Lithium dilution cardiac output measurement: a comparison with thermodilution

OBJECTIVE: To compare the results of cardiac output measurements obtained by lithium dilution and thermodilution. DESIGN: Case series, observational study. SETTING: High-dependency postoperative unit and intensive care unit of a teaching hospital. PATIENTS: Forty patients were studied. Thirty-four patients had undergoing heart surgery requiring cardiopulmonary bypass within the previous 2 days; the diagnoses in the other patients were myocardial infarct (n = 2), septicemia (n = 2), adult respiratory distress syndrome, and pericardectomy. INTERVENTIONS: Cardiac output was measured five times in each patient, using lithium dilution (single measurement) and bolus thermodilution (series of three to six measurements according to standard clinical practice, taking the average of the closest three). In a subgroup of 14 patients, cardiac output was also measured using "continuous thermodilution." MEASUREMENTS AND MAIN RESULTS: Comparing lithium dilution with bolus thermodilution, the mean of the differences (lithium dilution-thermodilution) was -0.25 +/- 0.46 [SD] L/min. Linear regression analysis gave y = 0.31 + 0.89x (r2 = .94) for lithium dilution vs. thermodilution. CONCLUSIONS: The overall agreement between the two methods was good. The variability of the thermodilution measurements was greater than that of the lithium dilution measurements. The lithium dilution method is at least as accurate as bolus thermodilution and, since pulmonary artery catheterization is not needed, it has the advantages of being safe and quick to perform.     

Operation compatibility: A neglected contribution to dual-task costs.

Traditionally, dual-task interference has been attributed to the consequences of task load exceeding capacity limitations. However, the current study demonstrates that in addition to task load, the mutual compatibility of the concurrent processes modulates whether 2 tasks can be performed in parallel. In 2 psychological refractory period experiments, task load and process compatibility were independently varied. In Experiment 1, participants performed 2 mental rotation tasks. Task load (rotation angle) and between-task compatibility in rotation direction were varied. Results suggest more considerable parallel execution of compatible than of incompatible operations, arguing for the need to attribute dual-task interference not only to structural but also to functional capacity limitations. Experiment 2 tested whether functional capacity limitations to dual-task performance can be caused only by demanding processes or whether they are also induced by relatively automatic processes. Results indicate that an irrelevant circular movement of Stimulus 2 interfered more with mental rotation of Stimulus 1 if the rotation directions were opposite than if they were equal. In conclusion, compatibility of concurrent processes constitutes an indispensable element in explaining dual-task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The localization of synaptophysin in the organ of Corti of the human as shown by immunoelectron microscopy

Synaptophysin, or p38, a polypeptide of molecular weight 38 kD, is a calcium-binding membrane protein found in synaptic vesicles of neurons and smooth surfaced vesicles of neuroendocrine cells. Six human neonatal and infant temporal bones were fixed in paraformaldehyde and glutaraldehyde, decalcified in EDTA and were than immunoreacted for synaptophysin (ICN Biomedicals) using the avidin-biotin reaction (ABC kit, Vector Labs). The tissue was then prepared for light microscopic surface preparation, radial sections of 5 microns, and serial section electron microscopy. At a light microscopic level, the inner spiral bundle, tunnel spiral bundle, upper tunnel crossing fibers and the base of outer hair cells were stained. At the base of outer hair cells, the immunoreactivity was seen to decrease from the base to the apex and from the first to third outer hair cells. At an electron microscopic level, immunoreactivity at the base of outer hair cells was limited to vesiculated efferent fibers. The degree of immunoreactivity between adjacent efferent fibers varied significantly. Immunoreactive vesiculated endings were also found in the supranuclear region of outer hair cells.     

Selective inactivation of glyceraldehyde-3-phosphate dehydrogenase by vinyl sulfones

Incubation of glyceraldehyde-3-phosphate dehydrogenase with vinyl sulfones resulted in a pseudo first-order loss of enzyme activity. The selective inactivation of the enzyme by vinyl sulfones is suggested from the structural requirement analysis and the enzyme susceptibility test. The enzyme inactivation was strongly reduced in the presence of NAD or glyceraldehyde-3-phosphate, and the prior treatment of the enzyme with 5,5'-dithio-bis-(2-nitrobenzoic acid) prevented the enzyme from the inactivation by vinyl sulfones (> or = 90%). Moreover, the early rapid phase of inactivation was much more responsive to L-cysteine reactivation, compared with the slower phase. Based on these results, it is proposed that vinyl sulfones inactivate the enzyme by inducing the oxidation of cysteine residue and/or covalent binding to cysteine residue in active site.     

What is the role of reassessment laparoscopy in the management of gynecologic cancers in 1995?

One hundred fifty-four patients with a diagnosis of ovarian, primary peritoneal, or fallopian tube carcinoma underwent 181 reassessment procedures to detect persistent or recurrent disease between January 1, 1989 and December 31, 1994 at Cedars-Sinai Medical Center. One hundred four laparoscopic procedures were performed. Eleven of these procedures were converted to laparotomy due to severe adhesions. Therefore, a total of 88 reassessment laparotomies were performed during the study period. Fifty-seven of 93 laparoscopies and 69 of 88 laparotomies were done as second-look procedures. There was no significant difference between the two groups with respect to patient age, tumor histology, degree of primary cytoreduction, and tumor stage or grade. Significant differences were found between laparoscopy and laparotomy groups in the following outcome variables evaluated: estimated blood loss (33.9 ml vs 164.9 ml, P = 0.0001), operative time (81.3 min vs 130.4 min, P = 0.0001), days of hospitalization (0.3 days vs 6.8 days, P = 0.0001), and direct cost/case ($2765 vs $5420, P = 0.0001). Despite obtaining 50% fewer biopsies with laparoscopy than laparotomy, the ability to detect disease was similar between these two groups: 47.3% vs 55.7% for all procedures and 52.6% vs 53.6% in the patients undergoing second-look procedures. Major complications in the laparoscopy group included transverse colon perforation (1), small bowel perforation (2), enterocutaneous fistula (1), and a retroperitoneal hematoma (1). Major complications in the laparotomy group included cystotomy (1), left ureteral injury (1), enterotomy (2), and SBO (4). Laparoscopy, when technically feasible, appears equally as effective as laparotomy in detecting persistent or recurrent malignant disease with less blood loss, less days spent in the hospital, less financial burden, and no increase in patient morbidity.