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Biomedical subjects

J Jean

Publications and source records attributed to J Jean.

12 recordsLinked to original sources
PubMed2002

A novel polymer produced by a bacterium isolated from a deep-sea hydrothermal vent polychaete annelid.

AIMS: The objective of the present work was to describe an aerobic, mesophilic and heterotrophic marine bacterium, designated HYD657, able to produce an exopolysaccharide (EPS). It was isolated from a East Pacific Rise deep-sea hydrothermal vent polychaete annelid. METHODS AND RESULTS: This micro-organism, on the basis of the phenotypical features and genotypic investigations, can be clearly assigned to the Alteromonas macleodii species and the name A. macleodii subsp. fijiensis biovar deepsane is proposed. Optimal growth occurs between 30 and 35 degrees C, at pH between 6.5 and 7.5 and at ionic strengths between 20 and 40 g x l(-1) NaCl. The G + C content of DNA was 46.5%. This bacterium excreted, under laboratory conditions, an EPS consisting of glucose, galactose, rhamnose, fucose and mannose as neutral sugars along with glucuronic and galacturonic acids and a diacidic hexose identified as a 3-0-(1 carboxyethyl)-D-glucuronic acid. Its average molecular mass was 1.6 x 10(6) Da. CONCLUSIONS: The bacterium HYD657, for which the name A. macleodii subsp. fijiensis biovar deepsane is proposed, produces an unusual EPS in specific medium. SIGNIFICANCE AND IMPACT OF THE STUDY: Due to its interesting biological activities, applications have been found in cosmetics. Its probable contribution to the filamentous microbial mat in the Alvinella pompejana microenvironment can be also mentioned.

Alteromonas↗
PubMed2001

Caloranaerobacter azorensis gen. nov., sp. nov., an anaerobic thermophilic bacterium isolated from a deep-sea hydrothermal vent.

A thermophilic, anaerobic, chemo-organotrophic bacterium, designated MV1087T, was isolated from a deep-sea hydrothermal chimney sample collected from the Mid-Atlantic Ridge. The cells were straight, motile and stained gram-negative. Growth was observed from 45 to 65 degrees C, with an optimum around 65 degrees C. No growth was observed at 40 or 70 degrees C. Growth was observed from pH 5.5 to 9.0 and the optimum pH was around 7. The salinity range for growth was 10-100 g sea salt l(-1) (corresponding to 6.5-65 g NaCl l(-1)) with an optimum at 30 g sea salt l(-1) (20 g NaCl l(-1)). Strain MV1087T was heterotrophic, able to ferment proteinaceous substrates, such as brain/heart infusion and gluten, and carbohydrates, such as glucose, xylan and starch. The DNA G+C content was 27 mol%. Phylogenetic analyses using 16S rDNA sequences indicated that strain MV1087T belonged to cluster XII of the Clostridium subphylum. Due to its phenotypic and genotypic characteristics, isolate MV1087T is proposed as a novel species of a new genus, Caloranaerobacter azorensis gen. nov., sp. nov. The type strain is MV1087T (= CNCM I-2543T = DSM 13643T).

Bacteria, Anaerobic↗
PubMed2001

Detection of hepatitis A virus by the nucleic acid sequence-based amplification technique and comparison with reverse transcription-PCR.

A nucleic acid sequence-based amplification (NASBA) technique for the detection of hepatitis A virus (HAV) in foods was developed and compared to the traditional reverse transcription (RT)-PCR technique. Oligonucleotide primers targeting the VP1 and VP2 genes encoding the major HAV capsid proteins were used for the amplification of viral RNA in an isothermal process resulting in the accumulation of RNA amplicons. Amplicons were detected by hybridization with a digoxigenin-labeled oligonucleotide probe in a dot blot assay format. Using the NASBA, as little as 0.4 ng of target RNA/ml was detected per comparison to 4 ng/ml for RT-PCR. When crude HAV viral lysate was used, a detection limit of 2 PFU (4 x 10(2) PFU/ml) was obtained with NASBA, compared to 50 PFU (1 x 10(4) PFU/ml) obtained with RT-PCR. No interference was encountered in the amplification of HAV RNA in the presence of excess nontarget RNA or DNA. The NASBA system successfully detected HAV recovered from experimentally inoculated samples of waste water, lettuce, and blueberries. Compared to RT-PCR and other amplification techniques, the NASBA system offers several advantages in terms of sensitivity, rapidity, and simplicity. This technique should be readily adaptable for detection of other RNA viruses in both foods and clinical samples.

Blueberry Plants↗
PubMed2000

Cardiac loading conditions modify the ventricular repolarization in conscious dogs with heart failure.

Changes in myocardial loading conditions influence the ventricular action potential via mechanoelectric feedback, a mechanism impaired in pathology. In vivo the QT interval of the electrocardiogram which reflects the action potential duration allows appropriate determination of its modifications. The effects of changes in cardiac loading conditions (load reduction with trinitrin; volume loading with Plasmion) on regional function and ventricular local electrogram were investigated in conscious dogs before (control) and after 4 weeks of rapid pacing (dilated cardiomyopathy, DCM). In controls both interventions increased heart rate. Trinitrin increased end-diastolic wall thickness (EDWth, P<0.001) and reduced absolute QT interval duration (P<0.05). Plasmion decreased EDWth (P<0.001) and increased left ventricular end diastolic pressure (LVEDP, P<0.001) without QT interval alteration. However, the corrected QT interval was unchanged in both interventions. In DCM, trinitrin did not change the QT interval. Plasmion increased LVEDP (P<0.01) and prolonged QT and corrected QT intervals (P<0.01) despite the tachycardia. In controls the changes in cardiac loading conditions did not modify the QT interval, suggesting intact endogenous regulation of repolarization. The impaired adaptation observed in DCM contributed to an increase in QT interval following volume loading. In this model, a prolonged repolarization after abrupt volume loading may result from enhanced or disclosed mechanoelectric feedback.

Animals↗
PubMed1999

Production and characterization of polyclonal antibodies against cholecalciferol (vitamin D3).

Vitamin D is one of the essential vitamins in the human diet for normal growth and function. In Canada and the USA, fortified milk and milk products are the essential source of vitamin D. The adult recommended nutrient intake of vitamin D is 200 to 400 I.U. (corresponding to 5 to 10 microg) per day. Additional amounts of vitamin D do not confer benefits and may even be toxic. However, a deficiency of this vitamin leads to inadequate absorption of calcium and phosphorus and faulty mineralization of bones and teeth. Actual methods for measuring vitamin D in milk are limited in terms of sensitivity, rapidity and simplicity. The objective of this manuscript was to develop a new molecular strategy for the production, purification and characterization of polyclonal antibodies to vitamin D. Specific antibodies were raised in rabbits against vitamin D using cationized bovine serum albumin (cBSA) as a carrier protein. Anti-vitamin D antibodies were recovered from rabbit sera by sequential affinity chromatographies through Protein A/G Agarose, cBSA Sepharose and cOVA-vitamin D Sepharose columns. Although the yields of anti-vitamin D were relatively low, recovered antibodies showed high specificity and affinity to vitamin D. The purified antibody was used to develop a solid-phase enzyme immunoassay in order to determine the exact concentration of vitamin D in phosphate buffer. Using this immunoassay, approximately 35 ng of vitamin D can be detected within 3 h. The signal obtained was proportional to the amount of vitamin D in the sample analyzed. The strategy developed in this paper appears to be very promising in terms of sensitivity, rapidity and simplicity. It offers a great potential for automation and use on a routine basis for the quantification of vitamin D in fortified milk and other milk products.

Animals↗
PubMed1996

Interactive electronic teaching (ISIS): has the future started?

Medical education of hypertensives as well as of other asymptomatic cardiovascular risk patients requires individualized, interactive and attractive strategies. Electronic teaching set up in hospital or clinic settings opens the way of the future, saving time and allowing more advantageous use of caretakers. ISIS (Initiation Sanitaire Informatisee et Scenarisee), a French computer assisted program for cardiovascular risk patients, combines a scientific information, divided in 12 sequential but independent modules, with a recreative imaginary trip in the world of ancient Egypt. To test the impact of this tool on patient health information retention, 158 hypertensives hospitalized in a day-hospital clinic were randomized into an intervention or ISIS group (IG, n = 79) and a control group (CG, n = 79). Both groups received cardiovascular education through standard means. In addition, IG patients underwent a 30 to 60 min session on the computer. Cardiovascular knowledge was tested by a nurse administering a standardized 28-item questionnaire before and two months after education. Retesting was done by telephone interview. A total of 138 completed questionnaires (69 from each group) were analyzed. Overall mean cardiovascular knowledge score before education (14.3 +/- 4.2, range 4-25) improved significantly after education (3.7 +/- 3.5, p = 0.0001). This improvement was more important in the IG than the CG (3.8 +/- 3.6 vs 2.4 +/- 3.2 respectively, p = 0.02), especially in hypertensives having a known disease for more than six months. Isis is now available in two languages: French and English. Patients' satisfaction and the conclusion of this comparative trial encourage confirmation of these first results in other French or English speaking populations, in order to test the long term effects of structured electronic teaching sessions on health behaviour, and to promote a wide use of computers and multimedia communication in hypertension control programs.

Adult↗
PubMed1995

Benefits of a computer-assisted education program for hypertensive patients compared with standard education tools.

ISIS (Initiation Sanitaire Informatisée et Scénarisée), a French computer-assisted hypertension and cardiovascular risk education program, was developed to provide patients at cardiovascular risk with a modern interactive educational tool combining rigorously scientific information with the aesthetic attractiveness of multimedia communication. To test the impact of this tool on patient health information retention, 158 hypertensives hospitalized for initial work-up (day hospital) or therapeutic adjustments (3 days) were randomized into control (n = 79) and ISIS (n = 79) groups. Both groups received cardiovascular education through standard means: physicians, nurses, dietitians and pamphlets. In addition, ISIS patients underwent a 30- to 60-min session on the computer with the ISIS program. Cardiovascular knowledge was tested by the same investigator administering a standardized 28-item questionnaire before and 2 months after education. Retesting was made by telephone. At the time of first assessment, all patients were aware that they would be retested. A total of 138 completed questionnaires (69 from each group) was analyzed. Overall mean cardiovascular knowledge score before education improved significantly after education. This improvement was greater in the ISIS than the control group. These results confirm the potential of computer-assisted education in hypertensives from a specialized center.

Adult↗
PubMed1994

[Evaluation of a computer assisted training program for hypertensive patients].

ISIS tutorial program (French abbreviation for Animated and Computerized Initiation into Health) was carried out for Macintosh type computers to place a modern and interactive learning device at cardiovascular risk patients' disposal. Such a program combines strict scientific explanations and aesthetic attractiveness of multimedia communication. To test the effect of this device on health knowledge gain, 158 hypertensives admitted in one-day or in half-week clinics for an initial check-up or for a therapeutic adjustment were randomised into two groups: a control group (n = 79), receiving usual education (contacts with physicians, nurses, dieticians, health oriented booklets), and an experimental or "ISIS" group (n = 79) undergoing an interactive session with the computer during 30 to 60 minutes, in addition to usual education. Health knowledge of both groups was assessed through a 28-item questionnaire, before any education procedure, two months after the discharge, through a standardized interview by phone, thanks to the same investigator. On the whole, 69 + 69 = 138 complete case records could be analysed. Initial health knowledge mean score, at admission to the hospital, was 14.3 +/- 4.2 (range: 4 to 25). This score significantly improved among the whole population (difference between the two evaluations: 3.7 +/- 3.5 points; p = 0.0001). Improvement was greater in ISIS group than in controls (p = 0.02). Among hypertensives with initial scores < or = 16, improvement was respectively 4.5 +/- 3.6 and 2.9 +/- 3.0 for ISIS and control groups (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

A comparative study between a computer-aided education (ISIS) and habitual education techniques for hypertensive patients.

ISIS is a patient education computer program about hypertension. It aims to be complementary to the habitual educational techniques by bringing into patient education the facility of multimedia features. Its efficiency in improving the knowledge about hypertension was tested among 158 hypertensive patients. Their prior knowledge was evaluated using a questionnaire. They were then randomly separated in a control group (CG) which had the regular education program and ISIS group or (IG) which, in addition, had an interactive session using ISIS. Two months after discharge, all the patients were asked the same questions over the telephone. A total of 138 observations (69 CG, 69 IG) were reported in the final analysis. The initial scores were significantly improved for both groups. The improvement is more evident in the IG, particularly among patients whose initial score was low and patients whose hypertension was discovered for more than 6 months. ISIS is actually used by hospitalized patients and by nurse students.

Computer Systems↗
PubMed1992

Comparative effects of a potassium channel blocking drug, UK-68,798, and a specific bradycardic agent, UL-FS 49, on exercise-induced ischemia in the dog: significance of diastolic time on ischemic cardiac function.

The effects of N-]4-(2-(2-[4-(methanesulphonamide)phenoxy]-N- methylethylamino)ethyl)phenyl]methanesulphonamide, free base (UK-68,798) (30 and 100 micrograms/kg i.v.), a class III antiarrhythmic with potassium channel blocking activity, on regional ventricular function during exercise-induced ischemia in conscious dogs were compared to those of 1,3,4,5-tetrahydro-7,8-dimethoxy-3-[3-(]2-ad3,4- dimethoxyphenyl]ethyl)methylamino)propyl]-2H-3-benzazepin-2-one, hydrochloride (UL-FS 49) (500 micrograms/kg, i.v.), a specific bradycardic agent. Studies were performed in chronically instrumented dogs trained to run on a motor-driven treadmill. After stenosis of the left anterior descending coronary artery, dogs were submitted to a submaximal exercise. UK-68,798 did not change the resting heart rate, but reduced exercise heart rate by 6.5 and 13.5% at 30 and 100 micrograms/kg, respectively (P less than .05). In a normal area, both doses of UK-68,798 slightly increased regional function. In an ischemic area, the lower dose of UK-68,798 (30 micrograms/kg) was without effect. At the higher dose (100 micrograms/kg), the ischemic dysfunction was worsened, because the percent systolic shortening was reduced from 22.6 +/- 2.6% in the control exercise to 11.1 +/- 5.6% in the presence of UK-68,798 (P less than .05). UL-FS 49 (500 micrograms/kg) reduced heart rate before and during exercise. At rest, UL-FS 49 slightly increased systolic shortening in normal and ischemic areas. In the ischemic area, UL-FS 49 reversed the exercise-induced dysfunction. Before and during exercise, UL-FS 49 (500 micrograms/kg) prolonged diastolic time significantly more than UK-68,798 (100 micrograms/kg; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗