Oral antibiotic treatment of right-sided staphylococcal endocarditis in injection drug users: prospective randomized comparison with parenteral therapy.

PURPOSE: To compare the efficacy and safety of inpatient oral antibiotic treatment (oral) versus standard parenteral antibiotic treatment (intravenous) for right-sided staphylococcal endocarditis in injection drug users. PATIENTS AND METHODS: In a prospective, randomized, non-blinded trial, febrile injection drug users were assigned to begin oral or intravenous (IV) treatment on admission, before blood culture results were available. Oral therapy consisted of ciprofloxacin and rifampin. Parenteral therapy was oxacillin or vancomycin, plus gentamicin for the first 5 days. Antibiotic dosing was adjusted for renal dysfunction. Administration of other antibacterial drugs was not permitted during the treatment or follow-up periods. Bacteremic subjects having right-sided staphylococcal endocarditis received 28 days of inpatient therapy with the assigned antibiotics. Test-of-cure blood cultures were obtained during inpatient observation 6 and 7 days after the completion of antibiotic therapy, and again at outpatient follow-up 1 month later. Criteria for treatment failure and for drug toxicity were prospectively defined. RESULTS: Of 573 injection drug users who were hospitalized because of a febrile illness and suspected right-sided staphylococcal endocarditis, 93 subjects (16.2%) had two or more sets of blood cultures positive for staphylococci; 85 of these bacteremic subjects (14.8%) satisfied diagnostic criteria for at least possible right-sided staphylococcal endocarditis (no other source of bacteremia was apparent) and entered the trial. Forty-four (oral, 19; IV, 25) of these 85 subjects completed inpatient treatment and evaluation including test-of-cure blood cultures. There were four treatment failures (oral, 1 [5.2%]; IV, 3 [12.0%]; not significant, Fisher's exact test). Drug toxicity was significantly more common in the parenterally treated group (oral, 3%; IV, 62%; P < 0.0001), consisting largely of oxacillin-associated increases in liver enzymes. CONCLUSIONS: For selected patients with right-sided staphylococcal endocarditis, oral ciprofloxacin plus rifampin is effective and is associated with less drug toxicity than is intravenous therapy.

CNS vasculitis in autoimmune disease: MR imaging findings and correlation with angiography.

BACKGROUND AND PURPOSE: MR findings in CNS vasculitis and their correlation with angiography have not been clearly defined. We therefore explored three hypotheses regarding CNS vasculitis associated with autoimmune disease: 1) MR imaging is highly sensitive; 2) a typical MR appearance exists; and, 3) MR and angiographic findings correlate well. METHODS: We studied 18 patients with CNS vasculitis associated with autoimmune disease, characterized the MR lesions by type, size, number, and location, and correlated the MR findings with those of angiography. RESULTS: All patients with CNS vasculitis had abnormalities on MR studies. On average, four +/- two lesions per patient were detected on MR images. The lesions were located in the subcortical white matter (n = 20), cortical gray matter (n = 16), deep gray matter (n = 16), deep white matter (n = 9), and cerebellum (n = 9). Only 65% of MR lesions were evident on angiograms; 44% of the lesions revealed on angiograms were detected by MR. CONCLUSION: MR imaging is sensitive for CNS vasculitis. Lesions attributable to CNS vasculitis in autoimmune disease are distributed nearly equally among cortical, subcortical, and deep gray matter structures. The modest correlation between MR imaging and angiography suggests that the two techniques provide different information about CNS vasculitis and that both types of studies are needed for the complete assessment of damage caused by vascular abnormalities.

Adenosine receptor blockade with 8-p-sulfophenyltheophylline aggravates coronary constriction.

We examined the role of adenosine in modulating the coronary constrictor effect of neuropeptide Y (NPY). Anesthetized dogs (n = 22) were instrumented to record hemodynamics and to collect arterial and coronary venous blood. In control dogs (n = 7), during the first 30 min before NPY, baseline coronary resistance fell slightly. By 10 min after NPY (42 nmol over 4 min), coronary resistance was increased by 30% and fell slowly to pre-NPY levels over the ensuing hour. Intravenous (7.5 mg/kg, n = 3) or intracoronary (to 100 microM arterial concentration, n = 12) infusion of 8-p-sulfophenyltheophylline (8-THEO) blocked the vasodilator effects of adenosine but did not alter the peak dilation seen with papaverine or reactive hyperemia. Over 30 min before NPY, infusion of 8-THEO increased baseline resistance by 31% as it reduced coronary blood flow, despite no change in other hemodynamic parameters or myocardial oxygen consumption. The coronary constrictor effect of NPY was magnified in the presence of adenosine receptor blockade. At 3 min, coronary resistance was increased by 34%, at 5 min by 52%, and at 10 min by 59%. The effect of adenosine receptor blockade on constriction due to NPY could not be attributed to a nonspecific alteration in cardiac function or oxygen consumption. In addition, the increase in baseline coronary resistance following receptor blockade correlated with the worsening of the coronary constriction following NPY (r = 0.48, P less than 0.05). Thus it appears that adenosine modulates an imposed constriction of coronary vessels and acts as a "host defense" to restore coronary tone toward normal.