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Biomedical subjects

J P Gautier

Publications and source records attributed to J P Gautier.

At least 19 recordsLinked to original sources
PubMed2001

Absorption, distribution and excretion of aflatoxin-derived ammoniation products in lactating cows.

Peanut meal naturally contaminated with 3.5 mg/kg aflatoxin B1 (AFB1) was spiked with radiolabelled AFB1 (meal 14C-I0) and decontaminated by a small-scale copy of an industrial ammoniation process (meal 14C-I1). During the process 15% of the radioactivity was lost, whereas 90% of the remaining radiolabel could not be extracted from the meal. In the extractable part, AFB1 accounted for 10% of the radiolabel, consistent with a total AFB1 reduction of more than 99%. No degradation products were observed in the extracts. Four lactating cows were fed with a diet containing 15% of either meal 14C-I0 or 14C-I1 for 10 days. On day 9 of this treatment, respectively 23 and 67% of the radiolabel was excreted in the urine and faeces of cows fed meal 14C-I0, as compared with 2 and 101% in the case of cows fed meal 14C-I1. Milk contained respectively 1.35 (meal 14C-I0) and 0.25% (meal 14C-I1) of the radiolabel. Milk samples taken during the equilibrium stage contained respectively 5 and 0.5 ng/ml of AFB1-derived compounds. Aflatoxin M1 (AFM1) accounted for 50-80% of these compounds in the case of milk from cows fed 14C-I0, as compared with 6-20% in the case of 14C-I1. AFB1 to AFM1 carry-over rates for 14C-I0 or 14C-I1 were estimated to be respectively 0.5 and 5.9%. Only liver and kidney samples contained detectable levels of the radiolabel, being respectively 260 and 37 micrograms/kg for cows fed meal 14C-I0, and 10 and 3 micrograms/kg for those fed meal 14C-I1. In the latter case, more than 55% of the radiolabel in the liver could not be extracted, as compared with 90% in the group fed meal 14C-I1. A small part of the extractable radiolabel in the livers of cows fed meal 14C-I0 could be attributed to AFB1 and AFM1 (less than 1% of total radioactivity). In the case of the animals fed 14C-I1 there were indications for the presence of AFB1 and AFM1 (6% of total radioactivity). Decontamination of the highly contaminated (non-radiolabelled) peanut meal by two different industrial ammoniation processes, resulted in a similar reduction of the initial AFB1 levels of 3.5 mg/kg to 15 micrograms/kg. Feeding of diets containing 15% of the non-treated and two treated peanut meals to cows for a period of 10 days, resulted in AFM1 levels in milk of respectively 2.1, 0.04 and 0.07 ng/ml. AFB1 to AFM1 carry-over rates were calculated to be respectively 0.5, 2.0, and 3.6%. It is concluded that the efficient reduction of aflatoxin levels by ammoniation of contaminated peanut meal results in a strong reduction of aflatoxin-related residues in milk and meat of cows, most likely caused by a decreased bioavailability of the degradation products.

Aflatoxins↗
PubMed2001

Genotoxicity testing of extracts from aflatoxin-contaminated peanut meal, following chemical decontamination.

One of the most important concerns in the decontamination of aflatoxin-containing feed commodities is the safety of the products for food-producing animals and for human consumption of products derived from these animals. A new method, based on the use of florisil and C18 solid phase extraction columns, was developed for the preparation of extracts from decontaminated peanut meal, which allowed testing with in vitro genotoxicity assays without interference of the residual aflatoxin B1. Recovery of degradation products in the extracts was evaluated by the use of radiolabelled [14C]-aflatoxin B1 (AFB1) added to naturally-contaminated peanut meal (3.5 mg AFB1/kg). The meal was treated by a small-scale version of an industrial decontamination process based on ammoniation. Following decontamination, more than 90% of the label could not be extracted from the meal. AFB1 accounted for about 10% of the radiolabel present in the extractable fraction, indicating a total AFB1 reduction of more than 99%. Decontamination of the meal by a number of other small- and industrial-scale ammonia-based processes resulted in similar efficiencies. Application of the extraction procedure resulted in AFB1-rich and AFB1-poor fractions, the latter containing half of the extractable decontamination products but less than 1% of the residual AFB1. Testing in the Salmonella/microsome mutagenicity assay (TA 100, with S9-mix) of the original crude extracts and AFB1-rich fractions prepared from non-treated and decontaminated meal, showed the positive results expected from the AFB1 contents as determined by HPLC analysis. Analysis and testing of the AFB1-poor fractions showed that the various decontamination processes not only resulted in a successful degradation of AFB1 but also did not produce other potent mutagenic compounds. Slight positive results obtained with these extracts were similar for the untreated and treated meals and may be due to unknown compounds originally present in the meal. Results obtained with an unscheduled DNA synthesis (UDS) and Comet assay with rat hepatocytes supported this conclusion. Positive results obtained with the micronucleus assay, using immortalized mouse hepatocytes (GKB), did not clearly reflect the mycotoxin levels and require further examination. It is concluded that the newly developed extraction procedure yields highly reproducible fractions and hence is very suitable for examining the possible formation of less potent degradation products of aflatoxins in short-term genotoxicity tests.

Aflatoxins↗
PubMed1999

Simian immunodeficiency virus (SIV) from sun-tailed monkeys (Cercopithecus solatus): evidence for host-dependent evolution of SIV within the C. lhoesti superspecies.

Recently we reported the characterization of simian immunodeficiency virus (SIVlhoest) from a central African l'hoest monkey (Cercopithecus lhoesti lhoesti) that revealed a distant relationship to SIV isolated from a mandrill (SIVmnd). The present report describes a novel SIV (SIVsun) isolated from a healthy, wild-caught sun-tailed monkey (Cercopithecus lhoesti solatus), another member of the l'hoest superspecies. SIVsun replicated in a variety of human T-cell lines and in peripheral blood mononuclear cells of macaques (Macaca spp.) and patas monkeys (Erythrocebus patas). A full-length infectious clone of SIVsun was derived, and genetic analysis revealed that SIVsun was most closely related to SIVlhoest, with an amino acid identity of 71% in Gag, 73% in Pol, and 67% in Env. This degree of similarity is reminiscent of that observed between SIVagm isolates from vervet, grivet, and tantalus species of African green monkeys. The close relationship between SIVsun and SIVlhoest, despite their geographically distinct habitats, is consistent with evolution from a common ancestor, providing further evidence for the ancient nature of the primate lentivirus family. In addition, this observation leads us to suggest that the SIVmnd lineage should be designated the SIVlhoest lineage.

Amino Acid Sequence↗
PubMed1993

On the occurrence of nocturnal and diurnal loud calls, differing in structure and duration, in red howlers (Alouatta seniculus) of French Guyana.

Structural patterns and 24-hour rhythms of the loud calls of Alouatta seniculus were studied in a wild population living in primary rain forest in French Guyana. These loud calls are low-pitched noisy hoarse sounds with an upper frequency limit around 3,000 Hz. Their spectral energy is concentrated in two clusters, each of which includes two dominant frequency bands. Loud calls comprise one or several vocal units with alternating crescendos and decrescendos. Five different types of units can be distinguished. Depending on their duration, loud calls can be roughly divided into two classes: long and short calls. Long calls (mean duration 3.28 min) include three phases. After the end of the calls, one or two blowing noises of weak amplitude may be heard. Short calls (mean duration 11 s) are frequently uttered in clusters of several calls given by the same troop at intervals of a few seconds to a few minutes. Observations carried out over the 24-hour cycle show that the calling rate is higher at night, with a peak around dawn and that long calls are more frequent at night, while short calls are mainly heard during the day. Most long calls are emitted from the sleeping sites and carry great distances. They probably play a role in inter-troop communication. Despite their intensity, short calls are used for short-distance communication. The occurrence of two different loud calls in Guyanan howlers and the amount of night calling in these monkeys are discussed with reference to studies of other howler populations.

Alouatta↗
PubMed1990

[Value of the combined Lastac laser-angioplasty technic in symptomatic superficial femoral occlusion].

The results of peripheral transluminal angioplasty are satisfactory in stenotic arteries but those observed in the recanalisation of occluded peripheral arteries are not so good. There would therefore seem to be a good therapeutic opportunity for laser between angioplasty and surgery for patients with symptomatic arterial occlusion. The authors report their experience with the Lastac laser in 12 patients with symptomatic superficial femoral arterial occlusion. This is a no-contact laser. All patients had surgical indications in case of failure to recanalise by laser, despite collateral circulation by the profunda artery which was inadequate on effort leading to claudication and a limited walking perimeter. After 1 initial failure, 11 successful procedures were performed. There were no perforations due to the Argon laser beam but 2 were observed with the guide wire which was rapidly sealed by the balloon catheter. A surgical haematoma at the percutaneous puncture point resulted in 1 reocclusion during the patient's hospital period so that the 11 technical successes became 10 clinical successes. At medium-term follow-up, one asymptomatic occlusion had occurred and one restenosis was successfully redilated. The advantages of a continuous Argon "Lastac" laser compared with a contact laser are its capacity for auto-control, its coaxial fibre placement and the absence of direct contact with the lesion. The coaxial fibre arrangement plays an important role in preventing vascular perforation. These factors enable it to be used with more safety in patients with arterial occlusion.

Angioplasty, Balloon↗
PubMed1990

[Future of premature infants of less than 33 weeks gestational age: results of an inquiry undertaken in 1985 in the Paris region].

Improvements in combining obstetrics and neonatology led to a trend to intervene earlier in premature babies born before the 33rd week of gestational age. The enquiry that was carried out in 1985 in the Paris geographical region had as its objective to assess on the one part how many premature deliveries occurred between the 25th and 33rd week of amenorrhea and on the other hand what happened in the short term to the infants born from these pregnancies, i.e., their mortality; and for those who survived, their quality of life. The study was carried out on a representative sample of the deliveries in 1985 in the four departments of the Paris region--Paris and the three departments of the Petite Couronne--where half of all deliveries were assessed. The enquiry covered 53,430 deliveries for which the overall prematurity rate was 4.5%, and those deliveries that occurred before 33 weeks of gestational age constituted 1.0% (539 babies). Twenty children were lost for follow-up after a year. This was 4.9% of the live births and 6.3% of the live children who left the neonatology centres. At 2 years of age, the numbers that were not followed up were eventually 24, which was 5.8% of live births and 7.6% of those that left the centres of neonatology. The results show a very high rate of antepartum mortality but also of mortality during and after labour. Only 379 infants out of the 539 (70%) were transferred into special care baby units. By 1 year of age, the survivors were 57% of the total number of deliveries and 75% of the live births and 82% of those transferred to the special units. As far as concerned those that were live born, the survival rate at the age of 1 year varied considerably according to the duration of the pregnancy. The number of those that survived a pregnancy of less than 27 weeks was low (31%). It was, at 28 weeks, 53%. This is the age where births have to be registered. It reached 87% of the live births that occurred at 32 weeks. One has to point out that there is no statistically significant difference between 27 and 28 weeks of gestation. Whereas there is a significant difference (p less than 0.05) with those delivered at 29 weeks (75%). 80% of those 291 infants that were examined at 1 year of age were considered to be normal as far as psychomotor and sensorial behaviour was concerned.(ABSTRACT TRUNCATED AT 400 WORDS)

Follow-Up Studies↗
PubMed1988

[Clinical and anatomo-pathologic study of 59 cases of sudden infant death].

A proper organization has been set up at Antoine-Béclère's hospital in order to study the infants who died suddenly. Between July 1985 and July 1987, 69 cases (10 babies less than 1 week of age) were admitted. The purpose of this work was, for the 59 sudden deaths of infants aged more than 1 week (35 males, 24 females), to present the results of a definite protocol of investigation (past history, clinical examination, laboratory and pathological data) for determining either the etiology or the mechanism of these deaths. A thorough investigation was performed in 45/52 cases (no autopsy in 7 cases). A definite diagnosis was possible in 38/45: 13 viral infections, 5 gastro-esophageal reflux, 13 viral infections associated with reflux, 9 with an additional event (massive alimentary inhalation, slipping under blankets, major hyperthermia) to either a viral infection or a reflux, 1 cardiac malformation, 1 metabolic disorder, 2 accidents and 1 infanticide. With this protocol, 7/45 deaths remained unexplained. This medical approach of the problem of sudden deaths in infants is beneficial to the counselling of the parents and to the management of subsequent children.

Autopsy↗
PubMed1985

[Cytogenetic study of Cercopithecus wolfi, Cercopithecus erythrotis and a hybrid Cercopithecus ascanius X Cercopithecus pogonias grayi].

The karyotypes of two species of Cercopithecus, C. wolfi and C. erythrotis, as well as that of a hybrid C. ascanius X C. pogonias grayi, are described and compared. The karyotype of C. erythrotis is similar to that of C. ascanius and C. cephus described previously. The karyotypes of C. wolfi and C. p. grayi differ by a single inversion. The karyotype of the hybrid shows that the two parental species differ by five rearrangements, three fissions and two inversions, an observation in agreement with our previous interpretation.

Animals↗
PubMed1983

[Vocal behavior of adult males and superspecific organization in polyspecific troops of monkeys].

Analysis of the vocal behaviour of adult males from different species of Cercopithecus monkeys in a polyspecific troop shows important species differences, which suggest a superspecific organization upon which the extraordinary stability of certain polyspecific associations can depend. In the community studied, the male Cercopithecus pogonias generally controlled the formation and disbanding of polyspecific troops, coordinated their movements and the spacing between troops, while Cercopithecus cephus seemed to be the 'follower' species. However, the roles were divided for defence against predators: male C. pogonias gave warning of aerial predators, while male C. cephus generally gave the alarm against terrestrial predators.

Animals↗
PubMed1983

Qualities and drawbacks of radiotransmitted vocalizations of monkeys through laryngophones: new perspectives in analysis.

Radiotransmitted (RT) calls of monkeys equipped with laryngeal microtransmitters are compared with those recorded by an external microphone (AT). Sharp attenuation of background noise and echoes results in better sonograms with RT than AT sounds. Sensitive detection of unvoiced calls or phonatory noises leads to knowledge of the motivational state of the animals and the mechanisms of their vocal production. However, the laryngophone acts as a low pass filter which limits RT spectra below 3 kHz. Constant distance and orientation between sound source and microphone permit us to get absolute (low-pitched call) or relative (high-pitched call) intensity measurements. Their generalization should be possible with the use of a specific weighting filter which would reconstitute the original energy of calls. The system has interesting applications in behavioral and ecological studies.

Acoustics↗