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Biomedical subjects

C Girard

Publications and source records attributed to C Girard.

At least 73 records · Page 4Linked to original sources
PubMed1998

A hospital-wide distributed PACS based on intranet.

A hospital-wide Picture Archiving and Communication System (PACS) is currently under development at the University Hospital of Geneva. After a first implementation including two oneterabyte optical libraries, the system is expanded to integrate all the imaging modalities of the hospital. The new storage requirement is 10 terabytes to cover three year archive. A large distributed image archive has been designed including new archive servers for long-term storage and display servers for medium-term storage. The acquisition, archive and distribution cycles are performed using separated networks combining Fast Ethernet and Ethernet. Image files are distributed to the wide-hospital using a prefetching strategy or an Intranet server, RADIOLAB. The first mode takes advantage of the fully integrated hospital information system DIOGENE 2 to allow the automatic retrieval of studies in advance. The second mode provides a convivial study selection from any conventional WWW (World Wide Web) browser. Image files are then transmitted to the user's display station using HTTP (HyperText Transfer Protocol) and handled by OSIRIS software, which acts as a helper or viewer. Such a system is expected to meet the time requirement, which is less than three seconds per image.

Computer Communication Networks↗
PubMed1997

Search for impact remains at the Frasnian-Famennian boundary in the stratotype area, southern France.

In order to detect whether the end-Frasnian worldwide biotic crisis is related to an extraterrestrial impact, the global stratotype section of the Frasnian-Famennian boundary and auxiliary sections within the stratotype area have been examined for impact indicators: iridium. Ni-rich spinel bearing spherules and glassy microtektites. This area is particularly well suited to the search for discrete events because it exhibits biostratigraphically continuous sections of sedimentologically homogenous off-shore deposits. Different environmental settings on oxygenated deep-water seamounts, such as the stratotype section at Coumiac, and in oxygen-depleted depressions (La Serre section) are available. The latter is investigated in more detail because it is the least condensed across the boundary, which is determined by the first occurrence of the typical morphotype of Palmatolepis triangularis, the indicator of the first Famennian conodont biozone. Samples from the biostratigraphically defined boundary and adjacent levels failed to provide significantly high Ir values and no Ni-rich spinel or microtektite has been recovered. This is in contradiction with the results of earlier investigations carried out by H. Geldsetzer on the same section. In contrast, the values of Ir concentrations that we measured are always very low or not detectable. The small overabundances observed in some samples, which are about two orders of magnitude lower than what is currently observed at the Cretaceous-Tertiary boundary, are probably due to the accumulation of the normal flux of cosmic dust during periods of relatively low depositional rates or to a terrestrial origin. At present, we have no evidence that an extraterrestrial impact occurred at the F-F transition.

Biological Evolution↗
PubMed1997

Morphological changes in the jejunum of calves naturally infected with Giardia spp. and Cryptosporidium spp.

Giardiosis and cryptosporidiosis are frequently diagnosed in calves at the large animal clinic of the veterinary school. Few studies have been reported in the literature regarding pathogenesis of these two intestinal protozoa. The aims of this study were to follow the histological changes in the villi and crypts and the changes in the number of intraepithelial lymphocytes in the jejunum of naturally infected calves during the acute phase of infection. For this purpose, 29 calves aged between 7 and 10 days were bought at a local auction. The animals were housed in individual pens to avoid cross-contamination. Fecal samples were examined microscopically for the presence of Giardia cysts and Cryptosporidium oocysts, three times per week for a period of 45 days. Six calves did not pass any cysts or oocysts and were used as controls. Fifteen calves passed Giardia cysts only, five passed both cysts and oocysts, and three passed oocysts only. The villus to crypt ratio index was 1.76 in the control group and 1.08 in the Giardia-infected group. In the Cryptosporidium-infected calves, the ratio was 1.18 and calves infected with both parasites had an index of 1.37. The number of intraepithelial lymphocytes per millimeter of jejunum tissue was 21 in the control group. This number was doubled in the calves infected with Giardia, but was slightly lower in the other infected groups. All of the infected calves had intermittent diarrhea and mucus was seen in many fecal samples.

Animals↗
PubMed1997

[Inhaled nitric oxide in anesthesia and intensive care].

The role of endothelium in vascular relaxation is linked to the existence of endothelium derived relaxing factors (EDRF) known since 1980. In 1987, nitric oxide (NO) was identified as one of these factors. NO acts in many physiologic and pathophysiologic events. Atmospheric NO is a pollutant. Inhaled NO allows selective pulmonary vasodilation and is used to treat pulmonary artery hypertension (PAH). As inhaled NO is inactivated immediately in the blood by linking to haemoglobin, systemic vasodilation does not occur and right ventricular coronary perfusion pressure does not decrease. This is particularly important in the treatment of right ventricular failure due to PAH following cardiothoracic surgery. In patients with an acute respiratory distress syndrome (ARDS), inhaled NO improves the perfusion of adequately ventilated pulmonary territories. Very low concentrations of NO, such as two parts per million, decrease intrapulmonary venous admixture and may reverse hypoxaemia. However its long term benefits in ARDS must be assessed more accurately with multicentre controlled studies. Inhaled NO also improves refractory hypoxaemia in neonates. Its bronchodilatory effect, demonstrated experimentally, does not occur in acute obstructive bronchopulmonatory disease. The toxicity of NO, and overall of its oxidated derivative NO2 requires precise conditions of administration and close monitoring of inhaled fractions. In that case, the risk of NO toxicity seems very low when compared to its therapeutic benefits in selected patients.

Administration, Inhalation↗
PubMed1997

Long conservation organs in heart transplantation: postoperative results and long-term follow-up in fourteen patients.

Between 1988 and 1995, 14 heart transplantations were performed after a long preservation period (10 to 13 hours). The transplantation procedure (Shumway) was standard, and our results were achieved through the implementation of a very strict reperfusion technique that included low pressure and low cardiopulmonary bypass output for the first 10 minutes. Three patients died during the postoperative period, and the survival rate was 75% at 1 year and 71% at 5 years. The results obtained with hearts stored for such long periods are comparable to the results obtained with hearts stored for less than 4 hours.

Adolescent↗
PubMed1996

[Aneurysms of the left ventricle without atheromatous coronary artery disease. Apropos of 2 cases].

Left ventricular aneurysms are usually secondary to myocardial infarction with atheromatous coronary artery disease. The authors report two rare cases of non-atheromatous left ventricular apical aneurysms. The first case was clearly post-traumatic but the diagnosis in the second case was more difficult. The authors discuss the aetiological diagnosis of these rare non-atheromatous aneurysms in adults and the therapeutic management with respect to these two cases and a review of the literature.

Coronary Angiography↗
PubMed1996

Inhaled nitric oxide: effects on hemodynamics, myocardial contractility, and regional blood flow in dogs with mechanically induced pulmonary artery hypertension.

BACKGROUND: Pulmonary artery hypertension with right ventricular failure is a frequent complication that occurs immediately after heart transplantation in which the use of inhaled nitric oxide may be effective. METHODS: The effects of pulmonary artery hypertension and nitric oxide on myocardial function and on pulmonary and systemic hemodynamic parameters were evaluated in eight anesthetized dogs. Pulmonary artery hypertension was induced by successive microbead injections into the pulmonary circulation. RESULTS: Microbead injections resulted in overt pulmonary artery hypertension (pulmonary artery pressure, + 190%; pulmonary vascular resistance, + 389%; ratio of pulmonary vascular resistance to systemic vascular resistance, 0.41). RESULTS: The end-diastolic length of the right ventricular outflow tract increased significantly along with an increase in right ventricular contractility (peak first derivative of left ventricular pressure as a function of time, + 100%; outflow tract systolic shortening, + 19%). Despite this compensatory mechanism, the increased pulmonary barrier resulted in a decrease in stroke volume (-31%). Systemic effects were observed, such as an increase in heart rate that maintained the cardiac output despite a decrease in left ventricular end-diastolic length (end-diastolic length in region of left anterior descending artery, - 9%). Right myocardial and septal blood flows were also significantly increased. CONCLUSIONS: Nitric oxide administration restored the stroke volume with a decrease in pulmonary artery hypertension and an improvement of the pulmonary vascular resistance to systemic vascular resistance ratio. Systemic blood pressure and coronary perfusion remained unaffected. This selective effect on the pulmonary circulation should be considered a major advantage of nitric oxide inhalation in the treatment of right ventricular dysfunction in acute pulmonary hypertension.

Acute Disease↗
PubMed1996

Intracardiac air clearing in valvular surgery guided by transesophageal echocardiography.

BACKGROUND AND AIMS OF THE STUDY: Air embolism during open heart surgery seems to be a common occurrence and may be responsible for neuropsychological deficit or myocardial damage. MATERIAL AND METHODS: Forty-two consecutive patients undergoing valvular surgery were studied using the long axis view of the heart by two dimensional transesophageal echocardiography (TEE). The patients were randomized into two groups of 21 each. In group 1, the routine air evacuation method was used. In group 2, the same air evacuation method was used and controlled with a Doppler ultrasonic probe adjusted around the root of the aorta. At the end of air evacuation, intracardiac microbubbles and retained air were analyzed with TEE and when air was founded, its location was communicated to the surgeons who tried to remove it by shaking the heart and tilting the operating table for 15 minutes. The patients were assessed for detection of cardiac or neurological postoperative complications. RESULTS: The incidences of microbubbles and retained air were 57% and 43% in group 1, and 62% and 38% in group 2 respectively (ns). The mean grade of microbubbles was lower in group 2: 1.4 +/- 0.8 vs. 2.2 +/- 0.9, p < 0.05. TEE allowed to significantly decrease (p < 0.05) retained air and mean grade of microbubbles to 14% and 1.3 +/- 0.8 in group 1, and to 10% and 0.8 +/- 0.8 in group 2, without statistical difference between the two groups. Despite the help of TEE, manual attempts to eradicate retained air were unsuccessful in five patients (three in group 1, two in group 2). CONCLUSIONS: The use of aortic ultrasonic probe allowed to reduce the amount of microbubbles. TEE was a useful tool not only for the detection of retained air but also for locating it, and guiding the procedure to eliminate it.

Adolescent↗