Antibody titers to hepatitis B surface antigen among vaccinated emergency physicians: three years' experience with a wellness booth.

STUDY OBJECTIVE: To determine antibody titers to hepatitis B surface antigen (anti-HBsAg) among previously vaccinated emergency physicians and to assess the degree of compliance with Centers for Disease Control and Prevention (CDC) postvaccination guidelines. METHODS: A descriptive analysis was performed of anti-HBsAg titer determinations and vaccination surveys among a self-selected group of emergency physicians attending the annual scientific assembly of the American College of Emergency Physicians in 1995, 1996, or 1997. RESULTS: Of 943 participants, titer levels were found to be protective in 768 (81%), borderline in 45 (5%), and nonreactive in 130 (14%). A total of 337 participants (36%) had not obtained postvaccination titer determinations, as advised by the CDC. More than 50% reported an occupational exposure to blood products within the previous 2 years. CONCLUSION: Despite their high risk for exposure to blood products, many previously vaccinated emergency physicians were not in compliance with CDC postvaccination guidelines.

The presentation of tetanus in an emergency department.

Traditionally, the literature has described a certain population as at risk for tetanus infection. We reviewed the demographics, clinical presentation, laboratory findings, management, and outcome of all patients who presented to our emergency department (ED) with tetanus in the last 10 years and compared our experience with this classic literature. We performed a retrospective case series review at a large, inner-city medical center; 11 cases of tetanus were identified from 1986 to 1997. Nine male and two female patients were identified with an average age of 45 years. All had an acute injury to the skin, and most (82%) reported having no history of recent immunization. The most common recorded symptoms were trismus and rigidity in the abdomen, neck, back, or extremities. There was only one misdiagnosis in the ED. Three patients died in the hospital, while the other eight were discharged either home or to a rehabilitation facility. In contrast to the classic literature, we found that tetanus in our inner city ED presented in recent immigrants, particularly younger men, over half of whom had received no childhood immunization. Laboratory results and cultures are of little diagnostic value, so timely recognition of the clinical presentation is important.

Phototherapy of cancer and atheromatous plaque with texaphyrins.

Cancer and cardiovascular disease are the leading causes of death in the western world. Photodynamic therapy (PDT) has demonstrated activity in the treatment of superficial cancerous lesions and as an intraoperative adjunct during surgical debulking. Texaphyrins are pure, synthetic water-soluble macrocycles that localize in both cancerous lesions and atheromatous plaque. Lutetium texaphyrin (PCI-0123) is activated by tissue-penetrating far red light (720-760 nm). Patient diagnosis and treatment planning is possible via magnetic resonance imaging (MRI) with the paramagnetic gadolinium texaphyrin (PCI-0120) or via fluorescence imaging using the diamagnetic PCI-0123. In this study it is shown that texaphyrins localize selectively in cancer and atheromatous plaque. PDT with PCI-0123 is found to cause selective photodamage to the diseased tissue. Specifically, PCI-0123 acts to eradicate the SMT-F murine mammary tumors and diet-induced atheromatous plaque in rabbits.

Lutetium texaphyrin (PCI-0123): a near-infrared, water-soluble photosensitizer.

Lutetium texaphyrin, PCI-0123, is a pure, water-soluble photosensitizer with a large broad absorption band centered at 732 nm. The compound was tested for photodynamic therapy (PDT) effectiveness in a murine mammary cancer model. The texaphyrin macrocycle as illustrated by magnetic resonance imaging and 14C-radiolabeled texaphyrin studies was shown to be tumor selective; a tumor-to-muscle ratio of 10.55 was seen after 5 h. Lutetium texaphyrin, at a drug dose of 20 mumol/kg with irradiation 5 h postinjection at 150 J/cm2 and 150 mW/cm2, had significant efficacy (P < 0.0001) in treating neoplasms of moderate size (40 +/- 14 mm3) and also had significant efficacy (P < 0.0001) in treating larger neoplasms (147 +/- 68 mm3). The PDT efficacy was correlated with the time interval between PCI-0123 administration and light exposure. A 100% cure rate was achieved when photoirradiation took place 3 h postinjection compared to 50% for 5 h using 10 mumol/kg and 150 J/cm2 at 150 mW/cm2. The PDT efficacy was attributable to the selective uptake/retention of the texaphyrin photosensitizer in addition to the depth of light penetration achievable at the 732 nm laser irradiation.

Gadolinium(III) texaphyrin: a tumor selective radiation sensitizer that is detectable by MRI.

Gadolinium(III) texaphyrin (Gd-tex2+) is representative of a new class of radiation sensitizers detectable by magnetic resonance imaging (MRI). This porphyrin-like complex has a high electron affinity [E1/2 (red.) approximately = -0.08 V versus normal hydrogen electrode] and forms a long-lived pi-radical cation upon exposure to hydrated electrons, reducing ketyl radicals, or superoxide ions. Consistent with these chemical findings, Gd-tex2+ was found to be an efficient radiation sensitizer in studies carried out with HT29 cells in in vitro as well as in in vivo single and multifraction irradiation studies with a murine mammary carcinoma model. Selective localization of Gd-tex2+ in tumors was confirmed by MRI scanning.

Nuclear magnetic relaxation dispersion studies of water-soluble gadolinium(III)-texaphyrin complexes.

Water proton 1/T1 nuclear magnetic relaxation dispersion (NMRD) profiles were measured for a water-soluble gadolinium(III) texaphyrin (Gd-tex) complex as a function of temperature and in the presence and absence of 5% human serum albumin (HSA). Upon dissolving the complex in water (0.259 mM), the water relaxivity values decreased with time but remained higher than those of free GD3+(aq) at all fields. Concurrent measurements of free Gd3+ using metallochromic dyes indicated that demetallation of the texaphyrin did not occur over a period of several days at 37 degrees C. The high relaxivity values and shape of the NMRD profile of this complex may be ascribed to a combination of large water coordination number (q estimated at 3.5) and long tau R. Upon mixing an aqueous solution of the complex with 5% HSA, the low-field water relaxivity slightly decreased whereas the high-field relaxivity increased relative to the free complex in water, and the relaxivities became nearly independent of temperature. These observations indicate that water exchange between the inner coordination sphere of Gd-tex and bulk water becomes limiting in the presence of HSA.

Preclinical evaluation of gadolinium (III) texaphyrin complex. A new paramagnetic contrast agent for magnetic resonance imaging.

RATIONALE AND OBJECTIVES: Gadolinium III texaphyrin (Gd[III] texaphyrin) complex, a new magnetic resonance imaging contrast (MRI) agent, was evaluated. METHODS: In vitro relaxivity (1.5 T) and stability studies (5% dextrose) were conducted. Subchronic toxicity (8 males, 8 females; 2-20 mumol Gd(III) texaphyrin complex/kg body weight; 3 times per week for 3 weeks). Biodistribution and excretion studies were conducted in Sprague-Dawley rats; MRI studies were conducted in normal and tumor-bearing rats and rabbits. RESULTS: Relaxivity values were as follows: r1 = 19 (mumol/L.sec)-1 and r2 = 22 (mumol/L.sec)-1. The 21-day subchronic toxicity study revealed no abnormalities. The compound is stable. Biodistribution demonstrated liver uptake. Magnetic resonance imaging in normal (n = 34) and tumor-bearing (n = 4) rats and normal (n = 8) and tumor-bearing (n = 19) rabbits revealed: significant (P < .05) contrast enhancement of liver and kidney after 1-17 mumol/kg of Gd(III) texaphyrin complex. Gadolinium (III) texaphyrin complex (2.5 mumol/kg) produced significant contrast enhancement of liver carcinomas in rabbits (n = 8). Thigh V2 carcinomas (n = 22) had selective (P < .05) enhancement, 5 mumol/kg. In rat fibrosarcomas (n = 4), 17 mumol Gd(III) texaphyrin complex produced significant enhancement up to 24 hours. CONCLUSIONS: Gadolinium (III) texaphyrin complex appears to be an effective and safe MRI contrast agent.

Effects on hemodynamics and left ventricular ejection fraction of intravenous bepridil for impaired left ventricular function secondary to coronary artery disease.

To define the hemodynamic effects of bepridil in patients with depressed left ventricular (LV) function, 22 patients with an LV ejection fraction (EF) of 0.45 or less were studied before and after 2 mg/kg (n = 11) and 4 mg/kg (n = 11) of intravenous bepridil. Maximal hemodynamic effects were evident between 15 and 30 minutes after drug infusion. After 2 mg/kg, heart rate decreased 9% (p less than 0.01), cardiac index 17% (p less than 0.01), LV dP/dt max 16% (p less than 0.01), stroke work index 14% (p less than 0.01) and mean aortic pressure 8% (difference not significant). Right atrial pressure increased 8% (not significant), pulmonary arterial wedge pressure 24% (p less than 0.01) and systemic vascular resistance 17% (p less than 0.01). After administering 4 mg/kg of bepridil the changes in heart rate, cardiac index, right atrial pressure, LV dP/dt max, mean aortic pressure and systemic vascular resistance were almost identical to those after the smaller dose. The larger dose produced a 40% (p less than 0.01) increase in pulmonary arterial wedge pressure and a 22% decrease in stroke work index (p less than 0.01), but only the change in wedge pressure was significantly greater (p less than 0.01) than that produced by the lower dose. Radionuclide-determined LVEF decreased 6% (p less than 0.05), from 0.33 +/- 0.14 after 2 mg/kg and 11% (p less than 0.05) from 0.27 +/- 0.11 after 4 mg/kg of bepridil. The data indicate that bepridil exerts significant negative inotropic and chronotropic effects in patients with impaired LV function.