The impact of rifaximin on the hospital burden and infections in patients with hepatic encephalopathy: a retrospective observational study.

Background and study aims: Advanced liver disease frequently culminates in hepatic encephalopathy (HE), which can be classified as covert or overt HE, with subtle or clinically obvious changes respectively. 30-40% of patients with cirrhosis develop overt HE, which negatively affects the patients' quality of life. Next to lactulose, rifaximin-α has been prescribed as a second line therapy to treat and reduce the risk of recurrence of overt HE. In this study, we aimed to evaluate the effect of rifaximin-α therapy, both on the number of occurring infections and on the evolution in hospital admissions of patients with overt HE. Patients and methods: A total of 66 cirrhotic patients, treated for at least 6 months with rifaximin-α at AZ Maria Middelares, between October 1st 2014 and January 1st 2020, were included in the study analysis. Medical records of all patients were evaluated over a period of 6 months prior and after initiation of rifaximin-α therapy. Results: Data analysis revealed that the included cirrhotic patients were severely ill, with a mean model for end-stage liver disease (MELD) score of 21, and a median Child Pugh score of 11. Among these patients, rifaximin-α treatment significantly downgraded the total number of infections, with a main effect on respiratory infections. Furthermore, rifaximin-α therapy led to a significant decrease in HE-related, as well as in other liver-related hospital admissions. Conclusions: This study confirms the potential value of rifaximin-aα in reducing the number of developing infections and hospital admissions in a severely ill cirrhotic patient population.

Scapular positioning in overhead athletes with and without shoulder pain: a case-control study.

Abnormalities of scapular positioning are considered important risk factors for developing shoulder disorders. This study analyses the scapular positioning pattern in a group of overhead athletes with and without shoulder pain. In a multi-center blinded case-control study, 36 shoulder pain athletes (19 men, 17 women), were compared with 36 unimpaired athletes free of shoulder pain, matched for gender, age, hand dominance and body mass index. The blinded assessor performed visual observation, the measurement of the distance between the acromion and the table, inclinometry and the kinetic medial rotation test for dynamic scapular control in random order. Athletes with shoulder pain demonstrate scapular asymmetry in the sagittal plane, observed visually as anterior tilting on the painful side. Athletes with shoulder pain show a lack of scapular motor control on their painful side in contrast to their pain-free side. No scapular positioning or motor control differences were found in athletes with or without shoulder pain.

Metabolism pathway of vinorelbine (Navelbine) in human: characterisation of the metabolites by HPLC-MS/MS.

The biotransformation of vinorelbine (VRL), an anti-neoplastic vinca-alkaloid derivate already marketed for nonsmall cell lung cancer and advanced breast cancer as an i.v. form and currently registered in several countries as an oral form, was investigated in human. Biological specimen from several human sources constituted the material for the metabolic identification in human. An isocratic liquid chromatographic system composed of 40 mM ammonium acetate (pH 3) and acetonitrile was used for separation of the potential metabolites of VRL. Tandem mass spectrometry with positive electrospray ionisation was used to enable the structural identification of the metabolites. A total of 17 metabolites (12 directly obtained from VRL and 5 involving sequential step pathways) were characterised with proposed structures for most of the metabolites. All metabolites went through phase I reactions by the way of deacetylation, dealkylation, oxidation and hydroxylation. No conjugates were observed. Despite the high number of metabolites quantified, VRL was the major compound observed whatever the matrix. Most of the metabolites rapidly disappeared from blood, except 4-O-deacetyl vinorelbine which was slowly cleared. Most of the enzymatic pathways involved in the metabolites strongly suggested the major role of cytochrome P450 in the biotransformation of vinorelbine.

Development of a sensitive liquid chromatography method coupled with a tandem mass spectrometric detection for the clinical analysis of vinflunine and 4-O-deacetyl vinflunine in blood, urine and faeces.

A sensitive and specific liquid chromatographic method coupled with tandem mass spectrometric detection was set up and fully validated for the simultaneous quantification of vinflunine (VFL) and its pharmacologically active metabolite, 4-O-deacetyl vinflunine (DVFL). The two compounds, as well as vinblastine (used as internal standard), were deproteinised from blood and faeces, analysed on a cyano type column and detected on a Micromass Quattro II system in the positive ion mode after ionisation using an electrospray ion source. In blood, linearity was assessed up to 200 ng/ml for vinflunine and 100 ng/ml for 4-O-deacetyl vinflunine. The lower limit of quantification was validated at 250 pg/ml for both compounds. In other biological media, the linearity was assessed within the same range; the limit of quantification was adjusted according to the expected concentration levels of each compound. This method was first developed in order to identify the structures and to elucidate the metabolic pathway of vinflunine. Thanks to its high sensitivity and specificity, the method has enabled the quantification of vinflunine and 4-O-deacetyl vinflunine in blood at trace levels, and has contributed to the knowledge of vinflunine metabolism by monitoring up to 10 metabolites.

Is cutaneous apoprotein B a better discriminator than serum lipoproteins for atherosclerosis?

Serum lipids, skin apoprotein B (apo B) and skin cholesterol measurements have been investigated in 2 populations: one with normal coronarography, the other with pathological coronarography. Within these 2 populations there were highly significant differences in serum apo B (P less than 0.001), skin cholesterol (P less than 0.01) and skin apo B (P less than 0.001) levels. Skin apo B is a valuable test because its increase is closely related to the coronary heart disease. From these 2 populations, 2 groups with normal serum apo B (less than 1.3 g/l) were selected and compared. No significant differences in the various serum lipids were observed except for triglycerides (P less than 0.05) and serum apo B (P less than 0.05). However, a very significant difference was noticed in the skin apo B (P less than 0.001). With this cutaneous apo B determination it was possible to foresee coronary heart disease in 75% of patients. This test can be therefore considered useful to predict coronary status.

Laboratory medicine in France. A jeopardized situation.

The expenses for health care in France have risen considerably during the present decade, ranking third after USA and Canada in the Western world. In spite of the very low cost of laboratory medicine (2.4% of the total expenditure in 1995), clinical laboratories have undergone a severe squeeze, due to two limiting factors; a decrease in the ordering of laboratory tests from private physicians and a reduction in the total expenses for laboratory services from the Social Security. Consequently, there has been unemployment of technical and secretarial staff and severe restriction in investment for buying new equipment. However, hospital laboratories will manage to assume their challenge in developing robotics, automation, molecular pathology techniques and expert systems. Private laboratories, in spite of their efforts to follow the technological advances in automation, will survive thanks to consolidation of regional networks that operate in a cooperative rather than competitive mode. Therefore, the challenge will be not in the adaptation of clinical laboratories, but in the limitation of overspending at the national level and in modification of the behaviour of irresponsible citizens accustomed to spending freely on health care services.

Automated technical validation--a real time expert system for decision support.

Dealing daily with various machines and various control specimens provides a lot of data that cannot be processed manually. In order to help decision-making we wrote specific software coping with the traditional QC, with patient data (mean of normals, delta check) and with criteria related to the analytical equipment (flags and alarms). Four machines (3 Ektachem 700 and 1 Hitachi 911) analysing 25 common chemical tests are controlled. Every day, three different control specimens and one more once a week (regional survey) are run on the various pieces of equipment. The data are collected on a 486 microcomputer connected to the central computer. For every parameter the standard deviation is compared with the published acceptable limits and the Westgard's rules are computed. The mean of normals is continuously monitored. The final decision induces either an alarm sound and the print-out of the cause of rejection or, if no alarms happen, the daily print-out of recorded data, with or without the Levey Jennings graphs.

New sensitive liquid chromatography method coupled with tandem mass spectrometric detection for the clinical analysis of vinorelbine and its metabolites in blood, plasma, urine and faeces.

A new sensitive and specific liquid chromatographic method coupled with tandem mass spectrometric detection was set up and validated for the simultaneous quantitation of vinorelbine, its main metabolite, 4-O-deacetylvinorelbine and two other minor metabolites, 20'-hydroxyvinorelbine and vinorelbine 6'-oxide. All these compounds, including vinblastine (used as internal standard) were deproteinised from blood, plasma and faeces (only diluted in urine), analysed on a cyano column and detected on a Micromass Quattro II system in the positive ion mode after ionisation, using an electrospray ion source. Under tandem mass spectrometry conditions, the specific product ions led one to accurately quantify vinorelbine and its metabolites in all biological fluids. In whole blood, linearity was assessed up to 200 ng/ml for vinorelbine and up to 50 ng/ml for the metabolites. The limit of quantitation was validated at 250 pg/ml for both vinorelbine and 4-O-deacetylvinorelbine. In the other biological media, the linearity was assessed within a same range and the limit of quantitation was adjusted according to the expected concentrations of each compound. This method was initially developed in order to identify the metabolite structures and to elucidate the metabolic pathway of vinorelbine. Thanks to its high sensitivity, this method has enabled the quantitation of vinorelbine and all its metabolites in whole blood over 168 h (i.e., 4-5 elimination half lives) whilst the previous liquid chromatographic methods allowed their measurement for a maximum of 48-72 h. Therefore, using this method has improved the reliability of the pharmacokinetic data analysis of vinorelbine.

Separation, identification and quantitation of ceramides in human cancer cells by liquid chromatography-electrospray ionization tandem mass spectrometry.

Ceramides are important intracellular second messengers that play a role in the regulation of cell growth, differentiation and programmed cell death. Qualitative and quantitative analysis of these second messengers requires sensitive and specific analytical methods to detect endogenous levels of individual ceramide species and to differentiate between them. Nine synthetic ceramides were separated by liquid chromatography coupled to tandem mass spectrometry on a C18 bonded silica column. The lipids were eluted in gradient elution mode using a mixture of water, acetonitrile and 2-propanol as mobile phase. They were detected by reaction monitoring performed on positive ion electrospray generated ions. Collision-induced fragmentations conducted on ceramides produced a well characteristic product ion at m/z 264, making multiple reaction monitoring (MRM) well suited for various ceramides quantitative measurements. After optimization of the extraction step, the proposed methodology was able to identify and quantify different ceramide species issued from human cancer cells. The method could be validated for C16, C18 and C20 ceramides, quantified at the nanogram level. The validation exhibits good results with respect to linearity, accuracy and precision.

Fully automated method for the liquid chromatographic-tandem mass spectrometric determination of cyproterone acetate in human plasma using restricted access material for on-line sample clean-up.

A new automated method for the quantitative analysis of cyproterone acetate (CPA) in human plasma has been developed using on-line solid phase extraction (SPE) prior to the LC-MS/MS determination. The method was based on the use of a pre-column packed with internal-surface reversed-phase material (LiChrospher RP-4 ADS, 25 mm x 2 mm) for sample clean-up coupled to LC separation on an octadecyl silica stationary phase by means of a column switching system. A 30 microl plasma sample volume was injected directly onto the pre-column using a mixture of water, acetonitrile and formic acid (90:10:0.1 (v/v/v)) adjusted to pH 4.0 with diluted ammonia as washing liquid. The analyte was then eluted in the back-flush mode with the LC mobile phase consisting of water, methanol and formic acid (10:90:0.1 (v/v/v)). The dispensing flow rates of the washing liquid and the LC mobile phase were 300 microl min(-1). Medroxyprogesterone acetate (MPA) was used as internal standard. The MS ionization of the analytes was achieved using electrospray (ESI) in the positive ion mode. The pseudomolecular ionic species of CPA and MPA (417.4 and 387.5) were selected to generate daughter ions at 357.4 and 327.5, respectively. Finally, the developed method was validated according to a new approach using accuracy profiles as a decision tool. Very good results with respect to accuracy, detectability, repeatability, intermediate precision and selectivity were obtained. The LOQ of cyproterone acetate was 300 pg ml(-1).

Synthesis of 16 alpha-3H androgen and estrogen substrates for 16 alpha-hydroxylase.

The synthesis of 16 alpha-3H androgens and estrogens is described. 1-(3H)-Acetic acid in the presence of zinc dust reacts with 16 alpha-bromo-17-ketosteroids to produce 16 alpha-3H-17-ketosteroids. This chemical reaction was used to prepare 16 alpha-3H-dehydroepiandrosterone (I) and 16 alpha-3H-estrone acetate (XI) from 16 alpha-bromo-dehydroepiandrosterone (X) and from 16 alpha-bromo-estrone acetate (XII), respectively. Using appropriate microbiological techniques, it was possible to convert these radiolabelled substrates into 16 alpha-3H-androstenedione (II) and 16 alpha-3H-estradiol-17 beta (VII). 16 alpha-3H-Estrone (VI) was obtained by the chemical hydrolysis of 16 alpha-3H-estrone acetate. The label distribution as determined by microbiological 16 alpha-hydroxylations indicated a specific labelling of 77% for androgens and 65% for estrogens in the 16 alpha position. These substrates can be used for measuring the 16 alpha hydroxylase activity, an important step in the biosynthesis of estriol (VIII) and estetrol (IX).

Skin cholesterol and skin apoprotein B in atherosclerosis.

In order to quantify the accumulation of apoprotein B in skin we determined the amount of apo B in the skin of atherosclerotic patients using a modified Hoff's method with extraction and electroimmunoassay. Skin biopsies were taken from the lower limbs of nineteen male patients with arteriosclerosis obliterans during revascularization and from the thoracic region of thirty male patients with ischemic heart disease during coronary bypass graft surgery and thirty one male patients with abnormalities of cardiac valves during valvuloplasty. A significant positive correlation between skin apo B and skin cholesterol was found in three groups. Our data support the hypothesis that cholesterol deposit in the skin of patients with atherosclerosis is derived from plasma lipoprotein B and that the content of skin lipids parallels with the development of atherosclerosis in man.

A data management program for the Electra 800 automatic analyser.

The Electra 800 automatic coagulation analyser rapidly performs most chronometric coagulation tests with high precision. To facilitate data handling, software, adaptable to any PC running under MS-DOS, was written to manage the analyser. Data are automatically collected via the RS232 interface or can be manually input. The software can handle 64 different analyses, all entirely 'user defined'. An 'electronic worksheet' presents the results in pages of ten patients. This enables the operator to assess the data and to perform verifications or complementary tests if necessary. All results outside a predetermined range can be flagged and results can be deleted, modified or added. A patient's previous files can be recalled as the data are archived at the end of the day. A 120 Mb disk can store approximately 130,000 patient files. A daily archive function can print the day's work in alphabetical order. A communication protocol allows connection to a mainframe computer. This program and the user's manual are available on request, free of charge, from the authors.

Nitazoxanide: pharmacokinetics and metabolism in man.

OBJECTIVES: Nitazoxanide (N), a new broad-spectrum parasiticidal agent, is rapidly deacetylated to tizoxanide (T). The objective of the study was to determine if metabolites other than T are present in the plasma and excreted after single dose oral administration of radiocarbon-labelled N in healthy subjects. METHODS: Six healthy volunteers received a single 500 mg oral dose of N labelled with 2.92 MBq radiocarbon. The radioactivity in blood, plasma, urine, feces and expired air was monitored at scheduled intervals for up to 10 days. Selected samples were assayed by HPLC for T and submitted to metabolite identification by mass spectrometry. In vitro experiments were also conducted (incubation with animal and human microsomes, deacetylation kinetics). Plasma and bile samples obtained in a patient treated with N for sporozoal infection were also assayed for T. RESULTS: Elimination of radiocarbon occurred both in the urine (31.5% of the dose on average) and in the feces (66.2% on average). T and T-glucuronide contributed 15% of total urine radioactivity. N was found to deacetylate extremely rapidly to T in plasma (half-life of about 6 minutes at 37 degrees C) as well as in presence of liver microsomes. T was the only species obtained by incubation with human microsomes while rat microsomes yielded hydroxylated T in addition. The main species identified in human plasma, urine and bile was T-glucuronide, the identification of which was confirmed by comparison with an authentic sample. No species other than T was detected in feces, indicating intensive intestinal deconjugation, while radioactivity and absorbance detectors showed largely unresolved clusters.

An atypical aortic atherosclerotic lesion in cynomolgus monkeys during hypercholesterolemia: a protection by smooth muscle cells against advanced lesions?

This study focuses on the fortuitous discovery of an atypical atherosclerotic lesion in four of 49 male adult cynomolgus monkeys (macacus fascicularis) which were maintained for a long time at a high level of hypercholesterolemia, and in seven of 19 female cynomolgus monkeys examined from the second to the 24th week of hypercholesterolemic diet: this lesion was in formation or already mature during this period of diet. This atypical lesion was formed by a collagen and elastic network surrounding synthetic smooth muscle cells without fibrofatty or fibrous plaques. Lipids were occasionally seen in the inner intima. The lesion appeared early (from the third week of diet). Once established, its morphology did not change. It became more extensive, but was not complicated by lipid overload in spite of prolonged, permanent hypercholesterolemia. This response to hypercholesterolemia is interesting because the activity of the smooth muscle cells differs from that observed in the classic lesion: they intervene earlier, their replication is very marked and rapid, their elastin secretion is greater and remains constant over time, and their phagocytic properties are reduced. This experimental study examines the installation and the maintenance of this lesion and raises the problem of its origin.

Computer program for connection and data management of an automated coagulation system: the KC 10.

In Europe, the KC 10, manufactured by Amelung Germany, is one of the instruments most commonly found in coagulation laboratories. For facilitating the work of technical validation, we wrote a software adapted to any IBM or compatible PC running under MS-DOS, to manage the analyser performance. Data are automatically collected via the BCD interface from the analyser or keyed in for the other techniques. The software deals with 64 different analyses entirely 'user defined'. An 'electronic worksheet' presents the results, by page of ten patients. This enables the laboratory technician to assess the coherence of the various data and to perform verifications or complementary tests if necessary. As an option, a blinking asterisk can signal all results outside predetermined range. By moving the cursor through the table, a test result can be deleted, modified or added. A function displays the patient's previous files in a window because the data are recorded in long-term archives at the end of the day. This long-term recording allows a search of previous files to decide additional tests if the patient is unknown. A daily archive function classifies and prints the whole day's work in alphabetical order. A protocol of communication allows connection to a mainframe Bayer-Technicon computer. This program and the user's manual are free, available on request from address above.

[Cutaneous apoprotein B and coronary atherosclerosis]. / Apoprotéine B cutanée et athérosclérose coronarienne.

Cutaneous and plasma lipids (cholesterol and Apoprotein B) were studied in 2 populations (average age 57.5 years), one with pathological and the other with normal coronary angiography. Skin biopsy was performed during the incision of thoracotomy. The concentrations of Apo B and cholesterol in the skin were compared to those of plasma lipids, lipoproteins and apoprotein B for the diagnosis of atherosclerosis. This study showed that skin Apo B was the best marker of coronary atherosclerosis in patients with plasma Apo B concentrations of less than 1.3 g/l. The skin Apo B concentration was closely correlated to the presence but not to the severity of this arterial pathology. The cardiovascular risk factors of this population, studied separately and in a cumulative manner, confirmed the results of previously published reports.

[Predictive value of plasma apolipoprotein B in myocardial infarction in young subjects. Correlations with coronarographic data]. / Valeur prédictive de l'apolipoprotéine B plasmatique dans l'infarctus du myocarde du sujet jeune. Corrélations avec les données coronarographiques.

In recent epidemiological studies, apolipoprotein-B (apo B), the main low density lipoprotein (LDL), was found to be significantly elevated in patients with early atherosclerosis. The aim of this study was to compare plasma apo B in a population of men who had suffered myocardial infarction before 45 years of age (N = 31) with a control population (N = 22). In the coronary group, there were 27 angiographies between the end of the first and third month. The plasma lipoproteins were separated by ultracentrifugation, cholesterol and triglycerides measured by enzymatic methods and apo B by Laurell's technique of immunoelectrophoresis. Our results showed significantly higher apo B in the coronary group (p less than 0.05). Serum cholesterol, triglycerides, very low density lipoprotein (VLDL) and LDL cholesterol were also significantly higher whilst high density lipoprotein (HDL) cholesterol was significantly lower. In addition, apo B levels correlated with the severity of the coronary lesions on angiography. Therefore, the plasma apo B level is a good predictive indicator of the presence of early coronary atherosclerosis and its severity.

[Cutaneous cholesterol in the young and aged coronary patient]. / Le cholestérol cutané du coronarien jeune et âgé.

Serum cholesterol (ch), its lipoprotein fractions and triglycerides were measured in three populations of proven coronary patients (less than 50 years, n = 56; between 50 and 65 years, n = 56; greater than 65 years, n = 23); the risk factor total ch/HDL ch was calculated. The level of skin cholesterol was also estimated by skin biopsy in each patient and compared to that of three control populations of the same age. The results indicated that 1) there was no significant difference in skin cholesterol of patients with myocardial infarction whatever their age, 2) there was a significant difference (p less than 0,001) with control subjects of the same age except in the over 65 population, 3) the total cholesterol was normal in all three groups, 4) the HDL cholesterol of coronary patients over 50 year old was normal and slightly reduced in younger coronary patients, 5) the ratio total ch/HDL ch was increased in coronary patients under 50, but normal after this age, 6) the triglyceride level was higher in the young coronary patients than in those over 50 years old. Four conclusions are drawn: 1) the total Ch/HDL ch ratio is a good indicator of coronary risk in patients under 50 years old but shows less sensitive variations than the level of skin cholesterol, 2) the ch/HDL ch in coronary patients between 50 and 65 years old is normal; the only laboratory finding which correlates with the coronary event is skin cholesterol; after 65 years of age the skin cholesterol stabilises to the same levels as found in control subjects; 3) from the outset, at whatever age infarction occurs, skin cholesterol is increased (about 0,45 mumol/100 ngr of fresh skin), whilst the risk factor is higher in the younger population; 4) skin cholesterol shows less variation in the three coronary groups than the other blood parameters measured. It would therefore appear to be a very discriminating index of coronary atherosclerosis.

[Quality control of analyses and automation]. / Contrôle de qualité des analyses et automation

Multichannel analysers are becoming more and more usual in biochemistry laboratories. Then, a very severe quality control program is requisite. In Toulouse a three years experiment was carried out on a computer connected twenty four channels Autochemist and an unconnected Technicon SMA 12/60. The traditional quality control from control lyophilized serums is still necessary and useful, mainly at the level of a region. The remaining valuable methods are automatic calibration and statistical controls on frequently tested samples from human polled serum and on results from patients, these being provided through various procedures.