Pharmacogenetics of tenofovir drug transporters in the context of HBV: Is there an impact?

BACKGROUND

Current treatments for chronic hepatitis B management include orally administered nucleos(t)ide analogues, such as tenofovir (TDF), which is an acyclic adenine nucleotide analogue used both in HBV and human immune deficiency virus (HIV). The course of HBV infection is mainly dependent on viral factors, such as HBV genotypes, immunological features and host genetic variables, but a few data are available in the context of HBV, in particular for polymorphisms of genes encoding proteins involved in drug metabolism and elimination. Consequently, the aim of this study was to evaluate the potential impact of genetic variants on TDF plasma and urine concentrations in patients with HBV, considering the role of HBV genotypes.

METHODS

A retrospective cohort study at the Infectious Disease Unit of Amedeo di Savoia Hospital, Torino, Italy, was performed. Pharmacokinetic analyses were performed through liquidi chromatography, whereas pharmacogenetic analyses through real-time PCR.

FINDINGS

Sixty - eight patients were analyzed: ABCC4 4976 C>T genetic variant showed an impact on urine TDF drug concentrations (p = 0.014). In addition, SLC22A6 453 AA was retained in the final regression multivariate model considering factors predicting plasma concentrations, while ABCC4 4976 TC/CC was the only predictor of urine concentrations in the univariate model.

INTERPRETATION

In conclusion, this is the first study showing a potential impact of genetic variants on TDF plasma and urine concentrations in the HBV context, but further studies in different and larger cohorts of patients are required.

POS0755 PREVALENCE AND RELEVANCE OF ANTIBODIES AGAINST CITRULLINATED ALPHA ENOLASE (ANTI-CEP1) IN CONNECTIVE TISSUE DISEASES

Background:

Anti-citrullinated alpha enolase antibodies have been investigated in rheumatoid arthritis and associated with bone erosion and interstitial lung disease but little is known about their prevalence and role in connective tissue diseases (CTDs).

Objectives:

The aim of this study was to investigate the prevalence and relevance of anti-CEP1 antibodies in CTDs.

Methods:

Serum samples from five independent patient cohorts were assessed: 1) established (est) primary Sjogren’s syndrome (pSS) N=78, 2) est-systemic lupus erythematosus (SLE) N=52, 3) est-systemic sclerosis (SSc) N=71, 4) pSS at disease onset N=30, 5) SLE at disease onset N=46 (cohorts 4 and 5 had at least 3 years of follow-up). Samples from ninety sex and age matched healthy donors (HD) and 200 patients with est-RA (disease controls) were also tested. Anti-CEP1 IgG antibodies were measured with a commercially available ELISA kit (Euroimmun, Luebeck, Germany).

Results:

Anti-CEP1 titer was significantly higher in est-pSS, est-SLE and est-SSc compared to HD, significantly lower in est-pSS and est-SSc compared to est-RA and comparable in est-SLE versus est-RA. We divided patients in every CTD group based on whether their anti-CEP1 titer was below or above the 25th, 50th and 75th percentile. In est-SLE anti-CEP1 values over the 25th percentile were associated with articular involvement (odds ratio, OR (95% confidence interval, CI)=11.5; 1.9-70.6, p=0.008). In est-pSS, no relationship between anti-CEP1>25th percentile and articular involvement was found but rather an association with rheumatoid factor positivity (OR (95% CI)=4.8, 1.6-14.1, p=0.004) and salivary gland swelling (OR (95% CI)=6.2, 1.3-29.1, p=0.021). In est-SSc no difference could be detected across the 3 groups. Anti-CEP-1 titers in pSS and SLE at onset did not differ from each other, were comparable also to those of HD and significantly lower than those of est-pSS, est-SLE and est-RA patients (all p<0.0001).). Of interest, we could retrieve a serum sample collected at the time of diagnosis for 5 patients from the cohort of established pSS and we observed that anti-CEP1 titers were significantly lower at pSS onset than during follow up (at least 12 months after the diagnosis, p=0.0024). No difference was observed in the clinical presentation at disease onset according to different anti-CEP1 titer and they did not predict the development of new clinical manifestations during follow-up.

Conclusion:

Anti-CEP-1 antibodies can be detected in CTDs at different title during the disease course and may increase overtime, at least in pSS. Although anti-CEP1 antibodies are associated with specific clinical manifestation in est-CTDs, such as articular involvement in est-SLE, they seem to lack a predictive value for future manifestations when measured at disease onset.

References:

[1]Alunno A, Bistoni O, Pratesi F et al Rheumatology (Oxford) 2018.

[2]Manca ML, Alunno A, D’Amato C et al. Joint Bone Spine 2018.

Disclosure of Interests:

None declared

The impact of COVID-19 outbreak on urolithiasis emergency department admissions, hospitalizations and clinical management in central Italy: a multicentric analysis

Introducción y objetivos

Nuestro objetivo fue evaluar el impacto de la enfermedad del coronavirus de 2019 (COVID-19) en los ingresos en los servicios de urgencias (SU), las hospitalizaciones y el manejo clínico de los pacientes con urolitiasis.

Pacientes y métodos

Realizamos un análisis retrospectivo multicéntrico de las admisiones en los servicios de urgencias de tres departamentos de urología de gran volumen (uno directamente implicado en el tratamiento de los pacientes de COVID-19 y dos no implicados) en Roma (Italia) entre marzo y abril de 2020 y en el mismo período de 2019. Se realizó un análisis estadístico del número de admisiones por urolitiasis, la tasa de complicaciones, hospitalización y el tipo de tratamiento recibido.

Resultados

Fueron incluidos 304 pacientes en el análisis. Se observó una reducción significativa en el número global de pacientes ingresados en urgencias por urolitiasis entre 2019 y 2020 (48,8%). Además, con respecto a la elección del tratamiento de los pacientes hospitalizados, se informó un aumento estadísticamente significativo de los procedimientos de extracción de cálculos en comparación con el drenaje urinario en 2020 (p = 0,015).

Conclusiones

Durante la pandemia de la COVID-19 en Roma ha habido una reducción significativa de los ingresos en urgencias por urolitiasis. Los pacientes ingresados en el SU tuvieron más complicaciones, necesitaron hospitalización con más frecuencia y en cuanto al manejo clínico, se prefirió la extracción temprana de los cálculos, en vez del drenaje urinario. Todos los urólogos deben ser conscientes de que en los próximos meses podrían enfrentar un mayor número de admisiones por urolitiasis y un manejo de casos más complicados.

FRI0565 PREVALENCE AND SIGNIFICANCE OF ANTIBODIES AGAINST CITRULLINATED ALPHA-ENOLASE (ANTI-CEP1) IN CONNECTIVE TISSUE DISEASES

Background:

Anti-cyclic citrullinated peptide (anti-CCP) auto-antibodies represent the current gold standard for the diagnosis of rheumatoid arthritis (RA). However, growing evidence suggests that a variety of other citrullinated self-proteins may act as autoantigens and lead to the production of autoantibodies (1). Furthermore, autoantibodies believed to be RA-specific have been detected also in patients with connective tissue diseases (CTDs). We recently demonstrated that antibodies against citrullinated alpha-enolase (anti-CEP1) are a biomarker of erosive disease and RA-associated interstitial lung disease (2).

Objectives:

The purpose of this study was to investigate the prevalence and possible prognostic value of anti-CEP-1 in patients with CTDs.

Methods:

Two hundred and twelve consecutive patients with CTDs (51 systemic lupus erythematosus (SLE), 85 primary Sjogren’s syndrome (pSS) and 76 systemic sclerosis (SSc)) were studied and compared to 97 sex and age matched normal controls (NC) and 267 patients with RA. Anti-CEP1 IgG were detected in serum samples with a commercial ELISA kit (Euroimmun).

Results:

The overall prevalence of anti-CEP1 in CTDs was 7% (15/212 patients). In detail, these antibodies were detectable in 4 out of 85 pSS (5%), 5 out of 51 SLE (10%) and 6/76 SSc (8%). The prevalence and the titer of anti-CEP1 in CTDs was significantly higher compared to NC and significantly lower compared to RA. Anti-CEP1 positive patients did not display a specific clinical and serological picture. Unlike in RA, anti-CEP1 did not correlate with CTD-associated ILD.

Conclusion:

This is the first study assessing anti-CEP1 in a large cohort of patients with CTDs. We demonstrated that the association of these autoantibodies with ILD is specific for RA since it is not observed in SLE, pSS and SSc. Furthermore, although being significantly more prevalent and at higher titer compared to NC, anti-CEP1 do not allow to discriminate different patient subsets displaying peculiar clinical or serological phenotypes. Based on our results, the application of anti-CEP1 in CTDs is not advisable, however larger studies may possibly identify correlations not evident in our cohort.

References:

[1] Bonifacio AF, Alunno A, La Paglia GMC, Valentini E, Leone MC, Bartoloni E, Gerli R. Novel autoantibodies in rheumatoid arthritis. Reumatismo 2019;71(1):1-12

[2] Alunno A, Bistoni O, Pratesi F, La Paglia GMC, Puxeddu I, Migliorini P, Gerli R. Anti-citrullinated alpha enolase antibodies, interstitial lung disease and bone erosion in rheumatoid arthritis. Rheumatology (Oxford). 2018;57(5):850-855

Disclosure of Interests:

Alessia Alunno: None declared, Francesco Carubbi Speakers bureau: Francesco Carubbi received speaker honoraria from Abbvie and Celgene outside this work., Onelia Bistoni: None declared, Matteo Antonucci: None declared, Elena Bartoloni Bocci: None declared, Roberto Giacomelli Grant/research support from: Actelion, Pfizer, Speakers bureau: Abbvie, Roche, Actelion, BMS, MSD, Ely Lilly, SOBI, Pfizer, Roberto Gerli: None declared

Heat shock influences the fatty acid composition of the muscle of the Antarctic fish Trematomus bernacchii

In the Ross Sea region (average temperature of -1.87 °C), shelf water warming up to +0.8-+1.4 °C is predicted by 2200, so there is an urgent need to understand how organisms can respond to rising temperatures. In this study, we analyzed the effect of a heat shock on the fatty acid (FAs) composition of muscle of the Antarctic teleost Trematomus bernacchii, caught in Terra Nova Bay (Ross Sea), and held in fish tanks at 0, +1 or +2 °C, for 1, 5 and 10 days. In general, heat shock produced, beyond a reduction in total lipid content correlated to the temperature, an increase in the percentage of saturated FAs, and a decrease in mono-unsaturated FAs; however, the level of poly-unsaturated FAs did not seem to directly correlate with temperature. Principal component analysis indicated that both temperature and exposure time affect the composition of FAs in the muscle probably through an alteration of the metabolic pathways of FAs. In this study, we demonstrated that T. bernacchii was capable to rapidly acclimatize to a heat shock. This study contributes to increasing knowledge on the effect of temperature on the lipid composition of T. bernacchii and is complementary to previous studies on the gene expression and biochemistry of this species face multiple stressors.

Distribution of Cd, Pb and Cu between dissolved fraction, inorganic particulate and phytoplankton in seawater of Terra Nova Bay (Ross Sea, Antarctica) during austral summer 2011-12

During the austral summer 2011-2012, the metal quotas of Cd, Pb and Cu in the phytoplankton of Terra Nova Bay (TNB, Antarctica) were measured for the first time. Evolution of all the three metal distributions between dissolved and particulate fractions during the season was also evaluated. Metal concentrations were mainly affected by the dynamic of the pack ice melting and phytoplankton activity. In mid-December when TNB area was covered by a thick pack ice layer and phytoplankton activity was very low, all the three metals were present mainly in their dissolved species. When the pack ice started to melt and the water column characteristics became ideal (i.e. moderate stratification, ice free area), the phytoplankton bloom occurred. Cd showed a nutrient-type behaviour with dissolved and particulate fractions mainly influenced by phytoplankton activity. Cd quota showed a mean value of 0.12 ± 0.07 nmol L^-1 (30-100% of the total particulate). Also Cu showed a nutrient-type behaviour, with its quota in phytoplankton varying between 0.08 and 2.1 nmol L^-1 (20-100% of the total particulate). Pb features the typical distribution of a scavenged element with very low algal content (0.03 ± 0.02 nmol L^-1, representing 20-50% of the total particulate). The vertical distribution of this element was influenced by several factors (e.g. pack ice melting, atmospheric inputs), the phytoplankton activity affecting Pb behaviour only partially. Metal:C ratios provide valuable information on the biological requirements for Cd, Pb and Cu, leading us to better understand their biogeochemical cycles.

Quantification of fatty acids in the muscle of Antarctic fish Trematomus bernacchii by gas chromatography-mass spectrometry: Optimization of the analytical methodology

This work presents data on the quantification of fatty acids (FAs, in terms of mass unit per tissue weight) in the muscle of Trematomus bernacchii, a key species in Antarctica, often used as bioindicator for contamination studies. Modifications in fatty acids content should be considered a useful biomarker to study how contaminants affect Antarctic biota. Until now, very few studies quantified fatty acids of muscle of T. bernacchii, and only as percentage of a single fatty acid on total lipids. To perform the quantification of fatty acids, we used an analytical method based on a fast microwave-assisted extraction of lipids from a lyophilized sample, a base-catalyzed trans-esterification of lipid extract to obtain Fatty Acids Methyl Esters (FAMEs), and a separation and identification of FAMEs by gas chromatography-mass spectrometry. With the optimized and validated method, a fast and accurate separation of Fatty Acids Methyl Esters was performed in 43 min. The linearity was checked up to about 320 μg mL^-1; limit of detection and limit of quantification are in the range 4-22 μg mL^-1 and 13-66 μg mL^-1, respectively. The optimized method showed a good accuracy and precision. Major fatty acids were 14:0, 16:0, 16:1n7, 18:1n9, 18:1n7, 20:1n9, 20:5n3 and 22:6n3. Quantified FAs compute for about 47 mg g^-1 tissue dry weight (dw), with 9.1 ± 0.1 mg g^-1 dw of saturated FAs, 25.5 ± 0.1 mg g^-1 dw of mono-unsaturated FAs, and 12.2 ± 0.1 mg g^-1 dw of poly-unsaturated FAs.

A Writing Program with Word Prediction for a Young Man with Multiple Disabilities: A Preliminary Assessment

This study assessed a writing program with word prediction, which completed the writing of a word and spoke it out only when there was certainty that such a word was the correct one. The assessment was carried out with a young man with multiple disabilities, who typically used a word-processing program without word prediction. The two programs were compared on the time required by the participant for writing general sentences, through a social validation assessment, and eventually a check on the participant's preference. Analysis showed the program with word prediction was significantly more effective in terms of the writing time, which was halved, and was deemed preferable by 40 raters (psychology students) involved in the social validation assessment and by the participant himself. Implications of the findings are discussed.

Enabling a Man with Multiple Disabilities and Limited Motor Behavior to Perform a Functional Task with Help of Microswitch Technology

This study evaluated the extent to which two microswitches used as interfaces would enable a man with multiple disabilities and limited motor behavior to operate an electric door opener at the entrance of the day center that he attended. Analysis showed the man (a) learned to use the two microswitches, (b) preferred the microswitch placed at his wheelchair's footrest (which also allowed more effective responding) over the microswitch placed at his wheelchair's armrest, and (c) maintained his positive performance at the 1- and 2-mo. postintervention checks. The results were discussed from a technical and practical standpoint and in terms of implications for the quality of life of persons with disabilities.

Enabling Two Adolescents with Multiple Disabilities to Choose among Environmental Stimuli through Different Procedural and Technological Approaches

Two single-case studies were carried out using different procedural and technological approaches to enable two adolescents with multiple disabilities to choose among environmental stimuli. Study I focused on replicating a recently developed procedure, which relied on samples of the auditory stimuli available as cues for choice responses. Study II assessed a new procedural and technical setup relying on the use of pictorial representations of the stimuli available as cues for choice responses. The auditory samples and the pictorial representations were presented through computer systems. The participants' choice responses relied on microswitches connected to the computer systems. The data of Study I fully supported previous findings with the same procedural approach. The participant learned to choose preferred stimuli and bypass nonpreferred ones. The data of Study II showed that the participant learned to concentrate his choice responses on a few stimuli, suggesting that these stimuli were actually preferred and that responding was purposeful. Implications of the results were discussed.

Bioactives and nutraceutical phytochemicals naturally occurring in virgin olive oil. The case study of the Nocellara del Belice Italian olive cultivar

This work reports on the composition and bionutritional value of organic virgin olive oil from the Nocellara del Belice variety, one cultivated in the olive areas of the Sicily region, Italy. Destoned oils obtained by processing olives with a destoning-based procedure were compared with conventional oils. This innovative technique, consisting in removing the stone from fruits prior to processing, strongly enhanced the already high-quality level of the conventional product. An in-depth analytical investigation from 2008 to 2010 showed how this innovative olive extraction process led to an excellent peculiar final product, mainly attributable to the improved biophenol and volatile composition, as well as higher concentrations of the lipophilic and vitamin antioxidants (tocopherols and tocotrienols). It had higher levels of oleocanthal (p-HPEA-EDA), a nutraceutical compound exerting actions against COX1 and COX2 (cycloxygenases). Its head-space aroma displayed new volatile phytomolecules and also had higher levels of green volatiles from the lipoxygenase (LOX)-pathway (one having as precursors the polyunsaturated fatty acids containing a cis-cis-1,4-pentadiene system). Among the other bioactives, we highlight its significant levels of trans-β-carotene and xanthophylls (lutein, violaxanthin, neoxanthin and other carotenoids). Its enhanced nutritional value was also attributable to the increased intensity of valuable tasting notes.

CLA-1/SR-BI is expressed in atherosclerotic lesion macrophages and regulated by activators of peroxisome proliferator-activated receptors

BACKGROUND

The scavenger receptors are cell-surface receptors for native and modified lipoproteins that play a critical role in the accumulation of lipids by macrophages. CLA-1/SR-BI binds HDL with high affinity and is involved in the cholesterol reverse-transport pathway. Peroxisome proliferator-activated receptors (PPARs) are transcription factors regulating the expression of genes implicated in lipid metabolism, cellular differentiation, and inflammation. Here, we investigated the expression of CLA-1/SR-BI in macrophages and its regulation by PPARs.

METHODS AND RESULTS

CLA-1 is undetectable in human monocytes and is induced upon differentiation into macrophages. Immunohistological analysis on human atherosclerotic lesions showed high expression of CLA-1 in macrophages of the lipid core colocalizing with PPARalpha and PPARgamma staining. Activation of PPARalpha and PPARgamma resulted in the induction of CLA-1 protein expression in monocytes and in differentiated macrophages. Finally, SR-BI expression is increased in atherosclerotic lesions of apoE-null mice treated with either PPARgamma or PPARalpha ligands.

CONCLUSIONS

Our data demonstrate that CLA-1/SR-BI is expressed in atherosclerotic lesion macrophages and induced by PPAR activation, identifying a potential role for PPARs in cholesterol homeostasis in atherosclerotic lesion macrophages.

Overexpression of human apolipoprotein A-II in mice induces hypertriglyceridemia due to defective very low density lipoprotein hydrolysis

Two lines of transgenic mice, hAIItg-delta and hAIItg-lambda, expressing human apolipoprotein (apo)A-II at 2 and 4 times the normal concentration, respectively, displayed on standard chow postprandial chylomicronemia, large quantities of very low density lipoprotein (VLDL) and low density lipoprotein (LDL) but greatly reduced high density lipoprotein (HDL). Hypertriglyceridemia may result from increased VLDL production, decreased VLDL catabolism, or both. Post-Triton VLDL production was comparable in transgenic and control mice. Postheparin lipoprotein lipase (LPL) and hepatic lipase activities decreased at most by 30% in transgenic mice, whereas adipose tissue and muscle LPL activities were unaffected, indicating normal LPL synthesis. However, VLDL-triglyceride hydrolysis by exogenous LPL was considerably slower in transgenic compared with control mice, with the apparent Vmax of the reaction decreasing proportionately to human apoA-II expression. Human apoA-II was present in appreciable amounts in the VLDL of transgenic mice, which also carried apoC-II. The addition of purified apoA-II in postheparin plasma from control mice induced a dose-dependent decrease in LPL and hepatic lipase activities. In conclusion, overexpression of human apoA-II in transgenic mice induced the proatherogenic lipoprotein profile of low plasma HDL and postprandial hypertriglyceridemia because of decreased VLDL catabolism by LPL.

Activation of proliferator-activated receptors alpha and gamma induces apoptosis of human monocyte-derived macrophages

Peroxisome proliferator-activated receptors (PPARs) have been implicated in metabolic diseases, such as obesity, diabetes, and atherosclerosis, due to their activity in liver and adipose tissue on genes involved in lipid and glucose homeostasis. Here, we show that the PPARalpha and PPARgamma forms are expressed in differentiated human monocyte-derived macrophages, which participate in inflammation control and atherosclerotic plaque formation. Whereas PPARalpha is already present in undifferentiated monocytes, PPARgamma expression is induced upon differentiation into macrophages. Immunocytochemistry analysis demonstrates that PPARalpha resides constitutively in the cytoplasm, whereas PPARgamma is predominantly nuclear localized. Transient transfection experiments indicate that PPARalpha and PPARgamma are transcriptionally active after ligand stimulation. Ligand activation of PPARgamma, but not of PPARalpha, results in apoptosis induction of unactivated differentiated macrophages as measured by the TUNEL assay and the appearance of the active proteolytic subunits of the cell death protease caspase-3. However, both PPARalpha and PPARgamma ligands induce apoptosis of macrophages activated with tumor necrosis factor alpha/interferon gamma. Finally, PPARgamma inhibits the transcriptional activity of the NFkappaB p65/RelA subunit, suggesting that PPAR activators induce macrophage apoptosis by negatively interfering with the anti-apoptotic NFkappaB signaling pathway. These data demonstrate a novel function of PPAR in human macrophages with likely consequences in inflammation and atherosclerosis.

Inhibition of LPL expression in human monocyte-derived macrophages is dependent on LDL oxidation state: a key role for lysophosphatidylcholine

The regulation of macrophage lipoprotein lipase (LPL) secretion and mRNA expression by atherogenic lipoproteins is of critical relevance to foam cell formation. LPL is present in arterial lesions and constitutes a bridging ligand between lipoproteins, proteoglycans, and cell receptors, thus favoring macrophage lipoprotein uptake and lipid accumulation. We investigated the effects of native and of oxidized lipoproteins on the expression of LPL in an in vitro human monocyte-macrophage system. Exposure of mature macrophages (day 12) to highly copper-oxidized human low density lipoprotein (LDL) (100 microg protein per milliliter) led to marked reduction in the expression of LPL activity (-62%, P<0.01) and mRNA level (-47%, P<0.05); native LDL, acetylated LDL, and LDL oxidized for <6 hours were without effect. The reduction in LPL activity became significant at a threshold of 6 hours of LDL oxidation (-31%, P<0.05). Among the biologically active sterols formed during LDL oxidation, only 7beta-hydroxycholesterol (5 microg/mL) induced a minor reduction in macrophage LPL activity, whereas 25-hydroxycholesterol was without effect. By contrast, lysophosphatidylcholine, whose LDL content increased in parallel with the degree of oxidation, induced significant reductions in LPL activity and mRNA levels at concentrations of 2 to 20 micromol/L (-34% to -53%, P<0.01). Our results demonstrate that highly oxidized LDL (>6-hour oxidation) exerts negative feedback on LPL secretion in human monocytes-macrophages via a reduction in mRNA levels. By contrast, native LDL and mildly oxidized LDL (<6-hour oxidation) did not exert a feedback effect on LPL expression. We speculate that the content of lysophosphatidylcholine and, to a lesser degree, of 7beta-hydroxycholesterol in oxidized LDLs is responsible for the downregulation of LPL activity and mRNA abundance in human monocyte-derived macrophages and may therefore modulate LPL-mediated pathways of lipoprotein uptake during conversion of macrophages to foam cells.

Expression of the PAF receptor in human monocyte-derived macrophages is downregulated by oxidized LDL: relevance to the inflammatory phase of atherogenesis

Human monocyte-derived macrophages play a major role in the initiation and progression of atherosclerotic lesions as a result of the production of a wide spectrum of proinflammatory and prothrombotic factors. Among such factors is a potent inflammatory phospholipid, platelet-activating factor (PAF), which is produced after macrophage activation. Because the cells involved in PAF biosynthesis are typically targets for the bioactions of PAF via specific cell surface receptors, we evaluated the expression of the PAF receptor in human monocyte-derived macrophages. Oxidized LDL (oxLDL) exerts multiple cellular effects that enhance lesion progression; we therefore investigated the potential modulation of expression of the macrophage PAF receptor by oxLDL. [3H]PAF bound to adherent human macrophages with a K(d) of 2.1 nmol/L and a B(max) of 19 fmol/10(6) cells; approximately 5300 binding sites per cell were detected. OxLDL (100 microg protein per milliliter) induced a twofold decrease in cellular PAF binding after 3 hours at 37 degrees C. Analysis of macrophage mRNA by reverse transcription-polymerase chain reaction (RT-PCR) revealed two forms corresponding to the PAF receptor, of which the leukocyte type (type 1 promoter) predominated. Expression of PAF receptor mRNA, evaluated by quantitative RT-PCR using an actin or a GAPDH mimic, was progressively reduced (up to 70%) by oxLDL up to 6 hours and remained low for at least 24 hours. Such downregulation was reversible after incubation of the cells for 24 hours in oxLDL-free medium. Addition of forskolin (3 micromol/L) or dibutyryl cAMP (1 mmol/L) to macrophage cultures reproduced the oxLDL-mediated inhibition of PAF receptor expression; carbamyl PAF reduced PAF binding and PAF mRNA to a similar degree (approximately 50%). These data demonstrate that atherogenic oxLDL downregulates the expression of both cellular PAF receptors and PAF receptor mRNA in macrophages, consistent with both a diminished bioresponse to PAF and decreased cell motility. Such diminished bioresponse to a powerful antacoid reflects the suppression of an acute inflammatory reaction, thereby leading to chronic, low-level inflammation, such as that characteristic of fatty streaks and more advanced atherosclerotic plaques.

Role of active changes in venous capacity by the carotid baroreflex: analysis with a mathematical model

To elucidate the role of venous capacity active changes in short-term cardiovascular homeostasis, a mathematical model of the carotid-sinus baroreflex system has been developed. In the model the cardiovascular system is represented as the series arrangement of six lumped compartments, which synthesize the fundamental hemodynamic properties of the systemic arterial, systemic venous, pulmonary arterial, and pulmonary venous circulations as well as of the left and right cardiac volumes. Cardiac outputs from the left and right ventricles are computed as a function of both downstream arterial pressure (afterload) and upstream atrial pressure (preload). Four distinct feedback regulatory mechanisms, working on systemic arterial resistance, heart rate, systemic venous unstressed volume, and systemic venous compliance, are assumed to operate on the cardiovascular system in response to carotid sinus pressure changes. All model parameters, both in the cardiovascular system and in feedback regulatory mechanisms, have been assigned on the basis of physiological data now available. The model is used here to simulate the pattern of the main hemodynamic quantities in the short time period (1-2 min) after acute carotid sinus activation in vagotomized subjects. Simulation results indicate that the model can reproduce experimental data quite well, with reference both to open-loop experiments and to an acute blood hemorrhage performed in closed-loop conditions. Moreover, computer simulations indicate that active changes in venous unstressed volume are of primary importance in regulating cardiac output and systemic arterial pressure during activation of the carotid sinus baroreflex.

Immunoglobulin-bound lipoproteins (Ig-Lp) as markers of familial hypercholesterolemia, xanthomatosis and atherosclerosis

In autoimmune hyper- or dislipidemia secondary to a monoclonal antilipoprotein gammapathy, immunoglobulin-lipoprotein (Ig-Lp) complexes are found in the circulating blood. In order to determine their possible significance in common types of hyperlipidemia we compared the Ig-Lp content of sera from 98 healthy blood donors and 155 outpatients from a Lipid Clinic, including 91 cases of hypercholesterolemia (55 familial and 36 non-familial), 15 cases of hypertriglyceridemia, 20 cases of mixed hyperlipidemia and 29 miscellaneous cases. Detection of the Ig-Lp was performed by an ELISA technique with polyclonal affinity purified anti-LDL + HDL as capture antibodies and peroxidase-labeled anti-Ig antibodies specific for IgA, IgG, IgM heavy chains as indicators. Two cases of monoclonal gammapathy (one IgA K and one IgG L) with dislipidemia served as positive controls for the test. IgG, IgA and IgM Lp were found in the sera of the blood donors, in very small quantities when compared with the monoclonal gammapathy cases. All three types of Ig-Lp were also found in the different hyperlipidemic populations studied. When blood donors were compared to hyperlipidemic patients, no difference was observed for IgG Lp. A significant increase in IgM Lp was found in patients with familial hypercholesterolemia (P less than 0.01). An increase in IgA Lp was also found in hypercholesterolemia, familial or not (P less than 0.01), and in patients with corneal arcus (P less than 0.0001), ischaemic disease (P less than 0.01), tendon xanthomas (P less than 0.05) or xanthelasma (P less than 0.05). Furthermore, in a group of 18 paired parents from 9 different families, positive interparent correlations were found for IgM Lp (r = 0.78; P = 0.013) and IgG Lp (r = 0.69; P = 0.038). Therefore IgM Lp may be markers for subpopulations of familial hypercholesterolemia, and IgA Lp markers for the risk of atherosclerotic ischemic disease and deposition of lipids in the cornea. It may be (1) that natural clones of autoanti-lipoprotein antibodies are responsible for the minute quantities of Ig-Lp found in normal people; (2) that the marked development of one of these clones is the cause of autoimmune hyper- or dyslipidemia and xanthomatosis associated with monoclonal gammapathy; (3) that the limited development of a clone produces the Ig-Lp particles found in hypercholesterolemic patients; (4) that there are types of Ig-Lp particles (IgA Lp) that may be harmful for tissues independently of hypercholesterolemia.

Cytotoxic effect of serum on fibroblasts in one case of normolipidemic plane xanthoma and myeloma IgG lambda

Serum was examined for a cytotoxic effect on cultured human fibroblasts, using 8 normal controls and 4 patients. Three of the patients had secondary lipidoses associated with monoclonal gammapathies of IgA kappa, IgG kappa and IgG lambda types. The fourth had systemic lupus erythematosus (SLE) with hyperlipidemia. Only serum containing the monoclonal IgG lambda was found to be cytotoxic. This circulating IgG lambda was strongly bound to HDL and behaved like an antilipoprotein antibody. The circulating immune complexes may be the serum factor responsible for the cytotoxicity and the cutaneous plane xanthomas, thus giving another example of 'antibody-dependent' cellular cytotoxicity previously described for endothelial cells in other diseases.

[Biological activity of 4-hydroxy-5-formylbenzoic acid derivatives. II. Esters and Schiff bases with antimicrobial activity]

A number of hitherto undescribed 4-hydroxy-5-formylbenzoic acid derivatives (A), have been prepared and characterized. (formula; see text) Esters (X = CH3) and Schiff's bases (Z = N-aryl) were prepared by conventional methods and were obtained in satisfactory yield and in a good state of purity. The prepared compounds have been tested for "in vitro" activity against Gram+ bacteria (S.epidermidis, B.subtilis, B.anthracis, M.paratuberculosis), Gram- bacteria (P.aeruginosa, S.typhi murium, E.coli Bb, S.typhi O, S.typhi infantis, S.paratyphi A, S.paratyphi B) and fungi (C.albicans, A.niger, S.cerevisiae) by agar-diffusion method (Kirby-Bauer modified). The prepared compounds, generally, showed inhibitory activity against Gram+ bacteria. Esters (A: X = CH3) showed antibacteric and antimycotic activity. The greatest activity was observed in the methyl ester (XV) of 4-hydroxy-5-formylbenzoic acid (I).

Biological activity of 4-hydroxy-5-formylbenzoic acid derivatives

A group of thirty 4-hydroxy-5-formylbenzoic acid derivatives of general formula: (formula; see text) where (formula; see text) have been prepared and characterized in an attempt to make available for testing a representative selection of hitherto undescribed hydroxyformylbenzoic acid derivatives. The products, which are listed in Table I, with pertinent data, have been obtained in satisfactory yield and in a good state of purity. The prepared compounds have been tested for "in vitro" activity against three fungi (A. niger, C. albicans, S. cerevisiae), six Gram- bacteria (E. coli Bb, S. typhi, S. infantis, S. paratyphi A, B. melitensis, P. mirabilis) and four Gram+ bacteria (M. paratuberculosis ATCC 607; S. epidermidis, B. subtilis, B. anthracis), by the agar diffusion method (Kirby-Bauer modified). In general, the results of the tests indicated that most of the compounds: a) didn't exhibit antifungal activity "in vitro"; b) had little activity on Gram- bacteria; showed inhibitory activity toward Gram+ species, in particular toward M. paratuberculosis. Other activities of pharmaceutical interest will be tested; the screening program includes tests for cardiac activity. The results of these studies will be published as soon as they are complete.

[Hypertriglyceridemia and tumors. Production of stable cultures of Green's lymphoma]

In Golden Hamster the Greene malignant lymphoma is a subcutaneous and homotransplantable tumor whose development is associated with a constant hypertriglyceridemia and a large-decreased plasma post-heparin lipase activity. The tumoral cell line is well maintained on a human fibroblast monolayer culture and is demonstrated to secrete two IgG immunoglobulins.

Chemical analysis of cryoglobulins observed in a case of essential IgG-IgA cryoglobulinaemia

In a case of essential mixed (IgG-IgA) cryoglobulinaemia the carbohydrate and aminoacid composition of cryoglobulins was chemically analyzed. A normal aminoacid and sialic acid composition was observed, whereas the glucide percentage was augmented with respect to the normal range for the two classes of Ig.

Inhibition of lipoprotein lipase activity by a monoclonal immunoglobulin in autoimmune hyperlipidemia

Autoimmune hyperlipidemia (AIH) may be induced a variety of antibodies which inhibit different stages of the lipolytic process by which the lipid load is removed from the circulating lipoproteins. In a patient having a monoclonal gammopathy and a nephrotic syndrome with a glomerulonephritis and a marked hypertriglyceridemia, it was found previously that the monoclonal IgG gamma Lac. reacted with human VLDL as well as with human serum albumin. Here it is demonstrated that the purified IgG gamma inhibits the lipolysis of triglyceride substrates by reacting with a substance (Lac. S) necessary for lipoprotein lipase activity. The interaction of IgG lambda Lac. with serum or HDL-activated triglyceride substrates inhibits the lipolytic activity of human and rat plasma post heparin and also adipose tissue lipases. It slightly inhibits the activity of swine pancreatic lipases. The Lac S. which reacts with IgG Lac. is associated to whole and delipidated VLDL and HDL and not to LDL or purified APo-A. It may be an Apo-C or a non-peptidic co-factor of the lipases which remains bound to the apoprotein core after delipidation. Its lack of species specificity and its presence as traces in HSA preparations favors the latter hypothesis. The Lac. substances is different from the Pg and As substances which were found to react with IgA anti-Pg and IgG anti-As antibodies in previously reported antilipoprotein AIH.

[Association of monoclonal gammopathy with chronic glomerulonephritis and autoimmune hyperlipemia. Course of disease during therapy]

A case of benign monoclonal gammapathy associated with an auto-immune hyperlipidaemia and a chronic glomerulopathy is reported. Extraction of the monoclonal immunoglobulin made it possible to demonstrate its anti-lipoprotein antibody activity. Parallel changes in serum lipid levels and monoclonal immunoglobulin levels under the influence of melphalan confirmed the direction relationship between the lipid and protein disorders. The pathogenesis of the glomerulopathy and of the massive and prolonged activation of the classical complement pathway is more difficult to affirm. It is nevertheless possible that the renal involvement is due to an auto-immune complex disease.

Nephrotic syndrome, monoclonal gammopathy and auto-immune hyperlipidaemia

Hyperlipidaemia, glomerulonephritis and IgG λ monoclonal gammopathy were found to be associated in two patients (Ler. and Lac.). A severe atherosclerosis was also present in the former patient. After a purification–activation procedure active IgG λ was obtained from the serum chylomicra and from the ammonium sulphate-precipitated serum gamma-globulins. In passive haemagglutination tests, including inhibition tests, the IgG λ Ler. reacted specifically with the protein moiety of human low density lipoproteins (LDL) and the IgG λ Lac. reacted with human, rat and rabbit very low density lipoproteins (VLDL) as well as with human serum albumin (HSA). These IgG λ behaved like autoantibodies though no activity was found in whole serum, in which they are probably blocked by the corresponding antigens. They are very similar, although not identical, to the autoantibodies found in auto-immune hyperlipidaemia (AIH) and it is proposed that in these patients the hyperlipidaemia is a variety of AIH. Finally it is suggested that the hyperlipidaemia associated with glomerulonephritis chiefly in the nephrotic syndrome may sometimes be AIH. If this is the case the renal lesions and the hyperlipidaemia may be different expressions of an immune complex disease which may also lead to other tissue lesions such as atherosclerosis.