The yellow fever vaccine: a history.

After failed attempts at producing bacteria-based vaccines, the discovery of a viral agent causing yellow fever and its isolation in monkeys opened new avenues of research. Subsequent advances were the attenuation of the virus in mice and later in tissue culture; the creation of the seed lot system to avoid spontaneous mutations; the ability to produce the vaccine on a large scale in eggs; and the removal of dangerous contaminants. An important person in the story is Max Theiler, who was Professor of Epidemiology and Public Health at Yale from 1964-67, and whose work on virus attenuation created the modern vaccine and earned him the Nobel Prize.

Hydrochlorothiazide-induced pulmonary edema with severe acute myocardial dysfunction.

A 73-year-old woman presented with acute pulmonary edema and hypotension less than 1 h after taking hydrochlorothiazide 50 mg, a reaction which has been reported as a rare but classic adverse drug response. Though prior cases have supported a noncardiogenic pulmonary edema syndrome, hemodynamic monitoring in this patient demonstrated a refractory low cardiac output state for more than 24 h. In the absence of other etiologies, this represents a new finding.

Isolated bilateral ostial coronary artery stenoses.

Isolated coronary ostial narrowing is rare and most often attributed to atherosclerotic disease of the aorta. A man with isolated, bilateral stenoses of the coronary ostia is presented, who also had severe peripheral vascular disease. A review of previous reports concerning coronary ostial disease is presented.

Is aggressive heparinization necessary for elective PTCA?

The optimal level of heparin anticoagulation for elective PTCA is unknown. To determine if PTCA complications are related to the level of anticoagulation, serial ACT values were prospectively measured in 189 patients undergoing 201 elective PTCA procedures. The mean heparin dose before balloon inflation (pre-inflation) was 10,100 units, and the mean dose per procedure was 13,200 units. The mean pre-inflation ACT was 295 sec, but was < 300 sec in more than 50% of patients. Acute complications were not related to any ACT parameter and the development of new intracoronary thrombus was not observed. In elective PTCA procedures, the routine monitoring of ACT values is unnecessary when standard heparin doses are used.

Effect of Buckberg cardioplegia and peripheral cardiopulmonary bypass on infarct size in the closed chest dog.

OBJECTIVES: To simulate a human catheterization laboratory setting of controlled reperfusion during myocardial infarction, regional infusion of commercially available Buckberg cardioplegic solution and peripheral vented bypass were administered in the closed chest dog. BACKGROUND: Studies in open-chest dogs have demonstrated a significant reduction in infarct size and improvement in regional wall motion with a similar controlled reperfusion method using infusion of substrate-enriched (Buckberg) cardioplegic solution during cardiopulmonary bypass coupled with left ventricular venting. METHODS: After 100 or 180 min of balloon occlusion of the proximal left anterior descending artery, controlled reperfusion was performed with cardioplegic infusion and vented bypass. Dogs matched for occlusion time underwent balloon deflation without bypass or cardioplegia (uncontrolled reperfusion groups). Microspheres were used to quantify coronary ischemia during balloon inflation. All four groups (n = 8 to 9 per group) were followed up at 1 week to determine regional wall motion and infarct size. RESULTS: Qualitative echocardiographic analysis demonstrated no significant difference among groups in recovery of regional wall motion at 1 week; however, wall motion improved significantly in all groups between the ischemia and 1-week recovery periods. The histologic infarct size compared with the area at risk for dogs with uncontrolled versus controlled reperfusion, respectively, was 17.9 +/- 10.5% versus 31.9 +/- 8.3% (p < 0.05) for dogs with 100 min of occlusion and 40.1 +/- 11.7% versus 46.2 +/- 8.4% (p = NS) for dogs with 180 min of occlusion. A greater rate-pressure product in the dogs with controlled reperfusion after 100 min of occlusion (p < 0.05) may explain the larger infarct size observed for that group. CONCLUSIONS: These results demonstrate that regional infusion of substrate-enriched cardioplegic solution in combination with peripheral vented bypass does not further reduce infarct size after prolonged ischemia in the closed chest dog (compared with uncontrolled reperfusion).

A fifty-question self-audit on ADA (American with Disabilities Act) compliance.

Three converging trends should cause employers to go beyond the minimum requirements of the ADA in recruiting, hiring, retaining, and promoting disabled workers. 1. The number of entry-level employees, ages eighteen to twenty-five, is decreasing to the extent that many businesses are finding it difficult to fill open, entry-level job positions. Hiring disabled people can help fill these positions. 2. The Education for the Handicapped Act of 1975 that requires mainstreaming disabled students is responsible for ensuring full educational benefits for all individuals with disabilities. 3. As we become more of an informational society, employees' brainpower becomes more important than their physical abilities. Therefore, effective compliance not only with the letter of the ADA, but also with the spirit of this law is simply good business.

Repeat coronary angioplasty as treatment for restenosis.

Repeat coronary angioplasty has become the standard approach to a first restenosis. However, the long-term outcome of such a strategy is not well defined. In the present study, 465 patients (mean age 58 years [range 27 to 79], 53% with multivessel disease) underwent a second angioplasty procedure at the same site. The procedure was successful in 96.8% with a 1.5% rate of in-hospital bypass surgery, a 0.9% incidence rate of myocardial infarction and no procedural deaths. Four hundred sixty-three patients (99.6%) were followed up for a mean of 40.5 months. Forty-nine patients (10.6%) underwent a third angioplasty procedure at the same site, 55 (11.8%) had coronary bypass surgery and 33 (7.1%) underwent angioplasty at a different site. During follow-up, 12 patients (2.6%) sustained a myocardial infarction and 21 (4.5%) died including 13 (2.8%) with cardiac death. Of the 442 surviving patients, 88% experienced sustained functional improvement and 78% were free of angina. The actuarial 5-year cardiac survival rate was 96% and the rate of freedom from cardiac death and myocardial infarction was 92%. For the subgroup of 49 patients who had a third angioplasty procedure at the same site, the success rate was 93.9% with a 2% incidence rate of myocardial infarction. There were no in-hospital deaths or coronary artery bypass operations. The mean follow-up interval for this subgroup was 30.5 months with a 22.4% cross-over rate to coronary bypass surgery, a 4.1% incidence rate of myocardial infarction and a 2% cardiac mortality rate. At last follow-up, 89% of patients had sustained functional improvement and 76% were free of angina. The combined angiographic and clinical restenosis rate was 48%. Repeat angioplasty as treatment for restenosis is an effective approach associated with a high success rate, low incidence of procedural complications, and sustained functional improvement in combination with an acceptable rate of bypass surgery. However, there is a trend toward diminished angioplasty efficacy after a second restenosis. Thus, decisions for further revascularization should be made after careful review of available options.

Angioplasty of the proximal left anterior descending coronary artery: initial success and long-term follow-up.

From 1984 to 1987, 537 consecutive patients (mean age 58 years; range 34 to 79) underwent angioplasty for proximal left anterior descending coronary artery disease. The procedure was clinically successful in 516 (96.1%). Procedural complications included myocardial infarction (2.2%; Q wave 0.9%, non-Q wave 1.3%), in-hospital bypass surgery (3%) and death (0.4%). Follow-up was obtained in 534 patients (99.8%) for a mean duration of 44 months (range 8 to 75). Follow-up cardiac catheterization, performed in 391 patients (76%), demonstrated a 39.6% angiographic restenosis rate. Ninety-eight (19%) of the patients with a clinically successful result required additional revascularization for recurrent left anterior descending artery disease by angioplasty (12.8%) or coronary artery bypass grafting (4.7%), or both (1.5%). During follow-up there was a 2.5% incidence rate of myocardial infarction (anterior myocardial infarction 1.6%), and 27 patients (5.2%) died, 14 (2.7%) of cardiac causes. The actuarial 5-year cardiac survival rate was 97%, freedom from cardiac death and myocardial infarction was 94% and freedom from cardiac death, myocardial infarction, coronary artery bypass surgery and repeat left anterior descending artery angioplasty was 77%. At last follow-up 76% of patients were free of angina and 88% reported sustained functional improvement. Angioplasty is an effective treatment for proximal left anterior descending coronary artery disease that has a high success rate, low incidence of procedural complications and provides excellent long-term cardiac survival, freedom from cardiac events and sustained functional improvement.

The effects of the ADA on group practice.

In this article, James Frierson, J.D., outlines the requirements for group practices under the Americans with Disabilities Act (ADA). Rules concerning required changes take effect in January of 1993 (and sooner for some groups), making it imperative that group practices be aware of the new law.

Refractory cardiogenic shock and complete heart block after unsuspected verapamil-SR and atenolol overdose.

A 57-year-old female presented with complete heart block and then developed refractory hypotension despite temporary pacing. Moderate left ventricular dysfunction with focal wall motion abnormalities, as well as severe hypoxemia, were demonstrated. However, neither significant coronary disease nor evidence for pulmonary embolus or other lung disease could be determined. Hemodynamic stabilization was achieved with the use of an intra-aortic balloon pump and multiple high-dose pressor agents. A retrospective diagnosis of toxic verapamil-SR and atenolol ingestion was confirmed, and the patient gradually recovered. The relevant literature is reviewed and various treatment approaches are discussed.

Vasodepressor syncope from neck cancer with associated C-6 dermatome neuralgia.

An unusual case of neck cancer with associated C-6 dermatome neuralgia causing vasodepressor syncope episodes is discussed. Pacemaker therapy proved not to be required. When evaluating syncope with bradycardia, it is important to search for underlying causes and to ascertain whether or not pacemaker therapy is indicated.

Anatomical determinants of O2 flux density at coronary capillaries.

Calculations indicate that the PO2 in plasma falls to zero approximately 3 microns from an erythrocyte at O2 consumption (VO2) characteristic of myocardium (Federspiel, W.A., and A. Popel, Microvasc. Res. 32: 164-189, 1986). We measured distances between individual red cells along capillaries in rat hearts rapidly frozen in situ. Cell spacing varied widely even in branches of the same capillary. Plasma gaps between red cells were divided into two populations, those less than 5 microns and those greater than 5 microns. Mean gap lengths were 2.1 and 16.5 microns, respectively. Although the number of long plasma gaps was underestimated, gaps greater than 5 microns accounted for one-third of observed capillary length. Frozen muscles were also viewed in cross section. Because the depth of penetration of light was approximately equal to 3 microns, counts of red cell-containing capillary profiles in cross section depend on cell spacing as well as on number of cell-containing flow paths. Counts varied markedly with arterial O2 partial pressure, indicating that the capillary surface area functional for O2 transport changes in response to stress. The adaptive role of change in O2 flux density (flux per area) is discussed in light of new knowledge of tissue O2 gradients.