Effect of isosorbide mononitrate on the human optic nerve and choroidal circulations

AIMS: To assess the effects of the nitric oxide donor 5-isosorbide mononitrate (ISMO) on blood flow in the optic nerve head (ON flow) and choroid (Ch flow). METHODS: Laser Doppler flowmetry was used to measure ON flow and Ch flow in 12 normal subjects by aiming the laser beam at the fovea and at the temporal rim, respectively. In a double masked, randomised, crossover design, each subject received orally on separate days either 20 mg of 5-isosorbide mononitrate (ISMO) or placebo. Ch flow and ON flow were determined monocularly at baseline and 1 hour after dosing. In the last six subjects, additional measurements were obtained at 3 hours. Mean arterial blood pressure (BPm), heart rate, and intraocular pressure (IOP) were monitored, and ocular perfusion pressure (PP) was estimated. RESULTS: No significant changes in ON flow, PP, IOP, or BPm were observed following placebo. Following ISMO, ON flow increased from baseline by 19.8% (SEM 9.3%) at 1 hour (paired t test, p = 0.058) and by 33.1% (7.5%) at 3 hours (p = 0.007). Compared with the changes following placebo, statistically significant increases in ON flow were observed both at 1 (p = 0.050) and 3 hours (p = 0.041) after ISMO treatment. Compared with placebo, PP decreased significantly 1 hour after ISMO dosing (p = 0.039), mainly as a function of reduced BPm. A significant inverse correlation (R = -0.618; p = 0.032) was observed between the percentage changes in PP and ON flow 1 hour following ISMO administration, but not after placebo. No significant change in foveal Ch flow was documented. CONCLUSIONS: These results suggest that, in normal subjects, ISMO increases significantly ON flow but not Ch flow. The inverse correlation observed between PP and ON flow suggests that the same mechanism(s) responsible for systemic vasodilatation and blood pressure decrease may also cause the ON flow increase.     

The impact of ethnicity on outcomes following coronary artery bypass graft surgery in the Veterans Health Administration

OBJECTIVES: We evaluated the effect of African American (AA) and Hispanic American (HA) ethnicity on mortality and complications following coronary artery bypass graft (CABG) surgery in the Veterans Health Administration (VHA). BACKGROUND: Few studies have examined the impact of ethnicity on outcomes following cardiovascular procedures. METHODS: This study included all 29,333 Caucasian, 2,570 AA, and 1,525 HA patients who underwent CABG surgery at any one of the 43 VHA cardiac surgery centers from January 1995 through March 2001. We evaluated the relationship between ethnicity (AA vs. Caucasian and HA vs. Caucasian) and 30-day mortality, 6-month mortality, and 30-day complications, adjusting for a wide array of demographic, cardiac, and noncardiac variables. RESULTS: After adjustment for baseline characteristics, AA and Caucasian patients had similar 30-day (AA/Caucasian odds ratio [OR] 1.07; 95% confidence interval [CI] 0.84 to 1.35; p = 0.59) and 6-month mortality risk (AA/Caucasian OR 1.10; 95% CI 0.91 to 1.34; p = 0.31). However, among patients with low surgical risk, AA ethnicity was associated with higher mortality (OR 1.52, CI 1.10 to 2.11, p = 0.01), and AA patients were more likely to experience complications following surgery (OR 1.28; 95% CI 1.14 to 1.45; p < 0.01). In contrast, HA patients had lower 30-day (HA/Caucasian OR 0.70; 95% CI 0.49 to 0.98; p = 0.04) and 6-month mortality risk (HA/Caucasian OR 0.66; 95% CI 0.50 to 0.88; p < 0.01) than Caucasian patients. CONCLUSIONS: Ethnicity does not appear to be a strong risk factor for adverse outcomes following CABG surgery in the VHA. Future studies are needed to determine why AA patients have more complications, but ethnicity should not affect the decision to offer the operation.     

Specific cutaneous infiltrates in chronic myelogenous leukemia

Specific leukemic infiltration of the skin is possible in all types of leukemia, and occurs most commonly in monocytic leukemias. We report the case of a 76-year-old woman with chronic myelogenous leukemia who showed specific cutaneous lesions one month before she died. In the absence of other signs of accelerated disease or blast crisis, cutaneous lesions should be considered an ominous sign in chronic myelogenous leukemia.     

Effect of coronary occlusion and myocardial viability on myocardial activity of technetium-99m-sestamibi.

The timing effect of sestamibi administration with respect to the onset of myocardial ischemia and reperfusion was studied in swine. In different groups of animals sestamibi was administered prior to coronary artery occlusion, during occlusion, or 1/2 hour following reperfusion. Sestamibi administered prior to coronary occlusion resulted in an insignificant decrease in 99mTc activity in the ischemic zone. However, infarct zone activity was reduced to 62 +/- 14% of the nonischemic zone. In contrast, administration during coronary occlusion resulted in similar significant reductions of both ischemic and infarct zone activity. Administration of sestamibi during reperfusion resulted in normal ischemic zone activity and markedly reduced activity in the infarct zone. Significantly reduced activity in the infarct zone was found to be independent of the timing of sestamibi administration with respect to the onset of myocardial ischemia and/or reperfusion. Thus, cell viability appears required for uptake and retention of isotope activity.     

Effect of topical carteolol on the normal human retinal circulation.

The effect of topical carteolol 1%, a beta-adrenergic blocker with intrinsic sympathomimetic activity, on the retinal circulation was investigated in 15 normal subjects using laser Doppler velocimetry and monochromatic fundus photography. In a double-masked randomized design, one eye received one drop of carteolol 1% and the fellow eye one drop of placebo. Vessel diameter, maximum erythrocyte velocity, and volumetric blood flow rate were determined in a major temporal vein of each eye just before instillation of the drops and then 120 min later. No significant changes in heart rate or mean brachial artery blood pressure were detected after treatment. Intraocular pressure decreased by 28% in the carteolol-treated eye (P less than 0.0001) and by 15% in the placebo-treated eye (P less than 0.001). No significant changes in vessel diameter, maximum erythrocyte velocity, and volumetric blood flow rate were observed in the carteolol-treated eyes (0.3%, 4.3%, and 3.6%, respectively) or the placebo-treated eyes (0.5%, 5.8%, and 6.7%, respectively).     

Diffusion-Weighted Imaging With Calculated Apparent Diffusion Coefficient of Enhancing Extra-Axial Masses

BACKGROUND AND PURPOSE: Sometimes intracranial contrast-enhancing tumors like meningiomas, metastases, lymphomas, and schwannomas can mimic each other. It was the aim of the present study to investigate if intracranial contrast-enhancing lesions can be reliably differentiated with the help of diffusion-weighted imaging with calculated apparent diffusion coefficients (ADCs). METHODS: 29 patients (ages ranging from 22 to 82 years, mean age of 58.6 years) were included. Nine meningiomas, 7 metastases, 6 lymphomas, and 7 schwannomas were investigated. The ADC value in the lesions and in the perifocal edema was analyzed. RESULTS: For the lymphomas, the authors measured the lowest ADC values in the contrast-enhancing part (0.59 +/- 0.09 . 10(-3) mm2/sec). The meningiomas showed a mean ADC value of 0.98 +/- 0.18 . 10(-3) mm2/sec. The schwannomas and metastases showed higher ADC values of 1.33 +/- 0.28 . 10(-3) mm2/sec and 1.05 +/- 0.20 . 10(-3) mm2/sec. The authors saw a statistically significant difference between lymphomas, meningiomas, and metastases concerning the ADC values in the contrast-enhancing part. CONCLUSIONS: In spite of a small sample size and partly a wide range of values, the authors found statistically significant differences between meningiomas, metastases, and lymphomas concerning ADC values. Nevertheless, a differentiation of these lesions only with the help of ADC values seems questionable.     

Action of leukotriene B4 in human granulosa cells in vitro

Leukotriene B4 directly enhanced progesterone release from superfusedhuman granulosa cells. This secretory effect was observed inconcentrations from 10^–12 to 10^–10 M. Lower andhigher concentrations failed to affect progesterone release.When we analysed the high performance liquid chromatographyprofile of supernatant from human granulosa cell cultures, wedetected a leukotriene B4 peak. In conclusion, these data supportthe hypothesis that leukotriene B4 may participate in the intracellularmechanism of progesterone release in human granulosa cells.     

High preovulatory serum luteinizing hormone level is unfavorable to conception.

Serum estradiol, progesterone and luteinizing hormone (LH) levels of 16 pregnant and 58 non-pregnant stimulated in vitro fertilization-embryo transfer (IVF-ET) or gamete intrafallopian transfer (GIFT) cycles have been compared with regard to their predictive value for achievement of pregnancy. Serum estradiol and progesterone pattern of the pregnant and non-pregnant group did not show any significant difference. Around the time of ovulation induction by human chorionic gonadotropin (hCG) the serum LH values proved to be higher in the non-pregnant group than in the pregnant one. In spite of having a permissive function, preovulatory serum estradiol and progesterone seem not to have a predictive value with regard to pregnancy. Elevated preovulatory serum LH is detrimental for pregnancy, therefore the measurement of serum LH beyond hCG administration also, and the cancellation of cycles with high serum LH levels shortly before oocyte retrieval is recommended.     

Myelographie bei Kindern und Jugendlichen mit Metrizamid (Amipaque®)

Summary The non-ionic water-soluble contrast medium metrizamide (Amipaque^®) allows the examination of all regions of the spinal canal. Excellent visualization, the low toxicity for nervous tissue, and small side effects make metrizamide the best contrast medium for myelography, even in infants and children. The technique used is described and results are demonstrated.