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D Joly

Publications and source records attributed to D Joly.

60 records · Page 4Linked to original sources

Interindividual differences in a set of biological rhythms documented during the high arctic summer (79 degrees N) in three healthy subjects.

The High Arctic summer with its permanent sunlight provides a situation in which one of the natural synchronizers, the light-dark alternation, is minimal. During the summers of 1981 and 1982 three healthy right-handed geographers who were performing field studies in Svalbard as part of their own research volunteered to document, 4-6 times per 24 hr for respectively 63, 141 and 147 days, a set of circadian rhythms: self-rated fatigue, oral temperature, grip strength of both hands, heart rate and times of awakening and retiring. Tests were performed before departure from France, in Svalbard (79 degrees N latitude) where their daily activities were often strenuous, and after returning to France. Time series were treated individually according to three methods: display of data as a function of time, cosinor analyses to quantify rhythm parameters, and spectral analyses to estimate component periods of rhythms. Circadian parameters such as period and acrophase of activity-rest, oral temperature and fatigue rhythms were not altered. On the other hand, the circadian rhythm in grip strength was altered: the period differed from 24 hr in one subject, while grip strength acrophase of the left, but not the right, hand of the other two subjects was phase shifted during the sojourn in Svalbard. A prominent circahemidian (about 12 hr) rhythm was observed in two subjects for their heart rate in Svalbard, while a prominent circadian rhythm (differing from exactly 24 hr) was observed in France associated with a small circahemidian component.

Activity Cycles↗

Portal vein thrombosis shown by ultrasonography.

While alcoholic cirrhosis is the most common cause of portal hypertension and associated gastrointestinal bleeding, portal vein occlusion can produce similar clinical manifestations. Ultrasonography is an accurate, noninvasive procedure for detecting portal vein thrombosis and distinguishing infrahepatic venous obstruction from intrahepatic obstruction due to cirrhosis.

Abdominal Injuries↗

Pathogenesis of twin-twin transfusion syndrome: the renin-angiotensin system hypothesis.

In spite of active perinatal management, twin-twin transfusion syndrome (TTTS) remains a severe disease with a high risk of neonatal mortality and morbidity. TTTS initially results from an unbalanced blood flow from a donor to a recipient twin. However, its pathogenesis remains unclear, although cardiovascular disturbances and regulation of fetal volemia and diuresis seem central in this syndrome. Previously, we demonstrated that the renin-angiotensin system (RAS) was up-regulated in donor twins as a consequence of hypovolemia, and down-regulated in recipients. This was the first evidence of the implication of the RAS in TTTS. We hypothesize that the RAS plays a key role in the pathogenesis of TTTS. In the donor, RAS up-regulation aggravates oligohydramnios and may increase arterial resistance, which could contribute to placental dysfunction leading to intrauterine growth restriction. In the recipient, paradoxical RAS activation, due to transfer of effectors such as angiotensin II through placental shunts, could explain fetal vascular disturbances and cardiomyopathy. According to our hypothesis, TTTS would appear similar to the classical model of hypertension referred to as '2 kidneys-1 clip' with a donor twin, comparable to the clipped kidney, intoxicating its cotwin, comparable to the normal kidney.

Female↗

Polycystic kidney disease: <<30 ans après>>.

Major progress has been achieved in autosomal dominant polycystic kidney disease in the last 30 years; Progress in imaging procedures has been decisive for diagnosis (by ultasonography), management of kidney and liver complications (by CT scan), and investigation and sometimes management of intracranial aneurysms (by MRI-angiography and endovascular treatment procedures). On the other hand, progress in molecular genetics has led to the identification of PKD1 and PDK2 genes, and their respective gene products, polycystin 1 and 2. A two-hit model for cyst formation has recently been put forward. The link between the gene defects and cyst fluid formation and progression is still unknown. In addition, cystic and non-cystic lesions coexist in the disease, underlining that the primary molecular defect is located upstream of the mechanism of cyst formation.

Animals↗

[Imaging in the diagnosis of vascular complications after hepatic transplantation].

Twenty-nine vascular complications which occurred after 388 hepatic transplantations performed over a 5 year period (14 arterial thromboses, 4 aneurysms and ruptures of the hepatic artery, 8 portal thromboses and 3 peri-anastomosis portal stenoses) were investigated retrospectively in order to determine the role of imagery in diagnosing these vascular complications. The best screening examination for the diagnosis of hepatic artery thrombosis appeared to be pulsed Doppler coupled with echography. It provides a means of selecting candidates for arteriography, the only investigation allowing certain diagnosis of thrombosis. False aneurysms, suspected in cases of severe post-operative sepsis should be investigated with arteriography even if CAT scans and echo-pulsed Doppler imagery is normal. The diagnosis of portal thrombosis and stenosis relies on echo-pulsed Doppler imagery. In these cases, arteriography is carried out before treatment to evaluate the extent of vascular involvement. Thus echography coupled with pulsed Doppler is the best first intention screening examination to be performed whenever a vascular complication is suspected after hepatic transplantation. Nevertheless, arteriography remains the key examination for the diagnosis and evaluation of these complications.

Cholangiography↗