Perioperative resuscitation knowledge base

PURPOSE: To assess the knowledge base of Canadian anesthesiologists regarding the management of perioperative cardiac arrest. METHODS: A random sample of 200 Canadian Anesthesia Society members were mailed a survey composed of 10 clinical vignettes, each involving a special perioperative resuscitation situation, with six multiple choice options for optimum management. Fourteen possible "lethal errors" (options which are unequivocally harmful to the patient) were identified among the possible choices. Each question had a single correct answer and contributed a single point towards a possible maximum of ten. An arbitrary passing score of 70%, similar to the American Heart Association (AHA) standard for Advanced Cardiac Life Support course (ACLS), was selected. Respondents were asked demographic information including: time since completing residency, time since last ACLS course, provision of cardiac anesthesia and attitude towards utility of AHA protocols in anesthesia practice. RESULTS: A total of 124 surveys were returned. The median score was five with a range of scores from zero to nine. Fifty-eight (56.3%) participants chose at least one "lethal error". Only 17 respondents (13.7%) attained the minimum score of 70% and avoided a "lethal error". Respondents who practiced cardiac anesthesia tended to achieve higher scores (P < 0.05) than generalists. All but one participant indicated that a Continuing Medical Education resource covering this material would be useful. CONCLUSIONS: This survey demonstrates a knowledge deficit concerning special perioperative resuscitation situations. Development of further appropriate research and educational material in this area is justified.     

Antiamphiphysin antibodies are associated with various paraneoplastic neurological syndromes and tumors

BACKGROUND: Antiamphiphysin antibodies react with a 128-kd protein found in synaptic vesicles.They were first described in patients with paraneoplastic stiff-man syndrome and breast cancer, but studies suggest that they can also occur in patients with other tumors and neurological disorders. OBJECTIVE: To determine if antiamphiphysin antibodies are associated with various paraneoplastic neurological syndromes and tumors. PATIENTS AND METHODS: Of 2800 serum samples tested by routine immunohistochemical procedures on sections of paraformaldehyde-fixed rat brain for the detection of autoantibodies associated with paraneoplastic neurological syndromes, 5 were selected because of labeling suggestive of antiamphiphysin antibodies and subsequently confirmed by the results of Western blot analysis using recombinant amphiphysin protein. Controls consisted of 40 patients with various nonparaneoplastic neurological diseases; 101 patients with cancer but without paraneoplastic neurological syndrome; 9 patients with small cell lung cancer, anti-Hu antibodies, and paraneoplastic neurological syndrome; 3 patients with M2-type antimitochondrial antibodies but no neurological disorder; and 30 normal subjects. RESULTS: Of the 5 patients with antiamphiphysin antibodies, patient 1 had sensory neuronopathy, encephalomyelitis, and breast cancer; patient 2 had limbic encephalitis, and small cell lung cancer was detected in the mediastinum after 24 months of follow-up; patient 3 had encephalomyelitis and ovarian carcinoma; and patients 4 and 5 had Lambert-Eaton myasthenic syndrome and small cell lung cancer (patient 4 subsequently developed cerebellar degeneration). None of the 5 had stiffness. Two patients (Nos. 2 and 4) had antimitochondrial antibodies. The two patients (Nos. 4 and 5) with Lambert-Eaton myasthenic syndrome had antibodies directed against the voltage-gated calcium channel, and patient 2 subsequently developed anti-Hu antibodies. In the controls, antiamphiphysin antibodies were detected by Western blot analysis in 3 of 8 patients with anti-Hu antibodies, but in none of the other groups. CONCLUSIONS: These data indicate that antiamphiphysin antibodies are not specific for one type of tumor or one neurological syndrome and can be associated with other neural and nonneural antibodies. The simultaneous association of several antibodies in some patients suggests multimodal autoantibody production.     

Pretranslational up-regulation of the hepatic microsomal delta4-3-oxosteroid 5alpha-oxidoreductase in male rat liver by all-trans-retinoic acid.

Administration of all-trans-retinoic acid (ATRA; 60 mg/kg daily for 3 days) to male rats increased the rate of 5alpha-dihydrotestosterone (5alpha-DHT) formation from testosterone in microsomal fractions in vitro. The formation of androstane-3alpha,17beta-diol from testosterone was also increased because of the higher concentration of 5alpha-DHT produced in microsomal incubations. Northern analysis confirmed that the increased rate of 5alpha-DHT formation was due to the pretranslational up-regulation in delta4-3-oxosteroid 5alpha-oxidoreductase (EC 1.3.99.5) mRNA expression in ATRA-treated male rat liver. Thus, ATRA elicited in male rat liver a partial feminization of the expression of this enzyme, which normally exhibits a female-selective distribution in the rat. Subsequent experiments evaluated whether the administration of human chorionic gonadotropin or thyroxine to ATRA-treated male rats decreases 5alpha-reductase activity to that observed in untreated male rat liver. Although these treatments did not decrease 5alpha-reductase to untreated male levels, it was found that administration of ATRA to gonadectomized male rats produced complete feminization of the enzyme. Again, up-regulation was confirmed at the mRNA level. The activity of the male-specific cytochrome P450 2C11 (as reflected by microsomal testosterone 16alpha-hydroxylation activity) was correspondingly decreased by treatments that increased steroid 5alpha-reductase activity. Thus, gonadectomy in combination with ATRA administration effected a more pronounced decrease in 16alpha-hydroxylation activity than either treatment alone. These findings suggest that ATRA is a novel positive regulator of the 5alpha-reductase that in combination with the removal of circulating androgen, which normally suppresses 5alpha-reductase levels, feminizes the expression of this enzyme in rat liver.     

Cross-linking and sequence-specific alkylation of DNA by aziridinylquinones. 3. Effects of alkyl substituents.

The cytotoxicities and DNA cross-linking abilities of several alkyl-substituted diaziridinylquinones have been investigated. The cytotoxicities were determined in DT-diaphorase-rich (H460 and HT29) and -deficient (H596 and BE) cell lines. It was shown that the cytotoxicities in these cell lines correlated with the relative rates of reduction by the purified human enzyme and with the cross-linking efficiencies. The rates of reduction by DT-diaphorase were more dependent on the structures of the compounds than the reduction potentials, as determined by cyclic voltammetry. A computer model was also used to explain high efficiency of cross-linking and the GNC sequence selectivity of the reduced methyl-substituted diaziridinylquinones.     

Visual perceptions of head-fixed and trunk-fixed anterior/posterior axes

The purpose of the present experiment was to determine the preferred visual straight ahead or anterior/posterior (a/p) axis at the perceptual level. The ability of 12 neurologically normal, young adult subjects to position a rod parallel to the head and trunk a/p axes while viewing eccentrically located visual targets were studied under six conditions: 1. fixed — subjects stood erect with the head aligned to the trunk and viewed a central target while visually aligning a hand-held rod to the head and trunk a/p axis. 2. eyes — subjects moved only their eyes to view eccentric targets and aligned the rod to the head and trunk a/p axis. 3. head-trunk — subjects viewed the eccentric targets by rotating the head about a vertical axis and aligned the rod to the trunk a/p axis. 4. head-head — subjects viewed the targets as in 3 and positioned the rod parallel to the head a/p axis. 5. trunk-head — subjects viewed the targets by rotating the trunk and head as a unit about the vertical axis and aligned the rod parallel to the head a/p axis (note that the head and trunk a/p axes were misaligned by the experimenter prior to target viewing). 6. trunk-trunk — subjects viewed targets as in 5 and positioned the rod parallel to the trunk a/p axis. Subjects performed 25–35 consecutive trials within each condition. Perceptual errors were similar for aligning the rod to the trunk and head a/p axes; however, moving the trunk produced much larger constant and variable perceptual errors than moving the head. In a second experiment, four subjects controlled the position of a lighted rod held by a robot arm in complete darkness. They were instructed to align the rod to either the head or trunk a/p axis under conditions similar to the fixed, head-trunk, and head-head tasks described above. Perceptual errors were much larger when aligning the rod to the head a/p axis than to trunk a/p axis when the head was moved. This shows that the trunk a/p axis is clearly preferred at the perceptual level when visual background cues are not present.These data strongly suggest that the visual coordinate system uses a trunk-fixed a/p axis to define the subjective straight-ahead direction and right/left position of a target. Implications of these findings for sensorimotor transformations in control of upper limb movements to visual targets are discussed.     

Malignant lymphoma, small lymphocytic type: a clinicopathologic study of 84 cases with suggested criteria for intermediate lymphocytic lymphoma.

Clinical and histopathologic findings were reviewed in 84 cases of malignant lymphoma of the small (well differentiated) lymphocytic type. The slides were studied without clinical information, and the following morphologic features were evaluated: pattern of growth, number of large lymphocytes, mitotic rate, degree of capsular involvement, presence of plasma cells and/or plasmacytoid lymphocytes, and presence of residual germinal centers. Subsequently, clinical information was obtained. The minimum follow-up period on living patients was 5 years. The patients were divided into 3 clinical categories: 1) monoclonal gammopathy (MG)-11 cases, 2) chronic lymphocytic leukemia (CLL) without MG-56 cases, and 3) those without MG or CLL at the time of lymph node biopsy-17 cases. The criterion for CLL was an initial absolute lymphocyte count less than 4000/mm3. Four of the patients with MG also had CLL, and 6 of those in the third group later developed CLL, from 1 to 61 months after lymph node biopsy. Generalized lymphadenopathy was the usual presentation in all 3 groups, and bone marrow examination was positive in all but 1 of the 49 cases, representing all 3 groups, in which it was performed. Median survival for the 84 patients was 51 months. The only clinical parameters which showed a significant association with poorer survival were age above 60 and anemia (Hb. conc. less than 11.0). There was no significant relationship between morphologic characteristics and clinical categories other than the association of plasmacytoid cells with MG in 6 cases. A mitotic rate of 30 or more mitoses per 20 high power fields (HPF), found in 5 cases with at least 1 in each clinical category, showed a highly significant association with decreased survival (p = .01). Variations in mitotic rate between 0 and 29 mitoses per 20 HPF and other morphologic parameters did not show a significant relationship with prognosis. It was concluded that malignant lymphoma of the small lymphocytic type is a definite clinicopathologic entity which may or may not exhibit MG or CLL, and it is proposed that the term "intermediate lymphocytic lymphoma" be applied only to those cases showing histopathologic characteristics of small lymphocytic lymphoma and a mitotic rate of 30 or more mitoses per 20 HPF.