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Biomedical subjects

J Adrian

Publications and source records attributed to J Adrian.

At least 19 recordsLinked to original sources
PubMed2006

Electrochemical magneto immunosensing of antibiotic residues in milk.

A novel electrochemical immunosensing strategy for the detection of sulfonamide antibiotics in milk based on magnetic beads is presented. Among the different strategies for immobilizing the class-specific anti-sulfonamide antibody to the magnetic beads--such as those based on the use of Protein A or carboxylate modified magnetic beads - ,the best strategy was found to be the covalent bonding on tosyl-activated magnetic beads. The immunological reaction for the detection of sulfonamide antibiotics performed on the magnetic bead is based on a direct competitive assay using a tracer with HRP peroxidase for the enzymatic labelling. After the immunochemical reactions, the modified magnetic beads can be easily captured by a magneto sensor made of graphite-epoxy composite (m-GEC), which is also used as the transducer for the electrochemical immunosensing. The electrochemical detection is thus achieved through a suitable substrate for the enzyme HRP and an electrochemical mediator. The electrochemical approach is also compared with a novel magneto-ELISA with optical detection. The performance of the electrochemical immunosensing strategy based on magnetic beads was successfully evaluated using spiked milk samples, and the detection limit was found to be 1.44 microg L(-1) (5.92 nmol L(-1)) for raw full cream milk. This strategy offers great promise for rapid, simple, cost-effective and on-site analysis of biological, food and environmental samples.

Animals↗
PubMed2006

Discovery of a novel series of inhibitors of human cytomegalovirus primase.

Infection by human cytomegalovirus (hCMV) remains a potent threat to susceptible people throughout the world. We have discovered a series of imidazolyl-pyrimidine compounds, which were found to be irreversible inhibitors of the hCMV UL70 primase based on results from radiolabeling and SAR studies. Two promising analogs are described that rival ganciclovir and cidofovir in antiviral potency and possess improved cytotoxicity profiles.

Antiviral Agents↗
PubMed2003

Catecholamine responses to environmental stressors in trained and untrained men after 3-day bed rest.

INTRODUCTION: The effect of decreased physical activity with reduced gravitational stress on activity, sensitivity, and reactivity of the sympathetic nervous system (SNS) is not fully recognized. We hypothesized that the effect is most pronounced in physically active subjects. Thus, basal plasma norepinephrine [NE] and epinephrine [E], and catecholamine responses to physiological stimuli were determined after 3 d of horizontal bed rest (BR) in subjects differing in level and kind of habitual activity. METHODS: Before and after BR, 11 untrained students, 8 endurance athletes, and 10 power/strength athletes were submitted to oral glucose tolerance test (OGTT) and orthostatic stand test (OST). Another 32 men (12 untrained, 10 endurance athletes, and 10 power/strength athletes) underwent cold pressor test (CPT) and graded exercise test (GET) performed until volitional exhaustion. RESULTS: After BR, basal [NE] was decreased only in athletes (p < 0.01). Increases in both catecholamines during OGTT were diminished (p < 0.05), particularly in endurance athletes. Plasma [NE] response to standing was not affected by BR in individual groups, but it was diminished in the whole group (p < 0.05). Bed rest did not affect the increases in catecholamines induced by CPT and GET. Heart rate response to OST, and BP responses to OST, CPT, and glucose ingestion were enhanced. CONCLUSIONS: Basal sympathetic activity is diminished after 3 d of BR in physically active men. Although catecholamine responses to glucose load and standing were reduced, the general reactivity and sensitivity of SNS were not attenuated since catecholamine responses to the most (exercise) and least (CPT) powerful stimuli were unchanged.

Adult↗
PubMed2000

Effects of three-day bed rest on metabolic, hormonal and circulatory responses to an oral glucose load in endurance or strength trained athletes and untrained subjects.

The study was designed to find out (1) whether the effect of 3-day bed rest on blood glucose (BG) and plasma insulin (IRI) responses to glucose ingestion depends on preceding physical activity and (2) whether plasma adrenaline (A), noradrenaline (NA) and cardiovascular changes following a glucose load are modified by bed rest. Eleven sedentary students (22.5+/-0.3 yrs), 8 long distance runners (18.6+/-0.3 yrs) and 10 strength trained athletes (21.2+/-2.1 yrs) were examined before and after bed rest. Plasma IRI, BG, NA, A, heart rate (HR), and blood pressure (BP) were measured during 2 hrs following glucose (75 g) ingestion. The responses of BG and IRI to glucose load were calculated as incremental areas under the curves (auc). Both in athletes and untrained subjects bed rest markedly increased IRIauc, while BGauc was elevated only in sedentary subjects (p<0.05). The greatest increases in IRIauc and IRI/BG ratios were found in the endurance athletes. The data from all subjects (n = 29) revealed that the initial plasma NA and glucose-induced increases in NA and A were lowered after bed rest (p < 0.01). These effects were most pronounced in the endurance athletes. Bed rest did not influence HR or BP in any group. It is concluded that (1) the athletes have more adequate compensation for the bed-rest-induced decrement in insulin sensitivity than sedentary men; (2) three-day bed rest diminishes basal sympathetic activity and attenuates sympathoadrenal response to oral glucose; (3) endurance athletes have greater sympathetic inhibition than strength athletes or sedentary men.

Administration, Oral↗
PubMed1999

Replication of reptilian paramyxovirus in avian host systems.

The reptilian paramyxovirus GOV replicated in chicken embryo fibroblasts, in embryonated chicken eggs and in explanted chorio-allantoic membrane with titres of up to 10(8.2) TCID50/ml at 28 degrees C. The virus did not multiply above 30 degrees C. GOV re-isolated from the avian host systems was identified by immunofluorescence and by immunogold-electron microscopy.

Allantois↗
PubMed1991

Synthesis and availability of niacin in roasted coffee.

The coffee bean contains about 1% of trigonelline that is demethylated at temperatures approaching 200 degrees C; it is partially converted into nicotinic acid. This operation is mainly proportional to the severity of dry heat treatment; various other physico-chemical factors also influence the synthesis of niacin during the roasting. The niacin content of weakly roasted commercial coffee is about 10 mg/100 g (American coffee) and it reaches 40 mg in heavy roasted coffees, i.e. Italian coffee. Caffeine-free coffee is lower in niacin than the corresponding raw coffee. The drinking retains 85% of the niacin formed during roasting; it is totally available for the organism and can constitute a noticeable part of the daily supply in niacin.

Animals↗
PubMed1991

Interaction between casein and vitamin A during food processing.

A particular relation exists between casein micelle and vitamin A. In vitro, large amounts of retinol are fixed to acid casein and its different fractions by hydrophobic bindings. The binding on the hydrophobic amino-acid residues (Trp, Phe) is greatly facilitated by a configurational change in the molecule exposed to physico-chemical parameters: alcalinity and heat treatments. Another amount of retinol is even more strongly fixed by a binding which can only be broken by saponification. Casein plays an important role in stabilizing retinol which does not degrade over time or during heat treatments. In vivo, when the retinol availability is measured by the vitamin A content in the liver, acid casein somewhat increases the retinol efficiency and, even more so, the retinal efficiency. Nevertheless, this favourable action is only observed under particular conditions: balanced diet, casein from milk, etc. For the moment, the animal data cannot be directly linked with the properties of binding appearing in vitro.

Animals↗
PubMed1990

[Abuse concerning the nature and the commercialization of weight-loss products].

Produces and products for slimming cures are extremely diversified, most of them being used per os. Among them, bulk materials (hydrocolloids, gums) that can reduce the food consumption must be distinguished from a profusion of substances with varied origin and nature whose efficiency and inocuousness often remain undertermined. Some commercial proposals are real untrue advertising. For example, the papain that is a proteolytic enzyme or the vitamin B6 that enables the aminoacid metabolism and the elongation of essential fatty acids. The bean husks are a particular case, they contain starch-blockers able to reduce the in vitro hydrolysis of carbohydrates. Meanwhile, they have no action on the calorie potential provided by the lipids, the alcohol, etc. More these anti-amylases are revealed ineffective under the conditions of digestion; their use in slimming cures is an abuse, opposite our actual knowledges. The homeopathic pharmaceuticals can be ranged in the same category. Their efficiency is not scientifically proved. The most of these substances transit through commercial networks that are hardly identified; more their run lasts only a few months and they are quickly renewed. They constitute an economical sector probably important and, in practice, escaping the elementary medical and regular checkings. An increased watching should be set up in order to reorganize the actual situation.

Advertising↗
PubMed1988

Affective, cognitive and subjective changes in patients undergoing cardiac surgery--a preliminary report.

Neuropsychiatric change following open-heart surgery has been investigated and emboli proposed as a major causative factor. However, few studies have thoroughly evaluated patients' status prior to surgery. The subjective experiences and neuropsychological status of five open-heart surgery patients was documented both pre- and postoperatively. It was found that prior to surgery patients presented with a wide range of cognitive and emotional problems, some of which were exacerbated by surgery. In particular psychomotor slowing was observed and persisted at six weeks following surgery. This report highlights the importance of conducting preoperative assessments in research which aims to evaluate the effects of different medical procedures on neuropsychiatric functioning.

Adult↗
PubMed1988

Effect of soybean and casein on the vitamin A status in the rat.

With a well-balanced diet containing 1.3 mg of retinol/kg, a limited quantity of acid casein (10%) provokes a maximal efficiency of retinol. At a rate of 5% or 25% of casein, the retinol efficiency is decreased and identical to that of soybean diets. In casein-soybean mixed diets, the variations of retinol efficiency are only imputable to the casein presence. With diets containing 6.5 mg of retinol/kg, the specific effect of casein disappears.

Animals↗
PubMed1988

Influence of vitamin A form and protein nature on the retinol status in the rat.

In comparison with soybean proteins, the acid casein increases the blood and liver concentrations of retinol when the diet contains 1 mg of retinol/kg. The effect of the acid casein is more important when the vitamin A is supplied to rats as retinal: with the alcohol form, the amount of liver retinol is 88.7 micrograms; with the aldehyde form, it reaches 137 micrograms.

Animals↗
PubMed1987

The psychomotor effects of single and repeated doses of hypnotic benzodiazepines.

Benzodiazepine hypnotics are used for short periods in low doses in healthy people when stressed and in patients with insomnia. This study examined psychomotor impairment in healthy young males and females after 1 and 7 nights of flunitrazepam (1 mg), nitrazepam (2.5 mg) and temazepam (10 mg). There were substantial inter-individual variations. Results showed that no drug significantly affected psychomotor performance at these doses after single or repeated administration. The number and severity of side-effects were significantly greater after the first night with temazepam and 7 nights with nitrazepam, although this may reflect a statistical artefact rather than a significant clinical finding. The difficulties in performing adequately controlled psychopharmacological studies at low doses are highlighted. Given the large intra- and inter-subject variances, small drug effects would necessitate large sample sizes (21 to 600 subjects at the 95% level of chance of detection) depending on the variable. The study suggests there is minimal impairment with low dose hypnotic drugs and a need to individualize treatment.

Adult↗
PubMed1986

Galactose metabolism in male and female rats. I. Blood and urinary differences.

When rats consumed a well-balanced diet containing 30% lactose or 30% glucose-galactose mixture, some differences of metabolic utilization arose between males and females. With lactose, the urinary excretion of lactose, galactose and galactitol was higher in females. With the glucose-galactose mixture, galactosury and galactitolury in males and females increased and were similar; but galactosaemia and galactitolaemia were more important in females.

Animals↗
PubMed1986

Protein value of some industrial dairy products.

Digestibility, Retention and Protein Efficiency Ratio of milk retentate, rennet-casein, acid-casein and two industrial caseinates were investigated on the rat. The PER of acid casein (3.15) and milk retentate (3.19) had the same value, whereas caseinates and rennet-casein had lower efficiency (between 2.95 and 2.57). Yet, the NPU data range in this decreasing order: milk retentate, rennet-casein, caseinates and acid-casein.

Animals↗