rigidified HBX dyes was modified and we demonstrate that this simple structural modification triggers major optical changes in terms of emission color, dual emission engineering, and importantly, fluorescent quantum yield. Investigation of the photophysical properties in solution and in the solid state of a series of ethynyl-TIPS extended HBX fluorophores, along with ab initio calculations demonstrate the very promising abilities of these dyes to act as bright dual-state emitters, in both solution (even in protic environments) and solid state.

Fast Carbon Isotope Exchange of Carboxylic Acids Enabled by Organic Photoredox Catalysis

Carbazole/cyanobenzene photocatalysts promote the direct isotopic carboxylate exchange of C(sp³) acids with labeled CO₂. Substrates that are not compatible with transition-metal-catalyzed degradation-reconstruction approaches or prone to thermally induced reversible decarboxylation undergo isotopic incorporation at room temperature in short reaction times. The radiolabeling of drug molecules and precursors with [¹¹C]CO₂ is demonstrated.

Fluorine-18-Labeled Fluorescent Dyes for Dual-Mode Molecular Imaging

Recent progress realized in the development of optical imaging (OPI) probes and devices has made this technique more and more affordable for imaging studies and fluorescence-guided surgery procedures. However, this imaging modality still suffers from a low depth of penetration, thus limiting its use to shallow tissues or endoscopy-based procedures. In contrast, positron emission tomography (PET) presents a high depth of penetration and the resulting signal is less attenuated, allowing for imaging in-depth tissues. Thus, association of these imaging techniques has the potential to push back the limits of each single modality. Recently, several research groups have been involved in the development of radiolabeled fluorophores with the aim of affording dual-mode PET/OPI probes used in preclinical imaging studies of diverse pathological conditions such as cancer, Alzheimer's disease, or cardiovascular diseases. Among all the available PET-active radionuclides, 18F stands out as the most widely used for clinical imaging thanks to its advantageous characteristics (t1/2 = 109.77 min; 97% β+ emitter). This review focuses on the recent efforts in the synthesis and radiofluorination of fluorescent scaffolds such as 4,4-difluoro-4-bora-diazaindacenes (BODIPYs), cyanines, and xanthene derivatives and their use in preclinical imaging studies using both PET and OPI technologies.

Practical implementation of automated closed-loop insulin delivery: A French position statement

Automated closed-loop (CL) insulin therapy has come of age. This major technological advance is expected to significantly improve the quality of care for adults, adolescents and children with type 1 diabetes. To improve access to this innovation for both patients and healthcare professionals (HCPs), and to promote adherence to its requirements in terms of safety, regulations, ethics and practice, the French Diabetes Society (SFD) brought together a French Working Group of experts to discuss the current practical consensus. The result is the present statement describing the indications for CL therapy with emphasis on the idea that treatment expectations must be clearly defined in advance. Specifications for expert care centres in charge of initiating the treatment were also proposed. Great importance was also attached to the crucial place of high-quality training for patients and healthcare professionals. Long-term follow-up should collect not only metabolic and clinical results, but also indicators related to psychosocial and human factors. Overall, this national consensus statement aims to promote the introduction of marketed CL devices into standard clinical practice.

Rapid suppression of bone formation marker in response to sleep restriction and circadian disruption in men

We describe the time course of bone formation marker (P1NP) decline in men exposed to ~ 3 weeks of sleep restriction with concurrent circadian disruption. P1NP declined within 10 days and remained lower with ongoing exposure. These data suggest even brief exposure to sleep and circadian disruptions may disrupt bone metabolism.

INTRODUCTION

A serum bone formation marker (procollagen type 1 N-terminal, P1NP) was lower after ~ 3 weeks of sleep restriction combined with circadian disruption. We now describe the time course of decline.

METHODS

The ~ 3-week protocol included two segments: "baseline," ≥ 10-h sleep opportunity/day × 5 days; "forced desynchrony" (FD), recurring 28 h day (circadian disruption) with sleep restriction (~ 5.6-h sleep per 24 h). Fasted plasma P1NP was measured throughout the protocol in nine men (20-59 years old). We tested the hypothesis that PINP would steadily decline across the FD intervention because the magnitude of sleep loss and circadian misalignment accrued as the protocol progressed. A piecewise linear regression model was used to estimate the slope (β) as ΔP1NP per 24 h with a change point mid-protocol to estimate the initial vs. prolonged effects of FD exposure.

RESULTS

Plasma P1NP levels declined significantly within the first 10 days of FD ([Formula: see text] = - 1.33 μg/L per 24 h, p < 0.0001) and remained lower than baseline with prolonged exposure out to 3 weeks ([Formula: see text] = - 0.18 μg/L per 24 h, p = 0.67). As previously reported, levels of a bone resorption marker (C-telopeptide (CTX)) were unchanged.

CONCLUSION

Sleep restriction with concurrent circadian disruption induced a relatively rapid decline in P1NP (despite no change in CTX) and levels remained lower with ongoing exposure. These data suggest (1) even brief sleep restriction and circadian disruption can adversely affect bone metabolism, and (2) there is no P1NP recovery with ongoing exposure that, taken together, could lead to lower bone density over time.

First Accurate Normalization of the β-delayed α Decay of ^{16}N and Implications for the ^{12}C(α,γ)^{16}O Astrophysical Reaction Rate

The ^{12}C(α,γ)^{16}O reaction plays a central role in astrophysics, but its cross section at energies relevant for astrophysical applications is only poorly constrained by laboratory data. The reduced α width, γ_{11}, of the bound 1^{-} level in ^{16}O is particularly important to determine the cross section. The magnitude of γ_{11} is determined via sub-Coulomb α-transfer reactions or the β-delayed α decay of ^{16}N, but the latter approach is presently hampered by the lack of sufficiently precise data on the β-decay branching ratios. Here we report improved branching ratios for the bound 1^{-} level [b_{β,11}=(5.02±0.10)×10^{-2}] and for β-delayed α emission [b_{βα}=(1.59±0.06)×10^{-5}]. Our value for b_{βα} is 33% larger than previously held, leading to a substantial increase in γ_{11}. Our revised value for γ_{11} is in good agreement with the value obtained in α-transfer studies and the weighted average of the two gives a robust and precise determination of γ_{11}, which provides significantly improved constraints on the ^{12}C(α,γ) cross section in the energy range relevant to hydrostatic He burning.

24-hour profile of serum sclerostin and its association with bone biomarkers in men

The osteocyte's role in orchestrating diurnal variations in bone turnover markers (BTMs) is unclear. We identified no rhythm in serum sclerostin (osteocyte protein). These results suggest that serum sclerostin can be measured at any time of day and the osteocyte does not direct the rhythmicity of other BTMs in men.

INTRODUCTION

The osteocyte exerts important effects on bone remodeling, but its rhythmicity and effect on the rhythms of other bone cells are not fully characterized. The purpose of this study was to determine if serum sclerostin displays rhythmicity over a 24-h interval, similar to that of other bone biomarkers.

METHODS

Serum sclerostin, FGF-23, CTX, and P1NP were measured every 2 h over a 24-h interval in ten healthy men aged 20-65 years. Maximum likelihood estimates of the parameters in a repeated measures model were used to determine if these biomarkers displayed a diurnal, sinusoidal rhythm.

RESULTS

No discernible 24-h rhythm was identified for sclerostin (p = 0.99) or P1NP (p = 0.65). CTX rhythmicity was confirmed (p < 0.001), peaking at 05:30 (range 01:30-07:30). FGF-23 levels were also rhythmic (p < 0.001), but time of peak was variable (range 02:30-11:30). The only significant association identified between these four bone biomarkers was for CTX and P1NP mean 24-h metabolite levels (r = 0.65, p = 0.04).

CONCLUSIONS

Sclerostin levels do not appear to be rhythmic in men. This suggests that in contrast to CTX, serum sclerostin could be measured at any time of day. The 24-h profiles of FGF-23 suggest that a component of osteocyte function is rhythmic, but its timing is variable. Our results do not support the hypothesis that osteocytes direct the rhythmicity of other bone turnover markers (CTX), at least not via a sclerostin-mediated mechanism.

Green, Yellow, and Red risk perception in everyday life - a communication tool

BACKGROUND

Adolescents have the highest risk for food allergy-related fatalities. Our main aim was to investigate the level of risk in everyday social situations as perceived by adolescents/young adults with peanut allergy, their families, and their friends.

METHODS

The web-based 'Colours Of Risks' (COR) questionnaire was completed by 70 patients (aged 12-23 years), 103 mothers and fathers, 31 siblings (aged 12-26 years), and 42 friends (aged 12-24 years). COR deals with six main contexts (home, school/university, work, visiting/social activities, special occasions/parties, and vacations), each with 1-12 items. Response categories are green (I feel safe), yellow (I feel uncertain), or red (I feel everything is risky).

RESULTS

There was a high level of agreement between participants in defining situations as safe, uncertain, or risky, but female patients and mothers rated fewer situations as safe compared to male patients and fathers. Being with close friends and family, and attending planned parties without alcohol were perceived as situations of low risk. While 94% of patients took an epinephrine auto-injector (EAI) into risky situations, only 65% took it into safe situations. In contrast to the close family, 31% of the friends did not know the patient had an EAI, and fewer knew how to administer the EAI.

CONCLUSION

Young adults with peanut allergy face challenges when moving from the safe home with ready assistance if needed, to independence with unpredictable surroundings and less certain help. Perceived 'safe' situations may in fact be the riskiest, as patients often do not take the EAI with them.

Quality of life in childhood, adolescence and adult food allergy: Patient and parent perspectives

BACKGROUND

Studies of children with food allergy typically only include the mother and have not investigated the relationship between the amount of allergen needed to elicit a clinical reaction (threshold) and health-related quality of life (HRQL). Our aims were (i) to compare self-reported and parent-reported HRQL in different age groups, (ii) to evaluate the impact of severity of allergic reaction and threshold on HRQL, and (iii) to investigate factors associated with patient-reported and parent-reported HRQL.

METHODS

Age-appropriate Food Allergy Quality of Life Questionnaires (FAQLQ) were completed by 73 children, 49 adolescents and 29 adults with peanut, hazelnut or egg allergy. Parents (197 mothers, 120 fathers) assessed their child's HRQL using the FAQLQ-Parent form. Clinical data and threshold values were obtained from a hospital database. Significant factors for HRQL were investigated using univariate and multivariate regression.

RESULTS

Female patients reported greater impact of food allergy on HRQL than males did. Egg and hazelnut thresholds did not affect HRQL, but lower peanut threshold was associated with worse HRQL. Both parents scored their child's HRQL better than the child's own assessment, but whereas mother-reported HRQL was significantly affected by limitations in the child's social life, father-reported HRQL was affected by limitations in the family's social life. Severity of allergic reaction did not contribute significantly to HRQL.

CONCLUSION

The risk of accidental allergen ingestion and limitations in social life are associated with worse HRQL. Fathers provide a unique perspective and should have a greater opportunity to contribute to food allergy research.

23Na(α,p)26Mg Reaction Rate at Astrophysically Relevant Energies

The production of 26Al in massive stars is sensitive to the 23Na(α,p)26Mg cross section. Recent experimental data suggest the currently recommended cross sections are underestimated by a factor of ∼40. We present here differential cross sections for the 23Na(α,p)26Mg reaction measured in the energy range E(c.m.)=1.7-2.5  MeV. Concurrent measurements of Rutherford scattering provide absolute normalizations that are independent of variations in target properties. Angular distributions are measured for both p0 and p1 permitting the determination of total cross sections. The results show no significant deviation from the statistical model calculations upon which the recommended rates are based. We therefore retain the previous recommendation without the increase in cross section and resulting stellar reaction rates by a factor of 40, impacting the 26Al yield from massive stars by more than a factor of 3.

Mutations in the Epstein-Barr virus latent membrane protein-1 (BNLF-1) gene in spontaneous lymphoblastoid cell lines: effect on in vitro transformation associated parameters and tumorigenicity in SCID and nude mice

Aims-(1) To study the frequency of putative malignancy associated point mutations and a 30 base pair (bp) deletion in exon 3 of the C-terminus of the Epstein-Barr virus (EBV) encoded latent membrane protein (LMP)-1 (BNLF-1) gene in wild type EBV strains. (2) To assess the influence of these mutations on the tumorigenicity of lymphoblastoid cell lines (LCL).Methods-Eight spontaneous EBV (wild type) infected LCL were established from seven subjects. Deletions and single base mutations in the C-terminus of the BNLF-1 gene were demonstrated using bi-directional solid phase dideoxy sequencing following PCR amplification of viral DNA from the LCL. Tumorigenicity of the LCL was assessed in SCID and nude mice. Serum dependent growth and ability to form colonies in soft agarose were assessed for representative LCL.Results-All LCL showed sequence differences compared with the prototypic EBV strain B95-8. The 30 bp deletion could be detected in three of eight LCL and a 69 bp deletion (including the 30 bp deletion) was identified in an additional LCL. A range of single base mutations (including those described previously in association with EBV related neoplasias) was also seen in some of the LCL. In transformation studies, the genetic variations did not seem to influence the in vitro behaviour of the LCL. In the tumorigenicity studies, the presence of the 30 bp deletion had no influence on the behaviour of the LCL which were, as expected, tumorigenic in SCID mice but not in nude mice. In contrast, the LCL carrying the 69 bp deletion was tumorigenic in both SCID and nude mice.Conclusions-Genetic changes described previously in the C-terminus of the LMP-1 gene in various malignancy derived EBV strains are also present frequently in wild type viruses and do not simply define tumour specific EBV strains. Changes within this region may, however, still be important for the tumorigenicity of LMP-1 and thus play a role in EBV oncogenesis.

Serum levels of mannan-binding lectin in chickens prior to and during experimental infection with avian infectious bronchitis virus

Mannan-binding lectin (MBL) is a glycoprotein and a member of the C-type lectin super family, the collectin family, and the acute phase protein family. The MBL exerts its function by directly binding to microbial surfaces through its carbohydrate recognition domains, followed by direct opsonization or complement activation via MBL-associated serine proteases (MASP)-1 and -2. Thus, MBL plays a major role in the first-line innate defense against pathogens. We investigated the MBL concentrations in serum during experimental infectious bronchitis virus (IBV) infections in chickens. The results showed that the acute phase MBL response to infection with IBV was, to a degree (P < 0.0068), dependent on whether the chickens were inoculated after 12 h of rest (dark) or after 12 h of activity (light). The acute phase response in chickens challenged after 12 h of activity peaked after 4.6 d with an increase of 24%, whereas the acute phase response in chickens challenged after 12 h of rest peaked after 3.1 d with an increase of 51%. The specific antibody titer against IBV was also tested, and a difference (P < 0.0091) between the two experimental groups was found with peak titer values of 6,816 and 4,349. However, the highest value was found in chickens inoculated after 12 h of activity. Thus, an inverse relation exists between the MBL response and the IBV specific antibody response. The ability of MBL to activate the complement cascade was tested in a heterologous system by deposition of human C4 on the chicken MBL/MASP complex. The complement activation was directly associated with the concentration of MBL in serum, indicating neutralization of the virus before the humoral antibody response took over.

Detection and subtyping (H5 and H7) of avian type A influenza virus by reverse transcription-PCR and PCR-ELISA

Avian influenza virus infections are a major cause of morbidity and rapid identification of the virus has important clinical, economical and epidemiological implications. We have developed a one-tube Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) for the rapid diagnosis of avian influenza A. A panel of reference influenza strains from various hosts including avian species, human, swine and horse were evaluated in a one tube RT-PCR using primers designed for the amplification of a 218 bp fragment of the NP gene. The PCR products were detected by PCR-ELISA by use of an internal catching probe confirming the NP influenza A origin. The PCR-ELISA was about 100 times more sensitive than detection of PCR products by agarose gel electrophoresis. RT-PCR and detection by PCR-ELISA is comparable in sensitivity to virus propagation in eggs. We also designed primers for the detection of the influenza. A subtypes H5 and H7 shown to have pathogenic potential in poultry. The H5 primers cover the cleavage site of the HA gene and specifically amplify influenza A subtype H5. The H7 primers also cover the HA cleavage site and detected all H7 reference strains investigated. In addition, the H7 primers also amplified very weak and/or additional bands on an agarose gel from other subtypes. However, the H7 origin and the pathogenic potential defined by the presence or absence of basic amino acids at the cleavage site can be determined by sequencing of the PCR product. As far as we know this is the first demonstration of RT-PCR detection on a panel of H7 strains using only one primer set.

Treatment of perforating collagenosis of diabetes and renal failure with allopurinol

We present a case of widespread reactive perforating collagenosis in a 63-year-old woman undergoing haemodialysis after diabetic nephropathy, who was treated successfully with allopurinol. The patient responded well and rapidly to a dose of 100 mg allopurinol daily. It is suggested that more patients with reactive perforating collagenosis may benefit from allopurinol therapy.

The association between multiple sclerosis and infection with Epstein-Barr virus and retrovirus

B-lymphoblastoid cell-lines may develop spontaneously in mononuclear cells from patients with multiple sclerosis, an observation rarely seen in healthy individuals. Examination of such spontaneously established B-cell lines reveal the presence of Epstein-Barr virus and retrovirus particles. We have speculated that in predisposed individuals, a dual infection with retrovirus and late acquired Epstein-Barr virus plays an aetiological role in the development of multiple sclerosis. This hypothesis is supported by a number of observations, including the finding that infection with Epstein-Barr virus may be a prerequisite for developing multiple sclerosis. The association between multiple sclerosis and infection with Epstein-Barr virus and retrovirus is evaluated in this study.

Molecular characterization of HERV-H variants associated with multiple sclerosis

Our objective was to characterize retroviral sequences by RT-PCR with gag and env primers on RNA from RT-positive retroviral particles produced by multiple sclerosis (MS) derived B-lymphoblastoid cell lines. Sequence variants with high homology to the potentially functional subgroup RGH of the human endogenous retrovirus RTVL-H/HERV-H family were found. The same sequences were also specifically found in the particulate fraction of a series of MS patient plasma samples and were absent in controls. South-Western blots demonstrate the presence of a nucleic acid binding protein, corresponding in size and function to the nucleocapsid protein, Gag NC, of other retroviruses. We also present indications for transmission of the retrovirus to PHA-stimulated lymphocytes from healthy individuals.

Epstein-Barr virus and multiple sclerosis

It has been suggested that the Epstein-Barr virus (EBV) plays a role in the etiology of multiple sclerosis (MS), but individual epidemiologic studies have been inconclusive, in part because of the high prevalence of previous infection among individuals without MS. We conducted a systematic review of case-control studies comparing EBV serology in MS patients and controls. Eight published investigations were identified, including a total of 1,005 cases and 1,060 controls. The summary odds ratio of MS comparing EBV seropositive individuals with EBV seronegative individuals was 13.5 (95% CI = 6.3-31.4). The strength and consistency of this association and the high sensitivity and specificity of EBV serology suggest that these results are not readily explained by an aspecific immune activation among MS patients. These findings support a role of EBV in the etiology of MS.

A single subtype of Epstein-Barr virus in members of multiple sclerosis clusters

OBJECTIVES

Epidemiological studies strongly indicate an infectious involvement in multiple sclerosis (MS). Epstein-Barr virus (EBV), to which all multiple sclerosis patients are seropositive, is also interesting from an epidemiological point of view. We have reported a cluster of MS patients with 8 members from a small Danish community called Fjelsø. To further evaluate the role of EBV in MS we have investigated the distribution of EBV subtypes in cluster members and in control cohorts.

MATERIALS AND METHODS

Blood mononuclear cells were isolated from cluster members, unrelated MS patients, healthy controls, including healthy schoolmates to the Fjelsø cluster patients and finally from persons with autoimmune diseases in order to investigate the number of 39 bp repeats in the EBNA 6-coding region in the EBV seropositive individuals.

RESULTS

We observed a preponderance of the subtype with 3 39 bp repeats in the EBNA 6-coding region both in the MS patients and the healthy controls. In the Fjels cluster all 8 cluster members were harbouring this subtype, which is significantly different from the finding in healthy controls (n = 16), which include 8 schoolmates to the cluster members and 8 randomly selected healthy persons (Fischer's exact test P = 0.0047), and also compared to all non-clustered individuals studied (P = 0.017).

CONCLUSION

Infection with the same subtype of EBV links together the 8 persons from the Fjelsø cluster who later developed MS. This finding adds to the possibility that development of MS is linked to infection with EBV.

Epstein-Barr virus strain characterization

The Epstein-Barr virus (EBV), a ubiquitous human herpesvirus originally described in cultured lymphoblasts from African Burkitt's lymphoma, is the causative agent of infectious mononucleosis, but appears to be involved in the pathogenesis of a variety of diseases. EBV has the ability to establish lifelong persistent infection, where only a restricted pattern of the viral proteins is expressed. Periodic reactivation of EBV occurs, where mature EBV particles are produced. Strain variation is potentially important in the biology and epidemiology of EBV, and in attempts to relate EBV to associated diseases. Analysis of the EBV genomes isolated from patients with EBV-associated diseases and from various parts of the world has so far failed to identify conclusive disease-specific viral subtypes. This review focuses on the different strategies which have been used for strain characterization or subtyping of EBV.

The significance of Epstein-Barr virus seropositivity in multiple sclerosis patients?

The objective of this study was to evaluate and investigate the significance of the previously found 100% seropositivity toward Epstein-Barr virus (EBV) found in multiple sclerosis (MS) patients in contrast to healthy controls. Using a commercially available ELISA-test (Biotest), which differentiates infections with EBV into previous infections, primary infections, reactivated infections and no previous infection, we found 137 of 138 MS patients and 124 of 138 healthy controls seropositive. A primary infection in 4 of the 124 EBV seropositive healthy controls in contrast to no primary infections in the MS EBV seropositive group was significant (P=0.049652, Fishers exact test). This may be suggestive of a lack of primary infections in MS patients, and thus strengthens the idea that MS patients are infected with EBV before development of MS. Further studies are in progress to analyse whether EBV infection is a prerequisite for the development of this disease.

Serial changes in atrial natriuretic peptide and endothelin-1 concentrations. Their relationships to the cardiac performance of patients hospitalized for acute myocardial infarction

AIM

The study was designed to assess temporal changes in atrial natriuretic peptide (ANP) and endothelin-1 (ET) concentrations in patients hospitalized for acute myocardial infarction (AMI) and their relationships to cardiac performance determined by radionuclide ventriculography.

PATIENTS AND METHODS

20 patients with first AMI were studied. Blood samples were drawn within the first 4-18 h, after 18-24 h, and on days 2, 3 and 6. Plasma concentrations of ANP and ET were measured in blood samples taken simultaneously. Radionuclide ventriculography was performed on the day of discharge to determine left-ventricular ejection fraction (LVEF), left-ventricular end-diastolic volume index, end-systolic volume index and left-ventricular stroke volume index.

RESULTS

Median concentrations of ET decreased from 2.15 pmol/l on admission to 1.45 pmol/l at discharge (32%, p < 0.001). Median ANP rose from 29 to 79 pg/ml (172%, p < 0.001). The increment in ANP and the decrease in ET concentrations from admission to discharge was inversely correlated (r = -0.81, p < 0.005). ANP was inversely correlated to LVEF (r = -0.82, p < 0.001) and to the end-systolic volume index at discharge (r = -0.73, p < 0.003).

CONCLUSION

Dynamic and inverse fluctuations in ET and ANP occur within the 1st week of AMI. The magnitude of endocrine activation in the ANP-ET system seems to reflect an impairment in the left-ventricular systolic performance.

[Changes among residents in homes for the aged in Bergen between 1985-96]

Homes for the aged are intended for elderly people who, by and large, are able to perform basic activities of daily living (ADL) on their own, but who, in spite of this, need or wish to live in an institutional setting, where only minor nursing facilities are available. The present study focuses on the changes in mental capacity and in the altered need for nursing assistance with ADL functions which developed among residents at 13 homes for the aged in the city of Bergen, between 1985 and 1996. In 1985, the average age for residents was 84 years; and in 1996 it was 87 years. The average duration of stay was 30 and 38 months, respectively. There was a significant increase in the proportion of mentally impaired residents (28% and 35%). There was also an increase in the percentage in need of intensive nursing care (34% and 41%). The changes in residents living in the homes were not caused by dementia. It is concluded that homes for the aged are used increasingly for elderly in need of nursing care. There is an obvious mismatch between tasks and resources.

[Prevalence of left ventricular hypertrophy in Danish patients with hypertension]

The aim of this investigation was to study the prevalence of left ventricular hypertrophy (LVH) in a hypertensive population with reference to a normotensive control group. From the general population, 3498 men and women aged 35, 45, 55 and 65 years old were invited to a health examination. Participants with blood pressure above 160 mmHg systolic and/or 95 mmHg diastolic or participants currently taking antihypertensive medication or having done so during the previous six months were asked to undergo an echocardiographic examination. Controls were randomly selected from the same population. Of 552 participants in the final study population, 194 were normotensive controls and 358 were in the hypertensive group. Echocardiographic measurements were made according to the "Penn" conventions and indexed for body surface. Cutoff values for LVH were 134 grams per m2 for males and 102 grams per m2 for women. Overall, we found that the prevalence of 1 VH was 14%/20% (men/women) in normotensives and 25%/26% in hypertensives (p < 0.01). By subdivision in age and sex groups we found that the relation between normotensives and hypertensives was significant in the age group of 65 years (p < 0.02 for males and p < 0.05 for females). The association between blood pressure and 1 VH in the general population is weak. 1 VH is only significantly more frequent among hypertensives as compared to normotensives in older people.

Sequence analysis of the Epstein-Barr virus (EBV) latent membrane protein-1 gene and promoter region: identification of four variants among wild-type EBV isolates

Sequence variations in the Epstein-Barr virus (EBV) encoded latent membrane protein-1 (LMP-1) gene have been described in a Chinese nasopharyngeal carcinoma-derived isolate (CAO), and in viral isolates from various EBV-associated tumors. It has been suggested that these genetic changes, which include loss of a Xho I restriction site (position 169425) and a C-terminal 30-base pair (bp) deletion (position 168287-168256), define EBV genotypes associated with increased tumorigenicity or with disease among particular geographic populations. To determine the frequency of LMP-1 variations in European wild-type virus isolates, we sequenced the LMP-1 promoter and gene in EBV from lymphoblastoid cell lines from healthy carriers and patients without EBV-associated disease. Sequence changes were often present, and defined at least four main groups of viral isolates, which we designate Groups A through D. The widespread prevalence of LMP-1 sequence variations, particularly the Xho I polymorphism and the 30-bp deletion, indicate that they cannot be used as simple markers for oncogenic viruses related to particular forms of EBV-associated tumor. Several of the structural changes detected occur, however, at sites where they may affect transcription, translation, or function of LMP-1. Future in vitro studies should aim to establish the functional importance of variations at these sites.

The implications of Epstein-Barr virus in multiple sclerosis--a review

The objective of this article is to bring together knowledge about Epstein-Barr virus (EBV) in relation to multiple sclerosis (MS) in order to evaluate its implications in this disease. All MS patients are EBV seropositive, but EBV is not normally detected in the brain. EBV can explain many of the epidemiological dogmas known in MS. In addition, other studies point towards the involvement of EBV in MS. Despite this, other co-actors seem also to be involved. We still need to know whether EBV may be an initiating factor in MS or whether it is a factor in the pathogenesis. Possible ways of EBV involvement are discussed: direct involvement, an autoimmune inducing factor or a transactivating factor. A current treatment study of MS patients with a specific herpes antiviral drug may add further information to the etiology and pathogenesis of MS.

Characterization of retroviruses from patients with multiple sclerosis

These studies were performed to characterize retroviruses found in cell lines spontaneously developed from peripheral blood mononuclear cells (PBMNC) from 6 multiple sclerosis patients, a patient with progressive myelopathy and a healthy control. The cell lines are B-lymphoblastoid and produce Epstein-Barr virus (EBV) particles or express EBV proteins. The B-lymphoblastoid cell lines are also characterized by production of low, fluctuating amounts of retrovirus. The low productivity complicates purification and characterization, but implementation of product-enhanced reverse transcriptase (PERT) assays has provided a highly useful tool for monitoring retrovirus production. By electron microscopy, the retroviral particles appear type-C-like. Functional assays indicate the presence of Pol, Gag and Env. Indirect ELISA demonstrates a significant relation between disease activity and reactivity towards retroviral peptides. Molecular characterization is primarily based on RT-PCR, cloning, sequencing and Northern- or Southern analyses. Molecular characterization is continuing.

Prevalence of left ventricular hypertrophy in a hypertensive population

AIMS

This investigation was set up to study the prevalence of left ventricular hypertrophy in a hypertensive population with reference to a normotensive control group. From the general population 3498 men and women aged 35, 45, 55 and 65 years old were invited to a health examination. Participants with blood pressure above 160 mmHg systolic or 95 mmHg diastolic or those taking antihypertensive medication or having done so during the previous 6 months were asked to undergo an echocardiographic examination. Normotensive controls were randomly selected from the same population. Of 552 participants in the final study population, 194 were normotensive controls and 358 were in the hypertensive group. Echocardiographic measurements were made according to the Penn conventions and indexed for body surface. Cut-off values for left ventricular hypertrophy were 134 g.m-2 for males and 102 g.m-2 for women.

RESULTS

Overall, the prevalence of left ventricular hypertrophy was 14%/20% (men/women) in normotensives and 25%/26% in hypertensives (P < 0.01). After subdivision by age and sex, there was a significant difference in the prevalence of left ventricular hypertrophy between normotensives and hypertensives only in the 65-year-old group (P < 0.02 for males and P < 0.05 for females).

CONCLUSIONS

The association between blood pressure and left ventricular hypertrophy in the general population is weak. Left ventricular hypertrophy is only significantly more frequent among hypertensives as compared to normotensives in older people.

[Paraquat poisoning. Treatment and prognosis]

Treatment of paraquat intoxication is most often in vain if initial treatment is delayed. We report a case where the patient was admitted 25 hours after oral intake of paraquat. The patient died due to respiratory insufficiency secondary to peroxidative pulmonary fibrosis in spite of combined continuous haemodialysis and haemofiltration. Principles of treatment are reviewed.

B-lymphoblastoid cell lines from multiple sclerosis patients and a healthy control producing a putative new human retrovirus and Epstein-Barr virus

On several occasions we have observed retrovirus-like particles (RVLPs) by transmission electron microscopy (EM) of cultured T cells from a patient with MS. Later we established spontaneously formed B-lymphoblastoid cell lines (LCLs) from a patient with an MS-like disease and from another patient with MS who had a reactivated Epstein-Barr virus (EBV) infection. Both LCLs were found by EM to produce RVLP and EBV particles. Reverse transcriptase (RT) assays were positive in purified viral material from both LCLs. To substantiate these findings we initiated an intensified culturing procedure and were able to establish LCLs from 5 out of 21 consecutive MS patients and 1 out of 13 consecutive healthy controls. All LCLs were found to produce both RVLP and EBV particles by EM. Whether the putative new retrovirus(es) and EBV have any causal relationship to MS is still not known, but the findings support this possibility.