Junior versus senior physicians for informing families of intensive care unit patients

To compare the effectiveness of information delivered to family members of critically ill patients by junior and senior physicians, we performed a prospective randomized multicenter trial in 11 French intensive care units. Patients (n = 220) were allocated at random to having their family members receive information by only junior or only senior physicians throughout the intensive care unit stay; there were 92 and 93 evaluable cases in the junior and senior groups, respectively, with no significant differences in baseline characteristics. Between Days 3 and 5, one family representative per patient was evaluated for comprehension of the diagnosis, prognosis, and treatment in the patient; satisfaction with information and care; and presence of symptoms of anxiety and depression. No significant differences were found between the two groups for any of these three criteria. Family members informed by a junior physician were more likely to feel they had not been given enough information time (additional time wanted: 3 [0-6.5] vs. 0 [0-5] minutes, p = 0.01) and to have sought additional explanations from their usual doctor (48.9 vs. 34.4%, p = 0.004). Specialty residents, if given opportunities for acquiring experience, can become proficient in communicating with families and share this task with senior physicians.     

Acoustical characterization of bone using a cylindrical model and time of flight method: edge reconstruction and ultrasound velocity determination in cortical bone and in medullar marrow

Our objective is to evaluate the external and internal dimensions of bone diaphysis and the speed of sound in cortical bone and in medullar marrow. The diaphysis is modelled by a cylindrical hollow tube. The theory of rays is used and an approximation allows us to break free from the data gained by ultrasonic field amplitude. Then, acoustical and dimensional parameters are only related to the time of flight of reflected and transmitted acoustic echoes in the tube. From the arrival time of particular echoes, the inverse problem resolution then allows us to experimentally determine the sought parameters. This method is validated in vitro on a bovine femur and gives satisfactory results.     

Development of leukemia and lymphosarcoma induced by bovine leukemia virus in sheep: a hematopathological study

The hematological and neoplastic disorders induced in sheep by experimental bovine leukemia virus (BLV) infection are described. Seventeen of 19 BLV-inoculated sheep developed a marked increase in peripheral blood lymphocytes by 36 months after the intraperitoneal injection of peripheral blood lymphocytes from a BLV-infected cow. This increase correlated with an increase in the number of circulating B lymphocytes as demonstrated by the presence of surface immunoglobulins (SIg) and a high cell proliferative response to lipopolysaccharide and was considered to be a persistent B cell lymphocytosis. Lymphosarcoma developed in five BLV-infected sheep between 19 and 38 months postinoculation and was preceded in four out of five of these cases by an elevation in peripheral blood lymphocytes which began 4 to 26 months before death due to lymphosarcoma. The majority of tumor cells in all lymphosarcoma cases were of the centroblastic type, and in two cases in which the presence of SIg was assayed, the majority of tumor cells were SIg-positive. Thus, BLV-induced lymphosarcoma in sheep seems to be a B lymphocyte-derived tumor.     

Involvement of superior mesenteric vessels and portal vein in pancreatic adenocarcinoma: Detection with CT during arterial portography

A prospective study was designed to determine the utility of computed tomography (CT) during arterial portography (CTAP) in the detection of superior mesenteric vessels and portal vein involvement in patients with pancreatic adenocarcinoma. Eighteen patients with adenocarcinoma of the head of the pancreas and eight patients with benign pancreatic disease were investigated with CTAP, dynamic contrast-enhanced CT, and angiography. Appropriate review was made to determine presence or absence of superior mesenteric vessels and portal vein involvement. Final diagnosis was obtained in all cases by surgical explorations. The overall accuracy rate for detecting or excluding superior mesenteric vessels and portal vein involvement was 96% (25 of 26 patients) with CTAP, 88% (23 of 26 patients) with dynamic contrast-enhanced CT, and 85% (22 of 26 patients) with angiography. No statistically significant difference in accuracy was found among the three techniques. Our results suggest that the use of CTAP is not indicated in the preoperative detection of superior mesenteric vessels and portal vein involvement in patients with pancreatic adenocarcinoma.     

Risk of post-traumatic stress symptoms in family members of intensive care unit patients

RATIONALE: Intensive care unit (ICU) admission of a relative is a stressful event that may cause symptoms of post-traumatic stress disorder (PTSD). OBJECTIVES: Factors associated with these symptoms need to be identified. METHODS: For patients admitted to 21 ICUs between March and November 2003, we studied the family member with the main potential decision-making role. MEASUREMENTS: Ninety days after ICU discharge or death, family members completed the Impact of Event Scale (which evaluates the severity of post-traumatic stress reactions), Hospital Anxiety and Depression Scale, and 36-item Short-Form General Health Survey during a telephone interview. Linear regression was used to identify factors associated with the risk of post-traumatic stress symptoms. MAIN RESULTS: Interviews were obtained for family members of 284 (62%) of the 459 eligible patients. Post-traumatic stress symptoms consistent with a moderate to major risk of PTSD were found in 94 (33.1%) family members. Higher rates were noted among family members who felt information was incomplete in the ICU (48.4%), who shared in decision making (47.8%), whose relative died in the ICU (50%), whose relative died after end-of-life decisions (60%), and who shared in end-of-life decisions (81.8%). Severe post-traumatic stress reaction was associated with increased rates of anxiety and depression and decreased quality of life. CONCLUSION: Post-traumatic stress reaction consistent with a high risk of PTSD is common in family members of ICU patients and is the rule among those who share in end-of-life decisions. Research is needed to investigate PTSD rates and to devise preventive and early-detection strategies.     

Cardiac fibroblasts inhibit β-adrenoceptor-dependent connexin43 expression in neonatal rat cardiomyocytes

Cardiac fibroblasts play an important role in adverse cardiac remodelling. As in many cardiac diseases connexin43 (Cx43) is altered, we wanted to elucidate whether fibroblasts may influence cardiac Cx43 expression. We used four different cell culture systems of neonatal rat cardiomyocytes (CM) and fibroblasts (FB): type 1, pure CM culture; type 2, co-culture of CM/FB; type 3, pure FB culture; type 4, Transwell® system: CM/FB co-cultured but separated by a microporous membrane. Stimulation of types 1–3 cell culture models with isoprenaline significantly enhanced Cx43-protein and Cx43-mRNA expression as well as phosphorylation of ERK and translocation of AP1 and CREB only in the CM cultures; whereas, the CM/FB co-cultures and the FB cultures did not respond to isoprenaline. Similarly, if CM and FB were separated by a microporous membrane (Transwell® system) the isoprenaline-induced increase in CM Cx43 was completely suppressed, suggesting the existence of a soluble factor responsible for the suppressant effect of FB. Angiotensin II determination in types 1 and 2 cell culture supernatants revealed that the CM/FB co-cultures exhibited a significant higher angiotensin II release than the CM cultures. Furthermore, we aimed to inhibit angiotensin II signal transduction pathway: blockade of AT₁ receptors or PKC inhibition restored the responsiveness of CM/FB co-cultures to isoprenaline. Moreover, external addition of angiotensin II to CM cultures also resulted in suppression of isoprenaline-stimulated Cx43 expression in an AT₁-receptor- and PKC-dependent manner. Thus, our study indicates that cardiac fibroblasts inhibit β-adrenoceptor-dependent Cx43 signalling in CM involving angiotensin II.     

Korotkoff sound: the cavitation hypothesis

Blood pressure is universally measured by the auscultatory method, but the origin of the Korotkoff sounds remains controversial. A reproducible, brief and high amplitude signal, simultaneous to the Korotkoff sound, and instantly followed by the systolic wave, was recorded amongst ten healthy subjects by a pulsed Doppler examination during the deflation of the sphygmomanometer. A device simulating the brachial artery was also built in order to reproduce the high amplitude signal. It is explained by the cavitation phenomenon which takes place when the blood changes to vapor due to the release of the cuff pressure. With the incoming flow, the cavitation bubbles collapse and the energy is released as noise.     

High-density rafts preferentially host the complement activator measles virus F glycoprotein but not the regulators of complement activation

The fusion (F) protein of measles virus (MeV) activates the alternative pathway of human complement in the presence of both CD46 and CD55 which regulate the complement activation [Devaux, P., Christiansen, D., Plumet, S., Gerlier, D., 2004. Cell surface activation of the alternative complement pathway by the fusion protein of measles virus. J. Gen. Virol. 85, 1665-1673]. The original observation of cold detergent-resistant membranes sedimenting at a higher density than the membrane rafts lead us to analyse the respective distribution of F, CD46 and C55 molecules in what we call heavy rafts (HRs) and in the classical low-density membrane rafts (Rs). Membrane rafts were isolated after cold TX100 solubilization and flotation on a sucrose gradient. The denser fractions collected from the lower part of the gradient could be further separated into a translucent pellet (HR) and a soluble supernatant (S). HR and R were both sensitive to TX100 solubilization after cholesterol depletion and solubilized by octyl-d-glucoside but differed in their lipid and protein composition. A proteomic analysis revealed that the HR fraction was derived from heterogeneous cellular membranes including plasma membrane, early endosomes and rough endoplasmic reticulum. Interestingly, CD55 and CD46 almost exclusively associated with R and S fractions, respectively, while after MeV infection or transient expression, MeV-F distributed almost equally between R, HR and S fractions. However more immature MeV-F(0) than mature MeV-F(1) proteins was associated with the HR fraction whereas this ratio was reverse in R and S fractions. After activation of the alternative pathway of human complement by F expressing cells, both C3b and F protein associated with R, HR and S fractions. When four or five of the five cysteines located in the transmembrane and cytoplasmic tail of F protein were substituted with serine residues, the mutated F distributed almost exclusively in HR fractions and was still efficient in activating the complement. We propose that the partitioning of F, CD46 and CD55 molecules in different membrane microdomains could account for the ability of F to escape complement regulation by the CD55 and CD46 regulators.