Fluctuations in visual neglect after stroke?

Clinical experience suggests that the visual neglect in stroke patients fluctuates over short periods of time. This fluctuation has been variously attributed to fatigue, time of day, previous activities, patient learning and compensation. Such fluctuations have clinical implications for the assessment and rehabilitation of visual neglect but do date no formal study has evaluated the extent of such fluctuation over the course of a day. Twenty-two patients with an acute stroke and 19 patients with convalescent stroke were examined for visual neglect twice on the same day using the Visual Neglect Recovery Index (VNRI), a valid and sensitive measure of the severity of neglect, which could be used to select acute patients for trials of treatment of neglect. The inter-test reliability was extremely high. In contrast to past clinical accounts most patients failed to show significant fluctuation. Although preliminary, this finding suggests that a single assessment of visual neglect, using the VNRI, could help select patients for treatment trials.     

Effect of not breastfeeding on the risk of diarrheal and respiratory mortality in children under 2 years of age in Metro Cebu, The Philippines

The effects of not breastfeeding on mortality due to diarrhea and acute lower respiratory infection (ALRI) in children under 2 years of age were examined using data from a 1988-1991 longitudinal study of 9,942 children in Metro Cebu, The Philippines. Cox regression methods were used to study the magnitude of the risks, possible interactions with birth weight and nutritional status, and the effect of additional confounding factors. Not breastfeeding had a greater effect on diarrheal mortality than on ALRI mortality. In the first 6 months of life, failing to initiate breastfeeding or ceasing to breastfeed resulted in an 8- to 10-fold increase in the rate of diarrheal mortality. The rate of mortality associated with both ALRI and diarrhea was increased nearly six times by not breastfeeding, but the rate of ALRI mortality alone was not increased. The data also suggested that the risk of mortality associated with not breastfeeding was greater for low birth weight infants and infants whose mothers had little formal education. After age 6 months, the protective effects of breastfeeding dropped dramatically. These findings underscore the importance of promoting breastfeeding, especially during the first 6 months of life, and of targeting high risk groups such as low birth weight babies and those of low socioeconomic status.     

Excimer laser angioplasty versus balloon angioplasty in functional and total coronary occlusions

Registries of excimer laser coronary angioplasty have reported good results in the treatment of complex coronary artery disease, including total or subtotal coronary occlusions. One hundred three patients (103 lesions) with a functional or total coronary occlusion were included in a randomized trial (Amsterdam-Rotterdam [AMRO] trial, total of 308 patients), 49 patients were allocated to laser angioplasty and 54 patients to balloon angioplasty. The primary clinical end points were death, myocardial infarction, coronary bypass surgery, or repeated coronary angioplasty of the randomized segment during a 6-month follow-up period. The primary angiographic end point was the minimal lumen diameter at follow-up in relation to the baseline value (net gain), as determined by an automated contour-detection algorithm. Laser angioplasty was followed by balloon angioplasty in all procedures. The angiographic success rate was 65% in patients treated with excimer laser-assisted balloon angioplasty compared with 61% in patients treated with balloon angioplasty alone. No deaths occurred. There were no significant differences between the laser angioplasty group and the balloon angioplasty group in the incidence of myocardial infarctions (1 patient vs 3, respectively, p = 0.36), coronary bypass surgery (4 patients vs 2, respectively, p = 0.34), repeat angioplasty (10 patients vs 8, respectively, p = 0.46) or primary clinical end point (15 patients vs 12, respectively, p = 0.34). The net gain in minimal lumen diameter and restenosis rate (>50% diameter stenosis at follow-up) were 0.81 +/- 0.74 mm and 66.7%, respectively, in patients treated with laser angioplasty compared with 1.04 +/- 0.68 mm and 48.5%, respectively, in patients treated with balloon angioplasty (p = 0.59 and p = 0.15, respectively). Excimer laser-assisted balloon angioplasty demonstrated no benefit over balloon angioplasty with respect to initial and long-term clinical and angiographic outcome in the treatment of patients with functional or total coronary occlusions of >10 mm in length.     

Why quality of life measures should be used in the treatment of patients with respiratory illness

Treatment of airways disease is directed towards improving patients' health and well-being. Measurements of airways function do not reflect all the disease activity present in the airways that may affect the patient. Spirometry correlates poorly with health. Physicians appear to estimate their patients' health using criteria different from the patients themselves. Quality of life questionnaires provide a method of quantifying the effect of disease on patients' lives. They can summarize a number of aspects of the disease and provide an overall estimate of the effect of disease and benefits due to therapy. They have the potential to identify a threshold response to treatment that may be considered "worthwhile", and allow comparison between therapies with respect to the health gain that each provides.     

Lipid hydroperoxides induce apoptosis in T cells displaying a HIV-associated glutathione peroxidase deficiency

8E5 is a chronically human immunodeficiency virus (HIV)-infected human T cell line, which we have previously shown to be extremely susceptible to hydrogen peroxide (H2O2)-induced apoptosis due to a HIV-associated catalase deficiency. Here we report that HIV gene expression additionally renders 8E5 cells 10-fold more sensitive than either uninfected A3.01 cells or HIV-infected but nonexpressing 8E5L cells to killing by 15-hydroperoxyeicosatetraenoic acid (15-HPETE), as well as several other hydroperoxy fatty acids. Whereas the viability of A3.01 and 8E5L cells was relatively unaffected by exposure to 10 microM 15-HPETE, similarly treated 8E5 cells underwent apoptosis, as demonstrated by morphological changes and the presence of fragmented DNA. The unique susceptibility of 8E5 cells was attributable to their inability to convert 15-HPETE to 15-hydroxy-eicosatetraenoic acid (15-HETE) owing to a marked reduction in glutathione peroxidase activity. Since oxidized lipids have been reported to accumulate in oxidatively stressed, HIV-infected individuals, a HIV-associated glutathione peroxidase deficiency may contribute to the depletion of CD4 T cells that occurs in the acquired immune deficiency syndrome (AIDS).     

Exercise VO2 estimation using recovery sampling

Various situations present a challenge to determine oxygen uptake (VO2) accurately simply because of the restrictions imposed by the equipment employed. This investigation was undertaken to 1) compare a select number of recovery VO2 measurements with respect to their accuracy in estimating actual exercise VO2 and 2) to determine whether absolute workload or VO2max affect this relationship. Fifteen subjects [8 highly trained (HT), VO2max +/- SD = 70.2 +/- 3.5 ml/kg . min-1 and 7 untrained (UT), VO2max = 49.7 +/- 3.8 ml/kg . min-1] completed a number of 5 min workbouts on a bicycle ergometer at 25-70% VO2max (VO2 = .899--3.879 l . min-1). VO2 and VCO2 (l . min-1) were monitored continuously throughout the exercise and for 5 min of recovery via a breath-by-breath system. The results indicated that 1) exercise VO2 +/- Sy.x can be estimated from several recovery collection periods, the first breath y = .953X + .441 +/- .319, the first two breaths y = 1.046X + .327 +/- .270, the first three breaths y = 1.089X + .260 +/- .241, and the second three breaths y = 1.101X + .387 +/- .234, and 2) VO2max does not affect this relationship (p greater than 0.05) while increasing absolute workload produces a greater exercise VO2 underestimation (p less than 0.05). It was concluded that using this method exercise VO2 can be estimated with reasonable accuracy (Sy.x = .234--.319, r = .92--.94, p less than 0.01).     

Jack bean urease (EC 3.5.1.5). V. On the mechanism of action of urease on urea, formamide, acetamide, N-methylurea, and related compounds

Acetamide and N-methylurea have been shown for the first time to be substrates for jack bean urease. In the enzymatic hydrolysis of urea, formamide, acetamide, and N-methylurea at pH 7.0 and 38 degrees C, kcat has the values 5870, 85, 0.55, and 0.075 s-1, respectively. The urease-catalyzed hydrolysis of all these substrates involves the active-site nickel ion(s). Enzymatic hydrolysis of the following compounds could not be detected: phenyl formate, p-nitroformanilide, trifluoroacetamide, p-nitrophenyl carbamate, thiourea, and O-methylisouronium ion. In the enzymatic hydrolysis of urea, the pH dependence of kcat between pH 3.4 and 7.8 indicates that at least two prototropic forms are active. Enzymatic hydrolysis of urea in the presence of methanol gave no detectable methyl carbamate. A mechanism of action for urease is proposed which involves initially an O-bonded complex between urea and an active-site Ni2+ ion and subsequently an O-bonded carbamato-enzyme intermediate.