Biomedical subjects

Y Guérin

Publications and source records attributed to Y Guérin.

43 records · Page 3Linked to original sources

PubMed1989

[Myocardial infarction during or after exertion related to sports. Clinical and coronary angiographic analysis of 10 cases].

The purpose of this study was to analyse characteristic of myocardial infractions that occur during, or immediately after sport-related exertion in subjects who are neither athletes nor professional sportsmen and who undergo coronary angiography. Ten cases where myocardial infraction developed during (n = 3) or immediately after (n = 7) a game were studied retrospectively. All patients were men aged from 21 to 61 years (mean 48.8 years); 8 of them were smokers and 5 had hypercholesterolaemia. The sports practised were tennis (3), cycling (2), football (2), skiing (2) and weight-lifting (1). The infarction was inferior or basal in 5 cases, lateral in 1 case and anterior or anteroseptal in 4 cases. Coronary lesions involved one vessel in 6 and two vessels in 2 patients aged from 47 to 61 years. They were absent in 2 patients aged 24 and 26 respectively, with methylergonovine-induced spasm in one case. The outcome over a 2.9 years follow-up period was favorable, except for one death 6 months after the infarction (patient aged 24, normal coronary arteries, spasm). The outstanding features in this study are: (1) the occurrence of infraction during the recovery period and the noxious role played by smoking; (2) the contrast between the presence of atherosclerotic coronary lesions in middle age subjects and their absence in younger subjects (infarction due to spasm or thrombosis?), and (3) the possible usefulness of an exercise test in sport players of more than 40 years of age.

Adult↗

PubMed1988

[Development of anesthetic technics for resection-anastomosis of the trachea].

A series is reported of 109 patients, 45 +/- 18 yr old, undergoing tracheal sleeve resection. 101 patients had iatrogenic tracheal stenosis, 5 tracheal cylindroma, 2 tracheal cancer and 1 tracheal trauma. 84 patients underwent preoperative laser coagulation to increase the airway internal diameter. Anaesthesia for the sleeve resection was induced by thiopentone, and maintained by an opiate, nitrous oxide and, if necessary, a volatile anesthetic. Patients were intubated, after having been given a muscle relaxant, with either a normal length and diameter tube with a low pressure cuff, or a narrow (internal diameter less than 6 mm) 50 cm long tube with or without a low pressure cuff. Patients with long tubes were ventilated with intermittent positive pressure, and the others with high frequency jet ventilation (HFJV) via a urethral catheter within the endotracheal tube. 20% of the long tubes had to be replaced during surgery because of perforation of the cuff by a tracheal stitch. In all, six patients died, one as a result of a pneumothorax and air embolus due to HFJV. Preoperative photocoagulation reduced the risk of induction and intubation; the choice of endotracheal tube no longer depended on the tracheal diameter, but on the method of ventilation chosen. However, HFJV has tended to be phased out, except for the surgery of lesions close to the carena; it has been replaced by intermittent positive pressure ventilation via long tubes. Because laser photocoagulation can completely cure small stenoses, these patients requiring surgery were those with long stenoses which were difficult to treat.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1988

Photoperiodic and melatonin treatments for the control of seasonal reproduction in sheep and goats.

The control of seasonal reproductive activity in sheep and goats in open sheds, needs extra-light (E) during the photosensitive phase (equivalent to long days, LD), followed by treatment with melatonin (equivalent to short days, SD). In autumn-born Ile-de-France or Lacaune ram lambs, 2 months of E followed by decreasing daylength for 90 days, advanced onset of the first breeding season by allowing males to reach their maximum testis volume and sperm production earlier than for untreated ram lambs. Substitution of decreasing daylength with melatonin implants allowed a transient increase in testis volume. Adult Ile-de-France rams maintained under short light rhythms with 2 month-period, demonstrated, during at least 2 consecutive years, a testis volume equivalent to that observed during the normal breeding season. These light-treated rams produced, during non-breeding season, spermatozoa in the same quantity and quality as during the normal breeding season. In anovulatory out-of-season dairy goats, E treatment was demonstrated to be necessary before melatonin treatment and melatonin to be necessary after E treatment to stimulate oestrous and ovulatory activities. Stimulation of the anovulatory females by the introduction of treated males ("male effect"), appeared to be necessary to obtain maximum stimulation of the treated females. Two months of E, followed by melatonin treatment (daily injection or drenching or subcutaneous implants) allowed cycles with ovulation to be maintained for more than 2 months. Although effective for control of out-of-season reproductive activity, melatonin slightly decreased milk production when applied soon after kidding. So, total control of reproduction in sheep and goats by manipulation of photoperiod in open sheds and melatonin treatments appears feasible in both sexes.

Animals↗

PubMed1987

Lamb production using superovulation, embryo bisection, and transfer.

In this study, 39 embryos from donor ewes superovulated with follicle stimulating hormone-pituitary (FSH-P) were bisected to produce pairs of monozygotic twin lambs for experimentation. Each pair obtained by bisecting 8-, 9- or 10-day-old embryos was immediately transferred surgically into a recipient ewe at the same physiological stage. Of the 39 recipients which received a pair of half-embryos by transfer into the uterine horn ipsilateral to the corpus luteum, 28 (72%) lambed. Eighteen of 28 recipients lambing (64%) produced pairs, i.e., 7 male and 11 female pairs. Ten of 28 lambings produced a single lamb, i.e., six males and four females. Overall yield (the number of lambs produced in relation to the number of embryos used) was 118%. This percentage tended to increase, depending on the day of collection (Day 8, 100%; Day 9, 118%; and Day 10, 131%).

Journal Article↗

PubMed1987

[Intrapulmonary right-left shunt associated with liver cirrhosis: diagnosis by contrast echocardiography].

The hypoxaemia associated with hepatic cirrhosis is classically attributed to an intrapulmonary shunt caused by small vascular abnormalities. Severe hypoxaemia (47 mmHg) associated with dyspnoea, cyanosis and clubbing was observed in a 57-year old man who presented with cirrhosis of the liver. At contrast echocardiography, a right-to-left shunt was demonstrated by the appearance of microcavities in the left atrium and ventricle after peripheral intravenous injection of the contrast medium. The intrapulmonary location of the shunt was determined by a 4 cardiac cycles interval between the arrival of the microcavities in the right heart and their appearance in the left heart. The right-to-left shunt was confirmed by the pure oxygen ventilation test and by pulmonary perfusion scintigraphy with radiolabelled albumin microaggregates. Pulmonary angiography proved normal. Thus, contrast echocardiography is capable of diagnosing right-to-left shunts associated with hepatic cirrhosis and to demonstrate their intrapulmonary location.

Arteriovenous Malformations↗

PubMed1986

[Seasonal variation in the testis diameter and sperm morphology in the Vendean ram and Texel ram].

Nineteen Vendean (V) rams (7 yearlings about 15 months old and 12 adults of greater than 2 years) and 13 Texel (T) adult (greater than 2 years) rams were controlled for body weight (BW), testis diameter (TD) and sperm morphology for two consecutive years (1982 and 1983) from February to June (T) or July (V) and from September to November the first year, from February to June and from September to October the second year. BW was recorded every month. TD was measured once weekly using a caliper. The percentage of abnormal spermatozoa (MA) was determined on each ejaculate (1 ej/ram/week) as described previously (Colas, 1980). BW increased rapidly (P less than 0.01) in the T rams the first 4 months and did not augment significantly any more afterwards. In the V breed, no significant variations appeared at any time of the experiment, except in the last month when BW decreased (P less than 0.05). However, in the yearlings (V), there was considerable body growth between February and October 1982 but no significant growth afterwards. In the adults, no statistical variations occurred at any time of the experimental period. TD varied greatly during the year in the V rams. During both years, it was minimal in May (59.0 +/- 5.7 m/m in 1982; 58.1 +/- 4.4 m/m in 1983); in September it was already regressing. There were also large seasonal variations in the TD profile of the T breed but its curve was different from one year to another: the mean value was minimal in February 1982 59.5 +/- 6.0 m/m) and from February (67.5 +/- 4.4 m/m) to May (68.6 +/- 5.0 m/m 1983. In both breeds, testicular growth always started in June, i.e. during the long days, whatever the year. The importance of the variations and their time of onset during the year suggest that both breeds were very sensitive to photoperiod. These results also permit a generalization of the idea that testicular activity in male sheep recommences in the long days. Both breeds showed large individual variations between the minimal values recorded in spring and the highest ones measured in September (2.7 to 78.0% and 2 to 100%, respectively, for V and T rams in 1982; 5.5 to 100% and 14 to 84% in 1983). On the whole, MA were more frequent from February to June than from September to October or November in both breeds. In the V breed, MA were highest in April (35.1% in 1982, 33.1% in 1983).(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗

PubMed1985

[Influence of the photoperiod on the production and fecundity of spermatozoa in the adult Ile-de-France ram].

Two groups, A and B, of 5 adult Ile-de-France rams each of the same age were exposed for 52 weeks (October 1975 to October 1976) to an artificial light regime reproducing natural variations of daylength (DL). In group A, DL increased from 8 to 16 h during the first 26 weeks and then decreased. In group B, DL varied in an opposite manner. Light intensity was constant (300 lux/m2) and ambient temperature was controlled (20 +/- 4 degrees C). The rams were collected using an artificial vagina twice weekly (2 X 2 ejaculates/male/week) during the whole experimental period (EP). The volume and concentration of each ejaculate were recorded. The pH of the raw semen was also measured on the first ejaculate once a week or every two weeks, according to material possibilities. The unselected ejaculates of all rams were used for artificial insemination (AI) on the same days in the same flocks between January and October 1976. AI (980 ewes) was always carried out after oestrus synchronization (FGA + PMSG). Amongst these ejaculates, some (3 ejaculates/male/group/period) could be used for both in vitro (pH) and in vivo (AI) measurements: - Weekly sperm production (SP) varied in an opposite manner in both groups during the whole EP. In group A, minimal (10.6 +/- 4.0.10(9) and maximal (25.5 +/- 5.1.10(9] levels were reached from weeks 12 to 28 and weeks 38 to 52, respectively. In group B, SP was maximal (21.8 +/- 2.3.10(9] from weeks 9 to 24 and minimal (12.7 +/- 5.2.10(9] from weeks 36 to 49. The differences between rams were significant within periods of high and low production. - The sperm pH was somewhat higher in both groups when DL increased and vice-versa. Fertility after AI was higher with rams exposed to short days than with rams exposed to long days (65.7 vs 56.7%; P less than 0.01). The season of AI had no effect on mean fertility (61.0 vs 62.3% for ewes inseminated from January to June and from July to October, respectively), whatever the DL. No correlation was found between the pH of the sperm and its fertilizing ability. From January to April, a highly significant correlation existed between fertility and prolificacy in the 10 rams (r = + 0.607). These results show that photoperiodism has an important effect on both ejaculated sperm production and fertility in rams.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗