What is the optimal channel density for transmyocardial laser revascularization?

BACKGROUND: Transmyocardial laser revascularization (TMR) has demonstrated reproducible relief of angina in patients with end-stage coronary disease. However, the optimum dose or channel density has not been elucidated. METHODS: Using a porcine model of chronic myocardial ischemia, 14 animals were treated with CO2 TMR and randomized as follows: group 1 was 1 channel per 2 cm2; group 2 was 1 channel per 1 cm2; and group 3 was 2 channels per 1 cm2. Left ventricular myocardial viability and function were assessed by magnetic resonance imaging (MRI) and echocardiography pretreatment, and repeated 6 weeks later. RESULTS: The MRI assessment of group 1 (1 channel/2 cm2) and group 2 (1 channel/cm2) demonstrated similar improvement in segmental contractility posttreatment of 12.11% +/- 5.15% and 12.47% +/- 9.51%, respectively. In contrast, group 3 (2 channels/cm2) showed significantly worse segmental contractility posttreatment: -18.52% +/- 7.16% (p = 0.01). Echocardiographic imaging revealed significant improvements in wall thickening in the ischemic zone for group 1 at 0.91 +/- 0.07 cm pretreatment versus 1.30 +/- 0.09 cm posttreatment, (p = 0.01); and for group 2 at 0.93 +/- 0.11 cm versus 1.42 +/- 0.18 cm, (p = 0.01). No significant improvement in wall thickening was seen in group 3 (0.84 +/- 0.06 cm versus 0.88 +/- 0.09 cm, p = n.s.). CONCLUSIONS: These data corroborate the empiric finding of an effective therapeutic dose range for TMR, 1 channel per 1 to 2 cm2. These results also demonstrate a detrimental effect when channel density is increased above the clinical standard of 1 channel per cm2 to a density of 2 channels per 1 cm2.

HIV type 1 and cytomegalovirus coinfection in the female genital tract.

The relationship between human immunodeficiency virus (HIV) type 1 and human cytomegalovirus (CMV) was studied in blood, saliva, and cervicovaginal lavage (CVL) specimens from 33 HIV-1-infected women. An association between HIV-1 RNA and CMV DNA was found in the CVL specimens, which also were tested for cytokine levels. Women with detectable CMV DNA in CVL specimens were more likely to have higher interleukin (IL)-1 beta and IL-8 levels than were women with undetectable CMV DNA in CVL specimens. More than 1 strain of CMV was detected in specimens from 2 patients. These results suggest mechanisms by which CMV coinfection could affect HIV-1 disease progression.

Analysis and characterization of antiviral drug-resistant cytomegalovirus isolates from solid organ transplant recipients.

The development of cytomegalovirus (CMV) disease and subsequent emergence of drug-resistant strains was examined in a large group of solid organ transplant recipients; drug-resistant CMV was detected in a total of 30 transplant recipients (20 lung, 5 kidney, 4 heart, and 1 liver). Drug resistance was confirmed both phenotypically and genotypically. The sequences of drug-resistant CMV strains from the same patient differed from drug-susceptible baseline sequences only at single sites previously confirmed to confer drug resistance. At least 1 isolate from each patient had a mutation in the UL97 phosphotransferase coding sequence. Mutations in the DNA polymerase gene were found in 6 of 38 sequenced strains. Lung transplant recipients had the highest incidence of drug-resistant virus: of the 30 patients, 28 were CMV-seronegative transplant recipients of CMV-seropositive organs, which strongly supports the premise that drug resistance is most prevalent in that transplant population.