Adiposity measures predict olfactory processing speed in older adult carriers of the apolipoprotein E ε4 allele.

OBJECTIVE: The current study investigated the relationship between adiposity and P3 latency. METHODS: Fifty-one adults in two age groups (18-25 and 65+) participated. Odor stimuli were delivered via olfactometer as participants focused on a computer screen. Each stimulus was followed by presentation on the screen of four odor identification choices. Participants attempted identification by button press. Olfactory event-related potentials (OERPs) were recorded. BMI and waist circumference were measured as indicators of adiposity. RESULTS: In bivariate analyses with all participants included, positive correlations for P3 latency with both BMI and waist circumference were observed, indicating that as adiposity increased latencies also increased. When each age group was separately examined, correlations between adiposity measures and latency remained statistically significant for older adults. Furthermore, ApoE ε4 allele status was examined. Latencies remained positively correlated with adiposity in older adult ε4 carriers; but not in non-carriers. CONCLUSIONS: This study indicates that adiposity predicts olfactory processing speed in older adults, specifically in ε4 carriers. SIGNIFICANCE: The results suggest that olfactory processing speed may be a useful measure for detecting and following the effects of adiposity on brain integrity and cognitive function in those at genetic risk for AD.

Chemotherapeutic stress mediated by certain antitumor antibiotics induces an atypical CD69+ surface phenotype in peripheral T-lymphocytes.

Surface antigen CD69 is a Type II integral membrane protein that is generally considered a cell activation marker expressed very early in the normal lymphocyte activation cascade. The conformation of this surface antigen suggests a putative role in transmembrane signal transduction, yet the precise function of this surface antigen has not been clearly elucidated. We had previously reported robust atypical CD69 expression in peripheral T-lymphocytes as concentration-dependent, phenotypic responses to actinomycin D-induced chemotherapeutic stress in the absence of secondary stimulation. Additional antitumor antibiotics were evaluated for inductive potential, and the incidence and respective magnitudes of this chemotherapeutic stress-induced shift in lymphocytic CD69 expression were assessed. Results indicated that atypical CD69 expression is a common response to chemotherapy drug-induced stress. Differences in the respective percentages of CD69 + T-lymphocytes, and the resulting numbers of CD69 surface antigens ultimately expressed by these cells, were documented following in vitro drug exposure. The effective drug concentrations required to mediate detectable shifts in the CD69+ phenotype differed among the selected drugs, as well, suggesting a concentration-dependent induction mechanism putatively related to drug modality. Static CD69 expression responses in CD3+ peripheral T-lymphocytes were also documented, which further suggests that the different intracellular modalities do not mediate proportional T-lymphocyte responses through elevated CD69 expression.

Arthroscopic ankle arthrodesis.

The obvious socioeconomic advantages are quite dramatic, with early weight-bearing and AFO immobilization allowing patients an early return to work. Outpatient surgery is a cost-effective benefit. Patient satisfactions as well as comfort are greatly enhanced, requiring only oral pain medication. All patients have tolerated their postoperative regimen and same-day discharge. Arthroscopic subtalar arthrodesis is a technically demanding procedure that requires some rather advanced arthroscopic skills to perform. Joint access is tight, restricted, and requires small instrumentation. Deformities cannot be corrected; therefore, at this stage, a fusion in situ must be considered. The learning curve is certainly far steeper because of the smaller patient population available for enhancing surgical skills. Overall, this procedure has stood the test of time and follow-up. The results appear to be excellent in terms of patient satisfaction, fusion rate time until union, and postoperative morbidity. The recognition and enhancement of this technique as well as the development of more advanced technology will certainly allow this arthroscopic subtalar arthrodesis technique to mature even further over time.

Olfactory event-related potentials and aging: normative data.

Unlike the clinical usages of evoked potentials (e.g. brain stem auditory evoked potentials for the assessment of auditory function), normative data for the olfactory event-related potential (OERP) have been unavailable. The principal objective was to establish normative data across the human life span for OERPs with a given set of parameters. Participants were 140 persons from seven age groups (16-19, 20-29, 30-39, 40-49, 50-59, 60-69 and 70-79 years of age), with equal numbers of males and females, screened for nasal health and dementia. The odor stimulus was amyl acetate, presented at nasal temperature in a humidified airstream delivered by an air-dilution olfactometer at a constant flow rate, using a 60-s inter-stimulus interval. OERPs were recorded at Fz, Cz, and Pz electrode sites, amplified and averaged over trials. Amplitudes of the N1/P2 and P3 and latencies of the P2 and P3 were analyzed. Processing speed decreased at a constant rate over decades for the sensory (P2 latency) as well as cognitive (P3 latency) components. Decline in amplitude over decades was also apparent. Normative data will be useful in research on olfactory function and in clinical assessment of olfactory functional status.

Developing guidelines for allocating catheterization laboratory resources: lessons from an Ontario Consensus Panel. Consensus Panel on Cardiac Catheterization Laboratory Services in Ontario and the Steering Committee of the Cardiac Care Network of Ontario.

In March 1997, the Ontario Ministry of Health asked the Cardiac Care Network of Ontario (CCN) to develop guidelines for allocating cardiac catheterization laboratory resources. A consensus panel of providers and planners used findings from the literature and expert opinion to recommend guidelines for the operation of cardiac catheterization laboratories and criteria to be considered when allocating additional cardiac catheterization laboratory resources. This article summarizes the consensus panel's major findings that may be of value to other jurisdictions, including need identification, clinical practice, system issues, location criteria and cost considerations. The article reflects the advice given to the Ontario Ministry of Health by the CCN and is not an official position paper of the Canadian Cardiovascular Society.

Shoulder injuries in overhead athletes. The "dead arm" revisited.

The following statements summarize this article: Three distinct categories of Type 2 SLAP lesions exist: (1) anterior, (2) posterior, and (3) combined anteroposterior. Posterior Type 2 SLAP lesions have distinct clinical and anatomic features that distinguish them from anterior Type 2 SLAP lesions. Posterior and combined Type 2 SLAP lesions can be disabling to overhead-throwing athletes because of posterosuperior instability and anteroinferior pseudolaxity. The Jobe relocation test is positive with posterosuperior pain in patients with posterior or combined anterior-posterior Type 2 SLAP lesions and is negative in patients with anterior Type 2 SLAP lesions. Rotator cuff tears are frequently associated with posterior or combined anterior-posterior SLAP lesions, are lesion-location specific, and typically begin from inside the joint as undersurface tears. Repair of posterior SLAP lesions can return overhead-throwing athletes to full overhead athletic functioning. The peel-back mechanism is a likely cause of posterior Type 2 SLAP lesions. To securely repair the posterosuperior labrum to resist torsional peel-back, sulure anchors must be placed posterior to the biceps at the corner of the glenoid. The repair must be protected against external rotation past 0 degree for 3 weeks to avoid undue premature torsional stresses on the repair from the peel-back mechanism. A tight posteroinferior capsule predisposes to Type 2 SLAP lesions in overhead athletes. Shoulders at risk for the dead arm syndrome have a marked loss of internal rotation caused by contracture of the posteroinferior capsule such that less than a 180 degrees arc of rotation is achieved with the arm abducted 90 degrees (the 180 degrees rule). Type 2 SLAP lesions that cause the dead arm syndrome in overhead-throwing athletes are most likely acceleration injuries that occur in late cocking rather than deceleration injuries in follow-through. Rehabilitation of athletes with the dead arm syndrome must include the entire kinetic chain. The root cause of the dead arm syndrome is the Type 2 SLAP lesion.

Relation between infarct artery patency at late angiography after acute myocardial infarction and signal-averaged electrocardiography.

The angiograms of 89 patients were reviewed from the LATE Ancillary Study (randomized trial of recombinant tissue plasminogen activator vs placebo in patients with symptom onset after 6 hours of myocardial infarction) to determine patency of the infarct-related artery (IRA). In the occluded IRA group (n = 35), the incidence of signal-averaged electrocardiographic abnormality (fQRS > 120 ms) was significantly higher (p = 0.04), the filtered QRS duration was significantly longer (p = 0.007), and the V40 was significantly shorter (p = 0.02), compared with the patent IRA group (n = 54).

Olfactory event-related potentials in young and elderly adults: evaluation of tracking task versus eyes open/closed recording.

The purpose of the present study was to evaluate olfactory event-related potentials (OERPs) elicited by amyl acetate from subjects performing a visuomotor tracking task compared with the no-task conditions of eyes open and eyes closed. Task condition did not produce any reliable effects for any amplitude measure. Task type weakly influenced only P2 latency. Elder adults evinced smaller P2 and N1/P2 amplitudes and longer N1 and P2 latencies than young adults. The results suggest that tracking task performance is not necessary to obtain robust OERPs from normal subjects of a wide age range.

Neuropsychological performance and cognitive olfactory event-related brain potentials in young and elderly adults.

The P3 event-related brain potential (ERP) reflects neuroelectric activity related to the speed of cognitive processing and allocation of attentional resources. The objective of the present study was to assess the relationship between the P3 and Slow Wave components of the olfactory event-related potential (OERP) with neuropsychological performance in young (n = 16) and elderly (n = 16) adults. OERPs were recorded monopolarly from midline electrode sites while subjects estimated the odor magnitude of each stimulus, eliciting highly reproducible P3s. Results showed that the late cognitive components (P3 amplitude, P3 latency and Slow Wave area) decline with age and that this decreased neuronal efficiency is associated with reductions in the neuropsychological performance indexed by the Trail Making Test and the California Verbal Learning Test.

Olfactory P3 in young and older adults.

Olfactory event-related potentials (OERPs) were recorded monopolarly at the Fz, Cz, and Pz electrode sites in 16 young adults and 16 older adults to assess aging effects on the olfactory P3. Amyl acetate was used to elicit the OERPs, with an intertrial interval of 45 s. Young adults produced significantly larger P3 amplitudes and shorter P3 peak latencies than older adults. The olfactory P3 response appears to be sensitive to age-related changes in the olfactory system and may reflect cognitive slowing in the central nervous system.

Induction of surface antigen CD69 expression in T-lymphocytes following exposure to actinomycin D.

The expression of surface antigen CD69 in immune response cells is typically associated with the early stage(s) of cell activation, with maximal expression levels within 4 h of appropriate antigenic or mitogenic stimulation, and maintenance of these high expression levels for 18-24 h. The expression profiles of CD69 in human peripheral blood mononuclear cells (PBMC) cultured with actinomycin D prior to mitogenic stimulation were evaluated by direct immunofluorescence using flow cytometry. Pretreatment of PBMC suspensions with low, non-toxic levels of actinomycin D stimulated CD3+ T-lymphocytes to express CD69 in a concentration-dependent manner. Furthermore, CD4+ T-lymphocytes were the primary cells responding in this fashion. Secondary mitogenic stimulation following antibiotic treatment potentiated cellular CD69 expression in these assays. CD69 expression was profoundly suppressed with in vitro actinomycin D concentrations >/=1-2 microg/ml, presumably by interference with cellular transcription/translation mechanisms. Parallel thymidine incorporation assays indicated that actinomycin D effectively inhibited thymidine uptake in a concentration-dependent manner, with complete inhibition at >/=0.1 microg/ml. The evaluation of cell cycling dynamics following antibiotic treatment, with and without secondary mitogen stimulation, indicated no substantial changes in DNA synthesis over controls. The diversity of these responses suggests that expression of CD69 may not solely reflect mitogenic activation status but may, under some conditions, result from induced cellular stress.

Phase 2 studies of adenosine cardioplegia.

BACKGROUND: Laboratory evidence supports the use of adenosine-supplemented cardioplegia. An initial phase 1 dose-ranging clinical evaluation demonstrated that an adenosine concentration of 15 mumol/L could be safely administered with warm blood cardioplegia and suggested that phase 2 studies were warranted. METHODS AND RESULTS: Two separate double-blind, randomized, placebo-controlled trials were performed in patients undergoing primary, isolated, nonemergent coronary artery bypass graft surgery. Patients were randomized to receive adenosine 15 mumol/L versus placebo in the first study (n = 200) and adenosine 50 or 100 mumol/L versus placebo in the second study (n = 128). Adenosine was infused with both initial and final doses of warm antegrade blood cardioplegia. The data from the 2 trials were combined using the methods of Mantel and Haenszel, and the results of the meta-analysis are presented as the relative risk with their associated 95% confidence intervals (CI). The different study groups were comparable with respect to all preoperative clinical characteristics, angiographic findings, and intraoperative variables. In both trials 1 and 2, no differences were found between groups in the incidence of the individual primary or secondary outcomes. Similarly, when both studies were combined, there was no significant evidence of any consistent treatment benefit (primary: death: relative risk [RR] = 1.02, 95% CI = 0.06, 16.6; myocardial infarction by CK-MB: RR = 0.84, CI = 0.54, 1.31; low output syndrome: RR = 1.38, CI = 0.29, 6.42; any of the above: RR = 0.98, CI = 0.78, 1.25; secondary: Q-wave myocardial infarction: RR = 1.30, CI = 0.41, 4.13; myocardial infarction by troponin T: RR = 0.7, CI = 0.40, 1.21; inotrope requirement: RR = 0.9, CI = 0.46, 1.79; intra-aortic balloon pump requirement: RR = 0.6, CI = 0.07, 4.81; P > 0.20). CONCLUSIONS: Despite promising experimental data, adenosine supplementation of warm blood cardioplegia did not demonstrate any statistically significant benefit in patients undergoing elective coronary artery bypass graft surgery. Although sample sizes were relatively small, based on our interim analyses, it is unlikely that increased patient enrollment would reveal any substantive clinical differences between groups.

The accuracy and interobserver agreement in detecting the 'gallop sounds' by cardiac auscultation.

STUDY OBJECTIVES: To determine the observer accuracy and interobserver agreement in identifying S4 and S3 by cardiac auscultation and whether they improve with increasing observer experience. DESIGN: Prospective, blinded study. SETTING: Cardiology and general internal medicine wards in a university-affiliated teaching hospital. PATIENTS: Forty patients with a cardiac diagnosis and 6 patients without were studied. MEASUREMENTS AND RESULTS: Two cardiologists, one general internist, three senior and two junior postgraduate internal medicine trainees, blinded to the patients' characteristics, examined the patients and documented their findings on a questionnaire. Computerized phonocardiogram was obtained in all patients as a gold standard and was interpreted by a blinded, independent cardiologist. The mean positive predictive values for S4 and S3 were 51% (range, 24 to 100%) and 71% (range, 50 to 88%), respectively. The mean negative predictive values for S4 and S3 were 82% (range, 67 to 94%) and 64% (range, 56 to 85%), respectively. The overall interobserver agreements for detecting S4 was K = 0.05 (95% confidence interval [CI], 0.01 to 0.09) and S3 was K = 0.18 (95% CI, 0.13 to 0.24). There was no apparent trend in the accuracy or interobserver agreement with regard to the level of observer experience. CONCLUSION: The agreement between observers and the phonocardiographic gold standard in the correct identification of S4 and S3 was poor and the lack of agreement did not appear to be a function of the experience of the observers. The overall interobserver agreement for the detection of either S4 or S3 was little better than chance alone.

Cardiac murmur associated with an abnormal chest x-ray film.

Investigation of a cardiac murmur and thrill in an asymptomatic 35-year-old man revealed a foreign body lying within the left ventricular cavity. Upon questioning, the man revealed that he had been shot in the chest years earlier. This is the first reported adult case of a retained intracardiac bullet causing a ventricular septal defect.

Type II SLAP lesions: three subtypes and their relationships to superior instability and rotator cuff tears.

One hundred two type II SLAP lesions without associated anterior instability, Bankart lesion, or anterior inferior labral pathology were surgically treated under arthroscopic control. There were three distinct type II SLAP lesions based on anatomic location: anterior (37%), posterior (31%), and combined anterior and posterior (31%). Preoperatively, the Speed and O'Brien tests were useful in predicting anterior lesions, whereas the Jobe relocation test was useful in predicting posterior lesions. Rotator cuff tears were present in 31% of patients and were found to be lesion-location specific. In posterior and combined anterior-posterior lesions, a drive-through sign was always present (despite absence of anterior-inferior labral pathology or a Bankart lesion) and was eliminated by repair of the posterior component of the SLAP lesion. We conclude that SLAP lesions with a posterior component develop posterior-superior instability that manifests itself by a secondary anterior-inferior pseudolaxity (drive-through sign), and that chronic superior instability leads to secondary lesion-location-specific rotator cuff tears that begin as partial thickness tears from inside the joint.

The peel-back mechanism: its role in producing and extending posterior type II SLAP lesions and its effect on SLAP repair rehabilitation.

A previously undescribed mechanism of injury for posterior Type II SLAP lesions is described. The primary feature of this mechanism is a torsional peel-back of the posterosuperior labrum. Secure fixation by posterior-superior placement of suture anchors into the posterosuperior corner of the glenoid is essential. The repair must be protected against torsional peel-back forces by avoiding external rotation beyond 0 degrees for 3 weeks.

Analysis of deaths while waiting for cardiac surgery among 29,293 consecutive patients in Ontario, Canada. The Steering Committee of the Cardiac Care Network of Ontario.

OBJECTIVES: To assess death rates among patients waiting for cardiac valve surgery or isolated coronary artery bypass surgery (CABG), and to determine independent risk factors for death while waiting for isolated CABG. DESIGN: Prospective cohort analysis based on an inclusive registry. SETTING: Nine cardiac surgical units in Ontario, Canada. PATIENTS: 29,293 consecutive patients scheduled for cardiac surgery between October 1991 and June 1995. MAIN OUTCOME MEASURES: Death rates while waiting for surgery were determined among patients scheduled for isolated CABG, isolated valve surgery, or combined procedures. Predictors of death among patients with isolated CABG were determined from multivariate analysis. RESULTS: There were 141 deaths (0.48%) among 29,293 patients. Adjusting for age, sex, and waiting time, patients waiting for valve surgery had a significantly increased risk of death compared with patients waiting for CABG alone (adjusted odds ratio 1.88, 95% confidence interval (CI) 1.23 to 2.88, p = 0.004). Results were similar for patients waiting for combined valve and CABG procedures compared with those who were waiting for isolated CABG. Independent risk factors for death while waiting for isolated CABG included: impaired left ventricular function (odds ratio 2.47, 95% CI 1.59 to 3.84, p < 0.001); advancing age (for each decade, odds ratio 1.41, 95% CI 1.10 to 1.80, p = 0.007); male sex (odds ratio 1.95, 95% CI 1.00 to 3.81, p = 0.05); and waiting longer than the maximum time recommended in Canadian guidelines for a patient's clinical profile (odds ratio 1.59, 95% CI 1.01 to 2.51, p = 0.044). After scaling waiting time to surgery or death continuously in days, the same predictors emerged. CONCLUSIONS: Patients waiting for valve surgery have a higher risk of death than patients waiting for isolated CABG. Guidelines to promote safer and fairer queuing for non-CABG cardiac surgery are needed. Shorter waiting lists, better compliance with existing guidelines, and guideline revisions to upgrade patients with left ventricular dysfunction could generate additional reductions in the already low risk of death for patients waiting for isolated CABG.

Discriminant validity of the SCL-90 dimensions of anxiety and depression.

Although the SCL-90 and other self-report measures of anxiety and depression have long been criticized for inadequate factor structure and unacceptably high correlations with each other, recent evidence indicates the use of homogeneous samples results in greatly improved discriminant validity. This study utilized homogeneous samples of anxious (N = 54) or depressed (N = 120) outpatients and a factor analysis was conducted on their responses to the depression and anxiety items on the SCL-90. Clearly separate factors for anxiety and depression emerged. Results are discussed with respect to implication for measures of depression and anxiety.